In certain aspects, the disclosure provides soluble heteromeric polypeptide complexes comprising an extracellular domain of a type I serine/threonine kinase receptor of the TGF-beta family and an extracellular domain of a type II serine/threonine kinase receptor of the TGF-beta family. In some embodiments, the disclosure provides soluble polypeptide complexes comprising an extracellular domain of a type II receptor selected from: ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII. In some embodiments, the disclosure provides soluble polypeptide complexes comprising an extracellular domain of a type I receptor selected from: ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7. Optionally the soluble complex is a heterodimer. In certain aspects, such soluble polypeptide complexes may be used to regulate (promote or inhibit) growth of tissues or cells including, for example, muscle, bone, cartilage, fat, neural tissue, tumors, cancerous cells, and/or cells of hematopoietic lineages, including red blood cells. In certain aspects, such soluble polypeptide complexes are can be used to improve muscle formation, bone formation, hematopoiesis, metabolic parameters, and disorders associated with these tissues, cellular networks, and endocrine systems.

Description

915 parts

›CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 15/092,609, filed Apr. 6, 2016 (now U.S. Pat. No. 10,227,393), which claims the benefit of priority to U.S. provisional application Ser. No. 62/143,579, filed Apr. 6, 2015. The disclosures of each of the foregoing applications are hereby incorporated by reference in their entirety.

›SEQUENCE LISTING

The instant application contains a Sequence Listing which has been submitted electronically in ASCII format and is hereby incorporated by reference in its entirety. Said ASCII copy, created on Jan. 18, 2019, is named 1848179-0002-080-102_SL.txt and is 605,660 bytes in size.

›BACKGROUND OF THE INVENTION

The transforming growth factor-beta (TGF-beta) superfamily contains a variety of growth factors that share common sequence elements and structural motifs. These proteins are known to exert biological effects on a large variety of cell types in both vertebrates and invertebrates. Members of the superfamily perform important functions during embryonic development in pattern formation and tissue specification and can influence a variety of differentiation processes, including adipogenesis, myogenesis, chondrogenesis, cardiogenesis, hematopoiesis, neurogenesis, and epithelial cell differentiation. The family is divided into two general phylogenetic clades: the more recently evolved members of the superfamily, which includes TGF-betas, Activins, and nodal and the clade of more distantly related proteins of the superfamily, which includes a number of BMPs and GDFs. Hinck (2012) FEBS Letters 586:1860-1870. TGF-beta family members have diverse, often complementary biological effects. By manipulating the activity of a member of the TGF-beta family, it is often possible to cause significant physiological changes in an organism. For example, the Piedmontese and Belgian Blue cattle breeds carry a loss-of-function mutation in the GDF8 (also called myostatin) gene that causes a marked increase in muscle mass. Grobet et al. (1997) Nat Genet., 17(1):71-4. Furthermore, in humans, inactive alleles of GDF8 are associated with increased muscle mass and, reportedly, exceptional strength. Schuelke et al. (2004) N Engl J Med, 350:2682-8.

Changes in muscle, bone, fat, red blood cells, and other tissues may be achieved by enhancing or inhibiting signaling (e.g., SMAD 1, 2, 3, 5, and/or 8) that is mediated by ligands of the TGF-beta family. Thus, there is a need for agents that regulate the activity of various ligands of the TGF-beta superfamily.

›SUMMARY OF THE INVENTION · 1 of 11

In part, the disclosure provides heteromultimeric complexes comprising at least one TGF-beta superfamily type I serine/threonine kinase receptor polypeptide (e.g., an ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7 polypeptide), including fragments and variants thereof, and at least one TGF-beta superfamily type II serine/threonine kinase receptor polypeptide (e.g., ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII), including fragments and variants thereof. In other aspects, the disclosure provides heteromultimeric complexes comprising at least two different TGF-beta superfamily type I serine/threonine kinase receptor polypeptide (e.g., an ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7 polypeptide), including fragments and variants thereof. In still other aspects, the disclosure provides heteromultimeric complexes comprising at least two different TGF-beta superfamily type II serine/threonine kinase receptor polypeptide (e.g., ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII), including fragments and variants thereof. Optionally, heteromultimeric complexes disclosed herein (e.g., an ActRIIB:ALK4 heterodimer) have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (e.g., an ActRIIB homodimer and ALK4 homodimer). Novel properties, including novel ligand binding attributes, are exhibited by heteromultimeric polypeptide complexes comprising type I and type II receptor polypeptides of the TGF-beta superfamily, as shown by Examples herein.

Heteromultimeric structures include, for example, heterodimers, heterotrimers, and higher order complexes. See, e.g., FIGS. 1, 2, 15, 16, 17, 18, 19 . In some embodiments heteromultimers of the disclosure are heterodimers. Preferably, TGF-beta superfamily type I and type II receptor polypeptides as described herein comprise a ligand-binding domain of the receptor, for example, an extracellular domain of a TGF-beta superfamily type I or type II receptor. Accordingly, in certain aspects, protein complexes described herein comprise an extracellular domain of a type II TGF-beta superfamily receptor selected from: ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII, as well as truncations and variants thereof, and an extracellular domain of a type I TGF-beta superfamily receptor selected from: ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7, as well as truncations and variants thereof. Preferably, TGF-beta superfamily type I and type II polypeptides as described herein, as well as protein complexes comprising the same, are soluble. In certain aspects, heteromultimer complexes of the disclosure bind to one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, Müllerian-inhibiting substance (MIS), and Lefty). Optionally, protein complexes of the disclosure bind to one or more of these ligands with a K D of greater than or equal to 10 −8 , 10 −9 , 10 −10 , 10 −11 , or 10 −12 . In general, heteromultimers of the disclosure antagonize (inhibit) one or more activities of at least one TGF-beta superfamily ligand, and such alterations in activity may be measured using various assays known in the art, including, for example, a cell-based assay as described herein. Preferably heteromultimers of the disclosure exhibit a serum half-life of at least 4, 6, 12, 24, 36, 48, or 72 hours in a mammal (e.g., a mouse or a human). Optionally, heteromultimers of the disclosure may exhibit a serum half-life of at least 6, 8, 10, 12, 14, 20, 25, or 30 days in a mammal (e.g., a mouse or a human).

In certain aspects, heteromultimers described herein comprise a first polypeptide covalently or non-covalently associated with a second polypeptide wherein the first polypeptide comprises the amino acid sequence of a TGF-beta superfamily type I receptor polypeptide and the amino acid sequence of a first member of an interaction pair and the second polypeptide comprises the amino acid sequence of a TGF-beta superfamily type II receptor polypeptide and the amino acid sequence of a second member of the interaction pair. In other aspects, heteromultimers described herein comprise a first polypeptide covalently or non-covalently associated with a second polypeptide wherein the first polypeptide comprises the amino acid sequence of a TGF-beta superfamily type I receptor polypeptide and the amino acid sequence of a first member of an interaction pair and the second polypeptide comprises the amino acid sequence of a different TGF-beta superfamily type I receptor polypeptide and the amino acid sequence of a second member of the interaction pair. In still other aspects, heteromultimers described herein comprise a first polypeptide covalently or non-covalently associated with a second polypeptide wherein the first polypeptide comprises the amino acid sequence of a TGF-beta superfamily type II receptor polypeptide and the amino acid sequence of a first member of an interaction pair and the second polypeptide comprises the amino acid sequence of a different TGF-beta superfamily type II receptor polypeptide and the amino acid sequence of a second member of the interaction pair. Optionally, the TGF-beta superfamily type I receptor polypeptide is connected directly to the first member of the interaction pair, or an intervening sequence, such as a linker, may be positioned between the amino acid sequence of the TGF-beta superfamily type I receptor polypeptide and the amino acid sequence of the first member of the interaction pair. Similarly, the TGF-beta superfamily type II receptor polypeptide may be connected directly to the second member of the interaction pair, or an intervening sequence, such as a linker, may be positioned between the amino acid sequence of the TGF-beta superfamily type II receptor polypeptide and the amino acid sequence of the second member of the interaction pair. Examples of linkers include, but are not limited to, the sequences TGGG (SEQ ID NO: 62), TGGGG (SEQ ID NO: 60), SGGGG (SEQ ID NO: 61), GGGG (SEQ ID NO: 59), and GGG (SEQ ID NO: 58).

›SUMMARY OF THE INVENTION · 2 of 11

Interaction pairs described herein are designed to promote dimerization or form higher order multimers. In some embodiments, the interaction pair may be any two polypeptide sequences that interact to form a complex, particularly a heterodimeric complex although operative embodiments may also employ an interaction pair that forms a homodimeric sequence. The first and second members of the interaction pair may be an asymmetric pair, meaning that the members of the pair preferentially associate with each other rather than self-associate. Accordingly, first and second members of an asymmetric interaction pair may associate to form a heterodimeric complex. Alternatively, the interaction pair may be unguided, meaning that the members of the pair may associate with each other or self-associate without substantial preference and thus may have the same or different amino acid sequences. Accordingly, first and second members of an unguided interaction pair may associate to form a homodimer complex or a heterodimeric complex. Optionally, the first member of the interaction action pair (e.g., an asymmetric pair or an unguided interaction pair) associates covalently with the second member of the interaction pair. Optionally, the first member of the interaction action pair (e.g., an asymmetric pair or an unguided interaction pair) associates non-covalently with the second member of the interaction pair. Optionally, the first member of the interaction pair (e.g., an asymmetrical or an unguided interaction pair) associates through both covalent and non-covalent mechanisms with the second member of the interaction pair.

In some embodiments, TGF-beta superfamily type I receptor polypeptides are fusion proteins that comprise an Fc domain of an immunoglobulin. Similarly, in some embodiments, TGF-beta superfamily type II receptor polypeptides are fusion proteins that comprise an Fc domain of an immunoglobulin. Traditional Fc fusion proteins and antibodies are examples of unguided interaction pairs, whereas a variety of engineered Fc domains have been designed as asymmetric interaction pairs [Spiess et al (2015) Molecular Immunology 67(2A): 95-106]. Therefore, a first member and/or a second member of an interaction pair described herein may comprise a constant domain of an immunoglobulin, including, for example, the Fc portion of an immunoglobulin. For example, a first member of an interaction pair may comprise an amino acid sequence that is derived from an Fc domain of an IgG (IgG1, IgG2, IgG3, or IgG4), IgA (IgA1 or IgA2), IgE, or IgM immunoglobulin. For example, the first member of an interaction pair may comprise, consist essentially of, or consist of an amino acid sequence that is at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 200-214. Optionally, a second member of an interaction pair may comprise an amino acid sequence that is derived from an Fc domain of an IgG (IgG1, IgG2, IgG3, or IgG4), IgA (IgA1 or IgA2), IgE, or IgM. Such immunoglobulin domains may comprise one or more amino acid modifications (e.g., deletions, additions, and/or substitutions) that promote heterodimer formation. For example, the second member of an interaction pair may comprise, consist essentially of, or consist of an amino acid sequence that is at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 200-214. In some embodiments, a first member and a second member of an interaction pair comprise Fc domains derived from the same immunoglobulin class and subtype. In other embodiments, a first member and a second member of an interaction pair comprise Fc domains derived from different immunoglobulin classes or subtypes. Similarly, a first member and/or a second member of an interaction pair (e.g., an asymmetric pair or an unguided interaction pair) comprise a modified constant domain of an immunoglobulin, including, for example, a modified Fc portion of an immunoglobulin. For example, protein complexes of the disclosure may comprise a first modified Fc portion of an immunoglobulin comprising an amino acid sequence that is at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to an amino acid sequence selected from the group: SEQ ID NOs: 200-214 and a second modified Fc portion of an immunoglobulin, which may be the same or different from the amino acid sequence of the first modified Fc portion of the immunoglobulin, comprising an amino acid sequence that is at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to an amino acid sequence selected from the group: SEQ ID NOs: 200-214. Such immunoglobulin domains may comprise one or more amino acid modifications (e.g., deletions, additions, and/or substitutions) that promote heterodimer formation.

In some embodiments, the disclosure provides heteromeric polypeptide complexes comprising a type I and type II TGF-beta superfamily receptor polypeptide, wherein the type II TGF-beta superfamily receptor polypeptide is derived from an ActRIIA receptor. In some embodiments, the disclosure provides heteromeric polypeptide complexes comprising at least two different type II TGF-beta superfamily receptor polypeptide, wherein at least one of the type II TGF-beta superfamily receptor polypeptide is derived from an ActRIIA receptor. For example, ActRIIA polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an ActRIIA sequence disclosed herein (e.g., SEQ ID NOs: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452). Optionally, ActRIIA polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 21-30 (e.g., amino acid residues 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) SEQ ID NO: 9, and b) ends at any one of amino acids 110-135 (e.g., 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134 or 135) of SEQ ID NO: 9. Optionally, ActRIIA polypeptides of the disclosure may be fusion proteins that further comprise one or more portions (domains) that are heterologous to ActRIIA. For example, an ActRIIA polypeptide may be fused to a heterologous polypeptide that comprises a multimerization domain, optionally with a linker domain positioned between the ActRIIA polypeptide and the heterologous polypeptide. In some embodiments, multimerization domains described herein comprise one component of an interaction pair. In certain aspects, heteromeric complexes that comprise an ActRIIA polypeptide further comprise at least one type I TGF-beta superfamily receptor polypeptide. For example, an ActRIIA heteromeric complex may further comprise an ALK1 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464. Optionally, ALK1 polypeptides in this and other embodiments may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 22-34 (e.g., amino acid residues 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, and 34) SEQ ID NO: 14, and b) ends at any one of amino acids 95-118 (e.g., amino acid residues 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, and 118) of SEQ ID NO: 14. In some embodiments, an ActRIIA heteromeric complex may further comprise an ALK2 polypeptide as described herein, including, for example, a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466. Optionally, ALK2 polypeptides in this and other embodiments may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 21-35 (e.g., amino acid residues 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, and 35) SEQ ID NO: 18, and b) ends at any one of amino acids 99-123 (e.g., amino acid residues 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, and 123) of SEQ ID NO: 18. In some embodiments, an ActRIIA heteromeric complex may further comprise an ALK3 polypeptide as described herein, including, for example, a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468. Optionally, in this and other embodiments ALK3 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 24-61 (e.g., amino acid residues 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, and 61) SEQ ID NO: 22, and b) ends at any one of amino acids 130-152 (e.g., amino acid residues 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, and 152) of SEQ ID NO: 22. In some embodiments, an ActRIIA heteromeric complex may further comprise an ALK4 polypeptide as described herein, including, for example, a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470. Optionally, in this and other embodiments ALK4 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 23-34 (e.g., amino acid residues 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34) SEQ ID NO: 26 or 83, and b) ends at any one of amino acids 101-126 (e.g., amino acid residues 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, and 126) of SEQ ID NO: 26 or 83. In some embodiments, an ActRIIA heteromeric complex may further comprise an ALK5 polypeptide as described herein, including, for example, a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472. Optionally, in this and other embodiments ALK5 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 25-36 (e.g., amino acid residues 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, and 36) SEQ ID NO: 30 or 87, and b) ends at any one of amino acids 106-126 (e.g., amino acid residues 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, and 126) of SEQ ID NO: 30 or 87. In some embodiments, an ActRIIA heteromeric complex may further comprise an ALK6 polypeptide as described herein, including, for example, a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474. Optionally, in this and other embodiments ALK6 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 14-32 (e.g., amino acid residues 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, and 32) SEQ ID NO: 34, and b) ends at any one of amino acids 102-126 (e.g., amino acid residues 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, and 126) of SEQ ID NO: 34. Optionally, in this and other embodiments ALK6 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 26-62 (e.g., amino acid residues 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, and 62) SEQ ID NO: 91, and b) ends at any one of amino acids 132-156 (e.g., amino acid residues 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, and 156) of SEQ ID NO: 91. In some embodiments, an ActRIIA heteromeric complex may further comprise an ALK7 polypeptide as described herein, including, for example, a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476. Optionally, in this and other embodiments, ALK7 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that begins at any one of amino acids 21-28 of SEQ ID NO: 38 (e.g., amino acids 21, 22, 23, 24, 25, 26, 27, or 28) and ends at any one of amino acids 92-113 of SEQ ID NO: 38 (e.g., amino acids 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, or 113 of SEQ ID NO: 38). In certain aspects, heteromeric complexes that comprise an ActRIIA polypeptide further comprise at least one different type II TGF-beta superfamily receptor polypeptide. For example, an ActRIIA heteromeric complex may further comprise an ActRIIB polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454. In some embodiments, an ActRIIA heteromeric complex may further comprise an BMPRII polypeptide as described herein, including, for example, a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456. In some embodiments, an ActRIIA heteromeric complex may further comprise an MISRII polypeptide as described herein, including, for example, a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458. In some embodiments, an ActRIIA heteromeric complex may further comprise an TGFBRII polypeptide as described herein, including, for example, a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462.

›SUMMARY OF THE INVENTION · 3 of 11

›SUMMARY OF THE INVENTION · 4 of 11

›SUMMARY OF THE INVENTION · 5 of 11

›SUMMARY OF THE INVENTION · 6 of 11

›SUMMARY OF THE INVENTION · 7 of 11

In some embodiments, the disclosure provides heteromeric polypeptide complexes comprising at least two different type I TGF-beta superfamily receptor polypeptide, wherein at least one of the type I TGF-beta superfamily receptor polypeptide is derived from an ALK1 receptor. For example, ALK1 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an ALK1 sequence disclosed herein (e.g., 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464). Optionally, ALK1 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 22-34 (e.g., amino acid residues 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, and 34) SEQ ID NO: 14, and b) ends at any one of amino acids 95-118 (e.g., amino acid residues 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, and 118) of SEQ ID NO: 14. Optionally, ALK1 polypeptides of the disclosure may be fusion proteins that further comprise one or more portions (domains) that are heterologous to ALK1. For example, an ALK1 polypeptide may be fused to a heterologous polypeptide that comprises a multimerization domain, optionally with a linker domain positioned between the ALK1 polypeptide and the heterologous polypeptide. In some embodiments, multimerization domains described herein comprise one component of an interaction pair. In some embodiments, heteromeric complexes that comprise an ALK1 polypeptide further comprise at least one different type I TGF-beta superfamily polypeptide. For example, an ALK1 heteromeric complex may further comprise an ALK2 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466. In some embodiments, an ALK1 heteromeric complex may further comprise an ALK3 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468. In some embodiments, an ALK1 heteromeric complex may further comprise an ALK4 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470. In some embodiments, an ALK1 heteromeric complex may further comprise an ALK5 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472. In some embodiments, an ALK1 heteromeric complex may further comprise an ALK6 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474. In some embodiments, an ALK1 heteromeric complex may further comprise an ALK7 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476.

In some embodiments, the disclosure provides heteromeric polypeptide complexes comprising at least two different type I TGF-beta superfamily receptor polypeptide, wherein at least one of the type I TGF-beta superfamily receptor polypeptide is derived from an ALK2 receptor. For example, ALK2 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an ALK2 sequence disclosed herein (e.g., 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466). Optionally, ALK2 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 21-35 (e.g., amino acid residues 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, and 35) SEQ ID NO: 18, and b) ends at any one of amino acids 99-123 (e.g., amino acid residues 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, and 123) of SEQ ID NO: 18. Optionally, ALK2 polypeptides of the disclosure may be fusion proteins that further comprise one or more portions (domains) that are heterologous to ALK2. For example, an ALK2 polypeptide may be fused to a heterologous polypeptide that comprises a multimerization domain, optionally with a linker domain positioned between the ALK2 polypeptide and the heterologous polypeptide. In some embodiments, multimerization domains described herein comprise one component of an interaction pair. In some embodiments, heteromeric complexes that comprise an ALK2 polypeptide further comprise at least one different type I TGF-beta superfamily polypeptide. For example, an ALK2 heteromeric complex may further comprise an ALK1 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464. In some embodiments, an ALK2 heteromeric complex may further comprise an ALK3 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468. In some embodiments, an ALK2 heteromeric complex may further comprise an ALK4 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470. In some embodiments, an ALK2 heteromeric complex may further comprise an ALK5 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472. In some embodiments, an ALK2 heteromeric complex may further comprise an ALK6 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474. In some embodiments, an ALK2 heteromeric complex may further comprise an ALK7 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476.

›SUMMARY OF THE INVENTION · 8 of 11

In some embodiments, the disclosure provides heteromeric polypeptide complexes comprising at least two different type I TGF-beta superfamily receptor polypeptide, wherein at least one of the type I TGF-beta superfamily receptor polypeptide is derived from an ALK3 receptor. For example, ALK3 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an ALK3 sequence disclosed herein (e.g., 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468). Optionally, ALK3 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 24-61 (e.g., amino acid residues 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, and 61) SEQ ID NO: 22, and b) ends at any one of amino acids 130-152 (e.g., amino acid residues 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, and 152) of SEQ ID NO: 22. Optionally, ALK3 polypeptides of the disclosure may be fusion proteins that further comprise one or more portions (domains) that are heterologous to ALK3. For example, an ALK3 polypeptide may be fused to a heterologous polypeptide that comprises a multimerization domain, optionally with a linker domain positioned between the ALK3 polypeptide and the heterologous polypeptide. In some embodiments, multimerization domains described herein comprise one component of an interaction pair. In some embodiments, heteromeric complexes that comprise an ALK3 polypeptide further comprise at least one different type I TGF-beta superfamily polypeptide. For example, an ALK3 heteromeric complex may further comprise an ALK2 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466. In some embodiments, an ALK3 heteromeric complex may further comprise an ALK1 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464. In some embodiments, an ALK3 heteromeric complex may further comprise an ALK4 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470. In some embodiments, an ALK3 heteromeric complex may further comprise an ALK5 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472. In some embodiments, an ALK3 heteromeric complex may further comprise an ALK6 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474. In some embodiments, an ALK3 heteromeric complex may further comprise an ALK7 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476.

In some embodiments, the disclosure provides heteromeric polypeptide complexes comprising at least two different type I TGF-beta superfamily receptor polypeptide, wherein at least one of the type I TGF-beta superfamily receptor polypeptide is derived from an ALK4 receptor. For example, ALK4 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an ALK4 sequence disclosed herein (e.g., 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470). Optionally, ALK4 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 23-34 (e.g., amino acid residues 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34) SEQ ID NO: 26 or 83, and b) ends at any one of amino acids 101-126 (e.g., amino acid residues 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, and 126) of SEQ ID NO: 26 or 83. Optionally, ALK4 polypeptides of the disclosure may be fusion proteins that further comprise one or more portions (domains) that are heterologous to ALK4. For example, an ALK4 polypeptide may be fused to a heterologous polypeptide that comprises a multimerization domain, optionally with a linker domain positioned between the ALK4 polypeptide and the heterologous polypeptide. In some embodiments, multimerization domains described herein comprise one component of an interaction pair. In some embodiments, heteromeric complexes that comprise an ALK4 polypeptide further comprise at least one different type I TGF-beta superfamily polypeptide. For example, an ALK4 heteromeric complex may further comprise an ALK2 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466. In some embodiments, an ALK4 heteromeric complex may further comprise an ALK3 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468. In some embodiments, an ALK4 heteromeric complex may further comprise an ALK1 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464. In some embodiments, an ALK4 heteromeric complex may further comprise an ALK5 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472. In some embodiments, an ALK4 heteromeric complex may further comprise an ALK6 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474. In some embodiments, an ALK4 heteromeric complex may further comprise an ALK7 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476.

›SUMMARY OF THE INVENTION · 9 of 11

In some embodiments, the disclosure provides heteromeric polypeptide complexes comprising at least two different type I TGF-beta superfamily receptor polypeptide, wherein at least one of the type I TGF-beta superfamily receptor polypeptide is derived from an ALK5 receptor. For example, ALK5 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an ALK5 sequence disclosed herein (e.g., 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472). Optionally, ALK5 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 25-36 (e.g., amino acid residues 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, and 36) SEQ ID NO: 30 or 87, and b) ends at any one of amino acids 106-126 (e.g., amino acid residues 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, and 126) of SEQ ID NO: 30 or 87. Optionally, ALK5 polypeptides of the disclosure may be fusion proteins that further comprise one or more portions (domains) that are heterologous to ALK5. For example, an ALK5 polypeptide may be fused to a heterologous polypeptide that comprises a multimerization domain, optionally with a linker domain positioned between the ALK5 polypeptide and the heterologous polypeptide. In some embodiments, multimerization domains described herein comprise one component of an interaction pair. In some embodiments, heteromeric complexes that comprise an ALK5 polypeptide further comprise at least one different type I TGF-beta superfamily polypeptide. For example, an ALK5 heteromeric complex may further comprise an ALK2 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466. In some embodiments, an ALK5 heteromeric complex may further comprise an ALK3 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468. In some embodiments, an ALK5 heteromeric complex may further comprise an ALK4 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470. In some embodiments, an ALK5 heteromeric complex may further comprise an ALK1 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464. In some embodiments, an ALK5 heteromeric complex may further comprise an ALK6 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474. In some embodiments, an ALK5 heteromeric complex may further comprise an ALK7 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476.

In some embodiments, the disclosure provides heteromeric polypeptide complexes comprising at least two different type I TGF-beta superfamily receptor polypeptide, wherein at least one of the type I TGF-beta superfamily receptor polypeptide is derived from an ALK6 receptor. For example, ALK6 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an ALK6 sequence disclosed herein (e.g., 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474). Optionally, ALK6 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 14-32 (e.g., amino acid residues 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, and 32) SEQ ID NO: 34, and b) ends at any one of amino acids 102-126 (e.g., amino acid residues 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, and 126) of SEQ ID NO: 34. Optionally, ALK6 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that a) begins at any one of amino acids of 26-62 (e.g., amino acid residues 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, and 62) SEQ ID NO: 91, and b) ends at any one of amino acids 132-156 (e.g., amino acid residues 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, and 156) of SEQ ID NO: 91. Optionally, ALK6 polypeptides of the disclosure may be fusion proteins that further comprise one or more portions (domains) that are heterologous to ALK6. For example, an ALK6 polypeptide may be fused to a heterologous polypeptide that comprises a multimerization domain, optionally with a linker domain positioned between the ALK6 polypeptide and the heterologous polypeptide. In some embodiments, multimerization domains described herein comprise one component of an interaction pair. In some embodiments, heteromeric complexes that comprise an ALK6 polypeptide further comprise at least one different type I TGF-beta superfamily polypeptide. For example, an ALK6 heteromeric complex may further comprise an ALK2 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466. In some embodiments, an ALK6 heteromeric complex may further comprise an ALK3 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468. In some embodiments, an ALK6 heteromeric complex may further comprise an ALK4 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470. In some embodiments, an ALK6 heteromeric complex may further comprise an ALK5 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472. In some embodiments, an ALK6 heteromeric complex may further comprise an ALK1 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464. In some embodiments, an ALK6 heteromeric complex may further comprise an ALK7 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476.

›SUMMARY OF THE INVENTION · 10 of 11

In some embodiments, the disclosure provides heteromeric polypeptide complexes comprising at least two different type I TGF-beta superfamily receptor polypeptide, wherein at least one of the type I TGF-beta superfamily receptor polypeptide is derived from an ALK7 receptor. For example, ALK7 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an ALK7 sequence disclosed herein (e.g., 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476). Optionally, ALK7 polypeptides may comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a polypeptide that begins at any one of amino acids 21-28 of SEQ ID NO: 38 (e.g., amino acids 21, 22, 23, 24, 25, 26, 27, or 28) and ends at any one of amino acids 92-113 of SEQ ID NO: 38 (e.g., amino acids 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, or 113 of SEQ ID NO: 38). Optionally, ALK7 polypeptides of the disclosure may be fusion proteins that further comprise one or more portions (domains) that are heterologous to ALK7. For example, an ALK7 polypeptide may be fused to a heterologous polypeptide that comprises a multimerization domain, optionally with a linker domain positioned between the ALK7 polypeptide and the heterologous polypeptide. In some embodiments, multimerization domains described herein comprise one component of an interaction pair. In some embodiments, heteromeric complexes that comprise an ALK7 polypeptide further comprise at least one different type I TGF-beta superfamily polypeptide. For example, an ALK7 heteromeric complex may further comprise an ALK2 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466. In some embodiments, an ALK7 heteromeric complex may further comprise an ALK3 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468. In some embodiments, an ALK7 heteromeric complex may further comprise an ALK4 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470. In some embodiments, an ALK7 heteromeric complex may further comprise an ALK5 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472. In some embodiments, an ALK7 heteromeric complex may further comprise an ALK6 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474. In some embodiments, an ALK7 heteromeric complex may further comprise an ALK1 polypeptide as described herein, including, e.g., a polypeptide comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to a sequence selected from SEQ ID NOs: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464.

In some embodiments, the TGF-beta superfamily type I and/or type II receptor polypeptides disclosed herein comprise one or more modified amino acid residues selected from: a glycosylated amino acid, a PEGylated amino acid, a farnesylated amino acid, an acetylated amino acid, a biotinylated amino acid, an amino acid conjugated to a lipid moiety, and an amino acid conjugated to an organic derivatizing agent. In some embodiments, the TGF-beta superfamily type I and/or type II polypeptides described herein are glycosylated and have a glycosylation pattern obtainable from the expression of the polypeptides in a mammalian cell, including, for example, a CHO cell.

In certain aspects the disclosure provides nucleic acids encoding any of the TGF-beta superfamily type I and/or type II polypeptides described herein. Nucleic acids disclosed herein may be operably linked to a promoter for expression, and the disclosure further provides cells transformed with such recombinant polynucleotides. Preferably the cell is a mammalian cell such as a COS cell or a CHO cell.

In certain aspects, the disclosure provides methods for making any of the TGF-beta superfamily type I and/or type II polypeptides described herein as well as protein complexes comprising such polypeptides. Such a method may include expressing any of the nucleic acids disclosed herein in a suitable cell (e.g., CHO cell or a COS cell). Such a method may comprise: a) culturing a cell under conditions suitable for expression of the TGF-beta superfamily type I or type II polypeptides described herein, wherein said cell is transformed with a type I or type II polypeptide expression construct; and b) recovering the type I or type II polypeptides so expressed. TGF-beta superfamily type I and/or type II polypeptides described herein, as well as protein complexes of the same, may be recovered as crude, partially purified, or highly purified fractions using any of the well-known techniques for obtaining protein from cell cultures.

›SUMMARY OF THE INVENTION · 11 of 11

In certain aspects, the disclosure provides methods for making any of the heteromultimeric complexes disclosed herein. Such a method may include expressing any of the nucleic acids disclosed herein in a suitable cell (e.g., CHO cell or a COS cell). Such a method may comprise: a) obtaining a cell that comprises a nucleic acid comprising the coding sequence for a TGF-beta superfamily type I receptor polypeptide disclosed herein and a nucleic acid comprising the coding sequence for a TGF-beta superfamily type II receptor polypeptide disclosed herein; (b) culturing such cell under conditions suitable for expression of the TGF-beta superfamily type I and type II polypeptides described herein; and c) recovering the heteromeric complex comprising such type I and type II polypeptides so expressed. Heteromultimeric complexes disclosed herein as crude, partially purified, or highly purified fractions using any of the well-known techniques for obtaining protein from cell cultures.

Any of the protein complexes described herein may be incorporated into a pharmaceutical preparation. Optionally, such pharmaceutical preparations are at least 80%, 85%, 90%, 95%, 97%, 98% or 99% pure with respect to other polypeptide components. Optionally, pharmaceutical preparations disclosed herein may comprise one or more additional active agents. In some embodiments, heteromultimers of the disclosure comprise less than 10%, 9%, 8%, 7%, 5%, 4%, 3%, 2%, or less than 1% type I receptor polypeptide homomultimers. In some embodiments, heteromultimers of the disclosure comprise less than 10%, 9%, 8%, 7%, 5%, 4%, 3%, 2%, or less than 1% type II receptor polypeptide homomultimers. In some embodiments, heteromultimers of the disclosure comprise less than 10%, 9%, 8%, 7%, 5%, 4%, 3%, 2%, or less than 1% type I receptor polypeptide homomultimers and less than 10%, 9%, 8%, 7%, 5%, 4%, 3%, 2%, or less than 1% type II receptor polypeptide homomultimers.

The disclosure further provides methods and heteromultimeric complexes for use in the treatment or prevention of various disease and disorders associated with, for example, muscle, bone, fat, red blood cells, and other tissues that are affected by one or more ligands of the TGF-beta superfamily. Such disease and disorders include, but are not limited to, disorders associated with muscle loss or insufficient muscle growth (e.g., muscle atrophy; muscular dystrophy, including Duchenne muscular dystrophy, Becker muscular dystrophy, and facioscapulohumeral muscular dystrophy; amyotrophic lateral sclerosis; and cachexia) and disorders associated with undesirable weight gain (e.g., obesity, type 2 diabetes or non-insulin dependent diabetes mellitus (NIDDM), cardiovascular disease, hypertension, osteoarthritis, stroke, respiratory problems, and gall bladder disease). In some embodiments, heteromultimeric complexes disclosed herein may be used to decrease body fat content or reduce the rate of increase in body fat content in a subject in need thereof. In some embodiments, heteromultimeric complexes disclosed herein may be used to reduce cholesterol and/or triglyceride levels in a patient.

›BRIEF DESCRIPTION OF THE DRAWINGS · 1 of 4

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

FIGS. 1A and 1B show two schematic examples of heteromeric protein complexes comprising type I receptor and type II receptor polypeptides. FIG. 1A depicts a heterodimeric protein complex comprising one type I receptor fusion polypeptide and one type II receptor fusion polypeptide, which can be assembled covalently or noncovalently via a multimerization domain contained within each polypeptide chain. Two assembled multimerization domains constitute an interaction pair, which can be either guided or unguided. FIG. 2A depicts a heterotetrameric protein complex comprising two heterodimeric complexes as in FIG. 1A . Complexes of higher order can be envisioned.

FIG. 2 shows a schematic example of a heteromeric protein complex comprising a type I receptor polypeptide (indicated as “I”) (e.g. a polypeptide that is at least 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an extracellular domain of an ALK1, ALK2, ALK3, ALK4, ALK5, ALK6 or ALK7 protein from humans or other species such as those described herein, e.g., SEQ ID Nos: 14, 15, 124, 126, 171, 172, 413, 414, 463, 464, 18, 19, 136, 138, 173, 174, 421, 422, 465, 466, 22, 23, 115, 117, 175, 176, 407, 408, 467, 468, 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, 470, 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, 472, 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, 474, 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476) and a type II receptor polypeptide (indicated as “II”) (e.g. a polypeptide that is at least 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an extracellular domain of an ActRIIA, ActRIIB, MISRII, BMPRII, or TGFBRII protein from humans or other species such as those described herein, e.g., 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, 452, 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, 454, 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, 456, 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, 458, 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462). In the illustrated embodiment, the type I receptor polypeptide is part of a fusion polypeptide that comprises a first member of an interaction pair (“C”), and the type II receptor polypeptide is part of a fusion polypeptide that comprises a second member of an interaction pair (“D”). In each fusion polypeptide, a linker may be positioned between the type I or type II receptor polypeptide and the corresponding member of the interaction pair. The first and second members of the interaction pair (C, D) may be a guided (asymmetric) pair, meaning that the members of the pair associate preferentially with each other rather than self-associate, or the interaction pair may be unguided, meaning that the members of the pair may associate with each other or self-associate without substantial preference and may have the same or different amino acid sequences. Traditional Fc fusion proteins and antibodies are examples of unguided interaction pairs, whereas a variety of engineered Fc domains have been designed as guided (asymmetric) interaction pairs [e.g., Spiess et al (2015) Molecular Immunology 67(2A): 95-106].

FIG. 3 shows an alignment of extracellular domains of human ActRIIA (SEQ ID NO: 500) and human ActRIIB (SEQ ID NO: 2) with the residues that are deduced herein, based on composite analysis of multiple ActRIIB and ActRIIA crystal structures, to directly contact ligand indicated with boxes.

FIG. 4 shows a multiple sequence alignment of various vertebrate ActRIIB precursor proteins without their intracellular domains (SEQ ID NOs: 501, 502, 503, 504, 505, and 506, respectively), human ActRIIA precursor protein without its intracellular domain (SEQ ID NO: 507), and a consensus ActRII precursor protein (SEQ ID NO: 508).

FIG. 5 shows multiple sequence alignment of Fc domains from human IgG isotypes using Clustal 2.1 (SEQ ID NOs: 208, 212, 210 and 209, respectively, in order of appearance). Hinge regions are indicated by dotted underline. Double underline indicates examples of positions engineered in IgG1 Fc to promote asymmetric chain pairing and the corresponding positions with respect to other isotypes IgG2, IgG3 and IgG4.

FIG. 6 shows ligand binding data for an ActRIIB-Fc:ALK4-Fc heterodimeric protein complex as compared to ActRIIB-Fc homodimer and ALK4-Fc homodimer. For each protein complex, ligands are ranked by k off , a kinetic constant that correlates well with ligand signaling inhibition, and listed in descending order of binding affinity (ligands bound most tightly are listed at the top). At left, yellow, red, green, and blue lines indicate magnitude of the off-rate constant. Solid black lines indicate ligands whose binding to heterodimer is enhanced or unchanged compared with homodimer, whereas dashed red lines indicate substantially reduced binding compared with homodimer. As shown, the ActRIIB-Fc:ALK4-Fc heterodimer displays enhanced binding to activin B compared with either homodimer, retains strong binding to activin A, GDF8, and GDF11 as observed with ActRIIB-Fc homodimer, and exhibits substantially reduced binding to BMP9, BMP10, and GDF3. Like ActRIIB-Fc homodimer, the heterodimer retains intermediate-level binding to BMP6.

FIG. 7 shows ligand binding data for an ActRIIB-Fc:ALK3-Fc heterodimeric protein complex as compared to ActRIIB-Fc homodimer and ALK3-Fc homodimer. Format is the same as in FIG. 6 . As shown, the ActRIIB-Fc:ALK3-Fc heterodimer binds BMP2 and BMP4 with exceptionally high affinity and displays greatly enhanced binding to BMP5, BMP6, BMP7, GDF5, GDF6, and GDF7 compared with either homodimer. Compared to ActRIIB homodimer, the ActRIIB-Fc:ALK3-Fc heterodimer displays reduced binding to activin A, activin B, BMP10, GDF8, and GDF11 and also discriminates among these ligands to a greater degree, particularly between activin A and activin B. In addition, the ability of ActRIIB-Fc homodimer to bind BMP9 and GDF3 with high affinity is absent for ActRIIB-Fc:ALK3-Fc heterodimer.

›BRIEF DESCRIPTION OF THE DRAWINGS · 2 of 4

FIG. 8 shows ligand binding data for an ActRIIB-Fc:ALK7-Fc heterodimeric protein complex as compared to ActRIIB-Fc homodimer and ALK7-Fc homodimer. Format is the same as in FIG. 6 . As shown, four of the five ligands with strong binding to ActRIIB-Fc homodimer (activin A, BMP10, GDF8, and GDF11) exhibit reduced binding to the ActRIIB-Fc:ALK7-Fc heterodimer, the exception being activin B which retains tight binding to the heterodimer. In addition, three ligands with intermediate binding to ActRIIB-Fc homodimer (GDF3, BMP6, and particularly BMP9) exhibit reduced binding to the ActRIIB-Fc:ALK7-Fc heterodimer. In contrast, BMP5 binds the ActRIIB-Fc:ALK7 heterodimer with intermediate strength despite only weak binding to ActRIIB-Fc homodimer. No ligands tested bind to ALK7-Fc homodimer.

FIG. 9 shows ligand binding data for an ActRIIB-Fc:ALK2-Fc heterodimeric protein complex as compared to ActRIIB-Fc homodimer and ALK2-Fc homodimer. Format is the same as in FIG. 6 . As shown, the ActRIIB-Fc:ALK2-Fc heterodimer exhibits preferential and strong binding to activin B, thus resembling ActRIIB-Fc:ALK7-Fc heterodimer ( FIG. 8 ). However, ActRIIB-Fc:ALK2-Fc heterodimer differs from ActRIIB-Fc:ALK7-Fc in part by retaining the tight binding to BMP9 characteristic of ActRIIB-Fc homodimer. No ligands tested bind to ALK2-Fc homodimer.

FIG. 10 shows ligand binding data for an ActRIIA-Fc:ALK4-Fc heterodimeric protein complex as compared to ActRIIA-Fc homodimer and ALK4-Fc homodimer. Format is the same as in FIG. 6 . As shown, the ActRIIA-Fc:ALK4-Fc heterodimer exhibits enhanced binding to activin A, and particularly enhanced binding to activin AC, compared to ActRIIA-Fc homodimer, while retaining strong binding to activin AB and GDF11. In addition, the ligand with highest affinity for ActRIIA-Fc homodimer, activin B, displays reduced affinity (albeit still within the high-affinity range) for the ActRIIA-Fc:ALK4-Fc heterodimer. The ActRIIA-Fc:ALK4-Fc heterodimer also exhibits markedly reduced binding to BMP10 compared to ActRIIA-Fc homodimer.

FIG. 11 shows ligand binding data for a BMPRII-Fc:ALK1-Fc heterodimeric protein complex as compared to ActRIIB-Fc homodimer and ALK1-Fc homodimer. Format is the same as in FIG. 6 . As shown, the BMPRII-Fc:ALK1-Fc heterodimer largely retains the strong binding to BMP9 and BMP10 characteristic of ALK1-Fc homodimer; however, the heterodimer displays modest selectivity for BMP10 over BMP9 not present with the homodimer. Also unlike ALK1-Fc homodimer, the BMPRII-Fc:ALK1-Fc heterodimer binds to BMP15, albeit with an off-rate approximately ten times faster than that of BMPRII-Fc homodimer.

FIG. 12 shows ligand binding data for a BMPRII-Fc:ALK3-Fc heterodimeric protein complex as compared to BMPRII-Fc homodimer and ALK3-Fc homodimer. Format is the same as in FIG. 6 . As shown, the BMPRII-Fc:ALK3-Fc heterodimer binds much more strongly to BMP6 than does ALK3-Fc homodimer, reflecting an off-rate nearly ten times slower. With its largely unchanged binding to BMP2 and BMP4, the BMPRII-Fc:ALK3 heterodimer can therefore be considered a joint inhibitor of BMP2, BMP4, and BMP6. This binding profile contrasts with that of ALK3-Fc homodimer, whose exceptionally strongly binding to BMP4 and BMP2 identifies it as highly selective for this ligand pair compared to four ligands with intermediate-level binding, including BMP6.

FIG. 13 shows ligand binding data for a BMPRII-Fc:ALK4-Fc heterodimeric protein complex as compared to BMPRII-Fc homodimer and ALK4-Fc homodimer. Format is the same as in FIG. 6 . BMPRII-Fc:ALK4-Fc heterodimer differs from both homodimers by binding several activin ligands with high or intermediate strength and differs from BMPRII-Fc homodimer by binding BMP15 only weakly. Most notably, BMPRII-Fc:ALK4-Fc heterodimer binds strongly and with high selectivity to the heterodimeric ligand activin AB.

FIG. 14 shows ligand binding data for two different TGFβRII-Fc:ALK5-Fc heterodimeric protein complexes as compared to TGFβRII-Fc homodimer and ALK5-Fc homodimer. Format is the same as in FIG. 6 . As shown, TGFβRII-Fc:ALK5-Fc heterodimers differ markedly from TGFβRII-Fc homodimer in their high selectivity for TGFβ2 while still retaining considerable affinity for TGFβ1 and TGFβ3. The heterodimer incorporating the long isoform of TGFβRII bound TGFβ2 more strongly and selectively than did its short-isoform counterpart. No ligands tested bind to ALK5-Fc homodimer.

FIGS. 15A-15D show schematic examples of heteromeric protein complexes comprising a type I receptor polypeptide (indicated as “I”) (e.g. a polypeptide that is at least 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an extracellular domain of an ALK1, ALK2, ALK3, ALK4, ALK5, ALK6 or ALK7 protein from humans or other species such as those described herein, e.g., SEQ ID Nos: 14, 15, 124, 126, 171, 172, 413, 414, 463, 464, 18, 19, 136, 138, 173, 174, 421, 422, 465, 466, 22, 23, 115, 117, 175, 176, 407, 408, 467, 468, 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, 470, 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, 472, 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, 474, 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476) and a type II receptor polypeptide (indicated as “II”) (e.g. a polypeptide that is at least 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an extracellular domain of an ActRIIA, ActRIIB, MISRII, BMPRII, or TGFBRII protein from humans or other species such as those described herein, e.g., 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, 452, 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, 454, 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, 456, 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, 458, 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462). In the illustrated embodiments, the a type I receptor polypeptide is part of a fusion polypeptide that comprises a first member of an interaction pair (“C 1 ”), and a type II receptor polypeptide is part of a fusion polypeptide that comprises a second member of an interaction pair (“C 2 ”). Suitable interaction pairs included, for example, heavy chain and/or light chain immunoglobulin interaction pairs, truncations, and variants thereof such as those described herein [e.g., Spiess et al (2015) Molecular Immunology 67(2A): 95-106]. In each fusion polypeptide, a linker may be positioned between the a type I receptor polypeptide or a type II receptor polypeptide and the corresponding member of the interaction pair. The first and second members of the interaction pair may be unguided, meaning that the members of the pair may associate with each other or self-associate without substantial preference, and they may have the same or different amino acid sequences. See FIG. 15A . Alternatively, the interaction pair may be a guided (asymmetric) pair, meaning that the members of the pair associate preferentially with each other rather than self-associate. See FIG. 15B . Complexes of higher order can be envisioned. See FIGS. 15C and 15D .

›BRIEF DESCRIPTION OF THE DRAWINGS · 3 of 4

FIGS. 16A-16G show schematic examples of heteromeric protein complexes comprising two type I receptor polypeptide (indicated as “I”) (e.g. a polypeptide that is at least 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an extracellular domain of an ALK1, ALK2, ALK3, ALK4, ALK5, ALK6 or ALK7 protein from humans or other species such as those described herein, e.g., SEQ ID Nos: 14, 15, 124, 126, 171, 172, 413, 414, 463, 464, 18, 19, 136, 138, 173, 174, 421, 422, 465, 466, 22, 23, 115, 117, 175, 176, 407, 408, 467, 468, 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, 470, 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, 472, 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, 474, 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476) and two type II receptor polypeptide (indicated as “II”) (e.g. a polypeptide that is at least 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an extracellular domain of an ActRIIA, ActRIIB, MISRII, BMPRII, or TGFBRII protein from humans or other species such as those described herein, e.g., 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, 452, 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, 454, 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, 456, 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, 458, 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462).

In the illustrated embodiment FIG. 16A , the first type I receptor polypeptide (from left to right) is part of a fusion polypeptide that comprises a first member of an interaction pair (“C 1 ”) and further comprises an additional first member of an interaction pair (“A 1 ”); and the second type I receptor polypeptide is part of a fusion polypeptide that comprises a second member of an interaction pair (“C 2 ”) and further comprises an first member of an interaction pair (“A 2 ”). The first type II receptor polypeptide (from left to right) is part of a fusion polypeptide that comprises a second member of an interaction pair (“B 1 ”); and the second type II receptor polypeptide is part of a fusion polypeptide that comprises a second member of an interaction pair (“B 2 ”). A 1 and A 2 may be the same or different; B 1 and B 2 may be the same or different, and C 1 and C 2 may be the same or different. In each fusion polypeptide, a linker may be positioned between the type I receptor polypeptide or type II receptor polypeptide and the corresponding member of the interaction pair as well as between interaction pairs. FIG. 16A is an example of an association of unguided interaction pairs, meaning that the members of the pair may associate with each other or self-associate without substantial preference and may have the same or different amino acid sequences.

In the illustrated embodiment FIG. 16B , the first type II receptor polypeptide (from left to right) is part of a fusion polypeptide that comprises a first member of an interaction pair (“C 1 ”) and further comprises an additional first member of an interaction pair (“A 1 ”); and the second type II receptor ActRIIB polypeptide is part of a fusion polypeptide that comprises a second member of an interaction pair (“B 2 ”). The first type I receptor polypeptide (from left to right) is part of a fusion polypeptide that comprises a second member of an interaction pair (“B 1 ”); and the second type I receptor polypeptide is part of a fusion polypeptide that comprises a second member of an interaction pair (“C 2 ”) and further comprises a first member of an interaction pair (“A 2 ”). In each fusion polypeptide, a linker may be positioned between the type I receptor or type II receptor polypeptide and the corresponding member of the interaction pair as well as between interaction pairs. FIG. 16B is an example of an association of guided (asymmetric) interaction pairs, meaning that the members of the pair associate preferentially with each other rather than self-associate.

Suitable interaction pairs included, for example, heavy chain and/or light chain immunoglobulin interaction pairs, truncations, and variants thereof as described herein [e.g., Spiess et al (2015) Molecular Immunology 67(2A): 95-106]. Complexes of higher order can be envisioned. See FIGS. 16C-16F . Using similar methods, particularly those that employ light and/or heavy chain immunoglobulins, truncations, or variants thereof, interaction pairs may be used to produce heterodimers that resemble antibody Fab and F(ab′)2 complexes [e.g., Spiess et al (2015) Molecular Immunology 67(2A): 95-106]. See FIG. 16G .

FIGS. 17A and 17B show schematic examples of a heteromeric protein complex comprising a type I receptor polypeptide (indicated as “I”) (e.g. a polypeptide that is at least 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an extracellular domain of an ALK1, ALK2, ALK3, ALK4, ALK5, ALK6 or ALK7 protein from humans or other species such as those described herein, e.g., SEQ ID Nos: 14, 15, 124, 126, 171, 172, 413, 414, 463, 464, 18, 19, 136, 138, 173, 174, 421, 422, 465, 466, 22, 23, 115, 117, 175, 176, 407, 408, 467, 468, 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, 470, 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, 472, 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, 474, 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476) and a type II receptor polypeptide (indicated as “II”) (e.g. a polypeptide that is at least 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% identical to an extracellular domain of an ActRIIA, ActRIIB, MISRII, BMPRII, or TGFBRII protein from humans or other species such as those described herein, e.g., 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, 452, 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, 454, 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, 456, 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, 458, 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462), and a ligand-binding domain of an antibody (e.g., a ligand binding domain derived form an antibody that binds to one or more TGF-beta superfamily ligands). In the illustrated embodiments, the type I receptor polypeptide is part of a fusion polypeptide that comprises a first member of an interaction pair (“C 1 ”), and further comprises an additional first member of an interaction pair (“A 1 ”). The type II receptor polypeptide is part of a fusion polypeptide that comprises a second member of an interaction pair (“B 1 ”). The variable heavy chain (V H ) polypeptide is part of a fusion polypeptide that comprises a second member of an interaction pair (“C 2 ”), and further comprises a first member of an interaction pair (“A 2 ”). The variable heavy chain (V L ) polypeptide is part of a fusion polypeptide that comprises a second member of an interaction pair (“B 2 ”). In each fusion polypeptide, a linker may be positioned between the type I receptor or type II receptor polypeptide and the corresponding member of the interaction pair, between interaction pairs, and between the V H and V L polypeptides and a member of the interaction pair. A 1 and A 2 may be the same or different; B 1 and B 2 may be the same or different, and C 1 and C 2 may be the same or different. Suitable interaction pairs included, for example, constant heavy chain and/or light chain immunoglobulin interaction pairs, truncations, and variants thereof as described herein [e.g., Spiess et al (2015) Molecular Immunology 67(2A): 95-106]. FIG. 17A is an example of an association of guided (asymmetric) interaction pairs, meaning that the members of the pair associate preferentially with each other rather than self-associate. FIG. 17B is an example of an association of unguided interaction pairs, meaning that the members of the pair may associate with each other or self-associate without substantial preference and may have the same or different amino acid sequences.

›BRIEF DESCRIPTION OF THE DRAWINGS · 4 of 4

FIG. 18 shows schematic examples of type I receptor: type II receptor single-trap polypeptides. Type I receptor: type II receptor single-trap polypeptides may contain multiple type I receptor domains (e.g., 1, 2, 3, 4, 5, 6, 7, 9, 10 or more domains), having the same or different sequences, and multiple type II receptor domains (e.g., 1, 2, 3, 4, 5, 6, 7, 9, 10 or more domains), having the same or different sequences. These type I receptor and type II receptor domains may be arranged in any order and may comprise one or more linker domains positions between one or more of the type II receptor and type II receptor domains. Such ligand traps may be useful as therapeutic agents to treat or prevent diseases or disorders described herein.

FIGS. 19A-19D show schematic examples of multimeric protein complexes comprising at least one type I receptor: type II receptor single-chain trap polypeptide. In the illustrated embodiments 19 A and 19 B, a first type I receptor: type II receptor single-chain trap polypeptide (from left to right) is part of a fusion polypeptide that comprises a first member of an interaction pair (“C 1 ”); and a second type I receptor: type II receptor single-chain trap polypeptide is part of a fusion polypeptide that comprises a second member of an interaction pair (“C 2 ”). C 1 and C 2 may be the same or different. The first and second type I receptor: type II receptor single-chain trap polypeptides may be the same or different. In each fusion polypeptide, a linker may be positioned between the type I receptor: type II receptor single-chain trap polypeptide and the corresponding member of the interaction pair. Suitable interaction pairs included, for example, heavy chain and/or light chain immunoglobulin interaction pairs, truncations, and variants thereof as described herein [e.g., Spiess et al (2015) Molecular Immunology 67(2A): 95-106]. FIG. 19A is an example of an association of unguided interaction pairs, meaning that the members of the pair may associate with each other or self-associate without substantial preference and may have the same or different amino acid sequences. FIG. 19B is an example of an association of guided (asymmetric) interaction pairs, meaning that the members of the pair associate preferentially with each other rather than self-associate. Complexes of higher order can be envisioned. In addition, such type I receptor: type II receptor single-chain trap polypeptides may be similarly be associated, covalently or non-covalently, with one or more type I receptor polypeptides and/or one or more type II receptor polypeptides. See FIG. 19C . Also, such type I receptor: type II receptor single-chain trap polypeptides may be similarly be associated, covalently or non-covalently, with one or more ligand-binding domain of an antibody (e.g., a ligand binding domain of an antibody that binds to one or more type I receptor: type II receptor heteromultimer binding-ligands). See FIG. 19D .

›DETAILED DESCRIPTION OF THE INVENTION · 1 of 7

1. Overview

In part, the present disclosure relates to heteromultimer complexes comprising an extracellular domain of a TGFβ superfamily type I receptor polypeptide and an extracellular domain of a TGFβ superfamily type II receptor polypeptide, heteromultimer complexes comprising an extracellular domain of at least two different TGFβ superfamily type I receptor polypeptides, heteromultimer complexes comprising an extracellular domain of at least two different TGFβ superfamily type II receptor polypeptides, methods of making such heteromultimer complexes, and uses thereof. As described herein, in some embodiments, heteromultimer complexes may comprise an extracellular domain of a TGFβ superfamily type I receptor polypeptide selected from: ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7. Similarly, in some embodiments, these heteromultimer complexes may comprise an extracellular domain of a TGFβ superfamily type II receptor polypeptide selected from: ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII. In certain preferred embodiments, heteromultimer complexes of the disclosure have an altered TGFβ superfamily ligand binding specificity/profile relative to a corresponding sample of a homomultimer complex (e.g., an ActRIIB:ALK4 heterodimer compared to an ActRIIB:ActRIIB homodimer complex or an ALK4:ALK4 homodimer complex).

The TGF-β superfamily is comprised of over 30 secreted factors including TGF-betas, activins, nodals, bone morphogenetic proteins (BMPs), growth and differentiation factors (GDFs), and anti-Mullerian hormone (AMH). See, e.g., Weiss et al. (2013) Developmental Biology, 2(1): 47-63. Members of the superfamily, which are found in both vertebrates and invertebrates, are ubiquitously expressed in diverse tissues and function during the earliest stages of development throughout the lifetime of an animal. Indeed, TGF-β superfamily proteins are key mediators of stem cell self-renewal, gastrulation, differentiation, organ morphogenesis, and adult tissue homeostasis. Consistent with this ubiquitous activity, aberrant TGF-beta superfamily signaling is associated with a wide range of human pathologies including, for example, autoimmune disease, cardiovascular disease, fibrotic disease, and cancer.

Ligands of the TGF-beta superfamily share the same dimeric structure in which the central 3½ turn helix of one monomer packs against the concave surface formed by the beta-strands of the other monomer. The majority of TGF-beta family members are further stabilized by an intermolecular disulfide bonds. This disulfide bond traverses through a ring formed by two other disulfide bonds generating what has been termed a ‘cysteine knot’ motif. See, e.g., Lin et al., (2006) Reproduction 132: 179-190 and Hinck et al. (2012) FEBS Letters 586: 1860-1870.

TGF-beta superfamily signaling is mediated by heteromeric complexes of type I and type II serine/threonine kinase receptors, which phosphorylate and activate downstream SMAD proteins (e.g., SMAD proteins 1, 2, 3, 5, and 8) upon ligand stimulation. See, e.g., Massagué (2000) Nat. Rev. Mol. Cell Biol. 1:169-178. These type I and type II receptors are transmembrane proteins, composed of a ligand-binding extracellular domain with cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase specificity. In general, type I receptors mediate intracellular signaling while the type II receptors are required for binding TGF-beta superfamily ligands. Type I and II receptors form a stable complex after ligand binding, resulting in phosphorylation of type I receptors by type II receptors.

The TGF-beta family can be divided into two phylogenetic branches based on the type I receptors they bind and the Smad proteins they activate. One is the more recently evolved branch, which includes, e.g., the TGF-betas, activins, GDF8, GDF9, GDF11, BMP3 and nodal, which signal through type I receptors that activate Smads 2 and 3 [Hinck (2012) FEBS Letters 586:1860-1870]. The other branch comprises the more distantly related proteins of the superfamily and includes, e.g., BMP2, BMP4, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF1, GDF5, GDF6, and GDF7, which signal through Smads 1, 5, and 8.

TGF-beta isoforms are the founding members of the TGF-beta superfamily, of which there are 3 known isoforms in mammals designated as TGF-beta1, TGF-beta2 and TGF-beta3. Mature bioactive TGF-beta ligands function as homodimers and predominantly signal through the type I receptor ALK5, but have also been found to additionally signal through ALK1 in endothelial cells. See, e.g., Goumans et al. (2003) Mol Cell 12(4): 817-828. TGF-beta1 is the most abundant and ubiquitously expressed isoform. TGF-beta1 is known to have an important role in wound healing, and mice expressing a constitutively active TGF-beta1 transgene develop fibrosis. See e.g., Clouthier et al., (1997) J Clin. Invest. 100(11): 2697-2713. TGF-beta1 is also involved in T cell activation and maintenance of T regulatory cells. See, e.g., Li et al., (2006) Immunity 25(3): 455-471. TGF-beta2 expression was first described in human glioblastoma cells, and is occurs in neurons and astroglial cells of the embryonic nervous system. TGF-beta2 is known to suppress interleukin-2-dependent growth of T lymphocytes. TGF-beta3 was initially isolated from a human rhabdomyosarcoma cell line and since has been found in lung adenocarcinoma and kidney carcinoma cell lines. TGF-beta3 is known to be important for palate and lung morphogenesis. See, e.g., Kubiczkova et al., (2012) Journal of Translational Medicine 10:183.

Activins are members of the TGF-beta superfamily and were initially discovered as regulators of secretion of follicle-stimulating hormone, but subsequently various reproductive and non-reproductive roles have been characterized. There are three principal activin forms (A, B, and AB) that are homo/heterodimers of two closely related 3 subunits (β A β A , β B β B , and β A β B , respectively). The human genome also encodes an activin C and an activin E, which are primarily expressed in the liver, and heterodimeric forms containing β C or β E are also known. In the TGF-beta superfamily, activins are unique and multifunctional factors that can stimulate hormone production in ovarian and placental cells, support neuronal cell survival, influence cell-cycle progress positively or negatively depending on cell type, and induce mesodermal differentiation at least in amphibian embryos. See, e.g., DePaolo et al. (1991) Proc Soc Ep Biol Med. 198:500-512; Dyson et al. (1997) Curr Biol. 7:81-84; and Woodruff (1998) Biochem Pharmacol. 55:953-963. In several tissues, activin signaling is antagonized by its related heterodimer, inhibin. For example, in the regulation of follicle-stimulating hormone (FSH) secretion from the pituitary, activin promotes FSH synthesis and secretion, while inhibin reduces FSH synthesis and secretion. Other proteins that may regulate activin bioactivity and/or bind to activin include follistatin (FS), follistatin-related protein (FSRP, also known as FLRG or FSTL3), and α 12 -macroglobulin.

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As described herein, agents that bind to “activin A” are agents that specifically bind to the (A subunit, whether in the context of an isolated β A subunit or as a dimeric complex (e.g., a β A β A homodimer or a β A β B heterodimer). In the case of a heterodimer complex (e.g., a β A β B heterodimer), agents that bind to “activin A” are specific for epitopes present within the β A subunit, but do not bind to epitopes present within the non-β A subunit of the complex (e.g., the β B subunit of the complex). Similarly, agents disclosed herein that antagonize (inhibit) “activin A” are agents that inhibit one or more activities as mediated by a β A subunit, whether in the context of an isolated β A subunit or as a dimeric complex (e.g., a β A β A homodimer or a β A β B heterodimer). In the case of β A β B heterodimers, agents that inhibit “activin A” are agents that specifically inhibit one or more activities of the β A subunit, but do not inhibit the activity of the non-(A subunit of the complex (e.g., the β B subunit of the complex). This principle applies also to agents that bind to and/or inhibit “activin B”, “activin C”, and “activin E”. Agents disclosed herein that antagonize “activin AB”, “activin AC”, “activin AE”, “activin BC”, or “activin BE” are agents that inhibit one or more activities as mediated by the β A subunit and one or more activities as mediated by the (β B subunit. The same principle applies to agents that bind to and/or inhibit “activin AC”, “activin AE”, “activin BC”, or “activin BE”.

Nodal proteins have functions in mesoderm and endoderm induction and formation, as well as subsequent organization of axial structures such as heart and stomach in early embryogenesis. It has been demonstrated that dorsal tissue in a developing vertebrate embryo contributes predominantly to the axial structures of the notochord and pre-chordal plate while it recruits surrounding cells to form non-axial embryonic structures. Nodal appears to signal through both type I and type II receptors and intracellular effectors known as SMAD proteins. Studies support the idea that ActRIIA and ActRIIB serve as type II receptors for nodal. See, e.g., Sakuma et al. (2002) Genes Cells. 2002, 7:401-12. It is suggested that Nodal ligands interact with their co-factors (e.g., Cripto or Cryptic) to activate activin type I and type II receptors, which phosphorylate SMAD2. Nodal proteins are implicated in many events critical to the early vertebrate embryo, including mesoderm formation, anterior patterning, and left-right axis specification. Experimental evidence has demonstrated that nodal signaling activates pAR3-Lux, a luciferase reporter previously shown to respond specifically to activin and TGF-beta. However, nodal is unable to induce pTlx2-Lux, a reporter specifically responsive to bone morphogenetic proteins. Recent results provide direct biochemical evidence that nodal signaling is mediated by SMAD2 and SMAD3, which also mediate signaling by TGF-betas and activins. Further evidence has shown that the extracellular protein Cripto or Cryptic is required for nodal signaling, making it distinct from activin or TGF-beta signaling.

The BMPs and GDFs together form a family of cysteine-knot cytokines sharing the characteristic fold of the TGF-beta superfamily. See, e.g., Rider et al. (2010) Biochem J., 429(1):1-12. This family includes, for example, BMP2, BMP4, BMP6, BMP7, BMP2a, BMP3, BMP3b (also known as GDF10), BMP4, BMP5, BMP6, BMP7, BMP8, BMP8a, BMP8b, BMP9 (also known as GDF2), BMP10, BMP11 (also known as GDF11), BMP12 (also known as GDF7), BMP13 (also known as GDF6), BMP14 (also known as GDF5), BMP15, GDF1, GDF3 (also known as VGR2), GDF8 (also known as myostatin), GDF9, GDF15, and decapentaplegic. Besides the ability to induce bone formation, which gave the BMPs their name, the BMP/GDFs display morphogenetic activities in the development of a wide range of tissues. BMP/GDF homo- and hetero-dimers interact with combinations of type I and type II receptor dimers to produce multiple possible signaling complexes, leading to the activation of one of two competing sets of SMAD transcription factors. BMP/GDFs have highly specific and localized functions. These are regulated in a number of ways, including the developmental restriction of BMP/GDF expression and through the secretion of several specific BMP antagonist proteins that bind with high affinity to the cytokines. Curiously, a number of these antagonists resemble TGF-beta superfamily ligands.

Growth and differentiation factor-8 (GDF8) is also known as myostatin. GDF8 is a negative regulator of skeletal muscle mass and is highly expressed in developing and adult skeletal muscle. The GDF8 null mutation in transgenic mice is characterized by a marked hypertrophy and hyperplasia of skeletal muscle. See, e.g., McPherron et al., Nature (1997) 387:83-90. Similar increases in skeletal muscle mass are evident in naturally occurring mutations of GDF8 in cattle and, strikingly, in humans. See, e.g., Ashmore et al. (1974) Growth, 38:501-507; Swatland and Kieffer, J. Anim. Sci. (1994) 38:752-757; McPherron and Lee, Proc. Natl. Acad. Sci. USA (1997) 94:12457-12461; Kambadur et al., Genome Res. (1997) 7:910-915; and Schuelke et al. (2004) N Engl J Med, 350:2682-8. Studies have also shown that muscle wasting associated with HIV-infection in humans is accompanied by increases in GDF8 protein expression. See, e.g., Gonzalez-Cadavid et al., PNAS (1998) 95:14938-43. In addition, GDF8 can modulate the production of muscle-specific enzymes (e.g., creatine kinase) and modulate myoblast cell proliferation. See, e.g., International Patent Application Publication No. WO 00/43781). The GDF8 propeptide can noncovalently bind to the mature GDF8 domain dimer, inactivating its biological activity. See, e.g., Miyazono et al. (1988) J. Biol. Chem., 263: 6407-6415; Wakefield et al. (1988) J. Biol. Chem., 263; 7646-7654; and Brown et al. (1990) Growth Factors, 3: 35-43. Other proteins which bind to GDF8 or structurally related proteins and inhibit their biological activity include follistatin, and potentially, follistatin-related proteins. See, e.g., Gamer et al. (1999) Dev. Biol., 208: 222-232.

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GDF11, also known as BMP11, is a secreted protein that is expressed in the tail bud, limb bud, maxillary and mandibular arches, and dorsal root ganglia during mouse development. See, e.g., McPherron et al. (1999) Nat. Genet., 22: 260-264; and Nakashima et al. (1999) Mech. Dev., 80: 185-189. GDF11 plays a unique role in patterning both mesodermal and neural tissues. See, e.g., Gamer et al. (1999) Dev Biol., 208:222-32. GDF11 was shown to be a negative regulator of chondrogenesis and myogenesis in developing chick limb. See, e.g., Gamer et al. (2001) Dev Biol., 229:407-20. The expression of GDF11 in muscle also suggests its role in regulating muscle growth in a similar way to GDF8. In addition, the expression of GDF11 in brain suggests that GDF11 may also possess activities that relate to the function of the nervous system. Interestingly, GDF11 was found to inhibit neurogenesis in the olfactory epithelium. See, e.g., Wu et al. (2003) Neuron., 37:197-207. Hence, GDF11 may have in vitro and in vivo applications in the treatment of diseases such as muscle diseases and neurodegenerative diseases (e.g., amyotrophic lateral sclerosis).

BMP7, also called osteogenic protein-1 (OP-1), is well known to induce cartilage and bone formation. In addition, BMP7 regulates a wide array of physiological processes. For example, BMP7 may be the osteoinductive factor responsible for the phenomenon of epithelial osteogenesis. It is also found that BMP7 plays a role in calcium regulation and bone homeostasis. Like activin, BMP7 binds to type II receptors, ActRIIA and ActRIIB. However, BMP7 and activin recruit distinct type I receptors into heteromeric receptor complexes. The major BMP7 type I receptor observed was ALK2, while activin bound exclusively to ALK4 (ActRIIB). BMP7 and activin elicited distinct biological responses and activated different SMAD pathways. See, e.g., Macias-Silva et al. (1998) J Biol Chem. 273:25628-36.

Anti-Mullerian hormone (AMH), also known as Mullerian-inhibiting substance (MIS), is a TGF-beta family glycoprotein. One AMH-associated type II receptor has been identified and is designated as AMHRII, or alternatively MISRII. AMH induces regression of the Mullerian ducts in the human male embryo. AMH is expressed in reproductive age women and does not fluctuate with cycle or pregnancy, but was found to gradual decrease as both oocyte quantity and quality decrease, suggesting AMH could serve as a biomarker for ovarian physiology. See e.g. Zec et al., (2011) Biochemia Medica 21(3): 219-30.

Activin receptor-like kinase-1 (ALK1), the product of the ACVRL1 gene known alternatively as ACVRLK1, is a type I receptor whose expression is predominantly restricted to endothelial cells. See, e.g., OMIM entry 601284. ALK1 is activated by the binding of TGF-beta family ligands such as BMP9 and BMP10, and ALK1 signaling is critical in the regulation of both developmental and pathological blood vessel formation. ALK1 expression overlaps with sites of vasculogenesis and angiogenesis in early mouse development, and ALK1 knockout mice die around embryonic day 11.5 because of severe vascular abnormalities (see e.g., Cunha and Pietras (2011) Blood 117(26):6999-7006.) ALK1 expression has also been described in other cell types such as hepatic stellate cells and chondrocytes. Additionally, ALK1 along with activin receptor-like kinase-2 (ALK2) have been found to be important for BMP9-induced osteogenic signaling in mesenchymal stem cells. See e.g., Cunha and Pietras (2011) Blood 117(26):6999-7006.

ALK2, the product of the ACVR1 gene known alternatively as ActRIA or ACVRLK2, is a type I receptor that has been shown to bind activins and BMPs. ALK2 is critical for embryogenesis as ALK2 knockout mice die soon after gastrulation. See, e.g., Mishina et al. (1999) Dev Biol. 213: 314-326 and OMIM entry 102576. Constitutively active mutations in ALK2 are associated with fibrodysplasia ossificans progressiva (FOP). FOP is rare genetic disorder that causes fibrous tissue, including muscle, tendon and ligament, to be ossified spontaneously or when damaged. An arginine to histidine mutation in codon 206 of ALK2 is naturally occurring mutation associated with FOP in humans. This mutation induces BMP-specific signaling via ALK2 without the binding of ligand. See, e.g., Fukuda et al., (2009) J Biol Chem. 284(11):7149-7156 and Kaplan et al., (2011) Ann N.Y. Acad Sci. 1237: 5-10. Activin receptor-like kinase-3 (ALK3), the product of the BMPRIA gene known alternatively as ACVRLK3, is a type I receptor mediating effects of multiple ligands in the BMP family. Unlike several type I receptors with ubiquitous tissue expression, ALK3 displays a restricted pattern of expression consistent with more specialized functionality. See, e.g., ten Dijke (1993) Oncogene, 8: 2879-2887 and OMIM entry 601299. ALK3 is generally recognized as a high affinity receptor for BMP2, BMP4, BMP7 and other members of the BMP family. BMP2 and BMP7 are potent stimulators of osteoblastic differentiation, and are now used clinically to induce bone formation in spine fusions and certain non-union fractures. ALK3 is regarded as a key receptor in mediating BMP2 and BMP4 signaling in osteoblasts. See, e.g., Lavery et al. (2008) J. Biol. Chem. 283: 20948-20958. A homozygous ALK3 knockout mouse dies early in embryogenesis (˜day 9.5), however, adult mice carrying a conditional disruption of ALK3 in osteoblasts have been recently reported to exhibit increased bone mass, although the newly formed bone showed evidence of disorganization. See, e.g., Kamiya (2008) J. Bone Miner. Res., 23:2007-2017; and Kamiya (2008) Development 135: 3801-3811. This finding is in startling contrast to the effectiveness of BMP2 and BMP7 (ligands for ALK3) as bone building agents in clinical use.

Activin receptor-like kinase-4 (ALK4), the product of the ACVR1B gene alternatively known as ACVRLK4, is a type I receptor that transduces signaling for a number of TGF-beta family ligands including activins, nodal and GDFs. ALK4 mutations are associated with pancreatic cancer and expression of dominant negative truncated ALK4 isoforms are highly expressed in human pituitary tumors. See, e.g., Tsuchida et al., (2008) Endocrine Journal 55(1):11-21 and OMIM entry 601300.

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Activin receptor-like kinase-5 (ALK5), the product of the TGFBR1 gene, is widely expressed in most cell types. Several TGF-beta superfamily ligands, including TGF-betas, activin, and GDF-8, signal via ALK5 and activate downstream Smad 2 and Smad 3. Mice deficient in ALK5 exhibit severe defects in the vascular development of the yolk sac and placenta, lack circulating red blood cells, and die mid-gestation. It was found that these embryos had normal hematopoietic potential, but enhanced proliferation and improper migration of endothelial cells. Thus, ALK5-dependent signaling is important for angiogenesis, but not for the development of hematopoietic progenitor cells and functional hematopoiesis. See, e.g. Larsson et al., (2001) The EMBO Journal, 20(7): 1663-1673 and OMIM entry 190181. In endothelial cells, ALK5 acts cooperatively and opposite to ALK1 signaling. ALK5 inhibits cell migration and proliferation, notably the opposite effect of ALK1. See, e.g., Goumans et al. (2003) Mol Cell 12(4): 817-828. Additionally, ALK5 is believed to negatively regulate muscle growth. Knockdown of ALK5 in the muscle a mouse model of muscular dystrophy was found to decrease fibrosis and increase expression of genes associate with muscle growth. See, e.g. Kemaladewi et al., (2014) Mol Ther Nucleic Acids 3, e156.

Activin receptor-like kinase-6 (ALK6) is the product of the BMPR1B gene, whose deficiency is associated with chrondodysplasia and limb defects in both humans and mice. See, e.g., Demirhan et al., (2005) J Med Genet. 42:314-317. ALK6 is widely expressed throughout the developing skeleton, and is required for chondrogenesis in mice. See, e.g., Yi et al., (2000) Development 127:621-630 and OMIM entry 603248.

Activin receptor-like kinase-7 (ALK7) is the product of the ACVR1C gene. ALK7 null mice are viable, fertile, and display no skeletal or limb malformations. GDF3 signaling through ALK7 appears to play a role in insulin sensitivity and obesity. This is supported by results that Alk7 null mice show reduced fat accumulation and resistance to diet-induced obesity. See, e.g., Andersson et al., (2008) PNAS 105(20): 7252-7256. ALK7-mediated Nodal signaling has been implicated to have both tumor promoting and tumor suppressing effects in a variety of different cancer cell lines. See, e.g., De Silva et al., (2012) Frontiers in Endocrinology 3:59 and OMIM entry 608981.

As used herein the term “ActRII” refers to the family of type II activin receptors. This family includes both the activin receptor type IIA (ActRIIA), encoded by the ACVR2A gene, and the activin receptor type IIB (ActRIIB), encoded by the ACVR2B gene. ActRII receptors are TGF-beta superfamily type II receptors that bind a variety of TGF-beta superfamily ligands including activins, GDF8 (myostatin), GDF11, and a subset of BMPs, notably BMP6 and BMP7. ActRII receptors are implicated in a variety of biological disorders including muscle and neuromuscular disorders (e.g., muscular dystrophy, amyotrophic lateral sclerosis (ALS), and muscle atrophy), undesired bone/cartilage growth, adipose tissue disorders (e.g., obesity), metabolic disorders (e.g., type 2 diabetes), and neurodegenerative disorders. See, e.g., Tsuchida et al., (2008) Endocrine Journal 55(1):11-21, Knopf et al., U.S. Pat. No. 8,252,900, and OMIM entries 102581 and 602730.

Transforming growth factor beta receptor II (TGFBRII), encoded by the TGFBR2 gene, is a type II receptor that is known to bind TGF-beta ligands and activate downstream Smad 2 and Smad 3 effectors. See, e.g., Hinck (2012) FEBS Letters 586: 1860-1870 and OMIM entry 190182. TGF-beta signaling through TGFBRII is critical in T-cell proliferation, maintenance of T regulatory cells and proliferation of precartilaginous stem cells. See, e.g., Li et al., (2006) Immunity 25(3): 455-471 and Cheng et al., Int. J. Mol. Sci. 2014, 15, 12665-12676. Bone morphogenetic protein receptor II (BMPRII), encoded by the BMPR2 gene, is a type II receptor that is thought to bind certain BMP ligands. In some instances, efficient ligand binding to BMPRII is dependent on the presence of the appropriate TGFBR type I receptors. See, e.g., Rosenzweig et al., (1995) PNAS 92:7632-7636. Mutations in BMPRII are associated pulmonary hypertension in humans. See OMIM entry 600799.

Müllerian-inhibiting substance receptor II (MISRII), the product of the AMHR2 gene known alternatively as anti-Müllerian hormone type II receptor, is a type II TGF-beta receptor. MISRII binds the MIS ligand, but requires the presence of an appropriate type I receptor, such as ALK3 or ALK6, for signal transduction. See, e.g., Hinck (2012) FEBS Letters 586:1860-1870 and OMIM entry 600956. MISRII is involved in sex differentiation in humans and is required for Müllerian regression in the human male. AMH is expressed in reproductive age women and does not fluctuate with cycle or pregnancy, but was found to gradual decrease as both oocyte quantity and quality decrease, suggesting AMH could serve as a biomarker of ovarian physiology. See, e.g., Zec et al., (2011) Biochemia Medica 21(3): 219-30 and OMIM entry 600956.

In certain aspects, the present disclosure relates to the use of a) heteromultimer complexes comprising an extracellular domain of a TGFβ superfamily type I receptor polypeptide (e.g., ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7) and an extracellular domain of a TGFβ superfamily type II receptor polypeptide (e.g., ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII) b) heteromultimer complexes comprising an extracellular domain of at least two TGFβ superfamily type I receptor polypeptide (e.g., ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7), and heteromultimer complexes comprising an extracellular domain of at least two TGFβ superfamily type II receptor polypeptide (e.g., ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII), preferably soluble heteromultimer complexes, to antagonize intracellular signaling transduction (e.g., Smad 2/3 and/or Smad 1/5/8 signaling) initiated by one or more TGFβ superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, Müllerian-inhibiting substance (MIS), and Lefty). As described herein, such antagonist heteromultimer complexes may be useful in the treatment or prevention of various disorders/conditions associated with, e.g., muscle loss, insufficient muscle growth, neurodegeneration, bone loss, reduced bone density and/or mineralization, insufficient bone growth, metabolic disorders such as obesity and red blood cell disorders such as anemia.

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In particular, the data of the present disclosure demonstrates that heteromultimer complexes comprising an extracellular domain of a TGFβ superfamily type I receptor polypeptide and an extracellular domain of a TGFβ superfamily type II receptor polypeptide have different ligand binding specificities/profiles in comparison to their corresponding homomultimer complexes.

The terms used in this specification generally have their ordinary meanings in the art, within the context of this disclosure and in the specific context where each term is used. Certain terms are discussed below or elsewhere in the specification to provide additional guidance to the practitioner in describing the compositions and methods of the disclosure and how to make and use them. The scope or meaning of any use of a term will be apparent from the specific context in which it is used.

The terms “heteromer” or “heteromultimer” is a complex comprising at least a first polypeptide and a second polypeptide, wherein the second polypeptide differs in amino acid sequence from the first polypeptide by at least one amino acid residue. The heteromer can comprise a “heterodimer” formed by the first and second polypeptide or can form higher order structures where polypeptides in addition to the first and second polypeptide are present. Exemplary structures for the heteromultimer include heterodimers, heterotrimers, heterotetramers and further oligomeric structures. Heterodimers are designated herein as X:Y or equivalently as X-Y, where X represents a first polypeptide and Y represents a second polypeptide. Higher-order heteromers and oligomeric structures are designated herein in a corresponding manner. In certain embodiments a heteromultimer is recombinant (e.g., one or more polypeptide components may be a recombinant protein), isolated and/or purified.

“Homologous,” in all its grammatical forms and spelling variations, refers to the relationship between two proteins that possess a “common evolutionary origin,” including proteins from superfamilies in the same species of organism, as well as homologous proteins from different species of organism. Such proteins (and their encoding nucleic acids) have sequence homology, as reflected by their sequence similarity, whether in terms of percent identity or by the presence of specific residues or motifs and conserved positions. However, in common usage and in the instant application, the term “homologous,” when modified with an adverb such as “highly,” may refer to sequence similarity and may or may not relate to a common evolutionary origin.

The term “sequence similarity,” in all its grammatical forms, refers to the degree of identity or correspondence between nucleic acid or amino acid sequences that may or may not share a common evolutionary origin.

“Percent (%) sequence identity” with respect to a reference polypeptide (or nucleotide) sequence is defined as the percentage of amino acid residues (or nucleic acids) in a candidate sequence that are identical to the amino acid residues (or nucleic acids) in the reference polypeptide (nucleotide) sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Alignment for purposes of determining percent amino acid sequence identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST, BLAST-2, ALIGN or Megalign (DNASTAR) software. Those skilled in the art can determine appropriate parameters for aligning sequences, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared. For purposes herein, however, % amino acid (nucleic acid) sequence identity values are generated using the sequence comparison computer program ALIGN-2. The ALIGN-2 sequence comparison computer program was authored by Genentech, Inc., and the source code has been filed with user documentation in the U.S. Copyright Office, Washington D.C., 20559, where it is registered under U.S. Copyright Registration No. TXU510087. The ALIGN-2 program is publicly available from Genentech, Inc., South San Francisco, Calif., or may be compiled from the source code. The ALIGN-2 program should be compiled for use on a UNIX operating system, including digital UNIX V4.0D. All sequence comparison parameters are set by the ALIGN-2 program and do not vary.

“Agonize”, in all its grammatical forms, refers to the process of activating a protein and/or gene (e.g., by activating or amplifying that protein's gene expression or by inducing an inactive protein to enter an active state) or increasing a protein's and/or gene's activity.

“Antagonize”, in all its grammatical forms, refers to the process of inhibiting a protein and/or gene (e.g., by inhibiting or decreasing that protein's gene expression or by inducing an active protein to enter an inactive state) or decreasing a protein's and/or gene's activity.

As used herein, unless otherwise stated, “does not substantially bind to X” is intended to mean that an agent has a K D that is greater than about 10 −7 , 10 −6 , 10 −5 , 10 −4 , or greater (e.g., no detectable binding by the assay used to determine the K D ) for “X”, wherein “X” is a specified agent such as protein or nucleic acid.

The terms “about” and “approximately” as used in connection with a numerical value throughout the specification and the claims denotes an interval of accuracy, familiar and acceptable to a person skilled in the art. In general, such interval of accuracy is +10%. Alternatively, and particularly in biological systems, the terms “about” and “approximately” may mean values that are within an order of magnitude, preferably <5-fold and more preferably <2-fold of a given value.

Numeric ranges disclosed herein are inclusive of the numbers defining the ranges.

The terms “a” and “an” include plural referents unless the context in which the term is used clearly dictates otherwise. The terms “a” (or “an”), as well as the terms “one or more,” and “at least one” can be used interchangeably herein. Furthermore, “and/or” where used herein is to be taken as specific disclosure of each of the two or more specified features or components with or without the other. Thus, the term “and/or” as used in a phrase such as “A and/or B” herein is intended to include “A and B,” “A or B,” “A” (alone), and “B” (alone). Likewise, the term “and/or” as used in a phrase such as “A, B, and/or C” is intended to encompass each of the following aspects: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone).

›DETAILED DESCRIPTION OF THE INVENTION · 6 of 7

Throughout this specification, the word “comprise” or variations such as “comprises” or “comprising” will be understood to imply the inclusion of a stated integer or groups of integers but not the exclusion of any other integer or group of integers.

2. TGF-Beta Superfamily Type I Receptor and Type II Receptor Complexes

In certain aspects, the present disclosure relates to heteromultimer complexes comprising one or more TGF-beta superfamily type I receptor polypeptides (e.g., ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7 proteins from humans or other species such as those described herein, e.g., SEQ ID NOs: 14, 15, 124, 126, 171, 172, 413, 414, 463, 464, 18, 19, 136, 138, 173, 174, 421, 422, 465, 466, 22, 23, 115, 117, 175, 176, 407, 408, 467, 468, 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, 470, 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, 472, 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, 474, 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476) and one or more TGF-beta superfamily type II receptor polypeptides (e.g., ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII proteins from humans or other species such as those described herein, e.g., SEQ ID NOs: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, 452, 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, 454, 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, 456, 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, 458, 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462); heteromultimer complexes comprising at least two different TGF-beta superfamily type I receptor polypeptides (e.g., ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7 proteins from humans or other species such as those described herein, e.g., SEQ ID NOs: 14, 15, 124, 126, 171, 172, 413, 414, 463, 464, 18, 19, 136, 138, 173, 174, 421, 422, 465, 466, 22, 23, 115, 117, 175, 176, 407, 408, 467, 468, 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, 470, 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, 472, 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, 474, 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476); and heteromultimer complexes comprising at least two different TGF-beta superfamily type II receptor polypeptides (e.g., ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII proteins from humans or other species such as those described herein, e.g., SEQ ID NOs: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, 452, 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, 454, 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, 456, 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, 458, 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462), which are generally referred to herein as “heteromultimer complexes” or “heteromultimers”. Preferably, heteromultimers are soluble, e.g., a heteromultimer comprises a soluble portion of at least one TGFβ superfamily type I receptor polypeptide and a soluble portion (domain) of at least one TGFβ superfamily type II receptor polypeptide. In general, the extracellular domains of TGFβ superfamily type I and type II receptors correspond to a soluble portion of the type I and type II receptor. Therefore, in some embodiments, heteromultimers of the disclosure comprise an extracellular domain of a TGFβ superfamily type I receptor polypeptide (e.g., one or more ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and/or ALK7 receptor extracellular domains) and/or an extracellular domain of a TGFβ superfamily type II receptor polypeptide (e.g., one or more ActRIIA, ActRIIB, TGFBRII, BMPRII, and/or MISRII receptor extracellular domains). Exemplary extracellular domains of ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, ALK7, ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII are disclosed herein and such sequences, as well as fragments, functional variants, and modified forms thereof, may be used in accordance with the inventions of the present disclosure (e.g., heteromultimers compositions and uses thereof). Heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers, and higher order oligomeric structures. See, e.g., FIGS. 1, 2 , and 15 - 17 . In certain preferred embodiments, heteromultimers of the disclosure are heterodimers.

A defining structural motif known as a three-finger toxin fold is important for ligand binding by type I and type II receptors and is formed by 10, 12, or 14 conserved cysteine residues located at varying positions within the extracellular domain of each monomeric receptor. See, e.g., Greenwald et al. (1999) Nat Struct Biol 6:18-22; Hinck (2012) FEBS Lett 586:1860-1870. The core ligand-binding domains of TGFβ superfamily receptors, as demarcated by the outermost of these conserved cysteines, corresponds to positions 29-109 of SEQ ID NO: 1 (ActRIIB precursor); positions 30-110 of SEQ ID NO: 9 (ActRIIA precursor); positions 34-95 of SEQ ID NO: 14 (ALK1 precursor); positions 35-99 of SEQ ID NO: 18 (ALK2 precursor); positions 61-130 of SEQ ID NO: 22 (ALK3 precursor); positions 34-101 of SEQ ID NOs: 26 and 83 (ALK4 precursors); positions 36-106 of SEQ ID NOs: 30 and 87 (ALK5 precursors); positions 32-102 of SEQ ID NO: 34 (ALK6 isoform B precursor); positions 28-92 of SEQ ID NOs: 38, 305, and 309 (ALK7 precursors); positions 51-143 of SEQ ID NO: 42 (TGFBRII isoform B precursor); positions 34-123 of SEQ ID NO: 46 and 71 (BMPRII precursors); positions 24-116 of SEQ ID NO: 50, 75, and 79 (MISRII precursors); positions 44-168 of SEQ ID NO: 67 (TGFBRII isoform A precursor); and positions 62-132 of SEQ ID NO: 91 (ALK6 isoform A precursor). The structurally less-ordered amino acids flanking these cysteine-demarcated core sequences can be truncated by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, or 37 residues on either terminus without necessarily altering ligand binding. Exemplary extracellular domains for N-terminal and/or C-terminal truncation include SEQ ID NOs: 2, 3, 5, 6, 10, 11, 15, 19, 23, 27, 31, 35, 39, 43, 47, 51, 68, 72, 76, 80, 84, 88, 92, 302, 306, 310, and 313.

›DETAILED DESCRIPTION OF THE INVENTION · 7 of 7

In preferred embodiments, heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity of one or more TGF-beta superfamily ligands including, but not limited to, BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty. In particular, heteromultimer complexes of the disclosure may be used to antagonize signaling transduction (e.g., Smad 2/3 and/or Smad 1/5/8 signaling) initiated by one or more TGFβ superfamily ligands, which may be determined, for example, using a cell-based assay such as those described herein. As described herein, such antagonist heteromultimer complexes may be useful in the treatment or prevention of various disorders/conditions associated with, e.g., muscle loss, insufficient muscle growth, neurodegeneration, bone loss, reduced bone density and/or mineralization, insufficient bone growth, and/or obesity. In some embodiments, heteromultimer complexes of the disclosure have different ligand binding specificities/profiles in comparison to their corresponding homomultimer complex (e.g., an ALK4:ActRIIB heterodimer vs. a corresponding ActRIIB or ALK4 homodimer).

As used herein, the term “ActRIIB” refers to a family of activin receptor type IIB (ActRIIB) proteins from any species and variants derived from such ActRIIB proteins by mutagenesis or other modification. Reference to ActRIIB herein is understood to be a reference to any one of the currently identified forms. Members of the ActRIIB family are generally transmembrane proteins, composed of a ligand-binding extracellular domain comprising a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “ActRIIB polypeptide” includes polypeptides comprising any naturally occurring polypeptide of an ActRIIB family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Examples of such variant ActRIIB polypeptides are provided throughout the present disclosure as well as in International Patent Application Publication Nos. WO 2006/012627, WO 2008/097541, and Wo 2010/151426, which are incorporated herein by reference in their entirety. Numbering of amino acids for all ActRIIB-related polypeptides described herein is based on the numbering of the human ActRIIB precursor protein sequence provided below (SEQ ID NO: 1), unless specifically designated otherwise.

The human ActRIIB precursor protein sequence is as follows:

The signal peptide is indicated with a single underline; the extracellular domain is indicated in bold font; and the potential, endogenous N-linked glycosylation sites are indicated with a double underline.

The processed (mature) extracellular ActRIIB polypeptide sequence is as follows:

(SEQ ID NO: 2)

GRGEAETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSG

›TIELVKKGCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLP

EA GGPEVTYEPPPTAPT .

In some embodiments, the protein may be produced with an “SGR . . . ” sequence at the N-terminus. The C-terminal “tail” of the extracellular domain is indicated by a single underline. The sequence with the “tail” deleted (a Δ15 sequence) is as follows:

(SEQ ID NO: 3)

GRGEAETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWRNSSG

›TIELVKKGCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHL

PEA.

A form of ActRIIB with an alanine at position 64 of SEQ ID NO: 1 (A64) is also reported in the literature. See, e.g., Hilden et al. (1994) Blood, 83(8): 2163-2170. Applicants have ascertained that an ActRIIB-Fc fusion protein comprising an extracellular domain of ActRIIB with the A64 substitution has a relatively low affinity for activin and GDF11. By contrast, the same ActRIIB-Fc fusion protein with an arginine at position 64 (R64) has an affinity for activin and GDF11 in the low nanomolar to high picomolar range. Therefore, sequences with an R64 are used as the “wild-type” reference sequence for human ActRIIB in this disclosure.

The form of ActRIIB with an alanine at position 64 is as follows:

The signal peptide is indicated by single underline and the extracellular domain is indicated by bold font.

The processed (mature) extracellular ActRIIB polypeptide sequence of the alternative A64 form is as follows:

(SEQ ID NO: 5)

GRGEAETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWANSSG

TIELVKKGCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHLP

›EA GGPEVTYEPPPTAPT

In some embodiments, the protein may be produced with an “SGR . . . ” sequence at the N-terminus. The C-terminal “tail” of the extracellular domain is indicated by single underline. The sequence with the “tail” deleted (a Δ15 sequence) is as follows:

(SEQ ID NO: 6)

GRGEAETRECIYYNANWELERTNQSGLERCEGEQDKRLHCYASWANSSG

TIELVKKGCWLDDFNCYDRQECVATEENPQVYFCCCEGNFCNERFTHL

›PEA · 1 of 3

A nucleic acid sequence encoding the human ActRIIB precursor protein is shown below (SEQ ID NO: 7), representing nucleotides 25-1560 of Genbank Reference Sequence NM_001106.3, which encode amino acids 1-513 of the ActRIIB precursor. The sequence as shown provides an arginine at position 64 and may be modified to provide an alanine instead. The signal sequence is underlined.

A nucleic acid sequence encoding processed extracellular human ActRIIB polypeptide is as follows (SEQ ID NO: 8). The sequence as shown provides an arginine at position 64, and may be modified to provide an alanine instead.

An alignment of the amino acid sequences of human ActRIIB extracellular domain and human ActRIIA extracellular domain are illustrated in FIG. 3 . This alignment indicates amino acid residues within both receptors that are believed to directly contact ActRII ligands. For example, the composite ActRII structures indicated that the ActRIIB-ligand binding pocket is defined, in part, by residues Y31, N33, N35, L38 through T41, E47, E50, Q53 through K55, L57, H58, Y60, S62, K74, W78 through N83, Y85, R87, A92, and E94 through F101. At these positions, it is expected that conservative mutations will be tolerated.

In addition, ActRIIB is well-conserved among vertebrates, with large stretches of the extracellular domain completely conserved. For example, FIG. 4 depicts a multi-sequence alignment of a human ActRIIB extracellular domain compared to various ActRIIB orthologs. Many of the ligands that bind to ActRIIB are also highly conserved. Accordingly, from these alignments, it is possible to predict key amino acid positions within the ligand-binding domain that are important for normal ActRIIB-ligand binding activities as well as to predict amino acid positions that are likely to be tolerant of substitution without significantly altering normal ActRIIB-ligand binding activities. Therefore, an active, human ActRIIB variant polypeptide useful in accordance with the presently disclosed methods may include one or more amino acids at corresponding positions from the sequence of another vertebrate ActRIIB, or may include a residue that is similar to that in the human or other vertebrate sequences. Without meaning to be limiting, the following examples illustrate this approach to defining an active ActRIIB variant. L46 in the human extracellular domain (SEQ ID NO: 2) is a valine in Xenopus ActRIIB (SEQ ID NO: 506), and so this position may be altered, and optionally may be altered to another hydrophobic residue, such as V, I or F, or a non-polar residue such as A. E52 in the human extracellular domain is a K in Xenopus , indicating that this site may be tolerant of a wide variety of changes, including polar residues, such as E, D, K, R, H, S, T, P, G, Y and probably A. T93 in the human extracellular domain is a K in Xenopus , indicating that a wide structural variation is tolerated at this position, with polar residues favored, such as S, K, R, E, D, H, G, P, G and Y. F108 in the human extracellular domain is a Y in Xenopus , and therefore Y or other hydrophobic group, such as I, V or L should be tolerated. E111 in the human extracellular domain is K in Xenopus , indicating that charged residues will be tolerated at this position, including D, R, K and H, as well as Q and N. R112 in the human extracellular domain is K in Xenopus , indicating that basic residues are tolerated at this position, including R and H. A at position 119 in the human extracellular domain is relatively poorly conserved, and appears as P in rodents and V in Xenopus , thus essentially any amino acid should be tolerated at this position.

Moreover, ActRII proteins have been characterized in the art in terms of structural and functional characteristics, particularly with respect to ligand binding [Attisano et al. (1992) Cell 68(1):97-108; Greenwald et al. (1999) Nature Structural Biology 6(1): 18-22; Allendorph et a. (2006) PNAS 103(20: 7643-7648; Thompson et al. (2003) The EMBO Journal 22(7): 1555-1566; as well as U.S. Pat. Nos. 7,709,605, 7,612,041, and 7,842,663]. In addition to the teachings herein, these references provide amply guidance for how to generate ActRIIB variants that retain one or more normal activities (e.g., ligand-binding activity).

For example, a defining structural motif known as a three-finger toxin fold is important for ligand binding by type I and type II receptors and is formed by conserved cysteine residues located at varying positions within the extracellular domain of each monomeric receptor [Greenwald et al. (1999) Nat Struct Biol 6:18-22; and Hinck (2012) FEBS Lett 586:1860-1870]. Accordingly, the core ligand-binding domains of human ActRIIB, as demarcated by the outermost of these conserved cysteines, corresponds to positions 29-109 of SEQ ID NO: 1 (ActRIIB precursor). Thus, the structurally less-ordered amino acids flanking these cysteine-demarcated core sequences can be truncated by about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, or 28 residues at the N-terminus and/or by about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 residues a the C-terminus without necessarily altering ligand binding. Exemplary ActRIIB extracellular domains for N-terminal and/or C-terminal truncation include SEQ ID NOs: 2, 3, 5, and 6.

Attisano et al. showed that a deletion of the proline knot at the C-terminus of the extracellular domain of ActRIIB reduced the affinity of the receptor for activin. An ActRIIB-Fc fusion protein containing amino acids 20-119 of present SEQ ID NO: 1, “ActRIIB(20-119)-Fc”, has reduced binding to GDF11 and activin relative to an ActRIIB(20-134)-Fc, which includes the proline knot region and the complete juxtamembrane domain (see, e.g., U.S. Pat. No. 7,842,663). However, an ActRIIB(20-129)-Fc protein retains similar, but somewhat reduced activity, relative to the wild-type, even though the proline knot region is disrupted.

›PEA · 2 of 3

Thus, ActRIIB extracellular domains that stop at amino acid 134, 133, 132, 131, 130 and 129 (with respect to SEQ ID NO: 1) are all expected to be active, but constructs stopping at 134 or 133 may be most active. Similarly, mutations at any of residues 129-134 (with respect to SEQ ID NO: 1) are not expected to alter ligand-binding affinity by large margins. In support of this, it is known in the art that mutations of P129 and P130 (with respect to SEQ ID NO: 1) do not substantially decrease ligand binding. Therefore, an ActRIIB polypeptide of the present disclosure may end as early as amino acid 109 (the final cysteine), however, forms ending at or between 109 and 119 (e.g., 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, or 119) are expected to have reduced ligand binding. Amino acid 119 (with respect to present SEQ ID NO: 1) is poorly conserved and so is readily altered or truncated. ActRIIB polypeptides ending at 128 (with respect to SEQ ID NO: 1) or later should retain ligand-binding activity. ActRIIB polypeptides ending at or between 119 and 127 (e.g., 119, 120, 121, 122, 123, 124, 125, 126, or 127), with respect to SEQ ID NO: 1, will have an intermediate binding ability. Any of these forms may be desirable to use, depending on the clinical or experimental setting.

At the N-terminus of ActRIIB, it is expected that a protein beginning at amino acid 29 or before (with respect to SEQ ID NO: 1) will retain ligand-binding activity. Amino acid 29 represents the initial cysteine. An alanine-to-asparagine mutation at position 24 (with respect to SEQ ID NO: 1) introduces an N-linked glycosylation sequence without substantially affecting ligand binding [U.S. Pat. No. 7,842,663]. This confirms that mutations in the region between the signal cleavage peptide and the cysteine cross-linked region, corresponding to amino acids 20-29, are well tolerated. In particular, ActRIIB polypeptides beginning at position 20, 21, 22, 23, and 24 (with respect to SEQ ID NO: 1) should retain general ligand-biding activity, and ActRIIB polypeptides beginning at positions 25, 26, 27, 28, and 29 (with respect to SEQ ID NO: 1) are also expected to retain ligand-biding activity. It has been demonstrated, e.g., U.S. Pat. No. 7,842,663, that, surprisingly, an ActRIIB construct beginning at 22, 23, 24, or 25 will have the most activity.

Taken together, a general formula for an active portion (e.g., ligand-binding portion) of ActRIIB comprises amino acids 29-109 of SEQ ID NO: 1. Therefore ActRIIB polypeptides may, for example, comprise, consist essentially of, or consist of an amino acid sequence that is at least 70%, 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to a portion of ActRIIB beginning at a residue corresponding to any one of amino acids 20-29 (e.g., beginning at any one of amino acids 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29) of SEQ ID NO: 1 and ending at a position corresponding to any one amino acids 109-134 (e.g., ending at any one of amino acids 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, or 134) of SEQ ID NO: 1. Other examples include polypeptides that begin at a position from 20-29 (e.g., any one of positions 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29) or 21-29 (e.g., any one of positions 21, 22, 23, 24, 25, 26, 27, 28, or 29) of SEQ ID NO: 1 and end at a position from 119-134 (e.g., any one of positions 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, or 134), 119-133 (e.g., any one of positions 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, or 133), 129-134 (e.g., any one of positions 129, 130, 131, 132, 133, or 134), or 129-133 (e.g., any one of positions 129, 130, 131, 132, or 133) of SEQ ID NO: 1. Other examples include constructs that begin at a position from 20-24 (e.g., any one of positions 20, 21, 22, 23, or 24), 21-24 (e.g., any one of positions 21, 22, 23, or 24), or 22-25 (e.g., any one of positions 22, 22, 23, or 25) of SEQ ID NO: 1 and end at a position from 109-134 (e.g., any one of positions 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, or 134), 119-134 (e.g., any one of positions 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, or 134) or 129-134 (e.g., any one of positions 129, 130, 131, 132, 133, or 134) of SEQ ID NO: 1. Variants within these ranges are also contemplated, particularly those having at least 70%, 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the corresponding portion of SEQ ID NO: 1.

The variations described herein may be combined in various ways. In some embodiments, ActRIIB variants comprise no more than 1, 2, 5, 6, 7, 8, 9, 10 or 15 conservative amino acid changes in the ligand-binding pocket, and zero, one, or more non-conservative alterations at positions 40, 53, 55, 74, 79 and/or 82 in the ligand-binding pocket. Sites outside the binding pocket, at which variability may be particularly well tolerated, include the amino and carboxy termini of the extracellular domain (as noted above), and positions 42-46 and 65-73 (with respect to SEQ ID NO: 1). An asparagine-to-alanine alteration at position 65 (N65A) actually improves ligand binding in the A64 background, and is thus expected to have no detrimental effect on ligand binding in the R64 background [U.S. Pat. No. 7,842,663]. This change probably eliminates glycosylation at N65 in the A64 background, thus demonstrating that a significant change in this region is likely to be tolerated. While an R64A change is poorly tolerated, R64K is well-tolerated, and thus another basic residue, such as H may be tolerated at position 64 [U.S. Pat. No. 7,842,663]. Additionally, the results of the mutagenesis program described in the art indicate that there are amino acid positions in ActRIIB that are often beneficial to conserve. With respect to SEQ ID NO: 1, these include position 80 (acidic or hydrophobic amino acid), position 78 (hydrophobic, and particularly tryptophan), position 37 (acidic, and particularly aspartic or glutamic acid), position 56 (basic amino acid), position 60 (hydrophobic amino acid, particularly phenylalanine or tyrosine). Thus, the disclosure provides a framework of amino acids that may be conserved in ActRIIB polypeptides. Other positions that may be desirable to conserve are as follows: position 52 (acidic amino acid), position 55 (basic amino acid), position 81 (acidic), 98 (polar or charged, particularly E, D, R or K), all with respect to SEQ ID NO: 1.

›PEA · 3 of 3

In certain embodiments, the disclosure relates to heteromultimers that comprise at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, ActRIIB polypeptides for use in accordance with the disclosure are soluble (e.g., an extracellular domain of ActRIIB). In other preferred embodiments, ActRIIB polypeptides for use in accordance with the disclosure bind to one or more TGF-beta superfamily ligands. Therefore, in some embodiments, ActRIIB polypeptides for use in accordance with the disclosure inhibit (antagonize) activity (e.g., inhibition of Smad signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimers of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists essentially of, or consists of an amino acid sequence that is at least 70%, 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to a portion of ActRIIB beginning at a residue corresponding to amino acids 20-29 (e.g., beginning at any one of amino acids 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29) of SEQ ID NO: 1 and ending at a position corresponding to amino acids 109-134 (e.g., ending at any one of amino acids 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, or 134) of SEQ ID NO: 1. In certain preferred embodiments, heteromultimers of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of an amino acid sequence that is at least 70%, 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical amino acids 29-109 of SEQ ID NO: 1 In other preferred embodiments, heteromultimers of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of an amino acid sequence that is at least 70%, 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical amino acids 25-131 of SEQ ID NO: 1 In some embodiments, heteromultimers of the disclosure comprise at least one ActRIIB polypeptide that is at least 70%, 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454. In certain embodiments, heteromultimers of the disclosure comprise at least one ActRIIB polypeptide wherein the amino acid position corresponding to L79 of SEQ ID NO: 1 is not an acidic amino acid (i.e., is not a naturally occurring D or E amino acid residue or artificial acidic amino acid).

In certain embodiments, the present disclosure relates to a protein complex comprising an ActRIIA polypeptide. As used herein, the term “ActRIIA” refers to a family of activin receptor type IIA (ActRIIA) proteins from any species and variants derived from such ActRIIA proteins by mutagenesis or other modification. Reference to ActRIIA herein is understood to be a reference to any one of the currently identified forms. Members of the ActRIIA family are generally transmembrane proteins, composed of a ligand-binding extracellular domain comprising a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “ActRIIA polypeptide” includes polypeptides comprising any naturally occurring polypeptide of an ActRIIA family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Examples of such variant ActRIIA polypeptides are provided throughout the present disclosure as well as in International Patent Application Publication No. WO 2006/012627, which is incorporated herein by reference in its entirety. Numbering of amino acids for all ActRIIA-related polypeptides described herein is based on the numbering of the human ActRIIA precursor protein sequence provided below (SEQ ID NO: 9), unless specifically designated otherwise.

The human ActRIIA precursor protein sequence is as follows:

The signal peptide is indicated by a single underline; the extracellular domain is indicated in bold font; and the potential, endogenous N-linked glycosylation sites are indicated by a double underline.

The processed extracellular human ActRIIA polypeptide sequence is as follows:

(SEQ ID NO: 10)

ILGRSETQECLFFNANWEKDRTNQTGVEPCYGDKDKRRHCFATWKNISGS

IEIVKQGCWLDDINCYDRTDCVEKKDSPEVYFCCCEGNMCNEKFSYFPEM

›EVTQPTSNPVTPKPP

The C-terminal “tail” of the extracellular domain is indicated by a single underline. The sequence with the “tail” deleted (a Δ15 sequence) is as follows:

(SEQ ID NO: 11)

ILGRSETQECLFFNANWEKDRTNQTGVEPCYGDKDKRRHCFATWKNISGS

›IEIVKQGCWLDDINCYDRTDCVEKKDSPEVYFCCCEGNMCNEKFSYFPEM

A nucleic acid sequence encoding the human ActRIIA precursor protein is shown below (SEQ ID NO: 12), corresponding to nucleotides 159-1700 of Genbank Reference Sequence NM_001616.4. The signal sequence is underlined.

The nucleic acid sequence encoding processed extracellular ActRIIA polypeptide is as follows:

A general formula for an active (e.g., ligand binding) ActRIIA polypeptide is one that comprises a polypeptide that starts at amino acid 30 and ends at amino acid 110 of SEQ ID NO: 9. Accordingly, ActRIIA polypeptides of the present disclosure may comprise a polypeptide that is at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% identical to amino acids 30-110 of SEQ ID NO: 9. Optionally, ActRIIA polypeptides of the present disclosure comprise a polypeptide that is at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% identical to amino acids amino acids 12-82 of SEQ ID NO: 9 optionally beginning at a position ranging from 1-5 (e.g., 1, 2, 3, 4, or 5) or 3-5 (e.g., 3, 4, or 5) and ending at a position ranging from 110-116 (e.g., 110, 111, 112, 113, 114, 115, or 116) or 110-115 (e.g., 110, 111, 112, 113, 114, or 115), respectively, and comprising no more than 1, 2, 5, 10 or 15 conservative amino acid changes in the ligand binding pocket, and zero, one or more non-conservative alterations at positions 40, 53, 55, 74, 79 and/or 82 in the ligand-binding pocket with respect to SEQ ID NO: 9.

In certain embodiments, the disclosure relates to heteromultimer complexes that comprise at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, ActRIIA polypeptides for use in accordance with inventions of the disclosure (e.g., heteromultimer complexes comprising an ActRIIA polypeptide and uses thereof) are soluble (e.g., an extracellular domain of ActRIIA). In other preferred embodiments, ActRIIA polypeptides for use in accordance with the inventions of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimer complexes of the disclosure comprise at least one ActRIIA polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of any one of SEQ ID NOs: 9, 10, 11, 118, 120, 409, or 410. In some embodiments, heteromultimer complexes of the disclosure comprise, consist, or consist essentially of at least one ActRIIA polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of any one of SEQ ID NOs: 9, 10, 11, 118, 120, 409, or 410.

In certain aspects, the present disclosure relates to protein complexes that comprise a TGFBRII polypeptide. As used herein, the term “TGFBRII” refers to a family of transforming growth factor-beta receptor II (TGFBRII) proteins from any species and variants derived from such proteins by mutagenesis or other modification. Reference to TGFBRII herein is understood to be a reference to any one of the currently identified forms. Members of the TGFBRII family are generally transmembrane proteins, composed of a ligand-binding extracellular domain with a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “TGFBRII polypeptide” includes polypeptides comprising any naturally occurring polypeptide of a TGFBRII family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Numbering of amino acids for all TGFBRII-related polypeptides described herein is based on the numbering of the human TGFBRII precursor protein sequence below (SEQ ID NO: 42), unless specifically designated otherwise.

The canonical human TGFBRII precursor protein sequence (NCBI Ref Seq NP_003233.4) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular TGFBRII polypeptide sequence is as follows:

(SEQ ID NO: 43)

TIPPHVQKSVNNDMIVTDNNGAVKFPQLCKFCDVRFSTCDNQKSCMSNCS

ITSICEKPQEVCVAVWRKNDENITLETVCHDPKLPYHDFILEDAASPKCI

›MKEKKKPGETFFMCSCSSDECNDNIIFSEEYNTSNPDLLLVIFQ

The nucleic acid sequence encoding TGFBRII precursor protein is shown below (SEQ ID NO:44), corresponding to nucleotides 383-2083 of Genbank Reference Sequence NM_003242.5. The signal sequence is underlined.

(SEQ ID NO: 44)

ATGGGTCGGGGGCTGCTCAGGGGCCTGTGGCCGCTGCACATCGTCCTGTG

GACGCGTATCGCCAGC

ACGATCCCACCGCACGTTCAGAAGTCGGTTAATA

ACGACATGATAGTCACTGACAACAACGGTGCAGTCAAGTTTCCACAACTG

TGTAAATTTTGTGATGTGAGATTTTCCACCTGTGACAACCAGAAATCCTG

CATGAGCAACTGCAGCATCACCTCCATCTGTGAGAAGCCACAGGAAGTCT

GTGTGGCTGTATGGAGAAAGAATGACGAGAACATAACACTAGAGACAGTT

TGCCATGACCCCAAGCTCCCCTACCATGACTTTATTCTGGAAGATGCTGC

TTCTCCAAAGTGCATTATGAAGGAAAAAAAAAAGCCTGGTGAGACTTTCT

TCATGTGTTCCTGTAGCTCTGATGAGTGCAATGACAACATCATCTTCTCA

GAAGAATATAACACCAGCAATCCTGACTTGTTGCTAGTCATATTTCAA GT

GACAGGCATCAGCCTCCTGCCACCACTGGGAGTTGCCATATCTGTCATCA

TCATCTTCTACTGCTACCGCGTTAACCGGCAGCAGAAGCTGAGTTCAACC

TGGGAAACCGGCAAGACGCGGAAGCTCATGGAGTTCAGCGAGCACTGTGC

CATCATCCTGGAAGATGACCGCTCTGACATCAGCTCCACGTGTGCCAACA

ACATCAACCACAACACAGAGCTGCTGCCCATTGAGCTGGACACCCTGGTG

GGGAAAGGTCGCTTTGCTGAGGTCTATAAGGCCAAGCTGAAGCAGAACAC

TTCAGAGCAGTTTGAGACAGTGGCAGTCAAGATCTTTCCCTATGAGGAGT

ATGCCTCTTGGAAGACAGAGAAGGACATCTTCTCAGACATCAATCTGAAG

CATGAGAACATACTCCAGTTCCTGACGGCTGAGGAGCGGAAGACGGAGTT

GGGGAAACAATACTGGCTGATCACCGCCTTCCACGCCAAGGGCAACCTAC

AGGAGTACCTGACGCGGCATGTCATCAGCTGGGAGGACCTGCGCAAGCTG

GGCAGCTCCCTCGCCCGGGGGATTGCTCACCTCCACAGTGATCACACTCC

ATGTGGGAGGCCCAAGATGCCCATCGTGCACAGGGACCTCAAGAGCTCCA

ATATCCTCGTGAAGAACGACCTAACCTGCTGCCTGTGTGACTTTGGGCTT

TCCCTGCGTCTGGACCCTACTCTGTCTGTGGATGACCTGGCTAACAGTGG

GCAGGTGGGAACTGCAAGATACATGGCTCCAGAAGTCCTAGAATCCAGGA

TGAATTTGGAGAATGTTGAGTCCTTCAAGCAGACCGATGTCTACTCCATG

GCTCTGGTGCTCTGGGAAATGACATCTCGCTGTAATGCAGTGGGAGAAGT

AAAAGATTATGAGCCTCCATTTGGTTCCAAGGTGCGGGAGCACCCCTGTG

TCGAAAGCATGAAGGACAACGTGTTGAGAGATCGAGGGCGACCAGAAATT

CCCAGCTTCTGGCTCAACCACCAGGGCATCCAGATGGTGTGTGAGACGTT

GACTGAGTGCTGGGACCACGACCCAGAGGCCCGTCTCACAGCCCAGTGTG

TGGCAGAACGCTTCAGTGAGCTGGAGCATCTGGACAGGCTCTCGGGGAGG

›AGCTGCTCGGAGGAGAAGATTCCTGAAGACGGCTCCCTAAACACTACCAA

The nucleic acid sequence encoding processed extracellular TGFBRII polypeptide is as follows:

(SEQ ID NO: 45)

ACGATCCCACCGCACGTTCAGAAGTCGGTTAATAACGACATGATAGTCAC

TGACAACAACGGTGCAGTCAAGTTTCCACAACTGTGTAAATTTTGTGATG

TGAGATTTTCCACCTGTGACAACCAGAAATCCTGCATGAGCAACTGCAGC

ATCACCTCCATCTGTGAGAAGCCACAGGAAGTCTGTGTGGCTGTATGGAG

AAAGAATGACGAGAACATAACACTAGAGACAGTTTGCCATGACCCCAAGC

TCCCCTACCATGACTTTATTCTGGAAGATGCTGCTTCTCCAAAGTGCATT

ATGAAGGAAAAAAAAAAGCCTGGTGAGACTTTCTTCATGTGTTCCTGTAG

CTCTGATGAGTGCAATGACAACATCATCTTCTCAGAAGAATATAACACCA

›GCAATCCTGACTTGTTGCTAGTCATATTTCAA

An alternative isoform of TGFBRII, isoform A (NP_001020018.1), is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular TGFBRII polypeptide sequence (isoform A) is as follows:

(SEQ ID NO: 68)

TIPPHVQKSDVEMEAQKDEIICPSCNRTAHPLRHINNDMIVTDNNGAVKF

PQLCKFCDVRFSTCDNQKSCMSNCSITSICEKPQEVCVAVWRKNDENITL

ETVCHDPKLPYHDFILEDAASPKCIMKEKKKPGETFFMCSCSSDECNDNI

›IFSEEYNTSNPDLLLVIFQ

A nucleic acid sequence encoding the TGFBRII precursor protein (isoform A) is shown below (SEQ ID NO: 69), corresponding to nucleotides 383-2158 of Genbank Reference Sequence NM_001024847.2. The signal sequence is underlined.

ATGGGTCGGGGGCTGCTCAGGGGCCTGTGGCCGCTGCACATCGTCCTGTG

GACGCGTATCGCCAGC

ACGATCCCACCGCACGTTCAGAAGTCGGATGTGG

AAATGGAGGCCCAGAAAGATGAAATCATCTGCCCCAGCTGTAATAGGACT

GCCCATCCACTGAGACATATTAATAACGACATGATAGTCACTGACAACAA

CGGTGCAGTCAAGTTTCCACAACTGTGTAAATTTTGTGATGTGAGATTTT

CCACCTGTGACAACCAGAAATCCTGCATGAGCAACTGCAGCATCACCTCC

ATCTGTGAGAAGCCACAGGAAGTCTGTGTGGCTGTATGGAGAAAGAATGA

CGAGAACATAACACTAGAGACAGTTTGCCATGACCCCAAGCTCCCCTACC

ATGACTTTATTCTGGAAGATGCTGCTTCTCCAAAGTGCATTATGAAGGAA

AAAAAAAAGCCTGGTGAGACTTTCTTCATGTGTTCCTGTAGCTCTGATGA

GTGCAATGACAACATCATCTTCTCAGAAGAATATAACACCAGCAATCCTG

ACTTGTTGCTAGTCATATTTCAA GTGACAGGCATCAGCCTCCTGCCACCA

CTGGGAGTTGCCATATCTGTCATCATCATCTTCTACTGCTACCGCGTTAA

CCGGCAGCAGAAGCTGAGTTCAACCTGGGAAACCGGCAAGACGCGGAAGC

TCATGGAGTTCAGCGAGCACTGTGCCATCATCCTGGAAGATGACCGCTCT

GACATCAGCTCCACGTGTGCCAACAACATCAACCACAACACAGAGCTGCT

GCCCATTGAGCTGGACACCCTGGTGGGGAAAGGTCGCTTTGCTGAGGTCT

ATAAGGCCAAGCTGAAGCAGAACACTTCAGAGCAGTTTGAGACAGTGGCA

GTCAAGATCTTTCCCTATGAGGAGTATGCCTCTTGGAAGACAGAGAAGGA

CATCTTCTCAGACATCAATCTGAAGCATGAGAACATACTCCAGTTCCTGA

CGGCTGAGGAGCGGAAGACGGAGTTGGGGAAACAATACTGGCTGATCACC

GCCTTCCACGCCAAGGGCAACCTACAGGAGTACCTGACGCGGCATGTCAT

CAGCTGGGAGGACCTGCGCAAGCTGGGCAGCTCCCTCGCCCGGGGGATTG

CTCACCTCCACAGTGATCACACTCCATGTGGGAGGCCCAAGATGCCCATC

GTGCACAGGGACCTCAAGAGCTCCAATATCCTCGTGAAGAACGACCTAAC

CTGCTGCCTGTGTGACTTTGGGCTTTCCCTGCGTCTGGACCCTACTCTGT

CTGTGGATGACCTGGCTAACAGTGGGCAGGTGGGAACTGCAAGATACATG

GCTCCAGAAGTCCTAGAATCCAGGATGAATTTGGAGAATGTTGAGTCCTT

CAAGCAGACCGATGTCTACTCCATGGCTCTGGTGCTCTGGGAAATGACAT

CTCGCTGTAATGCAGTGGGAGAAGTAAAAGATTATGAGCCTCCATTTGGT

TCCAAGGTGCGGGAGCACCCCTGTGTCGAAAGCATGAAGGACAACGTGTT

GAGAGATCGAGGGCGACCAGAAATTCCCAGCTTCTGGCTCAACCACCAGG

GCATCCAGATGGTGTGTGAGACGTTGACTGAGTGCTGGGACCACGACCCA

GAGGCCCGTCTCACAGCCCAGTGTGTGGCAGAACGCTTCAGTGAGCTGGA

GCATCTGGACAGGCTCTCGGGGAGGAGCTGCTCGGAGGAGAAGATTCCTG

›AAGACGGCTCCCTAAACACTACCAAA

A nucleic acid sequence encoding the processed extracellular TGFBRII polypeptide (isoform A) is as follows:

(SEQ ID NO: 70)

ACGATCCCACCGCACGTTCAGAAGTCGGATGTGGAAATGGAGGCCCAGAA

AGATGAAATCATCTGCCCCAGCTGTAATAGGACTGCCCATCCACTGAGAC

ATATTAATAACGACATGATAGTCACTGACAACAACGGTGCAGTCAAGTTT

CCACAACTGTGTAAATTTTGTGATGTGAGATTTTCCACCTGTGACAACCA

GAAATCCTGCATGAGCAACTGCAGCATCACCTCCATCTGTGAGAAGCCAC

AGGAAGTCTGTGTGGCTGTATGGAGAAAGAATGACGAGAACATAACACTA

GAGACAGTTTGCCATGACCCCAAGCTCCCCTACCATGACTTTATTCTGGA

AGATGCTGCTTCTCCAAAGTGCATTATGAAGGAAAAAAAAAAGCCTGGTG

AGACTTTCTTCATGTGTTCCTGTAGCTCTGATGAGTGCAATGACAACATC

›ATCTTCTCAGAAGAATATAACACCAGCAATCCTGACTTGTTGCTAGTCAT

ATTTCAA.

Either of the foregoing TGFβRII isoforms (SEQ ID NOs: 42, 43, 67, and 68) could incorporate an insertion of 36 amino acids (SEQ ID NO: 95) between the pair of glutamate residues (positions 151 and 152 of SEQ ID NO: 42; positions 129 and 130 of SEQ ID NO: 43; positions 176 and 177 of SEQ ID NO: 67; or positions 154 and 155 of SEQ ID NO: 68) located near the C-terminus of the TGFβRII ECD, as occurs naturally in the TGFβRII isoform C (Konrad et al., BMC Genomics 8:318, 2007).

(SEQ ID NO: 95)

›GRCKIRHIGS NNRLQRSTCQ NTGWESAHVM KTPGFR

In certain embodiments, the disclosure relates to heteromultimer complexes that comprise at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, TGFBRII polypeptides for use in accordance with inventions of the disclosure (e.g., heteromultimer complexes comprising a TGFBRII polypeptide and uses thereof) are soluble (e.g., an extracellular domain of TGFBRII). In other preferred embodiments, TGFBRII polypeptides for use in accordance with the inventions of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimer complexes of the disclosure comprise at least one TGFBRII polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NOs: 42, 43, 67, or 68, with or without insertion of SEQ ID NO: 95 as described above. In some embodiments, heteromultimer complexes of the disclosure consist or consist essentially of at least one TGFBRII polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NOs: 42, 43, 67, or 68, with or without insertion of SEQ ID NO: 95.

In certain aspects, the present disclosure relates to protein complexes that comprise a BMPRII polypeptide. As used herein, the term “BMPRII” refers to a family of bone morphogenetic protein receptor type II (BMPRII) proteins from any species and variants derived from such BMPRII proteins by mutagenesis or other modification. Reference to BMPRII herein is understood to be a reference to any one of the currently identified forms. Members of the BMPRII family are generally transmembrane proteins, composed of a ligand-binding extracellular domain with a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “BMPRII polypeptide” includes polypeptides comprising any naturally occurring polypeptide of a BMPRII family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Numbering of amino acids for all BMPRII-related polypeptides described herein is based on the numbering of the human BMPRII precursor protein sequence below (SEQ ID NO: 46), unless specifically designated otherwise.

The canonical human BMPRII precursor protein sequence (NCBI Ref Seq NP_001195.2) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular BMPRII polypeptide sequence is as follows:

(SEQ ID NO: 47)

SQNQERLCAFKDPYQQDLGIGESRISHENGTILCSKGSTCYGLWEKSKGD

INLVKQGCWSHIGDPQECHYEECVVTTTPPSIQNGTYRFCCCSTDLCNVN

›FTENFPPPDTTPLSPPHSFNRDET

A nucleic acid sequence encoding BMPRII precursor protein is shown below (SEQ ID NO: 48), as follows nucleotides 1149-4262 of Genbank Reference Sequence NM_001204.6. The signal sequence is underlined.

(SEQ ID NO: 48)

ATGACTTCCTCGCTGCAGCGGCCCTGGCGGGTGCCCTGGCTACCATGGAC

CATCCTGCTGGTCAGCACTGCGGCTGCT TCGCAGAATCAAGAACGGCTAT

GTGCGTTTAAAGATCCGTATCAGCAAGACCTTGGGATAGGTGAGAGTAGA

ATCTCTCATGAAAATGGGACAATATTATGCTCGAAAGGTAGCACCTGCTA

TGGCCTTTGGGAGAAATCAAAAGGGGACATAAATCTTGTAAAACAAGGAT

GTTGGTCTCACATTGGAGATCCCCAAGAGTGTCACTATGAAGAATGTGTA

GTAACTACCACTCCTCCCTCAATTCAGAATGGAACATACCGTTTCTGCTG

TTGTAGCACAGATTTATGTAATGTCAACTTTACTGAGAATTTTCCACCTC

CTGACACAACACCACTCAGTCCACCTCATTCATTTAACCGAGATGAGACA

ATAATCATTGCTTTGGCATCAGTCTCTGTATTAGCTGTTTTGATAGTTGC

CTTATGCTTTGGATACAGAATGTTGACAGGAGACCGTAAACAAGGTCTTC

ACAGTATGAACATGATGGAGGCAGCAGCATCCGAACCCTCTCTTGATCTA

GATAATCTGAAACTGTTGGAGCTGATTGGCCGAGGTCGATATGGAGCAGT

ATATAAAGGCTCCTTGGATGAGCGTCCAGTTGCTGTAAAAGTGTTTTCCT

TTGCAAACCGTCAGAATTTTATCAACGAAAAGAACATTTACAGAGTGCCT

TTGATGGAACATGACAACATTGCCCGCTTTATAGTTGGAGATGAGAGAGT

CACTGCAGATGGACGCATGGAATATTTGCTTGTGATGGAGTACTATCCCA

ATGGATCTTTATGCAAGTATTTAAGTCTCCACACAAGTGACTGGGTAAGC

TCTTGCCGTCTTGCTCATTCTGTTACTAGAGGACTGGCTTATCTTCACAC

AGAATTACCACGAGGAGATCATTATAAACCTGCAATTTCCCATCGAGATT

TAAACAGCAGAAATGTCCTAGTGAAAAATGATGGAACCTGTGTTATTAGT

GACTTTGGACTGTCCATGAGGCTGACTGGAAATAGACTGGTGCGCCCAGG

GGAGGAAGATAATGCAGCCATAAGCGAGGTTGGCACTATCAGATATATGG

CACCAGAAGTGCTAGAAGGAGCTGTGAACTTGAGGGACTGTGAATCAGCT

TTGAAACAAGTAGACATGTATGCTCTTGGACTAATCTATTGGGAGATATT

TATGAGATGTACAGACCTCTTCCCAGGGGAATCCGTACCAGAGTACCAGA

TGGCTTTTCAGACAGAGGTTGGAAACCATCCCACTTTTGAGGATATGCAG

GTTCTCGTGTCTAGGGAAAAACAGAGACCCAAGTTCCCAGAAGCCTGGAA

AGAAAATAGCCTGGCAGTGAGGTCACTCAAGGAGACAATCGAAGACTGTT

GGGACCAGGATGCAGAGGCTCGGCTTACTGCACAGTGTGCTGAGGAAAGG

ATGGCTGAACTTATGATGATTTGGGAAAGAAACAAATCTGTGAGCCCAAC

AGTCAATCCAATGTCTACTGCTATGCAGAATGAACGCAACCTGTCACATA

ATAGGCGTGTGCCAAAAATTGGTCCTTATCCAGATTATTCTTCCTCCTCA

TACATTGAAGACTCTATCCATCATACTGACAGCATCGTGAAGAATATTTC

CTCTGAGCATTCTATGTCCAGCACACCTTTGACTATAGGGGAAAAAAACC

GAAATTCAATTAACTATGAACGACAGCAAGCACAAGCTCGAATCCCCAGC

CCTGAAACAAGTGTCACCAGCCTCTCCACCAACACAACAACCACAAACAC

CACAGGACTCACGCCAAGTACTGGCATGACTACTATATCTGAGATGCCAT

ACCCAGATGAAACAAATCTGCATACCACAAATGTTGCACAGTCAATTGGG

CCAACCCCTGTCTGCTTACAGCTGACAGAAGAAGACTTGGAAACCAACAA

GCTAGACCCAAAAGAAGTTGATAAGAACCTCAAGGAAAGCTCTGATGAGA

ATCTCATGGAGCACTCTCTTAAACAGTTCAGTGGCCCAGACCCACTGAGC

AGTACTAGTTCTAGCTTGCTTTACCCACTCATAAAACTTGCAGTAGAAGC

AACTGGACAGCAGGACTTCACACAGACTGCAAATGGCCAAGCATGTTTGA

TTCCTGATGTTCTGCCTACTCAGATCTATCCTCTCCCCAAGCAGCAGAAC

CTTCCCAAGAGACCTACTAGTTTGCCTTTGAACACCAAAAATTCAACAAA

AGAGCCCCGGCTAAAATTTGGCAGCAAGCACAAATCAAACTTGAAACAAG

TCGAAACTGGAGTTGCCAAGATGAATACAATCAATGCAGCAGAACCTCAT

GTGGTGACAGTCACCATGAATGGTGTGGCAGGTAGAAACCACAGTGTTAA

CTCCCATGCTGCCACAACCCAATATGCCAATGGGACAGTACTATCTGGCC

AAACAACCAACATAGTGACACATAGGGCCCAAGAAATGTTGCAGAATCAG

TTTATTGGTGAGGACACCCGGCTGAATATTAATTCCAGTCCTGATGAGCA

TGAGCCTTTACTGAGACGAGAGCAACAAGCTGGCCATGATGAAGGTGTTC

TGGATCGTCTTGTGGACAGGAGGGAACGGCCACTAGAAGGTGGCCGAACT

AATTCCAATAACAACAACAGCAATCCATGTTCAGAACAAGATGTTCTTGC

ACAGGGTGTTCCAAGCACAGCAGCAGATCCTGGGCCATCAAAGCCCAGAA

GAGCACAGAGGCCTAATTCTCTGGATCTTTCAGCCACAAATGTCCTGGAT

GGCAGCAGTATACAGATAGGTGAGTCAACACAAGATGGCAAATCAGGATC

AGGTGAAAAGATCAAGAAACGTGTGAAAACTCCCTATTCTCTTAAGCGGT

GGCGCCCCTCCACCTGGGTCATCTCCACTGAATCGCTGGACTGTGAAGTC

AACAATAATGGCAGTAACAGGGCAGTTCATTCCAAATCCAGCACTGCTGT

TTACCTTGCAGAAGGAGGCACTGCTACAACCATGGTGTCTAAAGATATAG

›GAATGAACTGTCTG

The nucleic acid sequence encoding the extracellular BMPRII polypeptide is as follows:

(SEQ ID NO: 49)

TCGCAGAATCAAGAACGGCTATGTGCGTTTAAAGATCCGTATCAGCAAGA

CCTTGGGATAGGTGAGAGTAGAATCTCTCATGAAAATGGGACAATATTAT

GCTCGAAAGGTAGCACCTGCTATGGCCTTTGGGAGAAATCAAAAGGGGAC

ATAAATCTTGTAAAACAAGGATGTTGGTCTCACATTGGAGATCCCCAAGA

GTGTCACTATGAAGAATGTGTAGTAACTACCACTCCTCCCTCAATTCAGA

ATGGAACATACCGTTTCTGCTGTTGTAGCACAGATTTATGTAATGTCAAC

TTTACTGAGAATTTTCCACCTCCTGACACAACACCACTCAGTCCACCTCA

›TTCATTTAACCGAGATGAGACA

An alternative isoform of BMPRII, isoform 2 (GenBank: AAA86519.1) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular BMPRII polypeptide sequence (isoform 2) is as follows:

(SEQ ID NO: 72)

SQNQERLCAFKDPYQQDLGIGESRISHENGTILCSKGSTCYGLWEKSKGD

INLVKQGCWSHIGDPQECHYEECVVTTTPPSIQNGTYRFCCCSTDLCNVN

›FTENFPPPDTTPLSPPHSFNRDET

A nucleic acid sequence encoding human BMPRII precursor protein (isoform 2) is shown below (SEQ ID NO:73), corresponding to nucleotides 163-1752 of Genbank Reference Sequence U25110.1. The signal sequence is underlined.

(SEQ ID NO: 73)

ATGACTTCCTCGCTGCAGCGGCCCTGGCGGGTGCCCTGGCTACCATGGAC

CATCCTGCTGGTCAGCACTGCGGCTGCT TCGCAGAATCAAGAACGGCTAT

GTGCGTTTAAAGATCCGTATCAGCAAGACCTTGGGATAGGTGAGAGTAGA

ATCTCTCATGAAAATGGGACAATATTATGCTCGAAAGGTAGCACCTGCTA

TGGCCTTTGGGAGAAATCAAAAGGGGACATAAATCTTGTAAAACAAGGAT

GTTGGTCTCACATTGGAGATCCCCAAGAGTGTCACTATGAAGAATGTGTA

GTAACTACCACTCCTCCCTCAATTCAGAATGGAACATACCGTTTCTGCTG

TTGTAGCACAGATTTATGTAATGTCAACTTTACTGAGAATTTTCCACCTC

CTGACACAACACCACTCAGTCCACCTCATTCATTTAACCGAGATGAGACA

ATAATCATTGCTTTGGCATCAGTCTCTGTATTAGCTGTTTTGATAGTTGC

CTTATGCTTTGGATACAGAATGTTGACAGGAGACCGTAAACAAGGTCTTC

ACAGTATGAACATGATGGAGGCAGCAGCATCCGAACCCTCTCTTGATCTA

GATAATCTGAAACTGTTGGAGCTGATTGGCCGAGGTCGATATGGAGCAGT

ATATAAAGGCTCCTTGGATGAGCGTCCAGTTGCTGTAAAAGTGTTTTCCT

TTGCAAACCGTCAGAATTTTATCAACGAAAAGAACATTTACAGAGTGCCT

TTGATGGAACATGACAACATTGCCCGCTTTATAGTTGGAGATGAGAGAGT

CACTGCAGATGGACGCATGGAATATTTGCTTGTGATGGAGTACTATCCCA

ATGGATCTTTATGCAAGTATTTAAGTCTCCACACAAGTGACTGGGTAAGC

TCTTGCCGTCTTGCTCATTCTGTTACTAGAGGACTGGCTTATCTTCACAC

AGAATTACCACGAGGAGATCATTATAAACCTGCAATTTCCCATCGAGATT

TAAACAGCAGAAATGTCCTAGTGAAAAATGATGGAACCTGTGTTATTAGT

GACTTTGGACTGTCCATGAGGCTGACTGGAAATAGACTGGTGCGCCCAGG

GGAGGAAGATAATGCAGCCATAAGCGAGGTTGGCACTATCAGATATATGG

CACCAGAAGTGCTAGAAGGAGCTGTGAACTTGAGGGACTGTGAATCAGCT

TTGAAACAAGTAGACATGTATGCTCTTGGACTAATCTATTGGGAGATATT

TATGAGATGTACAGACCTCTTCCCAGGGGAATCCGTACCAGAGTACCAGA

TGGCTTTTCAGACAGAGGTTGGAAACCATCCCACTTTTGAGGATATGCAG

GTTCTCGTGTCTAGGGAAAAACAGAGACCCAAGTTCCCAGAAGCCTGGAA

AGAAAATAGCCTGGCAGTGAGGTCACTCAAGGAGACAATCGAAGACTGTT

GGGACCAGGATGCAGAGGCTCGGCTTACTGCACAGTGTGCTGAGGAAAGG

ATGGCTGAACTTATGATGATTTGGGAAAGAAACAAATCTGTGAGCCCAAC

›AGTCAATCCAATGTCTACTGCTATGCAGAATGAACGTAGG

A nucleic acid sequence encoding an extracellular BMPRII polypeptide (isoform 2) is as follows:

(SEQ ID NO: 74)

TCGCAGAATCAAGAACGGCTATGTGCGTTTAAAGATCCGTATCAGCAAGA

CCTTGGGATAGGTGAGAGTAGAATCTCTCATGAAAATGGGACAATATTAT

GCTCGAAAGGTAGCACCTGCTATGGCCTTTGGGAGAAATCAAAAGGGGAC

ATAAATCTTGTAAAACAAGGATGTTGGTCTCACATTGGAGATCCCCAAGA

GTGTCACTATGAAGAATGTGTAGTAACTACCACTCCTCCCTCAATTCAGA

ATGGAACATACCGTTTCTGCTGTTGTAGCACAGATTTATGTAATGTCAAC

TTTACTGAGAATTTTCCACCTCCTGACACAACACCACTCAGTCCACCTCA

›TTCATTTAACCGAGATGAGACA

In certain embodiments, the disclosure relates to heteromultimer complexes that comprise at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, BMPRII polypeptides for use in accordance with inventions of the disclosure (e.g., heteromultimer complexes comprising a BMPRII polypeptide and uses thereof) are soluble (e.g., an extracellular domain of BMPRII). In other preferred embodiments, BMPRII polypeptides for use in accordance with the inventions of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimer complexes of the disclosure comprise at least one BMPRII polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 46, 47, 71, 72, 121, 123, 411, or 412. In some embodiments, heteromultimer complexes of the disclosure consist or consist essentially of at least one BMPRII polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 46, 47, 71, 72, 121, 123, 411, or 412.

In certain aspects, the present disclosure relates to protein complexes that comprise an MISRII polypeptide. As used herein, the term “MISRII” refers to a family of Müllerian inhibiting substance receptor type II (MISRII) proteins from any species and variants derived from such MISRII proteins by mutagenesis or other modification. Reference to MISRII herein is understood to be a reference to any one of the currently identified forms. Members of the MISRII family are generally transmembrane proteins, composed of a ligand-binding extracellular domain with a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “MISRII polypeptide” includes polypeptides comprising any naturally occurring polypeptide of an MISRII family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Numbering of amino acids for all MISRII-related polypeptides described herein is based on the numbering of the human MISRII precursor protein sequence below (SEQ ID NO: 50), unless specifically designated otherwise.

The canonical human MISRII precursor protein sequence (NCBI Ref Seq NP_065434.1) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular MISRII polypeptide sequence is as follows:

(SEQ ID NO: 51)

PPNRRTCVFFEAPGVRGSTKTLGELLDTGTELPRAIRCLYSRCCFGIWNL

TQDRAQVEMQGCRDSDEPGCESLHCDPSPRAHPSPGSTLFTCSCGTDFCN

›ANYSHLPPPGSPGTPGSQGPQAAPGESIWMAL

A nucleic acid sequence encoding the MISRII precursor protein is shown below (SEQ ID NO: 52), corresponding to nucleotides 81-1799 of Genbank Reference Sequence NM_020547.2. The signal sequence is underlined.

(SEQ ID NO: 52)

›ATGCTAGGGTCTTTGGGGCTTTGGGCATTACTTCCCACAGCTGTGGAAGC

CCCCCAAACAGGCGAACCTGTGTGTTCTTTGAGGCCCCTGGAGTGCGGG

GAAGCACAAAGACACTGGGAGAGCTGCTAGATACAGGCACAGAGCTCCCC

AGAGCTATCCGCTGCCTCTACAGCCGCTGCTGCTTTGGGATCTGGAACCT

GACCCAAGACCGGGCACAGGTGGAAATGCAAGGATGCCGAGACAGTGATG

AGCCAGGCTGTGAGTCCCTCCACTGTGACCCAAGTCCCCGAGCCCACCCC

AGCCCTGGCTCCACTCTCTTCACCTGCTCCTGTGGCACTGACTTCTGCAA

TGCCAATTACAGCCATCTGCCTCCTCCAGGGAGCCCTGGGACTCCTGGCT

CCCAGGGTCCCCAGGCTGCCCCAGGTGAGTCCATCTGGATGGCACTG GTG

CTGCTGGGGCTGTTCCTCCTCCTCCTGCTGCTGCTGGGCAGCATCATCTT

GGCCCTGCTACAGCGAAAGAACTACAGAGTGCGAGGTGAGCCAGTGCCAG

AGCCAAGGCCAGACTCAGGCAGGGACTGGAGTGTGGAGCTGCAGGAGCTG

CCTGAGCTGTGTTTCTCCCAGGTAATCCGGGAAGGAGGTCATGCAGTGGT

TTGGGCCGGGCAGCTGCAAGGAAAACTGGTTGCCATCAAGGCCTTCCCAC

CGAGGTCTGTGGCTCAGTTCCAAGCTGAGAGAGCATTGTACGAACTTCCA

GGCCTACAGCACGACCACATTGTCCGATTTATCACTGCCAGCCGGGGGGG

TCCTGGCCGCCTGCTCTCTGGGCCCCTGCTGGTACTGGAACTGCATCCCA

AGGGCTCCCTGTGCCACTACTTGACCCAGTACACCAGTGACTGGGGAAGT

TCCCTGCGGATGGCACTGTCCCTGGCCCAGGGCCTGGCATTTCTCCATGA

GGAGCGCTGGCAGAATGGCCAATATAAACCAGGTATTGCCCACCGAGATC

TGAGCAGCCAGAATGTGCTCATTCGGGAAGATGGATCGTGTGCCATTGGA

GACCTGGGCCTTGCCTTGGTGCTCCCTGGCCTCACTCAGCCCCCTGCCTG

GACCCCTACTCAACCACAAGGCCCAGCTGCCATCATGGAAGCTGGCACCC

AGAGGTACATGGCACCAGAGCTCTTGGACAAGACTCTGGACCTACAGGAT

TGGGGCATGGCCCTCCGACGAGCTGATATTTACTCTTTGGCTCTGCTCCT

GTGGGAGATACTGAGCCGCTGCCCAGATTTGAGGCCTGACAGCAGTCCAC

CACCCTTCCAACTGGCCTATGAGGCAGAACTGGGCAATACCCCTACCTCT

GATGAGCTATGGGCCTTGGCAGTGCAGGAGAGGAGGCGTCCCTACATCCC

ATCCACCTGGCGCTGCTTTGCCACAGACCCTGATGGGCTGAGGGAGCTCC

TAGAAGACTGTTGGGATGCAGACCCAGAAGCACGGCTGACAGCTGAGTGT

GTACAGCAGCGCCTGGCTGCCTTGGCCCATCCTCAAGAGAGCCACCCCTT

TCCAGAGAGCTGTCCACGTGGCTGCCCACCTCTCTGCCCAGAAGACTGTA

CTTCAATTCCTGCCCCTACCATCCTCCCCTGTAGGCCTCAGCGGAGTGCC

TGCCACTTCAGCGTTCAGCAAGGCCCTTGTTCCAGGAATCCTCAGCCTGC

›CTGTACCCTTTCTCCTGTG

A nucleic acid sequence encoding the extracellular human MISRII polypeptide is as follows:

(SEQ ID NO: 53)

CCCCCAAACAGGCGAACCTGTGTGTTCTTTGAGGCCCCTGGAGTGCGGGG

AAGCACAAAGACACTGGGAGAGCTGCTAGATACAGGCACAGAGCTCCCCA

GAGCTATCCGCTGCCTCTACAGCCGCTGCTGCTTTGGGATCTGGAACCTG

ACCCAAGACCGGGCACAGGTGGAAATGCAAGGATGCCGAGACAGTGATGA

GCCAGGCTGTGAGTCCCTCCACTGTGACCCAAGTCCCCGAGCCCACCCCA

GCCCTGGCTCCACTCTCTTCACCTGCTCCTGTGGCACTGACTTCTGCAAT

GCCAATTACAGCCATCTGCCTCCTCCAGGGAGCCCTGGGACTCCTGGCTC

›CCAGGGTCCCCAGGCTGCCCCAGGTGAGTCCATCTGGATGGCACTG

An alternative isoform of the human MISRII precursor protein sequence, isoform 2 (NCBI Ref Seq NP_001158162.1), is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular MISRII polypeptide sequence (isoform 2) is as follows:

(SEQ ID NO: 76)

PPNRRTCVFFEAPGVRGSTKTLGELLDTGTELPRAIRCLYSRCCFGIWNL

TQDRAQVEMQGCRDSDEPGCESLHCDPSPRAHPSPGSTLFTCSCGTDFCN

›ANYSHLPPPGSPGTPGSQGPQAAPGESIWMAL

A nucleic acid sequence encoding the MISRII precursor protein (isoform 2) is shown below (SEQ ID NO: 77), corresponding to nucleotides 81-1514 of Genbank Reference Sequence NM_001164690.1. The signal sequence is underlined.

(SEQ ID NO: 77)

ATGCTAGGGTCTTTGGGGCTTTGGGCATTACTTCCCACAGCTGTGGAAGC

A CCCCCAAACAGGCGAACCTGTGTGTTCTTTGAGGCCCCTGGAGTGCGGG

GAAGCACAAAGACACTGGGAGAGCTGCTAGATACAGGCACAGAGCTCCCC

AGAGCTATCCGCTGCCTCTACAGCCGCTGCTGCTTTGGGATCTGGAACCT

GACCCAAGACCGGGCACAGGTGGAAATGCAAGGATGCCGAGACAGTGATG

AGCCAGGCTGTGAGTCCCTCCACTGTGACCCAAGTCCCCGAGCCCACCCC

AGCCCTGGCTCCACTCTCTTCACCTGCTCCTGTGGCACTGACTTCTGCAA

TGCCAATTACAGCCATCTGCCTCCTCCAGGGAGCCCTGGGACTCCTGGCT

CCCAGGGTCCCCAGGCTGCCCCAGGTGAGTCCATCTGGATGGCACTGGTG

CTGCTGGGGCTGTTCCTCCTCCTCCTGCTGCTGCTGGGCAGCATCATCTT

GGCCCTGCTACAGCGAAAGAACTACAGAGTGCGAGGTGAGCCAGTGCCAG

AGCCAAGGCCAGACTCAGGCAGGGACTGGAGTGTGGAGCTGCAGGAGCTG

CCTGAGCTGTGTTTCTCCCAGGTAATCCGGGAAGGAGGTCATGCAGTGGT

TTGGGCCGGGCAGCTGCAAGGAAAACTGGTTGCCATCAAGGCCTTCCCAC

CGAGGTCTGTGGCTCAGTTCCAAGCTGAGAGAGCATTGTACGAACTTCCA

GGCCTACAGCACGACCACATTGTCCGATTTATCACTGCCAGCCGGGGGGG

TCCTGGCCGCCTGCTCTCTGGGCCCCTGCTGGTACTGGAACTGCATCCCA

AGGGCTCCCTGTGCCACTACTTGACCCAGTACACCAGTGACTGGGGAAGT

TCCCTGCGGATGGCACTGTCCCTGGCCCAGGGCCTGGCATTTCTCCATGA

GGAGCGCTGGCAGAATGGCCAATATAAACCAGGTATTGCCCACCGAGATC

TGAGCAGCCAGAATGTGCTCATTCGGGAAGATGGATCGTGTGCCATTGGA

GACCTGGGCCTTGCCTTGGTGCTCCCTGGCCTCACTCAGCCCCCTGCCTG

GACCCCTACTCAACCACAAGGCCCAGCTGCCATCATGGAAGCTGGCACCC

AGAGGTACATGGCACCAGAGCTCTTGGACAAGACTCTGGACCTACAGGAT

TGGGGCATGGCCCTCCGACGAGCTGATATTTACTCTTTGGCTCTGCTCCT

GTGGGAGATACTGAGCCGCTGCCCAGATTTGAGGCCTGCAGTCCACCACC

CTTCCAACTGGCCTATGAGGCAGAACTGGGCAATACCCCTACCTCTGATG

AGCTATGGGCCTTGGCAGTGCAGGAGAGGAGGCGTCCCTACATCCCATCC

›ACCTGGCGCTGCTTTGCCACAGACCCTGATGGGC

The nucleic acid sequence encoding processed soluble (extracellular) human MISRII polypeptide (isoform 2) is as follows:

(SEQ ID NO: 78)

CCCCCAAACAGGCGAACCTGTGTGTTCTTTGAGGCCCCTGGAGTGCGGGG

AAGCACAAAGACACTGGGAGAGCTGCTAGATACAGGCACAGAGCTCCCCA

GAGCTATCCGCTGCCTCTACAGCCGCTGCTGCTTTGGGATCTGGAACCTG

ACCCAAGACCGGGCACAGGTGGAAATGCAAGGATGCCGAGACAGTGATGA

GCCAGGCTGTGAGTCCCTCCACTGTGACCCAAGTCCCCGAGCCCACCCCA

GCCCTGGCTCCACTCTCTTCACCTGCTCCTGTGGCACTGACTTCTGCAAT

GCCAATTACAGCCATCTGCCTCCTCCAGGGAGCCCTGGGACTCCTGGCTC

›CCAGGGTCCCCAGGCTGCCCCAGGTGAGTCCATCTGGATGGCACTG

An alternative isoform of the human MISRII precursor protein sequence, isoform 3 (NCBI Ref Seq NP_001158163.1), is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular MISRII polypeptide sequence (isoform 3) is as follows:

(SEQ ID NO: 80)

PPNRRTCVFFEAPGVRGSTKTLGELLDTGTELPRAIRCLYSRCCFGIWNL

TQDRAQVEMQGCRDSDEPGCESLHCDPSPRAHPSPGSTLFTCSCGTDFCN

›ANYSHLPPPGSPGTPGSQGPQAAPGESIWMAL

A nucleic acid sequence encoding human MISRII precursor protein (isoform 3) is shown below (SEQ ID NO: 81), corresponding to nucleotides 81-1514 of Genbank Reference Sequence NM_001164691.1. The signal sequence is underlined.

(SEQ ID NO: 81)

ATGCTAGGGTCTTTGGGGCTTTGGGCATTACTTCCCACAGCTGTGGAAGC

A CCCCCAAACAGGCGAACCTGTGTGTTCTTTGAGGCCCCTGGAGTGCGGG

GAAGCACAAAGACACTGGGAGAGCTGCTAGATACAGGCACAGAGCTCCCC

AGAGCTATCCGCTGCCTCTACAGCCGCTGCTGCTTTGGGATCTGGAACCT

GACCCAAGACCGGGCACAGGTGGAAATGCAAGGATGCCGAGACAGTGATG

AGCCAGGCTGTGAGTCCCTCCACTGTGACCCAAGTCCCCGAGCCCACCCC

AGCCCTGGCTCCACTCTCTTCACCTGCTCCTGTGGCACTGACTTCTGCAA

TGCCAATTACAGCCATCTGCCTCCTCCAGGGAGCCCTGGGACTCCTGGCT

CCCAGGGTCCCCAGGCTGCCCCAGGTGAGTCCATCTGGATGGCACTGGTG

CTGCTGGGGCTGTTCCTCCTCCTCCTGCTGCTGCTGGGCAGCATCATCTT

GGCCCTGCTACAGCGAAAGAACTACAGAGTGCGAGGTGAGCCAGTGCCAG

AGCCAAGGCCAGACTCAGGCAGGGACTGGAGTGTGGAGCTGCAGGAGCTG

CCTGAGCTGTGTTTCTCCCAGGTAATCCGGGAAGGAGGTCATGCAGTGGT

TTGGGCCGGGCAGCTGCAAGGAAAACTGGTTGCCATCAAGGCCTTCCCAC

CGAGGTCTGTGGCTCAGTTCCAAGCTGAGAGAGCATTGTACGAACTTCCA

GGCCTACAGCACGACCACATTGTCCGATTTATCACTGCCAGCCGGGGGGG

TCCTGGCCGCCTGCTCTCTGGGCCCCTGCTGGTACTGGAACTGCATCCCA

AGGGCTCCCTGTGCCACTACTTGACCCAGTACACCAGTGACTGGGGAAGT

TCCCTGCGGATGGCACTGTCCCTGGCCCAGGGCCTGGCATTTCTCCATGA

GGAGCGCTGGCAGAATGGCCAATATAAACCAGGTATTGCCCACCGAGATC

TGAGCAGCCAGAATGTGCTCATTCGGGAAGATGGATCGTGTGCCATTGGA

GACCTGGGCCTTGCCTTGGTGCTCCCTGGCCTCACTCAGCCCCCTGCCTG

GACCCCTACTCAACCACAAGGCCCAGCTGCCATCATGGAAGACCCTGATG

GGCTGAGGGAGCTCCTAGAAGACTGTTGGGATGCAGACCCAGAAGCACGG

CTGACAGCTGAGTGTGTACAGCAGCGCCTGGCTGCCTTGGCCCATCCTCA

AGAGAGCCACCCCTTTCCAGAGAGCTGTCCACGTGGCTGCCCACCTCTCT

GCCCAGAAGACTGTACTTCAATTCCTGCCCCTACCATCCTCCCCTGTAGG

CCTCAGCGGAGTGCCTGCCACTTCAGCGTTCAGCAAGGCCCTTGTTCCAG

›GAATCCTCAGCCTGCCTGTACCCTTTCTCCTGTG

A nucleic acid sequence encoding processed soluble (extracellular) human MISRII polypeptide (isoform 3) is as follows:

(SEQ ID NO: 82)

CCCCCAAACAGGCGAACCTGTGTGTTCTTTGAGGCCCCTGGAGTGCGGGG

AAGCACAAAGACACTGGGAGAGCTGCTAGATACAGGCACAGAGCTCCCCA

GAGCTATCCGCTGCCTCTACAGCCGCTGCTGCTTTGGGATCTGGAACCTG

ACCCAAGACCGGGCACAGGTGGAAATGCAAGGATGCCGAGACAGTGATGA

GCCAGGCTGTGAGTCCCTCCACTGTGACCCAAGTCCCCGAGCCCACCCCA

GCCCTGGCTCCACTCTCTTCACCTGCTCCTGTGGCACTGACTTCTGCAAT

GCCAATTACAGCCATCTGCCTCCTCCAGGGAGCCCTGGGACTCCTGGCTC

›CCAGGGTCCCCAGGCTGCCCCAGGTGAGTCCATCTGGATGGCACTG

In certain embodiments, the disclosure relates to heteromultimer complexes that comprise at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, MISRII polypeptides for use in accordance with inventions of the disclosure (e.g., heteromultimer complexes comprising a MISRII polypeptide and uses thereof) are soluble (e.g., an extracellular domain of MISRII). In other preferred embodiments, MISRII polypeptides for use in accordance with the inventions of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimer complexes of the disclosure comprise at least one MISRII polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NOs: 50, 51, 75, 76, 79, or 80. In some embodiments, heteromultimer complexes of the disclosure consist or consist essentially of at least one MISRII polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NOs: 50, 51, 75, 76, 79, or 80.

In certain aspects, the present disclosure relates to protein complexes that comprise an ALK1 polypeptide. As used herein, the term “ALK1” refers to a family of activin receptor-like kinase-1 proteins from any species and variants derived from such ALK1 proteins by mutagenesis or other modification. Reference to ALK1 herein is understood to be a reference to any one of the currently identified forms. Members of the ALK1 family are generally transmembrane proteins, composed of a ligand-binding extracellular domain with a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “ALK1 polypeptide” includes polypeptides comprising any naturally occurring polypeptide of an ALK1 family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Numbering of amino acids for all ALK1-related polypeptides described herein is based on the numbering of the human ALK1 precursor protein sequence below (SEQ ID NO: 14), unless specifically designated otherwise.

The human ALK1 precursor protein sequence (NCBI Ref Seq NP_000011.2) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular ALK1 polypeptide sequence is as follows:

(SEQ ID NO: 15)

DPVKPSRGPLVTCTCESPHCKGPTCRGAWCTVVLVREEGRHPQEHRGCGN

›LHRELCRGRPTEFVNHYCCDSHLCNHNVSLVLEATQPPSEQPGTDGQ

A nucleic acid sequence encoding human ALK1 precursor protein is shown below (SEQ ID NO: 16), corresponding to nucleotides 284-1792 of Genbank Reference Sequence NM_000020.2. The signal sequence is underlined.

(SEQ ID NO: 16)

ATGACCTTGGGCTCCCCCAGGAAAGGCCTTCTGATGCTGCTGATGGCCTT

GGTGACCCAGGGA

GACCCTGTGAAGCCGTCTCGGGGCCCGCTGGTGACCT

GCACGTGTGAGAGCCCACATTGCAAGGGGCCTACCTGCCGGGGGGCCTGG

TGCACAGTAGTGCTGGTGCGGGAGGAGGGGAGGCACCCCCAGGAACATCG

GGGCTGCGGGAACTTGCACAGGGAGCTCTGCAGGGGGCGCCCCACCGAGT

TCGTCAACCACTACTGCTGCGACAGCCACCTCTGCAACCACAACGTGTCC

CTGGTGCTGGAGGCCACCCAACCTCCTTCGGAGCAGCCGGGAACAGATGG

CCAG CTGGCCCTGATCCTGGGCCCCGTGCTGGCCTTGCTGGCCCTGGTGG

CCCTGGGTGTCCTGGGCCTGTGGCATGTCCGACGGAGGCAGGAGAAGCAG

CGTGGCCTGCACAGCGAGCTGGGAGAGTCCAGTCTCATCCTGAAAGCATC

TGAGCAGGGCGACAGCATGTTGGGGGACCTCCTGGACAGTGACTGCACCA

CAGGGAGTGGCTCAGGGCTCCCCTTCCTGGTGCAGAGGACAGTGGCACGG

CAGGTTGCCTTGGTGGAGTGTGTGGGAAAAGGCCGCTATGGCGAAGTGTG

GCGGGGCTTGTGGCACGGTGAGAGTGTGGCCGTCAAGATCTTCTCCTCGA

GGGATGAACAGTCCTGGTTCCGGGAGACTGAGATCTATAACACAGTGTTG

CTCAGACACGACAACATCCTAGGCTTCATCGCCTCAGACATGACCTCCCG

CAACTCGAGCACGCAGCTGTGGCTCATCACGCACTACCACGAGCACGGCT

CCCTCTACGACTTTCTGCAGAGACAGACGCTGGAGCCCCATCTGGCTCTG

AGGCTAGCTGTGTCCGCGGCATGCGGCCTGGCGCACCTGCACGTGGAGAT

CTTCGGTACACAGGGCAAACCAGCCATTGCCCACCGCGACTTCAAGAGCC

GCAATGTGCTGGTCAAGAGCAACCTGCAGTGTTGCATCGCCGACCTGGGC

CTGGCTGTGATGCACTCACAGGGCAGCGATTACCTGGACATCGGCAACAA

CCCGAGAGTGGGCACCAAGCGGTACATGGCACCCGAGGTGCTGGACGAGC

AGATCCGCACGGACTGCTTTGAGTCCTACAAGTGGACTGACATCTGGGCC

TTTGGCCTGGTGCTGTGGGAGATTGCCCGCCGGACCATCGTGAATGGCAT

CGTGGAGGACTATAGACCACCCTTCTATGATGTGGTGCCCAATGACCCCA

GCTTTGAGGACATGAAGAAGGTGGTGTGTGTGGATCAGCAGACCCCCACC

ATCCCTAACCGGCTGGCTGCAGACCCGGTCCTCTCAGGCCTAGCTCAGAT

GATGCGGGAGTGCTGGTACCCAAACCCCTCTGCCCGACTCACCGCGCTGC

GGATCAAGAAGACACTACAAAAAATTAGCAACAGTCCAGAGAAGCCTAAA

›GTGATTCAA

A nucleic acid sequence encoding processed extracellular ALK1 polypeptide is as follows:

(SEQ ID NO: 17)

GACCCTGTGAAGCCGTCTCGGGGCCCGCTGGTGACCTGCACGTGTGAGAG

CCCACATTGCAAGGGGCCTACCTGCCGGGGGGCCTGGTGCACAGTAGTGC

TGGTGCGGGAGGAGGGGAGGCACCCCCAGGAACATCGGGGCTGCGGGAAC

TTGCACAGGGAGCTCTGCAGGGGGCGCCCCACCGAGTTCGTCAACCACTA

CTGCTGCGACAGCCACCTCTGCAACCACAACGTGTCCCTGGTGCTGGAGG

›CCACCCAACCTCCTTCGGAGCAGCCGGGAACAGATGGCCAG

In certain embodiments, the disclosure relates to heteromultimer complexes that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, ALK1 polypeptides for use in accordance with inventions of the disclosure (e.g., heteromultimer complexes comprising an ALK1 polypeptide and uses thereof) are soluble (e.g., an extracellular domain of ALK1). In other preferred embodiments, ALK1 polypeptides for use in accordance with the inventions of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimer complexes of the disclosure comprise at least one ALK1 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 14, 15, 124, 126, 413, or 414. In some embodiments, heteromultimer complexes of the disclosure consist or consist essentially of at least one ALK1 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 14, 15, 124, 126, 413, or 414.

In certain aspects, the present disclosure relates to protein complexes that comprise an ALK2 polypeptide. As used herein, the term “ALK2” refers to a family of activin receptor-like kinase-2 proteins from any species and variants derived from such ALK2 proteins by mutagenesis or other modification. Reference to ALK2 herein is understood to be a reference to any one of the currently identified forms. Members of the ALK2 family are generally transmembrane proteins, composed of a ligand-binding extracellular domain with a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “ALK2 polypeptide” includes polypeptides comprising any naturally occurring polypeptide of an ALK2 family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Numbering of amino acids for all ALK2-related polypeptides described herein is based on the numbering of the human ALK2 precursor protein sequence below (SEQ ID NO: 18), unless specifically designated otherwise.

The human ALK2 precursor protein sequence (NCBI Ref Seq NP_001096.1) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular ALK2 polypeptide sequence is as follows:

(SEQ ID NO: 19)

MEDEKPKVNPKLYMCVCEGLSCGNEDHCEGQQCFSSLSINDGFHVYQKGC

FQVYEQGKMTCKTPPSPGQAVECCQGDWCNRNITAQLPTKGKSFPGTQNF

›HLE

A nucleic acid sequence encoding human ALK2 precursor protein is shown below (SEQ ID NO: 20), corresponding to nucleotides 431-1957 of Genbank Reference Sequence NM_001105.4. The signal sequence is underlined.

(SEQ ID NO: 20)

ATGGTAGATGGAGTGATGATTCTTCCTGTGCTTATCATGATTGCTCTCCC

CTCCCCTAGT

ATGGAAGATGAGAAGCCCAAGGTCAACCCCAAACTCTACA

TGTGTGTGTGTGAAGGTCTCTCCTGCGGTAATGAGGACCACTGTGAAGGC

CAGCAGTGCTTTTCCTCACTGAGCATCAACGATGGCTTCCACGTCTACCA

GAAAGGCTGCTTCCAGGTTTATGAGCAGGGAAAGATGACCTGTAAGACCC

CGCCGTCCCCTGGCCAAGCCGTGGAGTGCTGCCAAGGGGACTGGTGTAAC

AGGAACATCACGGCCCAGCTGCCCACTAAAGGAAAATCCTTCCCTGGAAC

ACAGAATTTCCACTTGGAG GTTGGCCTCATTATTCTCTCTGTAGTGTTCG

CAGTATGTCTTTTAGCCTGCCTGCTGGGAGTTGCTCTCCGAAAATTTAAA

AGGCGCAACCAAGAACGCCTCAATCCCCGAGACGTGGAGTATGGCACTAT

CGAAGGGCTCATCACCACCAATGTTGGAGACAGCACTTTAGCAGATTTAT

TGGATCATTCGTGTACATCAGGAAGTGGCTCTGGTCTTCCTTTTCTGGTA

CAAAGAACAGTGGCTCGCCAGATTACACTGTTGGAGTGTGTCGGGAAAGG

CAGGTATGGTGAGGTGTGGAGGGGCAGCTGGCAAGGGGAGAATGTTGCCG

TGAAGATCTTCTCCTCCCGTGATGAGAAGTCATGGTTCAGGGAAACGGAA

TTGTACAACACTGTGATGCTGAGGCATGAAAATATCTTAGGTTTCATTGC

TTCAGACATGACATCAAGACACTCCAGTACCCAGCTGTGGTTAATTACAC

ATTATCATGAAATGGGATCGTTGTACGACTATCTTCAGCTTACTACTCTG

GATACAGTTAGCTGCCTTCGAATAGTGCTGTCCATAGCTAGTGGTCTTGC

ACATTTGCACATAGAGATATTTGGGACCCAAGGGAAACCAGCCATTGCCC

ATCGAGATTTAAAGAGCAAAAATATTCTGGTTAAGAAGAATGGACAGTGT

TGCATAGCAGATTTGGGCCTGGCAGTCATGCATTCCCAGAGCACCAATCA

GCTTGATGTGGGGAACAATCCCCGTGTGGGCACCAAGCGCTACATGGCCC

CCGAAGTTCTAGATGAAACCATCCAGGTGGATTGTTTCGATTCTTATAAA

AGGGTCGATATTTGGGCCTTTGGACTTGTTTTGTGGGAAGTGGCCAGGCG

GATGGTGAGCAATGGTATAGTGGAGGATTACAAGCCACCGTTCTACGATG

TGGTTCCCAATGACCCAAGTTTTGAAGATATGAGGAAGGTAGTCTGTGTG

GATCAACAAAGGCCAAACATACCCAACAGATGGTTCTCAGACCCGACATT

AACCTCTCTGGCCAAGCTAATGAAAGAATGCTGGTATCAAAATCCATCCG

CAAGACTCACAGCACTGCGTATCAAAAAGACTTTGACCAAAATTGATAAT

›TCCCTCGACAAATTGAAAACTGACTGT

A nucleic acid sequence encoding the extracellular ALK2 polypeptide is as follows:

(SEQ ID NO: 21)

ATGGAAGATGAGAAGCCCAAGGTCAACCCCAAACTCTACATGTGTGTGTG

TGAAGGTCTCTCCTGCGGTAATGAGGACCACTGTGAAGGCCAGCAGTGCT

TTTCCTCACTGAGCATCAACGATGGCTTCCACGTCTACCAGAAAGGCTGC

TTCCAGGTTTATGAGCAGGGAAAGATGACCTGTAAGACCCCGCCGTCCCC

TGGCCAAGCCGTGGAGTGCTGCCAAGGGGACTGGTGTAACAGGAACATCA

CGGCCCAGCTGCCCACTAAAGGAAAATCCTTCCCTGGAACACAGAATTTC

›CACTTGGAG · 1 of 2

In certain embodiments, the disclosure relates to heteromultimer complexes that comprise at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, ALK2 polypeptides for use in accordance with inventions of the disclosure (e.g., heteromultimer complexes comprising an ALK2 polypeptide and uses thereof) are soluble (e.g., an extracellular domain of ALK2). In other preferred embodiments, ALK2 polypeptides for use in accordance with the inventions of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimer complexes of the disclosure comprise at least one ALK2 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 18 or 19. In some embodiments, heteromultimer complexes of the disclosure consist or consist essentially of at least one ALK2 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 18 or 19.

In certain aspects, the present disclosure relates to protein complexes that comprise an ALK3 polypeptide. As used herein, the term “ALK3” refers to a family of activin receptor-like kinase-3 proteins from any species and variants derived from such ALK3 proteins by mutagenesis or other modification. Reference to ALK3 herein is understood to be a reference to any one of the currently identified forms. Members of the ALK3 family are generally transmembrane proteins, composed of a ligand-binding extracellular domain with a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “ALK3 polypeptide” includes polypeptides comprising any naturally occurring polypeptide of an ALK3 family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Numbering of amino acids for all ALK3-related polypeptides described herein is based on the numbering of the human ALK3 precursor protein sequence below (SEQ ID NO: 22), unless specifically designated otherwise.

The human ALK3 precursor protein sequence (NCBI Ref Seq NP_004320.2) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular ALK3 polypeptide sequence is as follows:

A nucleic acid sequence encoding human ALK3 precursor protein is shown below (SEQ ID NO: 24), corresponding to nucleotides 549-2144 of Genbank Reference Sequence NM_004329.2. The signal sequence is underlined and the extracellular domain is indicated in bold font.

A nucleic acid sequence encoding the extracellular human ALK3 polypeptide is as follows:

A general formula for an active (e.g., ligand binding) ALK3 polypeptide is one that comprises a polypeptide that begins at any amino acid position 25-31 (i.e., position 25, 26, 27, 28, 29, 30, or 31) of SEQ ID NO: 22 and ends at any amino acid position 140-152 of SEQ ID NO: 22 (i.e., 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, or 152). See U.S. Pat. No. 8,338,377, the teachings of which are incorporated herein by reference in their entirety.

In certain embodiments, the disclosure relates to heteromultimer complexes that comprise at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, ALK3 polypeptides for use in accordance with inventions of the disclosure (e.g., heteromultimer complexes comprising an ALK3 polypeptide and uses thereof) are soluble (e.g., an extracellular domain of ALK3). In other preferred embodiments, ALK3 polypeptides for use in accordance with the inventions of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimer complexes of the disclosure comprise at least one ALK3 polypeptide that comprises, consists, or consists essentially of an amino acid beginning at any amino acid position 25-31 (i.e., position 25, 26, 27, 28, 29, 30, or 31) of SEQ ID NO: 22 and ending at any amino acid position 140-153 of SEQ ID NO: 22 (i.e., 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, or 152) of SEQ ID NO: 22. In some embodiments, heteromultimer complexes of the disclosure comprise at least one ALK3 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 22, 23, 115, 117, 407, or 408. In some embodiments, heteromultimer complexes of the disclosure consist or consist essentially of at least one ALK3 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 22, 23, 115, 117, 407, or 408.

In certain aspects, the present disclosure relates to protein complexes that comprise an ALK4 polypeptide. As used herein, the term “ALK4” refers to a family of activin receptor-like kinase-4 proteins from any species and variants derived from such ALK4 proteins by mutagenesis or other modification. Reference to ALK4 herein is understood to be a reference to any one of the currently identified forms. Members of the ALK4 family are generally transmembrane proteins, composed of a ligand-binding extracellular domain with a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “ALK4 polypeptide” includes polypeptides comprising any naturally occurring polypeptide of an ALK4 family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Numbering of amino acids for all ALK4-related polypeptides described herein is based on the numbering of the human ALK4 precursor protein sequence below (SEQ ID NO: 26), unless specifically designated otherwise.

›CACTTGGAG · 2 of 2

The canonical human ALK4 precursor protein sequence (NCBI Ref Seq NP_004293) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular human ALK4 polypeptide sequence is as follows:

(SEQ ID NO: 27)

SGPRGVQALLCACTSCLQANYTCETDGACMVSIFNLDGMEHHVRTCIPKV

ELVPAGKPFYCLSSEDLRNTHCCYTDYCNRIDLRVPSGHLKEPEHPSMWG

›PVE

A nucleic acid sequence encoding the ALK4 precursor protein is shown below (SEQ ID NO: 28), corresponding to nucleotides 78-1592 of Genbank Reference Sequence NM_004302.4. The signal sequence is underlined and the extracellular domain is indicated in bold font.

(SEQ ID NO: 28)

ATGGCGGAGTCGGCCGGAGCCTCCTCCTTCTTCCCCCTTGTTGTCCTCCT

GCTCGCCGGCAGCGGCGGG

TCCGGGCCCCGGGGGGTCCAGGCTCTGCTGT

GTGCGTGCACCAGCTGCCTCCAGGCCAACTACACGTGTGAGACAGATGGG

GCCTGCATGGTTTCCATTTTCAATCTGGATGGGATGGAGCACCATGTGCG

CACCTGCATCCCCAAAGTGGAG CTGGTCCCTGCCGGGAAGCCCTTCTACT

GCCTGAGCTCGGAGGACCTGCGCAACACCCACTGCTGCTACACTGACTAC

TGCAACAGGATCGACTTGAGGGTGCCCAGTGGTCACCTCAAGGAGCCTGA

GCACCCGTCCATGTGGGGCCCGGTGGAGCTGGTAGGCATCATCGCCGGCC

CGGTGTTCCTCCTGTTCCTCATCATCATCATTGTTTTCCTTGTCATTAAC

TATCATCAGCGTGTCTATCACAACCGCCAGAGACTGGACATGGAAGATCC

CTCATGTGAGATGTGTCTCTCCAAAGACAAGACGCTCCAGGATCTTGTCT

ACGATCTCTCCACCTCAGGGTCTGGCTCAGGGTTACCCCTCTTTGTCCAG

CGCACAGTGGCCCGAACCATCGTTTTACAAGAGATTATTGGCAAGGGTCG

GTTTGGGGAAGTATGGCGGGGCCGCTGGAGGGGTGGTGATGTGGCTGTGA

AAATATTCTCTTCTCGTGAAGAACGGTCTTGGTTCAGGGAAGCAGAGATA

TACCAGACGGTCATGCTGCGCCATGAAAACATCCTTGGATTTATTGCTGC

TGACAATAAAGATAATGGCACCTGGACACAGCTGTGGCTTGTTTCTGACT

ATCATGAGCACGGGTCCCTGTTTGATTATCTGAACCGGTACACAGTGACA

ATTGAGGGGATGATTAAGCTGGCCTTGTCTGCTGCTAGTGGGCTGGCACA

CCTGCACATGGAGATCGTGGGCACCCAAGGGAAGCCTGGAATTGCTCATC

GAGACTTAAAGTCAAAGAACATTCTGGTGAAGAAAAATGGCATGTGTGCC

ATAGCAGACCTGGGCCTGGCTGTCCGTCATGATGCAGTCACTGACACCAT

TGACATTGCCCCGAATCAGAGGGTGGGGACCAAACGATACATGGCCCCTG

AAGTACTTGATGAAACCATTAATATGAAACACTTTGACTCCTTTAAATGT

GCTGATATTTATGCCCTCGGGCTTGTATATTGGGAGATTGCTCGAAGATG

CAATTCTGGAGGAGTCCATGAAGAATATCAGCTGCCATATTACGACTTAG

TGCCCTCTGACCCTTCCATTGAGGAAATGCGAAAGGTTGTATGTGATCAG

AAGCTGCGTCCCAACATCCCCAACTGGTGGCAGAGTTATGAGGCACTGCG

GGTGATGGGGAAGATGATGCGAGAGTGTTGGTATGCCAACGGCGCAGCCC

GCCTGACGGCCCTGCGCATCAAGAAGACCCTCTCCCAGCTCAGCGTGCAG

›GAAGACGTGAAGATC

A nucleic acid sequence encoding the extracellular ALK4 polypeptide is as follows:

(SEQ ID NO: 29)

TCCGGGCCCCGGGGGGTCCAGGCTCTGCTGTGTGCGTGCACCAGCTGCCT

CCAGGCCAACTACACGTGTGAGACAGATGGGGCCTGCATGGTTTCCATTT

TCAATCTGGATGGGATGGAGCACCATGTGCGCACCTGCATCCCCAAAGTG

GAGCTGGTCCCTGCCGGGAAGCCCTTCTACTGCCTGAGCTCGGAGGACCT

GCGCAACACCCACTGCTGCTACACTGACTACTGCAACAGGATCGACTTGA

GGGTGCCCAGTGGTCACCTCAAGGAGCCTGAGCACCCGTCCATGTGGGGC

›CCGGTGGAG

An alternative isoform of human ALK4 precursor protein sequence, isoform C (NCBI Ref Seq NP_064733.3), is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular ALK4 polypeptide sequence (isoform C) is as follows:

(SEQ ID NO: 84)

SGPRGVQALLCACTSCLQANYTCETDGACMVSIFNLDGMEHHVRTCIPKV

ELVPAGKPFYCLSSEDLRNTHCCYTDYCNRIDLRVPSGHLKEPEHPSMWG

›PVE

A nucleic acid sequence encoding the ALK4 precursor protein (isoform C) is shown below (SEQ ID NO: 85), corresponding to nucleotides 78-1715 of Genbank Reference Sequence NM_020328.3. The signal sequence is underlined and the extracellular domain is indicated in bold font.

(SEQ ID NO: 85)

ATGGCGGAGTCGGCCGGAGCCTCCTCCTTCTTCCCCCTTGTTGTCCTCCT

GCTCGCCGGCAGCGGCGGG

TCCGGGCCCCGGGGGGTCCAGGCTCTGCTGT

GTGCGTGCACCAGCTGCCTCCAGGCCAACTACACGTGTGAGACAGATGGG

GCCTGCATGGTTTCCATTTTCAATCTGGATGGGATGGAGCACCATGTGCG

CACCTGCATCCCCAAAGTGGAG CTGGTCCCTGCCGGGAAGCCCTTCTACT

GCCTGAGCTCGGAGGACCTGCGCAACACCCACTGCTGCTACACTGACTAC

TGCAACAGGATCGACTTGAGGGTGCCCAGTGGTCACCTCAAGGAGCCTGA

GCACCCGTCCATGTGGGGCCCGGTGGAGCTGGTAGGCATCATCGCCGGCC

CGGTGTTCCTCCTGTTCCTCATCATCATCATTGTTTTCCTTGTCATTAAC

TATCATCAGCGTGTCTATCACAACCGCCAGAGACTGGACATGGAAGATCC

CTCATGTGAGATGTGTCTCTCCAAAGACAAGACGCTCCAGGATCTTGTCT

ACGATCTCTCCACCTCAGGGTCTGGCTCAGGGTTACCCCTCTTTGTCCAG

CGCACAGTGGCCCGAACCATCGTTTTACAAGAGATTATTGGCAAGGGTCG

GTTTGGGGAAGTATGGCGGGGCCGCTGGAGGGGTGGTGATGTGGCTGTGA

AAATATTCTCTTCTCGTGAAGAACGGTCTTGGTTCAGGGAAGCAGAGATA

TACCAGACGGTCATGCTGCGCCATGAAAACATCCTTGGATTTATTGCTGC

TGACAATAAAGCAGACTGCTCATTCCTCACATTGCCATGGGAAGTTGTAA

TGGTCTCTGCTGCCCCCAAGCTGAGGAGCCTTAGACTCCAATACAAGGGA

GGAAGGGGAAGAGCAAGATTTTTATTCCCACTGAATAATGGCACCTGGAC

ACAGCTGTGGCTTGTTTCTGACTATCATGAGCACGGGTCCCTGTTTGATT

ATCTGAACCGGTACACAGTGACAATTGAGGGGATGATTAAGCTGGCCTTG

TCTGCTGCTAGTGGGCTGGCACACCTGCACATGGAGATCGTGGGCACCCA

AGGGAAGCCTGGAATTGCTCATCGAGACTTAAAGTCAAAGAACATTCTGG

TGAAGAAAAATGGCATGTGTGCCATAGCAGACCTGGGCCTGGCTGTCCGT

CATGATGCAGTCACTGACACCATTGACATTGCCCCGAATCAGAGGGTGGG

GACCAAACGATACATGGCCCCTGAAGTACTTGATGAAACCATTAATATGA

AACACTTTGACTCCTTTAAATGTGCTGATATTTATGCCCTCGGGCTTGTA

TATTGGGAGATTGCTCGAAGATGCAATTCTGGAGGAGTCCATGAAGAATA

TCAGCTGCCATATTACGACTTAGTGCCCTCTGACCCTTCCATTGAGGAAA

TGCGAAAGGTTGTATGTGATCAGAAGCTGCGTCCCAACATCCCCAACTGG

TGGCAGAGTTATGAGGCACTGCGGGTGATGGGGAAGATGATGCGAGAGTG

TTGGTATGCCAACGGCGCAGCCCGCCTGACGGCCCTGCGCATCAAGAAGA

›CCCTCTCCCAGCTCAGCGTGCAGGAAGACGTGAAGATC

A nucleic acid sequence encoding the extracellular ALK4 polypeptide (isoform C) is as follows:

(SEQ ID NO: 86)

TCCGGGCCCCGGGGGGTCCAGGCTCTGCTGTGTGCGTGCACCAGCTGCCT

CCAGGCCAACTACACGTGTGAGACAGATGGGGCCTGCATGGTTTCCATTT

TCAATCTGGATGGGATGGAGCACCATGTGCGCACCTGCATCCCCAAAGTG

GAGCTGGTCCCTGCCGGGAAGCCCTTCTACTGCCTGAGCTCGGAGGACCT

GCGCAACACCCACTGCTGCTACACTGACTACTGCAACAGGATCGACTTGA

GGGTGCCCAGTGGTCACCTCAAGGAGCCTGAGCACCCGTCCATGTGGGGC

›CCGGTGGAG

In certain embodiments, the disclosure relates to heteromultimer complexes that comprise at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, ALK4 polypeptides for use in accordance with inventions of the disclosure (e.g., heteromultimer complexes comprising an ALK4 polypeptide and uses thereof) are soluble (e.g., an extracellular domain of ALK4). In other preferred embodiments, ALK4 polypeptides for use in accordance with the inventions of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimer complexes of the disclosure comprise at least one ALK4 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 26, 27, 83, 84, 104, 106, 403, or 404. In some embodiments, heteromultimer complexes of the disclosure consist or consist essentially of at least one ALK4 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 26, 27, 83, 84, 104, 106, 403, or 404.

In certain aspects, the present disclosure relates to protein complexes that comprise an ALK5 polypeptide. As used herein, the term “ALK5” refers to a family of activin receptor-like kinase-5 proteins from any species and variants derived from such ALK4 proteins by mutagenesis or other modification. Reference to ALK5 herein is understood to be a reference to any one of the currently identified forms. Members of the ALK5 family are generally transmembrane proteins, composed of a ligand-binding extracellular domain with a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “ALK5 polypeptide” includes polypeptides comprising any naturally occurring polypeptide of an ALK5 family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Numbering of amino acids for all ALK5-related polypeptides described herein is based on the numbering of the human ALK5 precursor protein sequence below (SEQ ID NO: 30), unless specifically designated otherwise.

The canonical human ALK5 precursor protein sequence (NCBI Ref Seq NP_004603.1) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular ALK5 polypeptide sequence is as follows:

(SEQ ID NO: 31)

AALLPGATALQCFCHLCTKDNFTCVTDGLCFVSVTETTDKVIHNSMCIAE

›IDLIPRDRPFVCAPSSKTGSVTTTYCCNQDHCNKIELPTTVKSSPGLGPV

A nucleic acid sequence encoding the ALK5 precursor protein is shown below (SEQ ID NO: 32), corresponding to nucleotides 77-1585 of Genbank Reference Sequence NM_004612.2. The signal sequence is underlined and the extracellular domain is indicated in bold font.

(SEQ ID NO: 32)

ATGGAGGCGGCGGTCGCTGCTCCGCGTCCCCGGCTGCTCCTCCTCGTGCT

GGCGGCGGCGGCGGCGGCGGCG

GCGGCGCTGCTCCCGGGGGCGACGGCGT

TACAGTGTTTCTGCCACCTCTGTACAAAAGACAATTTTACTTGTGTGACA

GATGGGCTCTGCTTTGTCTCTGTCACAGAGACCACAGACAAAGTTATACA

CAACAGCATGTGTATAGCTGAAATTGACTTAATTCCTCGAGATAGGCCGT

TTGTATGTGCACCCTCTTCAAAAACTGGGTCTGTGACTACAACATATTGC

TGCAATCAGGACCATTGCAATAAAATAGAACTTCCAACTACTGTAAAGTC

ATCACCTGGCCTTGGTCCTGTGGAACTG GCAGCTGTCATTGCTGGACCAG

TGTGCTTCGTCTGCATCTCACTCATGTTGATGGTCTATATCTGCCACAAC

CGCACTGTCATTCACCATCGAGTGCCAAATGAAGAGGACCCTTCATTAGA

TCGCCCTTTTATTTCAGAGGGTACTACGTTGAAAGACTTAATTTATGATA

TGACAACGTCAGGTTCTGGCTCAGGTTTACCATTGCTTGTTCAGAGAACA

ATTGCGAGAACTATTGTGTTACAAGAAAGCATTGGCAAAGGTCGATTTGG

AGAAGTTTGGAGAGGAAAGTGGCGGGGAGAAGAAGTTGCTGTTAAGATAT

TCTCCTCTAGAGAAGAACGTTCGTGGTTCCGTGAGGCAGAGATTTATCAA

ACTGTAATGTTACGTCATGAAAACATCCTGGGATTTATAGCAGCAGACAA

TAAAGACAATGGTACTTGGACTCAGCTCTGGTTGGTGTCAGATTATCATG

AGCATGGATCCCTTTTTGATTACTTAAACAGATACACAGTTACTGTGGAA

GGAATGATAAAACTTGCTCTGTCCACGGCGAGCGGTCTTGCCCATCTTCA

CATGGAGATTGTTGGTACCCAAGGAAAGCCAGCCATTGCTCATAGAGATT

TGAAATCAAAGAATATCTTGGTAAAGAAGAATGGAACTTGCTGTATTGCA

GACTTAGGACTGGCAGTAAGACATGATTCAGCCACAGATACCATTGATAT

TGCTCCAAACCACAGAGTGGGAACAAAAAGGTACATGGCCCCTGAAGTTC

TCGATGATTCCATAAATATGAAACATTTTGAATCCTTCAAACGTGCTGAC

ATCTATGCAATGGGCTTAGTATTCTGGGAAATTGCTCGACGATGTTCCAT

TGGTGGAATTCATGAAGATTACCAACTGCCTTATTATGATCTTGTACCTT

CTGACCCATCAGTTGAAGAAATGAGAAAAGTTGTTTGTGAACAGAAGTTA

AGGCCAAATATCCCAAACAGATGGCAGAGCTGTGAAGCCTTGAGAGTAAT

GGCTAAAATTATGAGAGAATGTTGGTATGCCAATGGAGCAGCTAGGCTTA

CAGCATTGCGGATTAAGAAAACATTATCGCAACTCAGTCAACAGGAAGGC

›ATCAAAATG

A nucleic acid sequence encoding the extracellular human ALK5 polypeptide is as follows:

(SEQ ID NO: 33)

GCGGCGCTGCTCCCGGGGGCGACGGCGTTACAGTGTTTCTGCCACCTCTG

TACAAAAGACAATTTTACTTGTGTGACAGATGGGCTCTGCTTTGTCTCTG

TCACAGAGACCACAGACAAAGTTATACACAACAGCATGTGTATAGCTGAA

ATTGACTTAATTCCTCGAGATAGGCCGTTTGTATGTGCACCCTCTTCAAA

AACTGGGTCTGTGACTACAACATATTGCTGCAATCAGGACCATTGCAATA

AAATAGAACTTCCAACTACTGTAAAGTCATCACCTGGCCTTGGTCCTGTG

›GAACTG

An alternative isoform of the human ALK5 precursor protein sequence, isoform 2 (NCBI Ref Seq XP_005252207.1), is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular ALK5 polypeptide sequence (isoform 2) is as follows:

(SEQ ID NO: 88)

AALLPGATALQCFCHLCTKDNFTCVTDGLCFVSVTETTDKVIHNSMCIAE

IDLIPRDRPFVCAPSSKTGSVTTTYCCNQDHCNKIELPTTGPFSVKSSPG

›LGPVEL

A nucleic acid sequence encoding human ALK5 precursor protein (isoform 2) is shown below (SEQ ID NO: 89), corresponding to nucleotides 77-1597 of Genbank Reference Sequence XM_005252150.1. The signal sequence is underlined and the extracellular domain is indicated in bold font.

(SEQ ID NO: 89)

ATGGAGGCGGCGGTCGCTGCTCCGCGTCCCCGGCTGCTCCTCCTCGTGCT

GGCGGCGGCGGCGGCGGCGGCG

GCGGCGCTGCTCCCGGGGGCGACGGCGT

TACAGTGTTTCTGCCACCTCTGTACAAAAGACAATTTTACTTGTGTGACA

GATGGGCTCTGCTTTGTCTCTGTCACAGAGACCACAGACAAAGTTATACA

CAACAGCATGTGTATAGCTGAAATTGACTTAATTCCTCGAGATAGGCCGT

TTGTATGTGCACCCTCTTCAAAAACTGGGTCTGTGACTACAACATATTGC

TGCAATCAGGACCATTGCAATAAAATAGAACTTCCAACTACTGGCCCTTT

TTCAGTAAAGTCATCACCTGGCCTTGGTCCTGTGGAACTG GCAGCTGTCA

TTGCTGGACCAGTGTGCTTCGTCTGCATCTCACTCATGTTGATGGTCTAT

ATCTGCCACAACCGCACTGTCATTCACCATCGAGTGCCAAATGAAGAGGA

CCCTTCATTAGATCGCCCTTTTATTTCAGAGGGTACTACGTTGAAAGACT

TAATTTATGATATGACAACGTCAGGTTCTGGCTCAGGTTTACCATTGCTT

GTTCAGAGAACAATTGCGAGAACTATTGTGTTACAAGAAAGCATTGGCAA

AGGTCGATTTGGAGAAGTTTGGAGAGGAAAGTGGCGGGGAGAAGAAGTTG

CTGTTAAGATATTCTCCTCTAGAGAAGAACGTTCGTGGTTCCGTGAGGCA

GAGATTTATCAAACTGTAATGTTACGTCATGAAAACATCCTGGGATTTAT

AGCAGCAGACAATAAAGACAATGGTACTTGGACTCAGCTCTGGTTGGTGT

CAGATTATCATGAGCATGGATCCCTTTTTGATTACTTAAACAGATACACA

GTTACTGTGGAAGGAATGATAAAACTTGCTCTGTCCACGGCGAGCGGTCT

TGCCCATCTTCACATGGAGATTGTTGGTACCCAAGGAAAGCCAGCCATTG

CTCATAGAGATTTGAAATCAAAGAATATCTTGGTAAAGAAGAATGGAACT

TGCTGTATTGCAGACTTAGGACTGGCAGTAAGACATGATTCAGCCACAGA

TACCATTGATATTGCTCCAAACCACAGAGTGGGAACAAAAAGGTACATGG

CCCCTGAAGTTCTCGATGATTCCATAAATATGAAACATTTTGAATCCTTC

AAACGTGCTGACATCTATGCAATGGGCTTAGTATTCTGGGAAATTGCTCG

ACGATGTTCCATTGGTGGAATTCATGAAGATTACCAACTGCCTTATTATG

ATCTTGTACCTTCTGACCCATCAGTTGAAGAAATGAGAAAAGTTGTTTGT

GAACAGAAGTTAAGGCCAAATATCCCAAACAGATGGCAGAGCTGTGAAGC

CTTGAGAGTAATGGCTAAAATTATGAGAGAATGTTGGTATGCCAATGGAG

CAGCTAGGCTTACAGCATTGCGGATTAAGAAAACATTATCGCAACTCAGT

›CAACAGGAAGGCATCAAAATG

A nucleic acid sequence encoding the processed extracellular ALK5 polypeptide is as follows:

(SEQ ID NO: 90)

GCGGCGCTGCTCCCGGGGGCGACGGCGTTACAGTGTTTCTGCCACCTCTG

TACAAAAGACAATTTTACTTGTGTGACAGATGGGCTCTGCTTTGTCTCTG

TCACAGAGACCACAGACAAAGTTATACACAACAGCATGTGTATAGCTGAA

ATTGACTTAATTCCTCGAGATAGGCCGTTTGTATGTGCACCCTCTTCAAA

AACTGGGTCTGTGACTACAACATATTGCTGCAATCAGGACCATTGCAATA

AAATAGAACTTCCAACTACTGGCCCTTTTTCAGTAAAGTCATCACCTGGC

›CTTGGTCCTGTGGAACTG

In certain embodiments, the disclosure relates to heteromultimer complexes that comprise at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, ALK5 polypeptides for use in accordance with inventions of the disclosure (e.g., heteromultimer complexes comprising an ALK5 polypeptide and uses thereof) are soluble (e.g., an extracellular domain of ALK5). In other preferred embodiments, ALK5 polypeptides for use in accordance with the inventions of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimer complexes of the disclosure comprise at least one ALK5 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 30, 31, 87, or 88. In some embodiments, heteromultimer complexes of the disclosure consist or consist essentially of at least one ALK5 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 30, 31, 87, or 88.

In certain aspects, the present disclosure relates to protein complexes that comprise an ALK6 polypeptide. As used herein, the term “ALK6” refers to a family of activin receptor-like kinase-6 proteins from any species and variants derived from such ALK6 proteins by mutagenesis or other modification. Reference to ALK6 herein is understood to be a reference to any one of the currently identified forms. Members of the ALK6 family are generally transmembrane proteins, composed of a ligand-binding extracellular domain with a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “ALK6 polypeptide” includes polypeptides comprising any naturally occurring polypeptide of an ALK6 family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Numbering of amino acids for all ALK6-related polypeptides described herein is based on the numbering of the human ALK6 precursor protein sequence below (SEQ ID NO: 34), unless specifically designated otherwise.

The canonical human ALK6 precursor protein sequence (NCBI Ref Seq NP_001194.1) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular ALK6 polypeptide sequence is as follows:

(SEQ ID NO: 35)

KKEDGESTAPTPRPKVLRCKCHHHCPEDSVNNICSTDGYCFTMIEEDDSG

LPVVTSGCLGLEGSDFQCRDTPIPHQRRSIECCTERNECNKDLHPTLPPL

›KNRDFVDGPIHHR

A nucleic acid sequence encoding the ALK6 precursor protein is shown below (SEQ ID NO: 36), corresponding to nucleotides 275-1780 of Genbank Reference Sequence NM_001203.2. The signal sequence is underlined and the extracellular domain is indicated in bold font.

(SEQ ID NO: 36)

ATGCTTTTGCGAAGTGCAGGAAAATTAAATGTGGGCACC

AAGAAAGAGGA

TGGTGAGAGTACAGCCCCCACCCCCCGTCCAAAGGTCTTGCGTTGTAAAT

GCCACCACCATTGTCCAGAAGACTCAGTCAACAATATTTGCAGCACAGAC

GGATATTGTTTCACGATGATAGAAGAGGATGACTCTGGGTTGCCTGTGGT

CACTTCTGGTTGCCTAGGACTAGAAGGCTCAGATTTTCAGTGTCGGGACA

CTCCCATTCCTCATCAAAGAAGATCAATTGAATGCTGCACAGAAAGGAAC

GAATGTAATAAAGACCTACACCCTACACTGCCTCCATTGAAAAACAGAGA

TTTTGTTGATGGACCTATACACCACAGG GCTTTACTTATATCTGTGACTG

TCTGTAGTTTGCTCTTGGTCCTTATCATATTATTTTGTTACTTCCGGTAT

AAAAGACAAGAAACCAGACCTCGATACAGCATTGGGTTAGAACAGGATGA

AACTTACATTCCTCCTGGAGAATCCCTGAGAGACTTAATTGAGCAGTCTC

AGAGCTCAGGAAGTGGATCAGGCCTCCCTCTGCTGGTCCAAAGGACTATA

GCTAAGCAGATTCAGATGGTGAAACAGATTGGAAAAGGTCGCTATGGGGA

AGTTTGGATGGGAAAGTGGCGTGGCGAAAAGGTAGCTGTGAAAGTGTTCT

TCACCACAGAGGAAGCCAGCTGGTTCAGAGAGACAGAAATATATCAGACA

GTGTTGATGAGGCATGAAAACATTTTGGGTTTCATTGCTGCAGATATCAA

AGGGACAGGGTCCTGGACCCAGTTGTACCTAATCACAGACTATCATGAAA

ATGGTTCCCTTTATGATTATCTGAAGTCCACCACCCTAGACGCTAAATCA

ATGCTGAAGTTAGCCTACTCTTCTGTCAGTGGCTTATGTCATTTACACAC

AGAAATCTTTAGTACTCAAGGCAAACCAGCAATTGCCCATCGAGATCTGA

AAAGTAAAAACATTCTGGTGAAGAAAAATGGAACTTGCTGTATTGCTGAC

CTGGGCCTGGCTGTTAAATTTATTAGTGATACAAATGAAGTTGACATACC

ACCTAACACTCGAGTTGGCACCAAACGCTATATGCCTCCAGAAGTGTTGG

ACGAGAGCTTGAACAGAAATCACTTCCAGTCTTACATCATGGCTGACATG

TATAGTTTTGGCCTCATCCTTTGGGAGGTTGCTAGGAGATGTGTATCAGG

AGGTATAGTGGAAGAATACCAGCTTCCTTATCATGACCTAGTGCCCAGTG

ACCCCTCTTATGAGGACATGAGGGAGATTGTGTGCATCAAGAAGTTACGC

CCCTCATTCCCAAACCGGTGGAGCAGTGATGAGTGTCTAAGGCAGATGGG

AAAACTCATGACAGAATGCTGGGCTCACAATCCTGCATCAAGGCTGACAG

CCCTGCGGGTTAAGAAAACACTTGCCAAAATGTCAGAGTCCCAGGACATT

›AAACTC

A nucleic acid sequence encoding processed extracellular ALK6 polypeptide is as follows:

(SEQ ID NO: 37)

AAGAAAGAGGATGGTGAGAGTACAGCCCCCACCCCCCGTCCAAAGGTCTT

GCGTTGTAAATGCCACCACCATTGTCCAGAAGACTCAGTCAACAATATTT

GCAGCACAGACGGATATTGTTTCACGATGATAGAAGAGGATGACTCTGGG

TTGCCTGTGGTCACTTCTGGTTGCCTAGGACTAGAAGGCTCAGATTTTCA

GTGTCGGGACACTCCCATTCCTCATCAAAGAAGATCAATTGAATGCTGCA

CAGAAAGGAACGAATGTAATAAAGACCTACACCCTACACTGCCTCCATTG

›AAAAACAGAGATTTTGTTGATGGACCTATACACCACAGG

An alternative isoform of human ALK6 precursor protein sequence, isoform 2 (NCBI Ref Seq NP_001243722.1) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular ALK6 polypeptide sequence (isoform 2) is as follows:

(SEQ ID NO: 92)

NFLDNMLLRSAGKLNVGTKKEDGESTAPTPRPKVLRCKCHHHCPEDSVNN

ICSTDGYCFTMIEEDDSGLPVVTSGCLGLEGSDFQCRDTPIPHQRRSIEC

›CTERNECNKDLHPTLPPLKNRDFVDGPIHHR

A nucleic acid sequence encoding human ALK6 precursor protein (isoform 2) is shown below, corresponding to nucleotides 22-1617 of Genbank Reference Sequence NM_001256793.1. The signal sequence is underlined and the extracellular domain is indicated in bold font.

(SEQ ID NO: 93)

ATGGGTTGGCTGGAAGAACTAAACTGGCAGCTTCACATTTTCTTGCTCAT

TCTTCTCTCTATGCACACAAGGGCA

AACTTCCTTGATAACATGCTTTTGC

GAAGTGCAGGAAAATTAAATGTGGGCACCAAGAAAGAGGATGGTGAGAGT

ACAGCCCCCACCCCCCGTCCAAAGGTCTTGCGTTGTAAATGCCACCACCA

TTGTCCAGAAGACTCAGTCAACAATATTTGCAGCACAGACGGATATTGTT

TCACGATGATAGAAGAGGATGACTCTGGGTTGCCTGTGGTCACTTCTGGT

TGCCTAGGACTAGAAGGCTCAGATTTTCAGTGTCGGGACACTCCCATTCC

TCATCAAAGAAGATCAATTGAATGCTGCACAGAAAGGAACGAATGTAATA

AAGACCTACACCCTACACTGCCTCCATTGAAAAACAGAGATTTTGTTGAT

GGACCTATACACCACAGG GCTTTACTTATATCTGTGACTGTCTGTAGTTT

GCTCTTGGTCCTTATCATATTATTTTGTTACTTCCGGTATAAAAGACAAG

AAACCAGACCTCGATACAGCATTGGGTTAGAACAGGATGAAACTTACATT

CCTCCTGGAGAATCCCTGAGAGACTTAATTGAGCAGTCTCAGAGCTCAGG

AAGTGGATCAGGCCTCCCTCTGCTGGTCCAAAGGACTATAGCTAAGCAGA

TTCAGATGGTGAAACAGATTGGAAAAGGTCGCTATGGGGAAGTTTGGATG

GGAAAGTGGCGTGGCGAAAAGGTAGCTGTGAAAGTGTTCTTCACCACAGA

GGAAGCCAGCTGGTTCAGAGAGACAGAAATATATCAGACAGTGTTGATGA

GGCATGAAAACATTTTGGGTTTCATTGCTGCAGATATCAAAGGGACAGGG

TCCTGGACCCAGTTGTACCTAATCACAGACTATCATGAAAATGGTTCCCT

TTATGATTATCTGAAGTCCACCACCCTAGACGCTAAATCAATGCTGAAGT

TAGCCTACTCTTCTGTCAGTGGCTTATGTCATTTACACACAGAAATCTTT

AGTACTCAAGGCAAACCAGCAATTGCCCATCGAGATCTGAAAAGTAAAAA

CATTCTGGTGAAGAAAAATGGAACTTGCTGTATTGCTGACCTGGGCCTGG

CTGTTAAATTTATTAGTGATACAAATGAAGTTGACATACCACCTAACACT

CGAGTTGGCACCAAACGCTATATGCCTCCAGAAGTGTTGGACGAGAGCTT

GAACAGAAATCACTTCCAGTCTTACATCATGGCTGACATGTATAGTTTTG

GCCTCATCCTTTGGGAGGTTGCTAGGAGATGTGTATCAGGAGGTATAGTG

GAAGAATACCAGCTTCCTTATCATGACCTAGTGCCCAGTGACCCCTCTTA

TGAGGACATGAGGGAGATTGTGTGCATCAAGAAGTTACGCCCCTCATTCC

CAAACCGGTGGAGCAGTGATGAGTGTCTAAGGCAGATGGGAAAACTCATG

ACAGAATGCTGGGCTCACAATCCTGCATCAAGGCTGACAGCCCTGCGGGT

›TAAGAAAACACTTGCCAAAATGTCAGAGTCCCAGGACATTAAACTC

A nucleic acid sequence encoding the processed extracellular ALK6 polypeptide is as follows:

(SEQ ID NO: 94)

AACTTCCTTGATAACATGCTTTTGCGAAGTGCAGGAAAATTAAATGTGGG

CACCAAGAAAGAGGATGGTGAGAGTACAGCCCCCACCCCCCGTCCAAAGG

TCTTGCGTTGTAAATGCCACCACCATTGTCCAGAAGACTCAGTCAACAAT

ATTTGCAGCACAGACGGATATTGTTTCACGATGATAGAAGAGGATGACTC

TGGGTTGCCTGTGGTCACTTCTGGTTGCCTAGGACTAGAAGGCTCAGATT

TTCAGTGTCGGGACACTCCCATTCCTCATCAAAGAAGATCAATTGAATGC

TGCACAGAAAGGAACGAATGTAATAAAGACCTACACCCTACACTGCCTCC

›ATTGAAAAACAGAGATTTTGTTGATGGACCTATACACCACAGG

In certain embodiments, the disclosure relates to heteromultimer complexes that comprise at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, ALK6 polypeptides for use in accordance with inventions of the disclosure (e.g., heteromultimer complexes comprising an ALK6 polypeptide and uses thereof) are soluble (e.g., an extracellular domain of ALK6). In other preferred embodiments, ALK6 polypeptides for use in accordance with the inventions of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimer complexes of the disclosure comprise at least one ALK6 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 34, 35, 91, or 92. In some embodiments, heteromultimer complexes of the disclosure consist or consist essentially of at least one ALK6 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 34, 35, 91, or 92.

In certain aspects, the present disclosure relates to protein complexes that comprise an ALK7 polypeptide. As used herein, the term “ALK7” refers to a family of activin receptor-like kinase-7 proteins from any species and variants derived from such ALK7 proteins by mutagenesis or other modification. Reference to ALK7 herein is understood to be a reference to any one of the currently identified forms. Members of the ALK7 family are generally transmembrane proteins, composed of a ligand-binding extracellular domain with a cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine kinase activity.

The term “ALK7 polypeptide” includes polypeptides comprising any naturally occurring polypeptide of an ALK7 family member as well as any variants thereof (including mutants, fragments, fusions, and peptidomimetic forms) that retain a useful activity. Numbering of amino acids for all ALK7-related polypeptides described herein is based on the numbering of the human ALK7 precursor protein sequence below (SEQ ID NO: 38), unless specifically designated otherwise.

Four naturally occurring isoforms of human ALK7 have been described. The sequence of canonical human ALK7 isoform 1 precursor protein (NCBI Ref Seq NP_660302.2) is as follows:

The signal peptide is indicated by a single underline and the extracellular domain is indicated in bold font.

The processed extracellular ALK7 isoform 1 polypeptide sequence is as follows:

(SEQ ID NO: 39)

ELSPGLKCVCLLCDSSNFTCQTEGACWASVMLTNGKEQVIKSCVSLPELN

›AQVFCHSSNNVTKTECCFTDFCNNITLHLPTASPNAPKLGPME

A nucleic acid sequence encoding human ALK7 isoform 1 precursor protein is shown below (SEQ ID NO: 40), corresponding to nucleotides 244-1722 of Genbank Reference Sequence NM_145259.2. The signal sequence is underlined and the extracellular domain is indicated in bold font.

(SEQ ID NO: 40)

ATGACCCGGGCGCTCTGCTCAGCGCTCCGCCAGGCTCTCCTGCTGCTCGC

AGCGGCCGCC

GAGCTCTCGCCAGGACTGAAGTGTGTATGTCTTTTGTGTG

ATTCTTCAAACTTTACCTGCCAAACAGAAGGAGCATGTTGGGCATCAGTC

ATGCTAACCAATGGAAAAGAGCAGGTGATCAAATCCTGTGTCTCCCTTCC

AGAACTGAATGCTCAAGTCTTCTGTCATAGTTCCAACAATGTTACCAAAA

CCGAATGCTGCTTCACAGATTTTTGCAACAACATAACACTGCACCTTCCA

ACAGCATCACCAAATGCCCCAAAACTTGGACCCATGGAG CTGGCCATCAT

TATTACTGTGCCTGTTTGCCTCCTGTCCATAGCTGCGATGCTGACAGTAT

GGGCATGCCAGGGTCGACAGTGCTCCTACAGGAAGAAAAAGAGACCAAAT

GTGGAGGAACCACTCTCTGAGTGCAATCTGGTAAATGCTGGAAAAACTCT

GAAAGATCTGATTTATGATGTGACCGCCTCTGGATCTGGCTCTGGTCTAC

CTCTGTTGGTTCAAAGGACAATTGCAAGGACGATTGTGCTTCAGGAAATA

GTAGGAAAAGGTAGATTTGGTGAGGTGTGGCATGGAAGATGGTGTGGGGA

AGATGTGGCTGTGAAAATATTCTCCTCCAGAGATGAAAGATCTTGGTTTC

GTGAGGCAGAAATTTACCAGACGGTCATGCTGCGACATGAAAACATCCTT

GGTTTCATTGCTGCTGACAACAAAGATAATGGAACTTGGACTCAACTTTG

GCTGGTATCTGAATATCATGAACAGGGCTCCTTATATGACTATTTGAATA

GAAATATAGTGACCGTGGCTGGAATGATCAAGCTGGCGCTCTCAATTGCT

AGTGGTCTGGCACACCTTCATATGGAGATTGTTGGTACACAAGGTAAACC

TGCTATTGCTCATCGAGACATAAAATCAAAGAATATCTTAGTGAAAAAGT

GTGAAACTTGTGCCATAGCGGACTTAGGGTTGGCTGTGAAGCATGATTCA

ATACTGAACACTATCGACATACCTCAGAATCCTAAAGTGGGAACCAAGAG

GTATATGGCTCCTGAAATGCTTGATGATACAATGAATGTGAATATCTTTG

AGTCCTTCAAACGAGCTGACATCTATTCTGTTGGTCTGGTTTACTGGGAA

ATAGCCCGGAGGTGTTCAGTCGGAGGAATTGTTGAGGAGTACCAATTGCC

TTATTATGACATGGTGCCTTCAGATCCCTCGATAGAGGAAATGAGAAAGG

TTGTTTGTGACCAGAAGTTTCGACCAAGTATCCCAAACCAGTGGCAAAGT

TGTGAAGCACTCCGAGTCATGGGGAGAATAATGCGTGAGTGTTGGTATGC

CAACGGAGCGGCCCGCCTAACTGCTCTTCGTATTAAGAAGACTATATCTC

›AACTTTGTGTCAAAGAAGACTGCAAAGCC

A nucleic acid sequence encoding the processed extracellular ALK7 polypeptide (isoform 1) is as follows:

(SEQ ID NO: 41)

GAGCTCTCGCCAGGACTGAAGTGTGTATGTCTTTTGTGTGATTCTTCAAA

CTTTACCTGCCAAACAGAAGGAGCATGTTGGGCATCAGTCATGCTAACCA

ATGGAAAAGAGCAGGTGATCAAATCCTGTGTCTCCCTTCCAGAACTGAAT

GCTCAAGTCTTCTGTCATAGTTCCAACAATGTTACCAAAACCGAATGCTG

CTTCACAGATTTTTGCAACAACATAACACTGCACCTTCCAACAGCATCAC

›CAAATGCCCCAAAACTTGGACCCATGGAG

The amino acid sequence of an alternative isoform of human ALK7, isoform 2 (NCBI Ref Seq NP_001104501.1), is shown in its processed form as follows (SEQ ID NO: 301), where the extracellular domain is indicated in bold font.

The amino acid sequence of the extracellular ALK7 polypeptide (isoform 2) is as follows: MLTNGKEQVIKSCVSLPELNAQVFCHSSNNVTKTECCFTDFCNNITLHLPTASPNAPKLGPME (SEQ ID NO: 302).

A nucleic acid sequence encoding the processed ALK7 polypeptide (isoform 2) is shown below (SEQ ID NO: 303), corresponding to nucleotides 279-1607 of NCBI Reference Sequence NM 001111031.1. The extracellular domain is indicated in bold font.

(SEQ ID NO: 303)

ATGCTAACCAATGGAAAAGAGCAGGTGATCAAATCCTGTGTCTCCCTTCC

AGAACTGAATGCTCAAGTCTTCTGTCATAGTTCCAACAATGTTACCAAAA

CCGAATGCTGCTTCACAGATTTTTGCAACAACATAACACTGCACCTTCCA

ACAGCATCACCAAATGCCCCAAAACTTGGACCCATGGAG CTGGCCATCAT

TATTACTGTGCCTGTTTGCCTCCTGTCCATAGCTGCGATGCTGACAGTAT

GGGCATGCCAGGGTCGACAGTGCTCCTACAGGAAGAAAAAGAGACCAAAT

GTGGAGGAACCACTCTCTGAGTGCAATCTGGTAAATGCTGGAAAAACTCT

GAAAGATCTGATTTATGATGTGACCGCCTCTGGATCTGGCTCTGGTCTAC

CTCTGTTGGTTCAAAGGACAATTGCAAGGACGATTGTGCTTCAGGAAATA

GTAGGAAAAGGTAGATTTGGTGAGGTGTGGCATGGAAGATGGTGTGGGGA

AGATGTGGCTGTGAAAATATTCTCCTCCAGAGATGAAAGATCTTGGTTTC

GTGAGGCAGAAATTTACCAGACGGTCATGCTGCGACATGAAAACATCCTT

GGTTTCATTGCTGCTGACAACAAAGATAATGGAACTTGGACTCAACTTTG

GCTGGTATCTGAATATCATGAACAGGGCTCCTTATATGACTATTTGAATA

GAAATATAGTGACCGTGGCTGGAATGATCAAGCTGGCGCTCTCAATTGCT

AGTGGTCTGGCACACCTTCATATGGAGATTGTTGGTACACAAGGTAAACC

TGCTATTGCTCATCGAGACATAAAATCAAAGAATATCTTAGTGAAAAAGT

GTGAAACTTGTGCCATAGCGGACTTAGGGTTGGCTGTGAAGCATGATTCA

ATACTGAACACTATCGACATACCTCAGAATCCTAAAGTGGGAACCAAGAG

GTATATGGCTCCTGAAATGCTTGATGATACAATGAATGTGAATATCTTTG

AGTCCTTCAAACGAGCTGACATCTATTCTGTTGGTCTGGTTTACTGGGAA

ATAGCCCGGAGGTGTTCAGTCGGAGGAATTGTTGAGGAGTACCAATTGCC

TTATTATGACATGGTGCCTTCAGATCCCTCGATAGAGGAAATGAGAAAGG

TTGTTTGTGACCAGAAGTTTCGACCAAGTATCCCAAACCAGTGGCAAAGT

TGTGAAGCACTCCGAGTCATGGGGAGAATAATGCGTGAGTGTTGGTATGC

CAACGGAGCGGCCCGCCTAACTGCTCTTCGTATTAAGAAGACTATATCTC

›AACTTTGTGTCAAAGAAGACTGCAAAGCC

A nucleic acid sequence encoding the extracellular ALK7 polypeptide (isoform 2) is as follows (SEQ ID NO: 304):

(SEQ ID NO: 304)

ATGCTAACCAATGGAAAAGAGCAGGTGATCAAATCCTGTGTCTCCCTTCC

AGAACTGAATGCTCAAGTCTTCTGTCATAGTTCCAACAATGTTACCAAAA

CCGAATGCTGCTTCACAGATTTTTGCAACAACATAACACTGCACCTTCCA

›ACAGCATCACCAAATGCCCCAAAACTTGGACCCATGGAG

The amino acid sequence of an alternative human ALK7 precursor protein, isoform 3 (NCBI Ref Seq NP_001104502.1), is shown as follows (SEQ ID NO: 305), where the signal pep tide is indicated by a single underline.

The amino acid sequence of the processed ALK7 polypeptide (isoform 3) is as follows (SEQ ID NO: 306). This isoform lacks a transmembrane domain and is therefore proposed to be soluble in its entirety (Roberts et al., 2003, Biol Reprod 68:1719-1726). N-terminal variants of SEQ ID NO: 306 are predicted as described below.

A nucleic acid sequence encoding the unprocessed ALK7 polypeptide precursor protein (isoform 3) is shown below (SEQ ID NO: 307), corresponding to nucleotides 244-1482 of NCBI Reference Sequence NM_001111032.1. The signal sequence is indicated by solid underline.

(SEQ ID NO: 307)

ATGACCCGGGCGCTCTGCTCAGCGCTCCGCCAGGCTCTCCTGCTGCTCGC

AGCGGCCGCC GAGCTCTCGCCAGGACTGAAGTGTGTATGTCTTTTGTGTG

ATTCTTCAAACTTTACCTGCCAAACAGAAGGAGCATGTTGGGCATCAGTC

ATGCTAACCAATGGAAAAGAGCAGGTGATCAAATCCTGTGTCTCCCTTCC

AGAACTGAATGCTCAAGTCTTCTGTCATAGTTCCAACAATGTTACCAAAA

CCGAATGCTGCTTCACAGATTTTTGCAACAACATAACACTGCACCTTCCA

ACAGGTCTACCTCTGTTGGTTCAAAGGACAATTGCAAGGACGATTGTGCT

TCAGGAAATAGTAGGAAAAGGTAGATTTGGTGAGGTGTGGCATGGAAGAT

GGTGTGGGGAAGATGTGGCTGTGAAAATATTCTCCTCCAGAGATGAAAGA

TCTTGGTTTCGTGAGGCAGAAATTTACCAGACGGTCATGCTGCGACATGA

AAACATCCTTGGTTTCATTGCTGCTGACAACAAAGATAATGGAACTTGGA

CTCAACTTTGGCTGGTATCTGAATATCATGAACAGGGCTCCTTATATGAC

TATTTGAATAGAAATATAGTGACCGTGGCTGGAATGATCAAGCTGGCGCT

CTCAATTGCTAGTGGTCTGGCACACCTTCATATGGAGATTGTTGGTACAC

AAGGTAAACCTGCTATTGCTCATCGAGACATAAAATCAAAGAATATCTTA

GTGAAAAAGTGTGAAACTTGTGCCATAGCGGACTTAGGGTTGGCTGTGAA

GCATGATTCAATACTGAACACTATCGACATACCTCAGAATCCTAAAGTGG

GAACCAAGAGGTATATGGCTCCTGAAATGCTTGATGATACAATGAATGTG

AATATCTTTGAGTCCTTCAAACGAGCTGACATCTATTCTGTTGGTCTGGT

TTACTGGGAAATAGCCCGGAGGTGTTCAGTCGGAGGAATTGTTGAGGAGT

ACCAATTGCCTTATTATGACATGGTGCCTTCAGATCCCTCGATAGAGGAA

ATGAGAAAGGTTGTTTGTGACCAGAAGTTTCGACCAAGTATCCCAAACCA

GTGGCAAAGTTGTGAAGCACTCCGAGTCATGGGGAGAATAATGCGTGAGT

GTTGGTATGCCAACGGAGCGGCCCGCCTAACTGCTCTTCGTATTAAGAAG

›ACTATATCTCAACTTTGTGTCAAAGAAGACTGCAAAGCC

A nucleic acid sequence encoding the processed ALK7 polypeptide (isoform 3) is as follows (SEQ ID NO: 308):

(SEQ ID NO: 308)

GAGCTCTCGCCAGGACTGAAGTGTGTATGTCTTTTGTGTGATTCTTCAAA

CTTTACCTGCCAAACAGAAGGAGCATGTTGGGCATCAGTCATGCTAACCA

ATGGAAAAGAGCAGGTGATCAAATCCTGTGTCTCCCTTCCAGAACTGAAT

GCTCAAGTCTTCTGTCATAGTTCCAACAATGTTACCAAAACCGAATGCTG

CTTCACAGATTTTTGCAACAACATAACACTGCACCTTCCAACAGGTCTAC

CTCTGTTGGTTCAAAGGACAATTGCAAGGACGATTGTGCTTCAGGAAATA

GTAGGAAAAGGTAGATTTGGTGAGGTGTGGCATGGAAGATGGTGTGGGGA

AGATGTGGCTGTGAAAATATTCTCCTCCAGAGATGAAAGATCTTGGTTTC

GTGAGGCAGAAATTTACCAGACGGTCATGCTGCGACATGAAAACATCCTT

GGTTTCATTGCTGCTGACAACAAAGATAATGGAACTTGGACTCAACTTTG

GCTGGTATCTGAATATCATGAACAGGGCTCCTTATATGACTATTTGAATA

GAAATATAGTGACCGTGGCTGGAATGATCAAGCTGGCGCTCTCAATTGCT

AGTGGTCTGGCACACCTTCATATGGAGATTGTTGGTACACAAGGTAAACC

TGCTATTGCTCATCGAGACATAAAATCAAAGAATATCTTAGTGAAAAAGT

GTGAAACTTGTGCCATAGCGGACTTAGGGTTGGCTGTGAAGCATGATTCA

ATACTGAACACTATCGACATACCTCAGAATCCTAAAGTGGGAACCAAGAG

GTATATGGCTCCTGAAATGCTTGATGATACAATGAATGTGAATATCTTTG

AGTCCTTCAAACGAGCTGACATCTATTCTGTTGGTCTGGTTTACTGGGAA

ATAGCCCGGAGGTGTTCAGTCGGAGGAATTGTTGAGGAGTACCAATTGCC

TTATTATGACATGGTGCCTTCAGATCCCTCGATAGAGGAAATGAGAAAGG

TTGTTTGTGACCAGAAGTTTCGACCAAGTATCCCAAACCAGTGGCAAAGT

TGTGAAGCACTCCGAGTCATGGGGAGAATAATGCGTGAGTGTTGGTATGC

CAACGGAGCGGCCCGCCTAACTGCTCTTCGTATTAAGAAGACTATATCTC

›AACTTTGTGTCAAAGAAGACTGCAAAGCC

The amino acid sequence of an alternative human ALK7 precursor protein, isoform 4 (NCBI Ref Seq NP_001104503.1), is shown as follows (SEQ ID NO: 309), where the signal pep tide is indicated by a single underline.

The amino acid sequence of the processed ALK7 polypeptide (isoform 4) is as follows (SEQ ID NO: 310). Like ALK7 isoform 3, isoform 4 lacks a transmembrane domain and is therefore proposed to be soluble in its entirety (Roberts et al., 2003, Biol Reprod 68:1719-1726). N-terminal variants of SEQ ID NO: 310 are predicted as described below.

A nucleic acid sequence encoding the unprocessed ALK7 polypeptide precursor protein (isoform 4) is shown below (SEQ ID NO: 311), corresponding to nucleotides 244-1244 of NCBI Reference Sequence NM_001111033.1. The signal sequence is indicated by solid underline.

(SEQ ID NO: 311)

ATGACCCGGGCGCTCTGCTCAGCGCTCCGCCAGGCTCTCCTGCTGCTCGC

AGCGGCCGCC GAGCTCTCGCCAGGACTGAAGTGTGTATGTCTTTTGTGTG

ATTCTTCAAACTTTACCTGCCAAACAGAAGGAGCATGTTGGGCATCAGTC

ATGCTAACCAATGGAAAAGAGCAGGTGATCAAATCCTGTGTCTCCCTTCC

AGAACTGAATGCTCAAGTCTTCTGTCATAGTTCCAACAATGTTACCAAAA

CCGAATGCTGCTTCACAGATTTTTGCAACAACATAACACTGCACCTTCCA

ACAGATAATGGAACTTGGACTCAACTTTGGCTGGTATCTGAATATCATGA

ACAGGGCTCCTTATATGACTATTTGAATAGAAATATAGTGACCGTGGCTG

GAATGATCAAGCTGGCGCTCTCAATTGCTAGTGGTCTGGCACACCTTCAT

ATGGAGATTGTTGGTACACAAGGTAAACCTGCTATTGCTCATCGAGACAT

AAAATCAAAGAATATCTTAGTGAAAAAGTGTGAAACTTGTGCCATAGCGG

ACTTAGGGTTGGCTGTGAAGCATGATTCAATACTGAACACTATCGACATA

CCTCAGAATCCTAAAGTGGGAACCAAGAGGTATATGGCTCCTGAAATGCT

TGATGATACAATGAATGTGAATATCTTTGAGTCCTTCAAACGAGCTGACA

TCTATTCTGTTGGTCTGGTTTACTGGGAAATAGCCCGGAGGTGTTCAGTC

GGAGGAATTGTTGAGGAGTACCAATTGCCTTATTATGACATGGTGCCTTC

AGATCCCTCGATAGAGGAAATGAGAAAGGTTGTTTGTGACCAGAAGTTTC

GACCAAGTATCCCAAACCAGTGGCAAAGTTGTGAAGCACTCCGAGTCATG

GGGAGAATAATGCGTGAGTGTTGGTATGCCAACGGAGCGGCCCGCCTAAC

TGCTCTTCGTATTAAGAAGACTATATCTCAACTTTGTGTCAAAGAAGACT

›GCAAAGCCTAA

A nucleic acid sequence encoding the processed ALK7 polypeptide (isoform 4) is as follows (SEQ ID NO: 312):

(SEQ ID NO: 312)

GAGCTCTCGCCAGGACTGAAGTGTGTATGTCTTTTGTGTGATTCTTCAAA

CTTTACCTGCCAAACAGAAGGAGCATGTTGGGCATCAGTCATGCTAACCA

ATGGAAAAGAGCAGGTGATCAAATCCTGTGTCTCCCTTCCAGAACTGAAT

GCTCAAGTCTTCTGTCATAGTTCCAACAATGTTACCAAAACCGAATGCTG

CTTCACAGATTTTTGCAACAACATAACACTGCACCTTCCAACAGATAATG

GAACTTGGACTCAACTTTGGCTGGTATCTGAATATCATGAACAGGGCTCC

TTATATGACTATTTGAATAGAAATATAGTGACCGTGGCTGGAATGATCAA

GCTGGCGCTCTCAATTGCTAGTGGTCTGGCACACCTTCATATGGAGATTG

TTGGTACACAAGGTAAACCTGCTATTGCTCATCGAGACATAAAATCAAAG

AATATCTTAGTGAAAAAGTGTGAAACTTGTGCCATAGCGGACTTAGGGTT

GGCTGTGAAGCATGATTCAATACTGAACACTATCGACATACCTCAGAATC

CTAAAGTGGGAACCAAGAGGTATATGGCTCCTGAAATGCTTGATGATACA

ATGAATGTGAATATCTTTGAGTCCTTCAAACGAGCTGACATCTATTCTGT

TGGTCTGGTTTACTGGGAAATAGCCCGGAGGTGTTCAGTCGGAGGAATTG

TTGAGGAGTACCAATTGCCTTATTATGACATGGTGCCTTCAGATCCCTCG

ATAGAGGAAATGAGAAAGGTTGTTTGTGACCAGAAGTTTCGACCAAGTAT

CCCAAACCAGTGGCAAAGTTGTGAAGCACTCCGAGTCATGGGGAGAATAA

TGCGTGAGTGTTGGTATGCCAACGGAGCGGCCCGCCTAACTGCTCTTCGT

ATTAAGAAGACTATATCTCAACTTTGTGTCAAAGAAGACTGCAAAGC

›CTAA · 1 of 34

Based on the signal sequence of full-length ALK7 (isoform 1) in the rat (see NCBI Reference Sequence NP_620790.1) and on the high degree of sequence identity between human and rat ALK7, it is predicted that a processed form of human ALK7 isoform 1 is as follows (SEQ ID NO: 313).

Active variants of processed ALK7 isoform 1 are predicted in which SEQ ID NO: 39 is truncated by 1, 2, 3, 4, 5, 6, or 7 amino acids at the N-terminus and SEQ ID NO: 313 is truncated by 1 or 2 amino acids at the N-terminus. Consistent with SEQ ID NO: 313, it is further expected that leucine is the N-terminal amino acid in the processed forms of human ALK7 isoform 3 (SEQ ID NO: 306) and human ALK7 isoform 4 (SEQ ID NO: 310).

In certain embodiments, the disclosure relates to heteromultimer complexes that comprise at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof. Preferably, ALK7 polypeptides for use in accordance with inventions of the disclosure (e.g., heteromultimer complexes comprising an ALK7 polypeptide and uses thereof) are soluble (e.g., an extracellular domain of ALK7). In other preferred embodiments, ALK7 polypeptides for use in accordance with the inventions of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands. In some embodiments, heteromultimer complexes of the disclosure comprise at least one ALK7 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 38, 39, 112, 114, 301, 302, 305, 306, 309, 310, 313, 405, or 406. In some embodiments, heteromultimer complexes of the disclosure consist or consist essentially of at least one ALK7 polypeptide that is at least 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, or 99% identical to the amino acid sequence of SEQ ID NO: 38, 39, 112, 114, 301, 302, 305, 306, 309, 310, 313, 405, or 406.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:ActRIIB heteromultimer complexes of the disclosure comprise at least one ALK1 polypeptide that comprises, consists of, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:ActRIIB heteromultimers of the disclosure comprises at least one ActRIIB polypeptide that comprises, consists, or consists essentially a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to amino acids 29-109 of SEQ ID NO: 1. In some embodiments, ALK1:ActRIIB heteromultimer complexes of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454. In certain preferred embodiments, ActRIIB polypeptides of the disclosure do not comprise an acidic amino acid (e.g., a naturally occurring D or E amino acid or artificially acidic amino acid). Preferably, ALK1:ActRIIB heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or ActRIIB). In other embodiments, ALK1:ActRIIB heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:ActRIIB heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and ActRIIB homomultimers). ALK1:ActRIIB heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:ActRIIB heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK2:ActRIIB heteromultimer complexes of the disclosure comprise at least one ALK2 polypeptide that comprises, consists of, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466 or amino acids 35-99 of SEQ ID NO: 18. In some embodiments, ALK2:ActRIIB heteromultimers of the disclosure comprises at least one ActRIIB polypeptide that comprises, consists, or consists essentially a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to amino acids 29-109 of SEQ ID NO: 1. In some embodiments, ALK2:ActRIIB heteromultimer complexes of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454. In certain preferred embodiments, ActRIIB polypeptides of the disclosure do not comprise an acidic amino acid (e.g., a naturally occurring D or E amino acid or artificially acidic amino acid). Preferably, ALK2:ActRIIB heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK2 and/or ActRIIB). In other embodiments, ALK2:ActRIIB heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK2:ActRIIB heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK2 and ActRIIB homomultimers). ALK2:ActRIIB heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK2:ActRIIB heteromultimer complexes of the disclosure are heterodimers.

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In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK3:ActRIIB heteromultimer complexes of the disclosure comprise at least one ALK3 polypeptide that comprises, consists of, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468 or amino acids 61-130 of SEQ ID NO: 22. In some embodiments, ALK3:ActRIIB heteromultimers of the disclosure comprises at least one ActRIIB polypeptide that comprises, consists, or consists essentially a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to amino acids 29-109 of SEQ ID NO: 1. In some embodiments, ALK3:ActRIIB heteromultimer complexes of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454. In certain preferred embodiments, ActRIIB polypeptides of the disclosure do not comprise an acidic amino acid (e.g., a naturally occurring D or E amino acid or artificially acidic amino acid). Preferably, ALK3:ActRIIB heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK3 and/or ActRIIB). In other embodiments, ALK3:ActRIIB heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK3:ActRIIB heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK3 and ActRIIB homomultimers). ALK3:ActRIIB heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK3:ActRIIB heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK4:ActRIIB heteromultimer complexes of the disclosure comprise at least one ALK4 polypeptide that comprises, consists of, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NO: 26 or 83. In some embodiments, ALK4:ActRIIB heteromultimers of the disclosure comprises at least one ActRIIB polypeptide that comprises, consists, or consists essentially a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to amino acids 29-109 of SEQ ID NO: 1. In some embodiments, ALK4:ActRIIB heteromultimer complexes of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454. In certain preferred embodiments, ActRIIB polypeptides of the disclosure do not comprise an acidic amino acid (e.g., a naturally occurring D or E amino acid or artificially acidic amino acid). Preferably, ALK4:ActRIIB heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK4 and/or ActRIIB). In other embodiments, ALK4:ActRIIB heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK4:ActRIIB heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK4 and ActRIIB homomultimers). ALK4:ActRIIB heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK4:ActRIIB heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK5:ActRIIB heteromultimer complexes of the disclosure comprise at least one ALK5 polypeptide that comprises, consists of, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472 or amino acids 36-106 of SEQ ID NO: 30 or 87. In some embodiments, ALK5:ActRIIB heteromultimers of the disclosure comprises at least one ActRIIB polypeptide that comprises, consists, or consists essentially a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to amino acids 29-109 of SEQ ID NO: 1. In some embodiments, ALK5:ActRIIB heteromultimer complexes of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454. In certain preferred embodiments, ActRIIB polypeptides of the disclosure do not comprise an acidic amino acid (e.g., a naturally occurring D or E amino acid or artificially acidic amino acid). Preferably, ALK5:ActRIIB heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK5 and/or ActRIIB). In other embodiments, ALK5:ActRIIB heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK5:ActRIIB heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK5 and ActRIIB homomultimers). ALK5:ActRIIB heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK5:ActRIIB heteromultimer complexes of the disclosure are heterodimers.

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In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK6:ActRIIB heteromultimer complexes of the disclosure comprise at least one ALK6 polypeptide that comprises, consists of, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474 or amino acids 32-102 of SEQ ID NO: 34 or amino acids 62-132 of SEQ ID NO: 91. In some embodiments, ALK6:ActRIIB heteromultimers of the disclosure comprises at least one ActRIIB polypeptide that comprises, consists, or consists essentially a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to amino acids 29-109 of SEQ ID NO: 1. In some embodiments, ALK6:ActRIIB heteromultimer complexes of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454. In certain preferred embodiments, ActRIIB polypeptides of the disclosure do not comprise an acidic amino acid (e.g., a naturally occurring D or E amino acid or artificially acidic amino acid). Preferably, ALK6:ActRIIB heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK6 and/or ActRIIB). In other embodiments, ALK6:ActRIIB heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK6:ActRIIB heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK6 and ActRIIB homomultimers). ALK6:ActRIIB heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK6:ActRIIB heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK7:ActRIIB heteromultimer complexes of the disclosure comprise at least one ALK7 polypeptide that comprises, consists of, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476 or amino acids 28-92 of SEQ ID Nos: 38, 305, and 309. In some embodiments, ALK7:ActRIIB heteromultimers of the disclosure comprises at least one ActRIIB polypeptide that comprises, consists, or consists essentially a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to amino acids 29-109 of SEQ ID NO: 1. In some embodiments, ALK7:ActRIIB heteromultimer complexes of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454. In certain preferred embodiments, ActRIIB polypeptides of the disclosure do not comprise an acidic amino acid (e.g., a naturally occurring D or E amino acid or artificially acidic amino acid). Preferably, ALK7:ActRIIB heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK7 and/or ActRIIB). In other embodiments, ALK7:ActRIIB heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK7:ActRIIB heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK7 and ActRIIB homomultimers). ALK7:ActRIIB heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK7:ActRIIB heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:ActRIIA heteromultimers of the disclosure comprise at least one ALK1 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:ActRIIA heteromultimers of the disclosure comprises at least one ActRIIA polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452 or amino acids 30-110 of SEQ ID NO: 9. Preferably, ALK1:ActRIIA heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or ActRIIA). In other preferred embodiments, ALK1:ActRIIA heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:ActRIIA heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and ActRIIA homomultimers). ALK1:ActRIIA heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:ActRIIA heteromultimer complexes of the disclosure are heterodimers.

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In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK2:ActRIIA heteromultimers of the disclosure comprise at least one ALK2 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466 or amino acids 35-99 of SEQ ID NO: 18. In some embodiments, ALK2:ActRIIA heteromultimers of the disclosure comprises at least one ActRIIA polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452 or amino acids 30-110 of SEQ ID NO: 9. Preferably, ALK2:ActRIIA heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK2 and/or ActRIIA). In other preferred embodiments, ALK2:ActRIIA heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK2:ActRIIA heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK2 and ActRIIA homomultimers). ALK2:ActRIIA heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK2:ActRIIA heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK3:ActRIIA heteromultimers of the disclosure comprise at least one ALK3 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468 or amino acids 61-130 of SEQ ID NO: 22. In some embodiments, ALK3:ActRIIA heteromultimers of the disclosure comprises at least one ActRIIA polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452 or amino acids 30-110 of SEQ ID NO: 9. Preferably, ALK3:ActRIIA heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK3 and/or ActRIIA). In other preferred embodiments, ALK3:ActRIIA heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK3:ActRIIA heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK3 and ActRIIA homomultimers). ALK3:ActRIIA heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK3:ActRIIA heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK4:ActRIIA heteromultimers of the disclosure comprise at least one ALK4 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NO: 26 or 83. In some embodiments, ALK4:ActRIIA heteromultimers of the disclosure comprises at least one ActRIIA polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452 or amino acids 30-110 of SEQ ID NO: 9. Preferably, ALK4:ActRIIA heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK4 and/or ActRIIA). In other preferred embodiments, ALK4:ActRIIA heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK4:ActRIIA heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK4 and ActRIIA homomultimers). ALK4:ActRIIA heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK4:ActRIIA heteromultimer complexes of the disclosure are heterodimers.

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In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK5:ActRIIA heteromultimers of the disclosure comprise at least one ALK5 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472 or amino acids 36-106 of SEQ ID NO: 30 or 87. In some embodiments, ALK5:ActRIIA heteromultimers of the disclosure comprises at least one ActRIIA polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452 or amino acids 30-110 of SEQ ID NO: 9. Preferably, ALK5:ActRIIA heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK5 and/or ActRIIA). In other preferred embodiments, ALK5:ActRIIA heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK5:ActRIIA heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK5 and ActRIIA homomultimers). ALK5:ActRIIA heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK5:ActRIIA heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK6:ActRIIA heteromultimers of the disclosure comprise at least one ALK6 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474 or amino acids 32-102 of SEQ ID NO: 34 or amino acids 62-132 of SEQ ID NO: 91. In some embodiments, ALK6:ActRIIA heteromultimers of the disclosure comprises at least one ActRIIA polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452 or amino acids 30-110 of SEQ ID NO: 9. Preferably, ALK6:ActRIIA heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK6 and/or ActRIIA). In other preferred embodiments, ALK6:ActRIIA heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK6:ActRIIA heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK6 and ActRIIA homomultimers). ALK6:ActRIIA heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK6:ActRIIA heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK7:ActRIIA heteromultimers of the disclosure comprise at least one ALK7 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476 or amino acids 28-93 of SEQ ID Nos: 38, 305, or 309. In some embodiments, ALK7:ActRIIA heteromultimers of the disclosure comprises at least one ActRIIA polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NOs: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452 or amino acids 30-110 of SEQ ID NO: 9. Preferably, ALK7:ActRIIA heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK7 and/or ActRIIA). In other preferred embodiments, ALK7:ActRIIA heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK7:ActRIIA heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK7 and ActRIIA homomultimers). ALK7:ActRIIA heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK7:ActRIIA heteromultimer complexes of the disclosure are heterodimers.

›CTAA · 6 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:TGFBRII heteromultimers of the disclosure comprise at least one ALK1 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:TGFBRII heteromultimer complexes of the disclosure comprise at least one TGFBRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462 or amino acids 44-168 of SEQ ID NO: 67 or amino acids 51-143 of SEQ ID NO: 42. Preferably, ALK1:TGFBRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or TGFBRII). In other preferred embodiments, ALK1:TGFBRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:TGFBRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and TGFBRII homomultimers). ALK1:TGFBRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:TGFBRII heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK2:TGFBRII heteromultimers of the disclosure comprise at least one ALK2 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466 or amino acids 35-99 of SEQ ID NO: 18. In some embodiments, ALK2:TGFBRII heteromultimer complexes of the disclosure comprise at least one TGFBRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462 or amino acids 44-168 of SEQ ID NO: 67 or amino acids 51-143 of SEQ ID NO: 42. Preferably, ALK2:TGFBRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK2 and/or TGFBRII). In other preferred embodiments, ALK2:TGFBRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK2:TGFBRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK2 and TGFBRII homomultimers). ALK2:TGFBRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK2:TGFBRII heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK3:TGFBRII heteromultimers of the disclosure comprise at least one ALK3 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468 or amino acids 61-130 of SEQ ID NO: 22. In some embodiments, ALK3:TGFBRII heteromultimer complexes of the disclosure comprise at least one TGFBRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462 or amino acids 44-168 of SEQ ID NO: 67 or amino acids 51-143 of SEQ ID NO: 42. Preferably, ALK3:TGFBRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK3 and/or TGFBRII). In other preferred embodiments, ALK3:TGFBRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK3:TGFBRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK3 and TGFBRII homomultimers). ALK3:TGFBRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK3:TGFBRII heteromultimer complexes of the disclosure are heterodimers.

›CTAA · 7 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK4:TGFBRII heteromultimers of the disclosure comprise at least one ALK4 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NO: 26 or 83. In some embodiments, ALK4:TGFBRII heteromultimer complexes of the disclosure comprise at least one TGFBRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462 or amino acids 44-168 of SEQ ID NO: 67 or amino acids 51-143 of SEQ ID NO: 42. Preferably, ALK4:TGFBRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK4 and/or TGFBRII). In other preferred embodiments, ALK4:TGFBRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK4:TGFBRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK4 and TGFBRII homomultimers). ALK4:TGFBRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK4:TGFBRII heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK5:TGFBRII heteromultimers of the disclosure comprise at least one ALK5 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472 or amino acids 36-106 of SEQ ID NO: 30 or 87. In some embodiments, ALK5:TGFBRII heteromultimer complexes of the disclosure comprise at least one TGFBRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462 or amino acids 44-168 of SEQ ID NO: 67 or amino acids 51-143 of SEQ ID NO: 42. Preferably, ALK5:TGFBRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK5 and/or TGFBRII). In other preferred embodiments, ALK5:TGFBRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK5:TGFBRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK5 and TGFBRII homomultimers). ALK5:TGFBRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK5:TGFBRII heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK6:TGFBRII heteromultimers of the disclosure comprise at least one ALK6 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474 or amino acids 32-102 of SEQ ID NO: 34 or amino acids 62-132 of SEQ ID NO: 91. In some embodiments, ALK6:TGFBRII heteromultimer complexes of the disclosure comprise at least one TGFBRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462 or amino acids 44-168 of SEQ ID NO: 67 or amino acids 51-143 of SEQ ID NO: 42. Preferably, ALK6:TGFBRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK6 and/or TGFBRII). In other preferred embodiments, ALK6:TGFBRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK6:TGFBRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK6 and TGFBRII homomultimers). ALK6:TGFBRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK6:TGFBRII heteromultimer complexes of the disclosure are heterodimers.

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In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK7:TGFBRII heteromultimers of the disclosure comprise at least one ALK7 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476 or amino acids 28-93 of SEQ ID Nos: 38, 305, or 309. In some embodiments, ALK7:TGFBRII heteromultimer complexes of the disclosure comprise at least one TGFBRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462 or amino acids 44-168 of SEQ ID NO: 67 or amino acids 51-143 of SEQ ID NO: 42. Preferably, ALK7:TGFBRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK7 and/or TGFBRII). In other preferred embodiments, ALK7:TGFBRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK7:TGFBRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK7 and TGFBRII homomultimers). ALK7:TGFBRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK7:TGFBRII heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:MISRII heteromultimers of the disclosure comprise at least one ALK1 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:MISRII heteromultimer complexes of the disclosure comprise at least one MISRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458 or amino acids 24-116 of SEQ ID Nos: 50, 75, or 79. Preferably, ALK1:MISRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or MISRII). In other preferred embodiments, ALK1:MISRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:MISRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and MISRII homomultimers). ALK1:MISRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:MISRII heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK2:MISRII heteromultimers of the disclosure comprise at least one ALK2 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466 or amino acids 35-99 of SEQ ID NO: 18. In some embodiments, ALK2:MISRII heteromultimer complexes of the disclosure comprise at least one MISRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458 or amino acids 24-116 of SEQ ID Nos: 50, 75, or 79. Preferably, ALK2:MISRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK2 and/or MISRII). In other preferred embodiments, ALK2:MISRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK2:MISRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK2 and MISRII homomultimers). ALK2:MISRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK2:MISRII heteromultimers of the disclosure are heterodimers.

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In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK3:MISRII heteromultimers of the disclosure comprise at least one ALK3 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468 or amino acids 61-130 of SEQ ID NO: 22. In some embodiments, ALK3:MISRII heteromultimer complexes of the disclosure comprise at least one MISRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458 or amino acids 24-116 of SEQ ID Nos: 50, 75, or 79. Preferably, ALK3:MISRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK3 and/or MISRII). In other preferred embodiments, ALK3:MISRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK3:MISRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK3 and MISRII homomultimers). ALK3:MISRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK3:MISRII heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK4:MISRII heteromultimers of the disclosure comprise at least one ALK4 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NO: 26 or 83. In some embodiments, ALK4:MISRII heteromultimer complexes of the disclosure comprise at least one MISRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458 or amino acids 24-116 of SEQ ID Nos: 50, 75, or 79. Preferably, ALK4:MISRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK4 and/or MISRII). In other preferred embodiments, ALK4:MISRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK4:MISRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK4 and MISRII homomultimers). ALK4:MISRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK4:MISRII heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK5:MISRII heteromultimers of the disclosure comprise at least one ALK5 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472 or amino acids 36-106 of SEQ ID NOs: 30 or 87. In some embodiments, ALK5:MISRII heteromultimer complexes of the disclosure comprise at least one MISRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458 or amino acids 24-116 of SEQ ID Nos: 50, 75, or 79. Preferably, ALK5:MISRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK5 and/or MISRII). In other preferred embodiments, ALK5:MISRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK5:MISRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK5 and MISRII homomultimers). ALK5:MISRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK5:MISRII heteromultimers of the disclosure are heterodimers.

›CTAA · 10 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK6:MISRII heteromultimers of the disclosure comprise at least one ALK6 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474 or amino acids 32-102 of SEQ ID NO: 34 or amino acids 62-132 SEQ ID NO: 91. In some embodiments, ALK6:MISRII heteromultimer complexes of the disclosure comprise at least one MISRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458 or amino acids 24-116 of SEQ ID Nos: 50, 75, or 79. Preferably, ALK6:MISRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK6 and/or MISRII). In other preferred embodiments, ALK6:MISRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK6:MISRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK6 and MISRII homomultimers). ALK6:MISRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK6:MISRII heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK7:MISRII heteromultimers of the disclosure comprise at least one ALK7 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476 or amino acids 28-93 of SEQ ID NOs: 38, 305, or 309. In some embodiments, ALK7:MISRII heteromultimer complexes of the disclosure comprise at least one MISRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458 or amino acids 24-116 of SEQ ID Nos: 50, 75, or 79. Preferably, ALK7:MISRII heteromultimer complexes of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK7 and/or MISRII). In other preferred embodiments, ALK7:MISRII heteromultimer complexes of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK7:MISRII heteromultimer complexes of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK7 and MISRII homomultimers). ALK7:MISRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK7:MISRII heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:BMPRII heteromultimer complexes of the disclosure comprise at least one ALK1 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:BMPRII heteromultimer complexes of the disclosure comprise at least one BMPRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456 or amino acids 34-123 of SEQ ID NO: 46 or 71. Preferably, ALK1:BMPRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or BMPRII). In other preferred embodiments, ALK1:BMPRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:BMPRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and BMPRII homomultimers). ALK1:BMPRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:BMPRII heteromultimer complexes of the disclosure are heterodimers.

›CTAA · 11 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK2:BMPRII heteromultimer complexes of the disclosure comprise at least one ALK2 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466 or amino acids 35-99 of SEQ ID NO: 18. In some embodiments, ALK2:BMPRII heteromultimer complexes of the disclosure comprise at least one BMPRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456 or amino acids 34-123 of SEQ ID NO: 46 or 71. Preferably, ALK2:BMPRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK2 and/or BMPRII). In other preferred embodiments, ALK2:BMPRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK2:BMPRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK2 and BMPRII homomultimers). ALK2:BMPRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK2:BMPRII heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK3:BMPRII heteromultimer complexes of the disclosure comprise at least one ALK3 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468 or amino acids 61-130 of SEQ ID NO: 22. In some embodiments, ALK3:BMPRII heteromultimer complexes of the disclosure comprise at least one BMPRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456 or amino acids 34-123 of SEQ ID NO: 46 or 71. Preferably, ALK3:BMPRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK3 and/or BMPRII). In other preferred embodiments, ALK3:BMPRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK3:BMPRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK3 and BMPRII homomultimers). ALK3:BMPRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK3:BMPRII heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK4:BMPRII heteromultimer complexes of the disclosure comprise at least one ALK4 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NOs: 26 or 83. In some embodiments, ALK4:BMPRII heteromultimer complexes of the disclosure comprise at least one BMPRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456 or amino acids 34-123 of SEQ ID NO: 46 or 71. Preferably, ALK4:BMPRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK4 and/or BMPRII). In other preferred embodiments, ALK4:BMPRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK4:BMPRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK4 and BMPRII homomultimers). ALK4:BMPRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK4:BMPRII heteromultimer complexes of the disclosure are heterodimers.

›CTAA · 12 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK5:BMPRII heteromultimer complexes of the disclosure comprise at least one ALK5 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: SEQ ID Nos: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472 or amino acids 36-106 of SEQ ID NOs: 30 or 87. In some embodiments, ALK5:BMPRII heteromultimer complexes of the disclosure comprise at least one BMPRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456 or amino acids 34-123 of SEQ ID NO: 46 or 71. Preferably, ALK5:BMPRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK5 and/or BMPRII). In other preferred embodiments, ALK5:BMPRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK5:BMPRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK5 and BMPRII homomultimers). ALK5:BMPRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK5:BMPRII heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK6:BMPRII heteromultimer complexes of the disclosure comprise at least one ALK6 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474 or amino acids 32-102 of SEQ ID NO: 34 or amino acids 62-132 of SEQ ID NO: 91. In some embodiments, ALK6:BMPRII heteromultimer complexes of the disclosure comprise at least one BMPRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456 or amino acids 34-123 of SEQ ID NO: 46 or 71. Preferably, ALK6:BMPRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK6 and/or BMPRII). In other preferred embodiments, ALK6:BMPRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK6:BMPRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK6 and BMPRII homomultimers). ALK6:BMPRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK6:BMPRII heteromultimer complexes of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK7:BMPRII heteromultimer complexes of the disclosure comprise at least one ALK7 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476 or amino acids 28-92 of SEQ ID NOs: 38, 305, or 309. In some embodiments, ALK7:BMPRII heteromultimer complexes of the disclosure comprise at least one BMPRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456 or amino acids 34-123 of SEQ ID NO: 46 or 71. Preferably, ALK7:BMPRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK7 and/or BMPRII). In other preferred embodiments, ALK6:BMPRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK7:BMPRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK7 and BMPRII homomultimers). ALK7:BMPRII heteromultimer complexes of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK7:BMPRII heteromultimer complexes of the disclosure are heterodimers.

›CTAA · 13 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:ALK2 heteromultimers of the disclosure comprise at least one ALK1 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:ALK2 heteromultimers of the disclosure comprise at least one ALK2 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466 or amino acids 35-99 of SEQ ID NO: 18. Preferably, ALK1:ALK2 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or ALK2). In other preferred embodiments, ALK1:ALK2 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF1S/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:ALK2 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and ALK2 homomultimers). ALK1:ALK2 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:ALK2 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:ALK3 heteromultimers of the disclosure comprise at least one ALK1 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:ALK3 heteromultimers of the disclosure comprise at least one ALK3 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468 or amino acids 61-130 of SEQ ID NO: 22. Preferably, ALK1:ALK3 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or ALK3). In other preferred embodiments, ALK1:ALK3 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:ALK3 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and ALK3 homomultimers). ALK1:ALK3 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:ALK3 heteromultimers of the disclosure are heterodimers.

›CTAA · 14 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:ALK4 heteromultimers of the disclosure comprise at least one ALK1 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:ALK4 heteromultimers of the disclosure comprise at least one ALK4 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NOs: 26 or 83. Preferably, ALK1:ALK4 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or ALK4). In other preferred embodiments, ALK1:ALK4 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:ALK4 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and ALK4 homomultimers). ALK1:ALK4 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:ALK4 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:ALK4 heteromultimers of the disclosure comprise at least one ALK1 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:ALK4 heteromultimers of the disclosure comprise at least one ALK4 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NOs: 26 or 83. Preferably, ALK1:ALK4 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or ALK4). In other preferred embodiments, ALK1:ALK4 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF1S/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:ALK4 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and ALK4 homomultimers). ALK1:ALK4 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:ALK4 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:ALK5 heteromultimers of the disclosure comprise at least one ALK1 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:ALK5 heteromultimers of the disclosure comprise at least one ALK5 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472 or amino acids 36-106 of SEQ ID NOs: 30 or 87. Preferably, ALK1:ALK5 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or ALK5). In other preferred embodiments, ALK1:ALK5 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF1S/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:ALK5 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and ALK5 homomultimers). ALK1:ALK5 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:ALK5 heteromultimers of the disclosure are heterodimers.

›CTAA · 15 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:ALK6 heteromultimers of the disclosure comprise at least one ALK1 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:ALK6 heteromultimers of the disclosure comprise at least one ALK6 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474 or amino acids 32-102 of SEQ ID NO: 34 or amino acids 62-132 of SEQ ID NO: 91. Preferably, ALK1:ALK6 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or ALK6). In other preferred embodiments, ALK1:ALK6 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:ALK6 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and ALK6 homomultimers). ALK1:ALK6 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:ALK6 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK1 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK1:ALK7 heteromultimers of the disclosure comprise at least one ALK1 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO: 14, 15, 124, 126, 171, 172, 413, 414, 463, and 464 or amino acids 34-95 of SEQ ID NO: 14. In some embodiments, ALK1:ALK7 heteromultimers of the disclosure comprise at least one ALK7 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476 or amino acids 28-92 of SEQ ID NOs: 38, 305, or 309. Preferably, ALK1:ALK7 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK1 and/or ALK7). In other preferred embodiments, ALK1:ALK7 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK1:ALK7 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK1 and ALK7 homomultimers). ALK1:ALK7 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK1:ALK7 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK2:ALK3 heteromultimers of the disclosure comprise at least one ALK2 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466 or amino acids 35-99 of SEQ ID NO: 18. In some embodiments, ALK2:ALK3 heteromultimers of the disclosure comprise at least one ALK3 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468 or amino acids 61-130 of SEQ ID NO: 22. Preferably, ALK2:ALK3 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK2 and/or ALK3). In other preferred embodiments, ALK2:ALK3 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK2:ALK3 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK2 and ALK3 homomultimers). ALK2:ALK3 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK2:ALK3 heteromultimers of the disclosure are heterodimers.

›CTAA · 16 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK2:ALK4 heteromultimers of the disclosure comprise at least one ALK2 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466 or amino acids 35-99 of SEQ ID NO: 18. In some embodiments, ALK2:ALK4 heteromultimers of the disclosure comprise at least one ALK4 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NOs: 26 or 83. Preferably, ALK2:ALK4 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK2 and/or ALK4). In other preferred embodiments, ALK2:ALK4 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK2:ALK4 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK2 and ALK4 homomultimers). ALK2:ALK4 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK2:ALK4 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK2:ALK5 heteromultimers of the disclosure comprise at least one ALK2 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466 or amino acids 35-99 of SEQ ID NO: 18. In some embodiments, ALK2:ALK5 heteromultimers of the disclosure comprise at least one ALK5 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472 or amino acids 36-106 of SEQ ID NOs: 30 or 87. Preferably, ALK2:ALK5 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK2 and/or ALK5). In other preferred embodiments, ALK2:ALK5 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK2:ALK5 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK2 and ALK5 homomultimers). ALK2:ALK5 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK2:ALK5 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK2:ALK6 heteromultimers of the disclosure comprise at least one ALK2 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466 or amino acids 35-99 of SEQ ID NO: 18. In some embodiments, ALK2:ALK6 heteromultimers of the disclosure comprise at least one ALK6 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474 or amino acids 32-102 of SEQ ID NO: 34 or amino acids 62-132 of SEQ ID NO: 91. Preferably, ALK2:ALK6 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK2 and/or ALK6). In other preferred embodiments, ALK2:ALK6 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK2:ALK6 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK2 and ALK6 homomultimers). ALK2:ALK6 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK2:ALK6 heteromultimers of the disclosure are heterodimers.

›CTAA · 17 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK2 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK2:ALK7 heteromultimers of the disclosure comprise at least one ALK2 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 18, 19, 136, 138, 173, 174, 421, 422, 465, and 466 or amino acids 35-99 of SEQ ID NO: 18. In some embodiments, ALK2:ALK7 heteromultimers of the disclosure comprise at least one ALK7 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476 or amino acids 28-92 of SEQ ID NOs: 38, 305, or 309. Preferably, ALK2:ALK7 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK2 and/or ALK7). In other preferred embodiments, ALK2:ALK7 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK2:ALK7 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK2 and ALK7 homomultimers). ALK2:ALK7 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK2:ALK7 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK3:ALK4 heteromultimers of the disclosure comprise at least one ALK3 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468 or amino acids 61-130 of SEQ ID NO: 22. In some embodiments, ALK3:ALK4 heteromultimers of the disclosure comprise at least one ALK4 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NOs: 26 or 83. Preferably, ALK3:ALK4 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK3 and/or ALK4). In other preferred embodiments, ALK3:ALK4 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK3:ALK4 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK3 and ALK4 homomultimers). ALK3:ALK4 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK3:ALK4 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK3:ALK5 heteromultimers of the disclosure comprise at least one ALK3 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468 or amino acids 61-130 of SEQ ID NO: 22. In some embodiments, ALK3:ALK5 heteromultimers of the disclosure comprise at least one ALK5 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472 or amino acids 36-106 of SEQ ID NOs: 30 or 87. Preferably, ALK3:ALK5 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK3 and/or ALK5). In other preferred embodiments, ALK3:ALK5 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK3:ALK5 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK3 and ALK5 homomultimers). ALK3:ALK5 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK3:ALK5 heteromultimers of the disclosure are heterodimers.

›CTAA · 18 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK3:ALK6 heteromultimers of the disclosure comprise at least one ALK3 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468 or amino acids 61-130 of SEQ ID NO: 22. In some embodiments, ALK3:ALK6 heteromultimers of the disclosure comprise at least one ALK6 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474 or amino acids 32-102 of SEQ ID NO: 34 or amino acids 62-132 of SEQ ID NO: 91. Preferably, ALK3:ALK6 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK3 and/or ALK6). In other preferred embodiments, ALK3:ALK6 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK3:ALK6 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK3 and ALK6 homomultimers). ALK3:ALK6 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK3:ALK6 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK3 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK3:ALK7 heteromultimers of the disclosure comprise at least one ALK3 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468 or amino acids 61-130 of SEQ ID NO: 22. In some embodiments, ALK3:ALK7 heteromultimers of the disclosure comprise at least one ALK7 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476 or amino acids 28-92 of SEQ ID NOs: 38, 305, or 309. Preferably, ALK3:ALK7 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK3 and/or ALK7). In other preferred embodiments, ALK3:ALK7 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK3:ALK7 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK3 and ALK7 homomultimers). ALK3:ALK7 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK3:ALK7 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK4:ALK5 heteromultimers of the disclosure comprise at least one ALK4 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NOs: 26 or 83. In some embodiments, ALK4:ALK5 heteromultimers of the disclosure comprise at least one ALK5 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472 or amino acids 36-106 of SEQ ID NOs: 30 or 87. Preferably, ALK4:ALK5 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK4 and/or ALK5). In other preferred embodiments, ALK4:ALK5 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK4:ALK5 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK4 and ALK5 homomultimers). ALK4:ALK5 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK4:ALK5 heteromultimers of the disclosure are heterodimers.

›CTAA · 19 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK4:ALK6 heteromultimers of the disclosure comprise at least one ALK4 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NOs: 26 or 83. In some embodiments, ALK4:ALK6 heteromultimers of the disclosure comprise at least one ALK6 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474 or amino acids 32-102 of SEQ ID NO: 34 or amino acids 62-132 of SEQ ID NO: 91. Preferably, ALK4:ALK6 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK4 and/or ALK6). In other preferred embodiments, ALK4:ALK6 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK4:ALK6 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK4 and ALK6 homomultimers). ALK4:ALK6 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK4:ALK6 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK4 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK4:ALK7 heteromultimers of the disclosure comprise at least one ALK4 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, and 470 or amino acids 34-101 of SEQ ID NOs: 26 or 83. In some embodiments, ALK4:ALK7 heteromultimers of the disclosure comprise at least one ALK7 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476 or amino acids 28-92 of SEQ ID NOs: 38, 305, or 309. Preferably, ALK4:ALK7 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK4 and/or ALK7). In other preferred embodiments, ALK4:ALK7 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK4:ALK7 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK4 and ALK7 homomultimers). ALK4:ALK7 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK4:ALK7 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK5:ALK6 heteromultimers of the disclosure comprise at least one ALK5 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472 or amino acids 36-106 of SEQ ID NOs: 30 or 87. In some embodiments, ALK5:ALK6 heteromultimers of the disclosure comprise at least one ALK6 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474 or amino acids 32-102 of SEQ ID NO: 34 or amino acids 62-132 of SEQ ID NO: 91. Preferably, ALK5:ALK6 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK5 and/or ALK6). In other preferred embodiments, ALK5:ALK6 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK5:ALK6 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK5 and ALK6 homomultimers). ALK5:ALK6 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK5:ALK6 heteromultimers of the disclosure are heterodimers.

›CTAA · 20 of 34

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK5 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK5:ALK7 heteromultimers of the disclosure comprise at least one ALK5 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, and 472 or amino acids 36-106 of SEQ ID NOs: 30 or 87. In some embodiments, ALK5:ALK7 heteromultimers of the disclosure comprise at least one ALK7 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476 or amino acids 28-92 of SEQ ID NOs: 38, 305, or 309. Preferably, ALK5:ALK7 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK5 and/or ALK7). In other preferred embodiments, ALK5:ALK7 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK5:ALK7 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK5 and ALK7 homomultimers). ALK5:ALK7 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK5:ALK7 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ALK6 polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ALK7 polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ALK6:ALK7 heteromultimers of the disclosure comprise at least one ALK6 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, and 474 or amino acids 32-102 of SEQ ID NO: 34 or amino acids 62-132 of SEQ ID NO: 91. In some embodiments, ALK6:ALK7 heteromultimers of the disclosure comprise at least one ALK7 polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, and 476 or amino acids 28-92 of SEQ ID NOs: 38, 305, or 309. Preferably, ALK5:ALK7 heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ALK6 and/or ALK7). In other preferred embodiments, ALK6:ALK7 heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF1S/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ALK6:ALK7 heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ALK6 and ALK7 homomultimers). ALK6:ALK7 heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ALK6:ALK7 heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ActRIIA:ActRIIB heteromultimers of the disclosure comprise at least one ActRIIA polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452 or amino acids 30-110 of SEQ ID NO: 9. In some embodiments, ActRIIA:ActRIIB heteromultimers of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454 or amino acids 29-109 of SEQ ID NO: 1 or 25-131 of SEQ ID NO: 1. Preferably, ActRIIA:ActRIIB heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ActRIIA and/or ActRIIB). In other preferred embodiments, ActRIIA:ActRIIB heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ActRIIA:ActRIIB heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ActRIIA and ActRIIB homomultimers). ActRIIA:ActRIIB heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ActRIIA:ActRIIB heteromultimers of the disclosure are heterodimers.

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In certain aspects, the disclosure relates to heteromultimers that comprise at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ActRIIA:BMPRII heteromultimers of the disclosure comprise at least one ActRIIA polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452 or amino acids 30-110 of SEQ ID NO: 9. In some embodiments, ActRIIA:BMPRII heteromultimers of the disclosure comprise at least one BMPRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456 or amino acids 34-123 of SEQ ID NO: 46 and 71. Preferably, ActRIIA:BMPRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ActRIIA and/or BMPRII). In other preferred embodiments, ActRIIA:BMPRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ActRIIA:BMPRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ActRIIA and BMPRII homomultimers). ActRIIA:BMPRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ActRIIA:BMPRII heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ActRIIA:TGFBRII heteromultimers of the disclosure comprise at least one ActRIIA polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452 or amino acids 30-110 of SEQ ID NO: 9. In some embodiments, ActRIIA:TGFBRII heteromultimers of the disclosure comprise at least one TGFBRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462 or amino acids 44-168 of SEQ ID NO: 67 or amino acids 51-143 of SEQ ID NO: 42. Preferably, ActRIIA:TGFBRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ActRIIA and/or BMPRII). In other preferred embodiments, ActRIIA:TGFBRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ActRIIA:TGFBRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ActRIIA and TGFBRII homomultimers). ActRIIA:TGFBRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ActRIIA:TGFBRII heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ActRIIA polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ActRIIA:MISRII heteromultimers of the disclosure comprise at least one ActRIIA polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, and 452 or amino acids 30-110 of SEQ ID NO: 9. In some embodiments, ActRIIA:MISRII heteromultimers of the disclosure comprise at least one MISRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458 or amino acids 24-116 of SEQ ID NO: 50, 75, and 79. Preferably, ActRIIA:MISRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ActRIIA and/or MISRII). In other preferred embodiments, ActRIIA:MISRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ActRIIA:MISRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ActRIIA and MISRII homomultimers). ActRIIA:MISRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ActRIIA:MISRII heteromultimers of the disclosure are heterodimers.

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In certain aspects, the disclosure relates to heteromultimers that comprise at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ActRIIB:BMPRII heteromultimers of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454 or amino acids 29-109 of SEQ ID NO: 1 or 25-131 of SEQ ID NO: 1. In some embodiments, ActRIIB:BMPRII heteromultimers of the disclosure comprise at least one BMPRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456 or amino acids 34-123 of SEQ ID NO: 46 and 71. Preferably, ActRIIB:BMPRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ActRIIB and/or BMPRII). In other preferred embodiments, ActRIIB:BMPRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ActRIIB:BMPRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ActRIIB and BMPRII homomultimers). ActRIIB:BMPRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ActRIIB:BMPRII heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ActRIIB:TGFBRII heteromultimers of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454 or amino acids 29-109 of SEQ ID NO: 1 or 25-131 of SEQ ID NO: 1. In some embodiments, ActRIIB:TGFBRII heteromultimers of the disclosure comprise at least one TGFBRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462 or amino acids 44-168 of SEQ ID NO: 67 or amino acids 51-143 of SEQ ID NO: 42. Preferably, ActRIIB:TGFBRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ActRIIB and/or TGFBRII). In other preferred embodiments, ActRIIB:TGFBRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ActRIIB:TGFBRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ActRIIB and TGFBRII homomultimers). ActRIIB:TGFBRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ActRIIB:TGFBRII heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one ActRIIB polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, ActRIIB:MISRII heteromultimers of the disclosure comprise at least one ActRIIB polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454 or amino acids 29-109 of SEQ ID NO: 1 or 25-131 of SEQ ID NO: 1. In some embodiments, ActRIIB:MISRII heteromultimers of the disclosure comprise at least one MISRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458 or amino acids 24-116 of SEQ ID NO: 50, 75, and 79. Preferably, ActRIIB:MISRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of ActRIIB and/or MISRII). In other preferred embodiments, ActRIIB:MISRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, ActRIIB:MISRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., ActRIIB and MISRII homomultimers). ActRIIB:MISRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, ActRIIB:MISRII heteromultimers of the disclosure are heterodimers.

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In certain aspects, the disclosure relates to heteromultimers that comprise at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, BMPRII:TGFBRII heteromultimers of the disclosure comprise at least one BMPRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456 or amino acids 34-123 of SEQ ID NO: 46 or 71. In some embodiments, BMPRII:TGFBRII heteromultimers of the disclosure comprise at least one TGFBRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462 or amino acids 44-168 of SEQ ID NO: 67 or amino acids 51-143 of SEQ ID NO: 42. Preferably, BMPRII:TGFBRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of BMPRII and/or TGFBRII). In other preferred embodiments, BMPRII:TGFBRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, BMPRII:TGFBRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., BMPRII and TGFBRII homomultimers). BMPRII:TGFBRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, BMPRII:TGFBRII heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one BMPRII polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, BMPRII:MISRII heteromultimers of the disclosure comprise at least one BMPRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, and 456 or amino acids 34-123 of SEQ ID NO: 46 or 71. In some embodiments, BMPRII:MISRII heteromultimers of the disclosure comprise at least one MISRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458 or amino acids 24-116 of SEQ ID NO: 50, 75, or 79. Preferably, BMPRII:MISRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of BMPRII and/or MISRII). In other preferred embodiments, BMPRII:MISRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, BMPRII:MISRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., BMPRII and MISRII homomultimers). BMPRII:MISRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, BMPRII:MISRII heteromultimers of the disclosure are heterodimers.

In certain aspects, the disclosure relates to heteromultimers that comprise at least one TGFBRII polypeptide, which includes fragments, functional variants, and modified forms thereof, and at least one MISRII polypeptide, which includes fragments, functional variants, and modified forms thereof. In some embodiments, TGFBRII:MISRII heteromultimers of the disclosure comprise at least one TGFBRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462 or amino acids 44-168 of SEQ ID NO: 67 or amino acids 51-143 of SEQ ID NO: 42. In some embodiments, TGFBRII:MISRII heteromultimers of the disclosure comprise at least one MISRII polypeptide that comprises, consists, or consists essentially of a sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96% 97%, 98%, 99%, or 100% identical to the amino acid sequence of any one of SEQ ID Nos: 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, and 458 or amino acids 24-116 of SEQ ID NO: 50, 75, or 79. Preferably, TGFBRII:MISRII heteromultimers of the present disclosure are soluble (e.g., comprise an extracellular domain of TGFBII and/or MISRII). In other preferred embodiments, TGFBRII:MISRII heteromultimers of the disclosure bind to and/or inhibit (antagonize) activity (e.g., induction of Smad 2/3 and/or Smad 1/5/8 signaling) of one or more TGF-beta superfamily ligands (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty). In some embodiments, TGFBRII:MISRII heteromultimers of the disclosure have different ligand binding specificities/profiles compared to their corresponding homomultimer complexes (i.e., TGFBRII and MISRII homomultimers). TGFBRII:MISRII heteromultimers of the disclosure include, e.g., heterodimers, heterotrimers, heterotetramers and further oligomeric structures. In certain preferred embodiments, TGFBRII:MISRII heteromultimers of the disclosure are heterodimers.

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In some embodiments, the present disclosure contemplates making functional variants by modifying the structure of a TGF-beta superfamily type I receptor polypeptide (e.g., ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7) and/or a TGF-beta superfamily type II receptor polypeptide (e.g., ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII) for such purposes as enhancing therapeutic efficacy or stability (e.g., shelf-life and resistance to proteolytic degradation in vivo). Variants can be produced by amino acid substitution, deletion, addition, or combinations thereof. For instance, it is reasonable to expect that an isolated replacement of a leucine with an isoleucine or valine, an aspartate with a glutamate, a threonine with a serine, or a similar replacement of an amino acid with a structurally related amino acid (e.g., conservative mutations) will not have a major effect on the biological activity of the resulting molecule. Conservative replacements are those that take place within a family of amino acids that are related in their side chains. Whether a change in the amino acid sequence of a polypeptide of the disclosure results in a functional homolog can be readily determined by assessing the ability of the variant polypeptide to produce a response in cells in a fashion similar to the wild-type polypeptide, or to bind to one or more TGF-beta superfamily ligands including, for example, BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty.

In some embodiments, the present disclosure contemplates making functional variants by modifying the structure of the TGF-beta superfamily type I receptor polypeptide and/or TGF-beta superfamily type II receptor polypeptide for such purposes as enhancing therapeutic efficacy or stability (e.g., increased shelf-life and/or increased resistance to proteolytic degradation).

In certain embodiments, the present disclosure contemplates specific mutations of a TGF-beta superfamily type I receptor polypeptide (e.g., ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7) and/or a TGF-beta superfamily type II receptor polypeptide (e.g., ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII) receptor of the disclosure so as to alter the glycosylation of the polypeptide. Such mutations may be selected so as to introduce or eliminate one or more glycosylation sites, such as O-linked or N-linked glycosylation sites. Asparagine-linked glycosylation recognition sites generally comprise a tripeptide sequence, asparagine-X-threonine or asparagine-X-serine (where “X” is any amino acid) which is specifically recognized by appropriate cellular glycosylation enzymes. The alteration may also be made by the addition of, or substitution by, one or more serine or threonine residues to the sequence of the polypeptide (for O-linked glycosylation sites). A variety of amino acid substitutions or deletions at one or both of the first or third amino acid positions of a glycosylation recognition site (and/or amino acid deletion at the second position) results in non-glycosylation at the modified tripeptide sequence. Another means of increasing the number of carbohydrate moieties on a polypeptide is by chemical or enzymatic coupling of glycosides to the polypeptide. Depending on the coupling mode used, the sugar(s) may be attached to (a) arginine and histidine; (b) free carboxyl groups; (c) free sulfhydryl groups such as those of cysteine; (d) free hydroxyl groups such as those of serine, threonine, or hydroxyproline; (e) aromatic residues such as those of phenylalanine, tyrosine, or tryptophan; or (f) the amide group of glutamine. Removal of one or more carbohydrate moieties present on a polypeptide may be accomplished chemically and/or enzymatically. Chemical deglycosylation may involve, for example, exposure of a polypeptide to the compound trifluoromethanesulfonic acid, or an equivalent compound. This treatment results in the cleavage of most or all sugars except the linking sugar (N-acetylglucosamine or N-acetylgalactosamine), while leaving the amino acid sequence intact. Enzymatic cleavage of carbohydrate moieties on polypeptides can be achieved by the use of a variety of endo- and exo-glycosidases as described by Thotakura et al. [Meth. Enzymol. (1987) 138:350]. The sequence of a polypeptide may be adjusted, as appropriate, depending on the type of expression system used, as mammalian, yeast, insect, and plant cells may all introduce differing glycosylation patterns that can be affected by the amino acid sequence of the peptide. In general, TGF-beta superfamily type I and II receptor complexes of the present disclosure for use in humans may be expressed in a mammalian cell line that provides proper glycosylation, such as HEK293 or CHO cell lines, although other mammalian expression cell lines are expected to be useful as well.

The present disclosure further contemplates a method of generating mutants, particularly sets of combinatorial mutants of a TGF-beta superfamily type I receptor polypeptide (e.g., ALK1, ALK2, ALK3, ALK4, ALK5, ALK6, and ALK7) and/or a TGF-beta superfamily type II receptor polypeptide (e.g., ActRIIA, ActRIIB, TGFBRII, BMPRII, and MISRII) of the present disclosure, as well as truncation mutants. Pools of combinatorial mutants are especially useful for identifying functionally active (e.g., ligand binding) TGF-beta superfamily type I and/or TGF-beta superfamily type II receptor sequences. The purpose of screening such combinatorial libraries may be to generate, for example, polypeptides variants which have altered properties, such as altered pharmacokinetic or altered ligand binding. A variety of screening assays are provided below, and such assays may be used to evaluate variants. For example, TGF-beta superfamily type I and II receptor complex variants may be screened for ability to bind to a TGF-beta superfamily ligand (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty), to prevent binding of a TGF-beta superfamily ligand to a TGF-beta superfamily receptor, and/or to interfere with signaling caused by an TGF-beta superfamily ligand.

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The activity of a TGF-beta superfamily heteromultimer complex of the disclosure also may be tested, for example in a cell-based or in vivo assay. For example, the effect of a heteromultimer complex on the expression of genes or the activity of proteins involved in muscle production in a muscle cell may be assessed. This may, as needed, be performed in the presence of one or more recombinant TGF-beta superfamily ligand proteins (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty), and cells may be transfected so as to produce a TGF-beta superfamily type I and II receptor complex, and optionally, a TGF-beta superfamily ligand. Likewise, a heteromultimer complex of the disclosure may be administered to a mouse or other animal, and one or more measurements, such as muscle formation and strength may be assessed using art-recognized methods. Similarly, the activity of a heteromultimer, or variants thereof, may be tested in osteoblasts, adipocytes, and/or neuronal cells for any effect on growth of these cells, for example, by the assays as described herein and those of common knowledge in the art. A SMAD-responsive reporter gene may be used in such cell lines to monitor effects on downstream signaling.

Combinatorial-derived variants can be generated which have increased selectivity or generally increased potency relative to a reference TGF-beta superfamily heteromultimer complex. Such variants, when expressed from recombinant DNA constructs, can be used in gene therapy protocols. Likewise, mutagenesis can give rise to variants which have intracellular half-lives dramatically different than the corresponding unmodified TGF-beta superfamily heteromultimer complex. For example, the altered protein can be rendered either more stable or less stable to proteolytic degradation or other cellular processes which result in destruction, or otherwise inactivation, of an unmodified polypeptide. Such variants, and the genes which encode them, can be utilized to alter polypeptide complex levels by modulating the half-life of the polypeptide. For instance, a short half-life can give rise to more transient biological effects and, when part of an inducible expression system, can allow tighter control of recombinant polypeptide complex levels within the cell. In an Fc fusion protein, mutations may be made in the linker (if any) and/or the Fc portion to alter one or more activities of the TGF-beta superfamily heteromultimer complex including, for example, immunogenicity, half-life, and solubility.

A combinatorial library may be produced by way of a degenerate library of genes encoding a library of polypeptides which each include at least a portion of potential TGF-beta superfamily type I and/or II receptor sequences. For instance, a mixture of synthetic oligonucleotides can be enzymatically ligated into gene sequences such that the degenerate set of potential TGF-beta superfamily type I and/or II receptor encoding nucleotide sequences are expressible as individual polypeptides, or alternatively, as a set of larger fusion proteins (e.g., for phage display).

There are many ways by which the library of potential homologs can be generated from a degenerate oligonucleotide sequence. Chemical synthesis of a degenerate gene sequence can be carried out in an automatic DNA synthesizer, and the synthetic genes can then be ligated into an appropriate vector for expression. The synthesis of degenerate oligonucleotides is well known in the art. See, e.g., Narang, S A (1983) Tetrahedron 39:3; Itakura et al. (1981) Recombinant DNA, Proc. 3rd Cleveland Sympos. Macromolecules, ed. AG Walton, Amsterdam: Elsevier pp 273-289; Itakura et al. (1984) Annu. Rev. Biochem. 53:323; Itakura et al. (1984) Science 198:1056; Ike et al. (1983) Nucleic Acid Res. 11:477. Such techniques have been employed in the directed evolution of other proteins. See, e.g., Scott et al., (1990) Science 249:386-390; Roberts et al. (1992) PNAS USA 89:2429-2433; Devlin et al. (1990) Science 249: 404-406; Cwirla et al., (1990) PNAS USA 87: 6378-6382; as well as U.S. Pat. Nos. 5,223,409, 5,198,346, and 5,096,815.

Alternatively, other forms of mutagenesis can be utilized to generate a combinatorial library. For example, TGF-beta superfamily heteromultimer complexes of the disclosure can be generated and isolated from a library by screening using, for example, alanine scanning mutagenesis [see, e.g., Ruf et al. (1994) Biochemistry 33:1565-1572; Wang et al. (1994) J. Biol. Chem. 269:3095-3099; Balint et al. (1993) Gene 137:109-118; Grodberg et al. (1993) Eur. J. Biochem. 218:597-601; Nagashima et al. (1993) J. Biol. Chem. 268:2888-2892; Lowman et al. (1991) Biochemistry 30:10832-10838; and Cunningham et al. (1989) Science 244:1081-1085], by linker scanning mutagenesis [see, e.g., Gustin et al. (1993) Virology 193:653-660; and Brown et al. (1992) Mol. Cell Biol. 12:2644-2652; McKnight et al. (1982) Science 232:316], by saturation mutagenesis [see, e.g., Meyers et al., (1986) Science 232:613]; by PCR mutagenesis [see, e.g., Leung et al. (1989) Method Cell Mol Biol 1:11-19]; or by random mutagenesis, including chemical mutagenesis [see, e.g., Miller et al. (1992) A Short Course in Bacterial Genetics, CSHL Press, Cold Spring Harbor, N.Y.; and Greener et al. (1994) Strategies in Mol Biol 7:32-34]. Linker scanning mutagenesis, particularly in a combinatorial setting, is an attractive method for identifying truncated (bioactive) forms of TGF-beta superfamily type I and/or II receptor polypeptides.

A wide range of techniques are known in the art for screening gene products of combinatorial libraries made by point mutations and truncations, and, for that matter, for screening cDNA libraries for gene products having a certain property. Such techniques will be generally adaptable for rapid screening of the gene libraries generated by the combinatorial mutagenesis of TGF-beta superfamily heteromultimer complexes of the disclosure. The most widely used techniques for screening large gene libraries typically comprise cloning the gene library into replicable expression vectors, transforming appropriate cells with the resulting library of vectors, and expressing the combinatorial genes under conditions in which detection of a desired activity facilitates relatively easy isolation of the vector encoding the gene whose product was detected. Preferred assays include TGF-beta superfamily ligand (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty) binding assays and/or TGF-beta superfamily ligand-mediated cell signaling assays.

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In certain embodiments, TGF-beta superfamily type I and II heteromultimer complexes of the disclosure may further comprise post-translational modifications in addition to any that are naturally present in the TGF-beta superfamily type I and/or II receptor polypeptide. Such modifications include, but are not limited to, acetylation, carboxylation, glycosylation, phosphorylation, lipidation, and acylation. As a result, the TGF-beta superfamily type I and II heteromultimer complex may comprise non-amino acid elements, such as polyethylene glycols, lipids, polysaccharide or monosaccharide, and phosphates. Effects of such non-amino acid elements on the functionality of a heteromultimer complex may be tested as described herein for other heteromultimer complex variants. When a polypeptide of the disclosure is produced in cells by cleaving a nascent form of the polypeptide, post-translational processing may also be important for correct folding and/or function of the protein. Different cells (e.g., CHO, HeLa, MDCK, 293, WI38, NIH-3T3 or HEK293) have specific cellular machinery and characteristic mechanisms for such post-translational activities and may be chosen to ensure the correct modification and processing of the TGF-beta superfamily type I and/or type II receptor polypeptides as well as heteromultimers comprising the same.

In certain aspects, the polypeptides disclosed herein may form protein complexes comprising at least one TGF-beta superfamily type I polypeptide associated, covalently or non-covalently, with at least one type II receptor polypeptide. Preferably, polypeptides disclosed herein form heterodimeric complexes, although higher order heteromultimeric complexes (heteromultimers) are also included such as, but not limited to, heterotrimers, heterotetramers, and further oligomeric structures (see, e.g., FIGS. 1, 2, and 15-17 ). In some embodiments, TGF-beta superfamily type I and/or type II receptor polypeptides of the present disclosure comprise at least one multimerization domain. As disclosed herein, the term “multimerization domain” refers to an amino acid or sequence of amino acids that promote covalent or non-covalent interaction between at least a first polypeptide and at least a second polypeptide. Polypeptides disclosed herein may be joined covalently or non-covalently to a multimerization domain. Preferably, a multimerization domain promotes interaction between a first polypeptide (e.g., TGF-beta superfamily type I polypeptide) and a second polypeptide (e.g., TGF-beta superfamily type II polypeptide) to promote heteromultimer formation (e.g., heterodimer formation), and optionally hinders or otherwise disfavors homomultimer formation (e.g., homodimer formation), thereby increasing the yield of desired heteromultimer (see, e.g., FIG. 2 ).

Many methods known in the art can be used to generate TGF-beta superfamily complexes of the disclosure. For example, non-naturally occurring disulfide bonds may be constructed by replacing on a first polypeptide (e.g., TGF-beta superfamily type I polypeptide) a naturally occurring amino acid with a free thiol-containing residue, such as cysteine, such that the free thiol interacts with another free thiol-containing residue on a second polypeptide (e.g., TGF-beta superfamily type II polypeptide) such that a disulfide bond is formed between the first and second polypeptides. Additional examples of interactions to promote heteromultimer formation include, but are not limited to, ionic interactions such as described in Kjaergaard et al., WO2007147901; electrostatic steering effects such as described in Kannan et al., U.S. Pat. No. 8,592,562; coiled-coil interactions such as described in Christensen et al., U.S. 20120302737; leucine zippers such as described in Pack & Plueckthun, (1992) Biochemistry 31: 1579-1584; and helix-turn-helix motifs such as described in Pack et al., (1993) Bio/Technology 11: 1271-1277. Linkage of the various segments may be obtained via, e.g., covalent binding such as by chemical cross-linking, peptide linkers, disulfide bridges, etc., or affinity interactions such as by avidin-biotin or leucine zipper technology.

In certain aspects, a multimerization domain may comprise one component of an interaction pair. In some embodiments, the polypeptides disclosed herein may form protein complexes comprising a first polypeptide covalently or non-covalently associated with a second polypeptide, wherein the first polypeptide comprises the amino acid sequence of a TGF-beta superfamily type I polypeptide and the amino acid sequence of a first member of an interaction pair; and the second polypeptide comprises the amino acid sequence of a TGF-beta superfamily type II polypeptide and the amino acid sequence of a second member of an interaction pair. The interaction pair may be any two polypeptide sequences that interact to form a complex, particularly a heterodimeric complex although operative embodiments may also employ an interaction pair that can form a homodimeric complex. One member of the interaction pair may be fused to a TGF-beta superfamily type I or type II polypeptide as described herein, including for example, a polypeptide sequence comprising, consisting essentially of, or consisting of an amino acid sequence that is at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% identical to the sequence of any one of SEQ ID NOs: 14, 15, 124, 126, 171, 172, 413, 414, 463, 464, 18, 19, 136, 138, 173, 174, 421, 422, 465, 466, 22, 23, 115, 117, 175, 176, 407, 408, 467, 468, 26, 27, 83, 84, 104, 106, 177, 178, 403, 404, 469, 470, 30, 31, 87, 88, 139, 141, 179, 180, 423, 424, 471, 472, 34, 35, 91, 92, 142, 144, 181, 182, 425, 426, 473, 474, 38, 39, 301, 302, 305, 306, 309, 310, 313, 112, 114, 183, 184, 405, 406, 475, 476, 9, 10, 11, 118, 120, 151, 152, 409, 410, 451, 452, 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, 454, 46, 47, 71, 72, 121, 123, 155, 156, 411, 412, 455, 456, 50, 51, 75, 76, 79, 80, 133, 135, 161, 162, 419, 420, 457, 458, 42, 43, 67, 68, 127, 129, 130, 132, 157, 158, 159, 160, 415, 416, 417, 418, 459, 460, 461, and 462. An interaction pair may be selected to confer an improved property/activity such as increased serum half-life, or to act as an adaptor on to which another moiety is attached to provide an improved property/activity. For example, a polyethylene glycol moiety may be attached to one or both components of an interaction pair to provide an improved property/activity such as improved serum half-life.

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The first and second members of the interaction pair may be an asymmetric pair, meaning that the members of the pair preferentially associate with each other rather than self-associate. Accordingly, first and second members of an asymmetric interaction pair may associate to form a heterodimeric complex (see, e.g., FIG. 2 ). Alternatively, the interaction pair may be unguided, meaning that the members of the pair may associate with each other or self-associate without substantial preference and thus may have the same or different amino acid sequences. Accordingly, first and second members of an unguided interaction pair may associate to form a homodimer complex or a heterodimeric complex. Optionally, the first member of the interaction pair (e.g., an asymmetric pair or an unguided interaction pair) associates covalently with the second member of the interaction pair. Optionally, the first member of the interaction pair (e.g., an asymmetric pair or an unguided interaction pair) associates non-covalently with the second member of the interaction pair.

As specific examples, the present disclosure provides fusion proteins comprising TGF-beta superfamily type I or type II polypeptides fused to a polypeptide comprising a constant domain of an immunoglobulin, such as a CH1, CH2, or CH3 domain of an immunoglobulin or an Fc domain. Fc domains derived from human IgG1, IgG2, IgG3, and IgG4 are provided herein. Other mutations are known that decrease either CDC or ADCC activity, and collectively, any of these variants are included in the disclosure and may be used as advantageous components of a heteromultimeric complex of the disclosure. Optionally, the IgG1 Fc domain of SEQ ID NO: 208 has one or more mutations at residues such as Asp-265, Lys-322, and Asn-434 (numbered in accordance with the corresponding full-length IgG1). In certain cases, the mutant Fc domain having one or more of these mutations (e.g., Asp-265 mutation) has reduced ability of binding to the Fcγ receptor relative to a wildtype Fc domain. In other cases, the mutant Fc domain having one or more of these mutations (e.g., Asn-434 mutation) has increased ability of binding to the MHC class I-related Fc-receptor (FcRN) relative to a wildtype Fc domain.

An example of a native amino acid sequence that may be used for the Fc portion of human IgG1 (G1Fc) is shown below (SEQ ID NO: 208). Dotted underline indicates the hinge region, and solid underline indicates positions with naturally occurring variants. In part, the disclosure provides polypeptides comprising, consisting of, or consisting essentially of an amino acid sequence with 70%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to SEQ ID NO: 208. Naturally occurring variants in G1Fc would include E134D and M136L according to the numbering system used in SEQ ID NO: 208 (see Uniprot P01857).

An example of a native amino acid sequence that may be used for the Fc portion of human IgG2 (G2Fc) is shown below (SEQ ID NO: 209). Dotted underline indicates the hinge region and double underline indicates positions where there are data base conflicts in the sequence (according to UniProt P01859). In part, the disclosure provides polypeptides comprising, consisting of, or consisting essentially of an amino acid sequence with 70%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to SEQ ID NO: 209.

Two examples of amino acid sequences that may be used for the Fc portion of human IgG3 (G3Fc) are shown below. The hinge region in G3Fc can be up to four times as long as in other Fc chains and contains three identical 15-residue segments preceded by a similar 17-residue segment. The first G3Fc sequence shown below (SEQ ID NO: 210) contains a short hinge region consisting of a single 15-residue segment, whereas the second G3Fc sequence (SEQ ID NO: 211) contains a full-length hinge region. In each case, dotted underline indicates the hinge region, and solid underline indicates positions with naturally occurring variants according to UniProt P01859. In part, the disclosure provides polypeptides comprising, consisting of, or consisting essentially of an amino acid sequence with 70%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to SEQ ID NOs: 210 and 211.

Naturally occurring variants in G3Fc (for example, see Uniprot P01860) include E68Q, P76L, E79Q, Y81F, D97N, N100D, T124A, S169N, S169del, F221Y when converted to the numbering system used in SEQ ID NO: 210, and the present disclosure provides fusion proteins comprising G3Fc domains containing one or more of these variations. In addition, the human immunoglobulin IgG3 gene (IGHG3) shows a structural polymorphism characterized by different hinge lengths [see Uniprot P01859]. Specifically, variant WIS is lacking most of the V region and all of the CH1 region. It has an extra interchain disulfide bond at position 7 in addition to the 11 normally present in the hinge region. Variant ZUC lacks most of the V region, all of the CH1 region, and part of the hinge. Variant OMM may represent an allelic form or another gamma chain subclass. The present disclosure provides additional fusion proteins comprising G3Fc domains containing one or more of these variants.

An example of a native amino acid sequence that may be used for the Fc portion of human IgG4 (G4Fc) is shown below (SEQ ID NO: 212). Dotted underline indicates the hinge region. In part, the disclosure provides polypeptides comprising, consisting of, or consisting essentially of an amino acid sequence with 70%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to SEQ ID NO: 212.

A variety of engineered mutations in the Fc domain are presented herein with respect to the G1Fc sequence (SEQ ID NO: 208), and analogous mutations in G2Fc, G3Fc, and G4Fc can be derived from their alignment with G1Fc in FIG. 5 . Due to unequal hinge lengths, analogous Fc positions based on isotype alignment ( FIG. 5 ) possess different amino acid numbers in SEQ ID NOs: 208, 209, 210, and 212. It can also be appreciated that a given amino acid position in an immunoglobulin sequence consisting of hinge, CH2, and CH3 regions (e.g., SEQ ID NOs: 208, 209, 210, 211, or 212) will be identified by a different number than the same position when numbering encompasses the entire IgG1 heavy-chain constant domain (consisting of the C H 1, hinge, CH2, and CH3 regions) as in the Uniprot database. For example, correspondence between selected CH3 positions in a human G1Fc sequence (SEQ ID NO: 208), the human IgG1 heavy chain constant domain (Uniprot P01857), and the human IgG1 heavy chain is as follows.

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A problem that arises in large-scale production of asymmetric immunoglobulin-based proteins from a single cell line is known as the “chain association issue”. As confronted prominently in the production of bispecific antibodies, the chain association issue concerns the challenge of efficiently producing a desired multichain protein from among the multiple combinations that inherently result when different heavy chains and/or light chains are produced in a single cell line [see, for example, Klein et al (2012) mAbs 4:653-663]. This problem is most acute when two different heavy chains and two different light chains are produced in the same cell, in which case there are a total of 16 possible chain combinations (although some of these are identical) when only one is typically desired. Nevertheless, the same principle accounts for diminished yield of a desired multichain fusion protein that incorporates only two different (asymmetric) heavy chains.

Various methods are known in the art that increase desired pairing of Fc-containing fusion polypeptide chains in a single cell line to produce a preferred asymmetric fusion protein at acceptable yields [see, for example, Klein et al (2012) mAbs 4:653-663; and Spiess et al (2015) Molecular Immunology 67(2A): 95-106]. Methods to obtain desired pairing of Fc-containing chains include, but are not limited to, charge-based pairing (electrostatic steering), “knobs-into-holes” steric pairing, SEEDbody pairing, and leucine zipper-based pairing. See, for example, Ridgway et al (1996) Protein Eng 9:617-621; Merchant et al (1998) Nat Biotech 16:677-681; Davis et al (2010) Protein Eng Des Sel 23:195-202; Gunasekaran et al (2010); 285:19637-19646; Wranik et al (2012) J Biol Chem 287:43331-43339; U.S. Pat. No. 5,932,448; WO 1993/011162; WO 2009/089004, and WO 2011/034605. As described herein, these methods may be used to generate heterodimers comprising TGF-beta superfamily type I and type II receptor polypeptides, at least two different TGF-beta superfamily type I receptor polypeptides, and at least two different TGF-beta superfamily type II receptor polypeptides. See FIGS. 15-17 .

For example, one means by which interaction between specific polypeptides may be promoted is by engineering protuberance-into-cavity (knob-into-holes) complementary regions such as described in Arathoon et al., U.S. Pat. No. 7,183,076 and Carter et al., U.S. Pat. No. 5,731,168. “Protuberances” are constructed by replacing small amino acid side chains from the interface of the first polypeptide (e.g., a first interaction pair) with larger side chains (e.g., tyrosine or tryptophan). Complementary “cavities” of identical or similar size to the protuberances are optionally created on the interface of the second polypeptide (e.g., a second interaction pair) by replacing large amino acid side chains with smaller ones (e.g., alanine or threonine). Where a suitably positioned and dimensioned protuberance or cavity exists at the interface of either the first or second polypeptide, it is only necessary to engineer a corresponding cavity or protuberance, respectively, at the adjacent interface.

At neutral pH (7.0), aspartic acid and glutamic acid are negatively charged and lysine, arginine, and histidine are positively charged. These charged residues can be used to promote heterodimer formation and at the same time hinder homodimer formation. Attractive interactions take place between opposite charges and repulsive interactions occur between like charges. In part, protein complexes disclosed herein make use of the attractive interactions for promoting heteromultimer formation (e.g., heterodimer formation), and optionally repulsive interactions for hindering homodimer formation (e.g., homodimer formation) by carrying out site directed mutagenesis of charged interface residues.

For example, the IgG1 CH3 domain interface comprises four unique charge residue pairs involved in domain-domain interactions: Asp356-Lys439′, Glu357-Lys370′, Lys392-Asp399′, and Asp399-Lys409′ [residue numbering in the second chain is indicated by (′)]. It should be noted that the numbering scheme used here to designate residues in the IgG1 CH3 domain conforms to the EU numbering scheme of Kabat. Due to the 2-fold symmetry present in the CH3-CH3 domain interactions, each unique interaction will represented twice in the structure (e.g., Asp-399-Lys409′ and Lys409-Asp399′). In the wild-type sequence, K409-D399′ favors both heterodimer and homodimer formation. A single mutation switching the charge polarity (e.g., K409E; positive to negative charge) in the first chain leads to unfavorable interactions for the formation of the first chain homodimer. The unfavorable interactions arise due to the repulsive interactions occurring between the same charges (negative-negative; K409E-D399′ and D399-K409E′). A similar mutation switching the charge polarity (D399K′; negative to positive) in the second chain leads to unfavorable interactions (K409′-D399K′ and D399K-K409′) for the second chain homodimer formation. But, at the same time, these two mutations (K409E and D399K′) lead to favorable interactions (K409E-D399K′ and D399-K409′) for the heterodimer formation.

The electrostatic steering effect on heterodimer formation and homodimer discouragement can be further enhanced by mutation of additional charge residues which may or may not be paired with an oppositely charged residue in the second chain including, for example, Arg355 and Lys360. The table below lists possible charge change mutations that can be used, alone or in combination, to enhance heteromultimer formation of the polypeptide complexes disclosed herein.

In some embodiments, one or more residues that make up the CH3-CH3 interface in a fusion protein of the instant application are replaced with a charged amino acid such that the interaction becomes electrostatically unfavorable. For example, a positive-charged amino acid in the interface (e.g., a lysine, arginine, or histidine) is replaced with a negatively charged amino acid (e.g., aspartic acid or glutamic acid). Alternatively, or in combination with the forgoing substitution, a negative-charged amino acid in the interface is replaced with a positive-charged amino acid. In certain embodiments, the amino acid is replaced with a non-naturally occurring amino acid having the desired charge characteristic. It should be noted that mutating negatively charged residues (Asp or Glu) to His will lead to increase in side chain volume, which may cause steric issues. Furthermore, His proton donor- and acceptor-form depends on the localized environment. These issues should be taken into consideration with the design strategy. Because the interface residues are highly conserved in human and mouse IgG subclasses, electrostatic steering effects disclosed herein can be applied to human and mouse IgG1, IgG2, IgG3, and IgG4. This strategy can also be extended to modifying uncharged residues to charged residues at the CH3 domain interface.

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In part, the disclosure provides desired pairing of asymmetric Fc-containing polypeptide chains using Fc sequences engineered to be complementary on the basis of charge pairing (electrostatic steering). One of a pair of Fc sequences with electrostatic complementarity can be arbitrarily fused to the TGF-beta superfamily type I or type II receptor polypeptide of the construct, with or without an optional linker, to generate a TGF-beta superfamily type I or type II receptor fusion polypeptide This single chain can be coexpressed in a cell of choice along with the Fc sequence complementary to the first Fc to favor generation of the desired multichain construct (e.g., a TGF-beta superfamily heteromeric complex). In this example based on electrostatic steering, SEQ ID NO: 200 [human G1Fc(E134K/D177K)] and SEQ ID NO: 201 [human G1Fc(K170D/K187D)] are examples of complementary Fc sequences in which the engineered amino acid substitutions are double underlined, and the TGF-beta superfamily type I or type II receptor polypeptide of the construct can be fused to either SEQ ID NO: 200 or SEQ ID NO: 201, but not both. Given the high degree of amino acid sequence identity between native hG1Fc, native hG2Fc, native hG3Fc, and native hG4Fc, it can be appreciated that amino acid substitutions at corresponding positions in hG2Fc, hG3Fc, or hG4Fc (see FIG. 5 ) will generate complementary Fc pairs which may be used instead of the complementary hG1Fc pair below (SEQ ID NOs: 200 and 201).

In part, the disclosure provides desired pairing of asymmetric Fc-containing polypeptide chains using Fc sequences engineered for steric complementarity. In part, the disclosure provides knobs-into-holes pairing as an example of steric complementarity. One of a pair of Fc sequences with steric complementarity can be arbitrarily fused to the TGF-beta superfamily type I or type II polypeptide of the construct, with or without an optional linker, to generate a TGF-beta superfamily type I or type II fusion polypeptide. This single chain can be coexpressed in a cell of choice along with the Fc sequence complementary to the first Fc to favor generation of the desired multichain construct. In this example based on knobs-into-holes pairing, SEQ ID NO: 202 [human G1Fc(T144Y)] and SEQ ID NO: 203 [human G1Fc(Y185T)] are examples of complementary Fc sequences in which the engineered amino acid substitutions are double underlined, and the TGF-beta superfamily type I or type II polypeptide of the construct can be fused to either SEQ ID NO: 202 or SEQ ID NO: 203, but not both. Given the high degree of amino acid sequence identity between native hG1Fc, native hG2Fc, native hG3Fc, and native hG4Fc, it can be appreciated that amino acid substitutions at corresponding positions in hG2Fc, hG3Fc, or hG4Fc (see FIG. 5 ) will generate complementary Fc pairs which may be used instead of the complementary hG1Fc pair below (SEQ ID NOs: 202 and 203).

An example of Fc complementarity based on knobs-into-holes pairing combined with an engineered disulfide bond is disclosed in SEQ ID NO: 204 [hG1Fc(S132C/T144W)] and SEQ ID NO: 205 [hG1Fc(Y127C/T144S/L146A/Y185V)]. The engineered amino acid substitutions in these sequences are double underlined, and the TGF-beta superfamily type I or type II polypeptide of the construct can be fused to either SEQ ID NO: 204 or SEQ ID NO: 205, but not both. Given the high degree of amino acid sequence identity between native hG1Fc, native hG2Fc, native hG3Fc, and native hG4Fc, it can be appreciated that amino acid substitutions at corresponding positions in hG2Fc, hG3Fc, or hG4Fc (see FIG. 5 ) will generate complementary Fc pairs which may be used instead of the complementary hG1Fc pair below (SEQ ID NOs: 204 and 205).

In part, the disclosure provides desired pairing of asymmetric Fc-containing polypeptide chains using Fc sequences engineered to generate interdigitating β-strand segments of human IgG and IgA CH3 domains. Such methods include the use of strand-exchange engineered domain (SEED) CH3 heterodimers allowing the formation of SEEDbody fusion proteins [see, for example, Davis et al (2010) Protein Eng Design Sel 23:195-202]. One of a pair of Fc sequences with SEEDbody complementarity can be arbitrarily fused to the TGF-beta superfamily type I or type II polypeptide of the construct, with or without an optional linker, to generate a TGF-beta superfamily type I or type II fusion polypeptide. This single chain can be coexpressed in a cell of choice along with the Fc sequence complementary to the first Fc to favor generation of the desired multichain construct. In this example based on SEEDbody (Sb) pairing, SEQ ID NO: 206 [hG1Fc(SbAG)] and SEQ ID NO: 207 [hG1Fc(SbGA)] are examples of complementary IgG Fc sequences in which the engineered amino acid substitutions from IgA Fc are double underlined, and the TGF-beta superfamily type I or type II polypeptide of the construct can be fused to either SEQ ID NO: 206 or SEQ ID NO: 207, but not both. Given the high degree of amino acid sequence identity between native hG1Fc, native hG2Fc, native hG3Fc, and native hG4Fc, it can be appreciated that amino acid substitutions at corresponding positions in hG1Fc, hG2Fc, hG3Fc, or hG4Fc (see FIG. 5 ) will generate an Fc monomer which may be used in the complementary IgG-IgA pair below (SEQ ID NOs: 206 and 207).

In part, the disclosure provides desired pairing of asymmetric Fc-containing polypeptide chains with a cleavable leucine zipper domain attached at the C-terminus of the Fc CH3 domains. Attachment of a leucine zipper is sufficient to cause preferential assembly of heterodimeric antibody heavy chains. See, e.g., Wranik et al (2012) J Biol Chem 287:43331-43339. As disclosed herein, one of a pair of Fc sequences attached to a leucine zipper-forming strand can be arbitrarily fused to the TGF-beta superfamily type I or type II polypeptide of the construct, with or without an optional linker, to generate a TGF-beta superfamily type I or type II fusion polypeptide. This single chain can be coexpressed in a cell of choice along with the Fc sequence attached to a complementary leucine zipper-forming strand to favor generation of the desired multichain construct. Proteolytic digestion of the construct with the bacterial endoproteinase Lys-C post purification can release the leucine zipper domain, resulting in an Fc construct whose structure is identical to that of native Fc. In this example based on leucine zipper pairing, SEQ ID NO: 213 [hG1Fc-Ap1 (acidic)] and SEQ ID NO: 214 [hG1Fc-Bp1 (basic)] are examples of complementary IgG Fc sequences in which the engineered complimentary leucine zipper sequences are underlined, and the TGF-beta superfamily type I or type II polypeptide of the construct can be fused to either SEQ ID NO: 213 or SEQ ID NO: 214, but not both. Given the high degree of amino acid sequence identity between native hG1Fc, native hG2Fc, native hG3Fc, and native hG4Fc, it can be appreciated that leucine zipper-forming sequences attached, with or without an optional linker, to hG1Fc, hG2Fc, hG3Fc, or hG4Fc (see FIG. 5 ) will generate an Fc monomer which may be used in the complementary leucine zipper-forming pair below (SEQ ID NOs: 213 and 214).

›CTAA · 30 of 34

As described above, various methods are known in the art that increase desired pairing of Fc-containing fusion polypeptide chains in a single cell line to produce a preferred asymmetric fusion protein at acceptable yields [Klein et al (2012) mAbs 4:653-663; and Spiess et al (2015) Molecular Immunology 67(2A): 95-106]. In addition, heteromultimers as described herein may be generated using a combination of heavy and light chain fusion proteins comprising either an TGF-beta superfamily type I or TGF-beta superfamily type II polypeptide. For example, in some embodiments, a TGF-beta superfamily type I receptor polypeptide polypeptide may be fused, with or without a linker domain, to an immunoglobulin heavy chain (IgG1, IgG2, IgG3, IgG4, IgM, IgA1, or IgA2) that comprises at least a portion of the C H 1 domain. Similarly, a TGF-beta superfamily type II receptor polypeptide may be fused, with or without a linker domain, to an immunoglobulin light chain (kappa or lambda) that comprises at least a portion of the light chain constant domain (C L ). In alternative embodiments, a TGF-beta superfamily type I receptor polypeptide may be fused, with or without a linker domain, to an immunoglobulin heavy chain (IgG1, IgG2, IgG3, IgG4, IgM, IgA1, or IgA2) that comprises at least a portion of the C H 1 domain, and a TGF-beta superfamily type II receptor polypeptide may be fused, with or without a linker domain, to an immunoglobulin light chain (kappa or lambda) that comprises at least a portion of the light chain constant domain (C L ). This design takes advantage of the natural ability of the heavy chains to heterodimerize with light chains. In particular, heterodimerization of a heavy and light chain occurs between the C H 1 with the C L , which is generally stabilized by covalent linking of the two domains via a disulfide bridge. Constructs employing the full-length heavy chain, or at least a portion of the heavy chain comprising the hinge region, could give rise to antibody-like molecules comprising two “light chains” and two “heavy chains”. See FIG. 16 . A potential advantage of this design is that it may more closely mimic the naturally occurring TGF-beta superfamily type I receptor polypeptide-ligand-TGF-beta superfamily type II receptor polypeptide complex and may display higher affinity for the ligand than comparable single heterodimers. In some embodiments, this design may be modified by incorporating various heavy chain truncations including, for example, truncations that comprise the C H 1 domain and some or all of the hinge domain (giving rise to F(ab′)2-like molecules) as well as truncations that only comprise the C H 1 domain or a fragment thereof (giving rise to Fab-like molecules). See FIG. 16G . Various methods for designing such heteromultimer constructs are described in US 2009/0010879, Klein et al [(2012) mAbs 4:653-663], and Spiess et al [(2015) Molecular Immunology 67(2A): 95-106] the contents of which are incorporated in their entirety herein.

In some embodiments, it is desirable to generate antibody-like heterodimers comprising at least one branch of the complex comprising an TGF-beta superfamily type I receptor polypeptide-C L :TGF-beta superfamily type II receptor polypeptide-C H 1 heterodimer pair and at least a second branch comprising an TGF-beta superfamily type II receptor polypeptide-C L :TGF-beta superfamily type I receptor polypeptide r-C H 1 heterodimer pair. See, e.g., FIG. 16B . Such heterodimer complexes can be generated, for example, using combinations of heavy chain and light chain asymmetrical pairing technologies [Spiess et al (2015) Molecular Immunology 67(2A): 95-106]. For example, in CrossMab technology, [Schaefer et al (2011). Proc. Natl. Acad. Sci. U.S.A. 108: 11187-11192] light chain mispairing is overcome using domain crossovers and heavy chains heterodimerized using knobs-into-holes [Merchant et al (1998) Nat. Biotechnol. 16: 677-681]. For the domain crossovers either the variable domains or the constant domains are swapped between light and heavy chains to create two asymmetric Fab arms that drive cognate light chain pairing while preserving the structural and functional integrity of the variable domain [Fenn et al (2013) PLoS ONE 8: e61953]. An alternative approach for overcoming light chain mispairing is designing heavy and light chains with orthogonal Fab interfaces [Lewis (2014) Nat. Biotechnol. 32: 191-198]. This has been accomplished by computational modeling [Das et al (2008) Annu. Rev. Biochem. 77: 363-382] in combination with X-ray crystallography to identify mutations at the V H /V L and C H 1/C L interfaces. For the heterodimers generated using this methodology, it may be necessary to engineer mutations into both V H /V L and C H 1/C L interfaces to minimize heavy/light chain mispairing. The designed orthogonal Fab interface may be used in conjunction with a heavy chain heterodimerization strategy to facilitate efficient IgG production in a single host cell. Electrostatic steering may also be used to generate orthogonal Fab interfaces to facilitate the construction of such heterodimers. Peptide linkers may be used to ensure cognate pairing of light and heavy chains in a format known as “LUZ-Y” [Wranik et al (2012) J. Biol. Chem. 287: 43331-43339], wherein heavy chain heterodimerization is accomplished using leucine zippers which may be subsequently removed by proteolysis in vitro.

Alternatively, heteromultimers may comprise one or more single-chain ligand traps as described herein, optionally which may be covalently or non-covalently associated with one or more TGF-beta superfamily type I receptor polypeptides or TGF-beta superfamily type I receptor polypeptides as well as additional TGF-beta superfamily type I receptor polypeptide:TGF-beta superfamily type II receptor polypeptide single chain ligand traps [US 2011/0236309 and US2009/0010879]. See FIG. 12 . As described herein, single-chain ligand traps do not require fusion to any multimerization domain such as coiled-coil Fc domains to be multivalent. In general, single-chain ligand traps of the present disclosure comprise at least one TGF-beta superfamily type I receptor polypeptide domain and one TGF-beta superfamily type I receptor polypeptide domain. The TGF-beta superfamily type I receptor polypeptide and TGF-beta superfamily type I receptor polypeptide domains, generally referred to herein as binding domains (BD), optionally may be joined by a linker region.

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For example, in one aspect, the present disclosure provides heteromultimers comprising a polypeptide having the following structure:

(<BD1>-linker1) k -[<BD2>-linker2-{<BD3>-linker3} f ] n -(<BD4>) m -(linker4-BD5> d ) h

where: n and h are independently greater than or equal to one; d, f, m, and k are independently equal to or greater than zero; BD1, BD2, BD3, BD4, and BD5 are independently TGF-beta superfamily type I receptor polypeptide or TGF-beta superfamily type II receptor polypeptide domains, wherein at least one of BD1, BD2, BD3, and BD4 is an TGF-beta superfamily type I receptor polypeptide domain, and wherein at least one of BD1, BD2, BD3, and BD4 is an TGF-beta superfamily type II receptor polypeptide domain, and linker1, linker2, linker3, and linker 4 are independently greater than or equal to zero. In some embodiment, TGF-beta superfamily type I receptor polypeptide:TGF-beta superfamily type II receptor polypeptide single-chain traps comprise at least two different TGF-beta superfamily type I receptor polypeptide. In some embodiments, TGF-beta superfamily type I receptor polypeptide:TGF-beta superfamily type II receptor polypeptide single-chain traps comprise at least two different TGF-beta superfamily type II receptor polypeptide polypeptides. In some embodiment, TGF-beta superfamily type I receptor polypeptide:TGF-beta superfamily type I receptor polypeptide single-chain traps comprise at least two different linkers. Depending on the values of selected for d, f, h, k, m, and n, the heteromultimer structure may comprise a large number of repeating units in various combinations or may be a relatively simple structure.

In another aspect, the present disclosure provides heteromultimers comprising a polypeptide having the following structure:

<BD 1>-linker 1-<BD2>

In yet another aspect, the present disclosure provides heteromultimers comprising a polypeptide having the following structure:

<BD 1>-(linker2-<BD2>) n

where n is greater than or equal one.

Another aspect of the invention provides heteromultimers comprising a polypeptide having the following structure:

(<BD1>-linker1-<BD 1>) f -linker2-(<BD2>-linker3-<BD3>) g

wherein f and g are greater than or equal to one.

In an embodiment where BD2 and BD3 are the same, and f and g are the same number, this can result in a substantially mirror symmetric structure around linker 2, subject to differences in the linkers. In instances where BD2 is different from BD3 and/or where f and g are different numbers, different structures will be produced. It is within the capacity of one of ordinary skill in the art to select suitable binding domains, linkers, and repeat frequencies in light of the disclosure herein and knowledge in the art. Specific, non-limiting examples of such single-chain ligand traps in accordance with the present disclosure are represented schematically in FIG. 18 .

The linkers (1, 2, 3, and 4) may be the same or different. The linker region provides a segment that is distinct from the structured ligand-binding domains of TGF-beta superfamily type I receptor polypeptide and TGF-beta superfamily type II receptor polypeptide and thus can be used for conjugation to accessory molecules (e.g., molecules useful in increasing stability such as PEGylation moieties) without having to chemically modify the binding domains. The linker may include an unstructured amino acid sequence that may be either the same as or derived from conservative modifications to the sequence of a natural unstructured region in the extracellular portion of the receptor for the ligand of interest or another receptor in the TGF-β superfamily. In other instances, such linkers may be entirely artificial in composition and origin but will contain amino acids selected to provide an unstructured flexible linker with a low likelihood of encountering electrostatic or steric hindrance complications when brought into close proximity to the ligand of interest. Linker length will be considered acceptable when it permits binding domains located on each of the N- and C-termini of the linker to bind their natural binding sites on their natural ligand such that, with both binding domains so bound, the ligand is bound with a higher affinity than it would be bound by binding of only one of the binding domains. In some instances, the number of amino acid residues in the linker of either natural or artificial origin is selected to be equal to or greater than the minimum required distance for simultaneous (bridged) binding to two binding sites on the TGF-beta superfamily type I receptor polypeptide and/or TGF-beta superfamily type II receptor polypeptide ligand. For example, and without wishing to be limiting in any manner, the linker length may be between about 1-10 amino acids, 10-20 amino acids, 18-80 amino acids, 25-60 amino acids, 35-45 amino acids, or any other suitable length.

Linkers may be designed to facilitate purification of the polypeptide. The exact purification scheme chosen will determine what modifications are needed, for example and without wishing to be limiting, additions of purification “tags” such as His tags is contemplated; in other examples, the linker may include regions to facilitate the addition of cargo or accessory molecules. When such additions affect the unstructured nature of the linker or introduce potential electrostatic or steric concerns, appropriate increases to the linker length will be made to ensure that the two binding domains are able to bind their respective sites on the ligand. In light of the methods and teachings herein, such determinations could be made routinely by one skilled in the art.

In addition, the present design permits linkage of other cargo molecules (for example imaging agents like fluorescent molecules), toxins, etc. For example, and without wishing to be limiting in any manner, single-chain polypeptides can be modified to add one or more cargo and/or accessory molecules (referred to collectively herein by R1, R2, R3, R4, etc.):

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Without limiting the generality of R substituents available, R1, R2, R3, R4, R5, R6, R7, R8, R9, may or may not be present; when present, they may be the same or different, and may independently be one or more of: a fusion protein for targeting, for example, but not limited to such as an antibody fragment (e.g. single chain Fv) and/or a single domain antibody (sdAb); a radiotherapy and/or imaging agent, for example, but not limited to a radionuceotide (e.g. 123 I, 111 In, 18 F, 64 C, 68 Y, 124 I, 131 I, 90 Y, 177 Lu, 57 Cu, 213 Bi, 211 At), a fluorescent dye (e.g. Alexa Fluor, Cy dye) and/or a fluorescent protein tag (e.g. GFP, DsRed); a cytotoxic agent for chemotherapy, for example, but not limited to doxorubicin, calicheamicin, a maytansinoid derivatives (e.g. DM1, DM4), a toxin (eg. truncated Pseudomonas endotoxin A, diphteria toxin); a nanoparticle-based carrier, for example, but not limited to polyethylene glycol (PEG), a polymer-conjugated to drug, nanocarrier or imaging agent (e.g. of a polymer N-(2-hydorxylpropyl) methacrylamide (HPMA), glutamic acid, PEG, dextran); a drug (for example, but not limited to doxorubicin, camptothecin, paclitaxel, palatinate); a nanocarrier, for example, but not limited to a nanoshell or liposome; an imaging agent, for example, but not limited to Supermagnetic Iron Oxide (SPIO); a dendrimer; and/or a solid support for use in ligand purification, concentration or sequestration (e.g. nanoparticles, inert resins, suitable silica supports).

In general, it will not be preferable to have cargo or accessory molecules in all possible positions, as this may cause steric or electrostatic complications. However, the effects of adding a cargo or accessory molecule to any given position or positions on the structure can be determined routinely in light of the disclosure herein by modeling the linker between the binding domains and carrying out molecular dynamics simulations to substantially minimize molecular mechanics energy and reduce steric and electrostatic incompatibility between the linker and the TGF-beta superfamily type I receptor polypeptide and TGF-beta superfamily type II receptor polypeptideas taught herein.

It may be preferable to add the cargo or accessory molecule to the linker portion of the agent, rather to the binding domain, to reduce the likelihood of interference in binding function. However, addition to the binding domain is possible and could be desirable in some instances and the effect of such an addition can be determined routinely in advance by modeling the binding agent and the linker with the proposed addition as described herein.

Conjugation methodologies may be performed using commercial kits that enable conjugation via common reactive groups such as primary amines, succinimidyl (NHS) esters and sulfhydral-reactive groups. Some non-limiting examples are: Alexa Fluor 488 protein labeling kit (Molecular Probes, Invitrogen detection technologies) and PEGylation kits (Pierce Biotechnology Inc.).

In certain aspects, TGF-beta superfamily type I receptor polypeptide:TGF-beta superfamily type II receptor polypeptide single-chain traps may be covalently or non-covalently associated with one or more TGF-beta superfamily type I receptor polypeptides or TGF-beta superfamily type II receptor polypeptide as well as additional TGF-beta superfamily type I receptor polypeptide:TGF-beta superfamily type II receptor polypeptide single chain ligand traps to form higher order heteromultimers, which may be used in accordance with the methods described herein. See, e.g., FIG. 19 . For example, an TGF-beta superfamily type I receptor polypeptide: TGF-beta superfamily type II receptor polypeptide single chain ligand trap may further comprise a multimerization domain as described herein. In some embodiments, TGF-beta superfamily type I receptor polypeptide:TGF-beta superfamily type II receptor polypeptide single chain ligand traps comprise a constant domain of an Ig immunoglobulin. Such immunoglobulins constant domains may be selected to promote symmetrical or asymmetrical complexes comprising at least one single-chain TGF-beta superfamily type I receptor polypeptide:TGF-beta superfamily type II receptor polypeptide trap.

In certain aspects, an TGF-beta superfamily type I receptor polypeptide: TGF-beta superfamily type II receptor polypeptide single-chain trap, or combinations of such traps, may be used as TGF-beta superfamily antagonists to treat or prevent an TGF-beta superfamily disorder or disease as described herein (e.g., kidney disease and/or a metabolic disorder or condition).

It is understood that different elements of the fusion proteins (e.g., immunoglobulin Fc fusion proteins) may be arranged in any manner that is consistent with desired functionality. For example, a TGF-beta superfamily type I and/or type II receptor polypeptide domain may be placed C-terminal to a heterologous domain, or alternatively, a heterologous domain may be placed C-terminal to a TGF-beta superfamily type I and/or type II receptor polypeptide domain. The TGF-beta superfamily type I and/or type II receptor polypeptide domain and the heterologous domain need not be adjacent in a fusion protein, and additional domains or amino acid sequences may be included C- or N-terminal to either domain or between the domains.

For example, a TGF-beta superfamily type I and/or type II receptor fusion protein may comprise an amino acid sequence as set forth in the formula A-B-C. The B portion corresponds to a TGF-beta superfamily type I and/or type II receptor polypeptide domain. The A and C portions may be independently zero, one, or more than one amino acid, and both the A and C portions when present are heterologous to B. The A and/or C portions may be attached to the B portion via a linker sequence. A linker may be rich in glycine (e.g., 2-10, 2-5, 2-4, 2-3 glycine residues) or glycine and proline residues and may, for example, contain a single sequence of threonine/serine and glycines or repeating sequences of threonine/serine and/or glycines, e.g., GGG (SEQ ID NO: 58), GGGG (SEQ ID NO: 59), TGGGG (SEQ ID NO: 60), SGGGG (SEQ ID NO: 61), TGGG (SEQ ID NO: 62), or SGGG (SEQ ID NO: 63) singlets, or repeats. In certain embodiments, a TGF-beta superfamily type I and/or type II receptor fusion protein comprises an amino acid sequence as set forth in the formula A-B-C, wherein A is a leader (signal) sequence, B consists of a TGF-beta superfamily type I and/or type II receptor polypeptide domain, and C is a polypeptide portion that enhances one or more of in vivo stability, in vivo half-life, uptake/administration, tissue localization or distribution, formation of protein complexes, and/or purification. In certain embodiments, a TGF-beta superfamily type I and/or type II receptor fusion protein comprises an amino acid sequence as set forth in the formula A-B-C, wherein A is a TPA leader sequence, B consists of a TGF-beta superfamily type I and/or type II receptor polypeptide domain, and C is an immunoglobulin Fc domain. Preferred fusion proteins comprise the amino acid sequence set forth in any one of SEQ ID NOs: 100, 102, 104, 106, 112, 114, 115, 117, 118, 120, 121, 123, 124, 126, 127, 129, 401, 402, 403, 404, 405, 406, 407, 408, 409, 410, 411, 412, 413, 414, 415, and 416.

›CTAA · 33 of 34

In some embodiments, TGF-beta superfamily receptor heteromultimer complexes of the present disclosure further comprise one or more heterologous portions (domains) so as to confer a desired property. For example, some fusion domains are particularly useful for isolation of the fusion proteins by affinity chromatography. Well-known examples of such fusion domains include, but are not limited to, polyhistidine, Glu-Glu, glutathione S-transferase (GST), thioredoxin, protein A, protein G, an immunoglobulin heavy-chain constant region (Fc), maltose binding protein (MBP), or human serum albumin. For the purpose of affinity purification, relevant matrices for affinity chromatography, such as glutathione-, amylase-, and nickel- or cobalt-conjugated resins are used. Many of such matrices are available in “kit” form, such as the Pharmacia GST purification system and the QIAexpress™ system (Qiagen) useful with (HIS6 (SEQ ID NO: 509)) fusion partners. As another example, a fusion domain may be selected so as to facilitate detection of the ligand trap polypeptides. Examples of such detection domains include the various fluorescent proteins (e.g., GFP) as well as “epitope tags,” which are usually short peptide sequences for which a specific antibody is available. Well-known epitope tags for which specific monoclonal antibodies are readily available include FLAG, influenza virus haemagglutinin (HA), and c-myc tags. In some cases, the fusion domains have a protease cleavage site, such as for factor Xa or thrombin, which allows the relevant protease to partially digest the fusion proteins and thereby liberate the recombinant proteins therefrom. The liberated proteins can then be isolated from the fusion domain by subsequent chromatographic separation.

In certain embodiments, TGF-beta superfamily type I and/or type II receptor polypeptides of the present disclosure contain one or more modifications that are capable of stabilizing the polypeptides. For example, such modifications enhance the in vitro half-life of the polypeptides, enhance circulatory half-life of the polypeptides, and/or reduce proteolytic degradation of the polypeptides. Such stabilizing modifications include, but are not limited to, fusion proteins (including, for example, fusion proteins comprising a TGF-beta superfamily type I and/or type II receptor polypeptide domain and a stabilizer domain), modifications of a glycosylation site (including, for example, addition of a glycosylation site to a polypeptide of the disclosure), and modifications of carbohydrate moiety (including, for example, removal of carbohydrate moieties from a polypeptide of the disclosure). As used herein, the term “stabilizer domain” not only refers to a fusion domain (e.g., an immunoglobulin Fc domain) as in the case of fusion proteins, but also includes nonproteinaceous modifications such as a carbohydrate moiety, or nonproteinaceous moiety, such as polyethylene glycol.

In preferred embodiments, TGF-beta superfamily heteromultimer complexes to be used in accordance with the methods described herein are isolated polypeptide complexes. As used herein, an isolated protein (or protein complex) or polypeptide (or polypeptide complex) is one which has been separated from a component of its natural environment. In some embodiments, a heteromultimer complex of the disclosure is purified to greater than 95%, 96%, 97%, 98%, or 99% purity as determined by, for example, electrophoretic (e.g., SDS-PAGE, isoelectric focusing (IEF), capillary electrophoresis) or chromatographic (e.g., ion exchange or reverse phase HPLC). Methods for assessment of antibody purity are well known in the art [See, e.g., Flatman et al., (2007) J. Chromatogr. B 848:79-87]. In some embodiments, heteromultimer preparations of the disclosure are substantially free of TGF-beta superfamily type I receptor polypeptide homomultimers and/or TGF-beta superfamily type II receptor polypeptide homomultimers. For example, in some embodiments, heteromultimer preparations comprise less than about 10%, 9%, 8%, 7%, 5%, 4%, 3%, 2%, or less than 1% of TGF-beta superfamily type I receptor polypeptide homomultimers. In some embodiments, heteromultimer preparations comprise less than about 10%, 9%, 8%, 7%, 5%, 4%, 3%, 2%, or less than 1% of TGF-beta superfamily type II receptor polypeptide homomultimers. In some embodiments, heteromultimer preparations comprise less than about 10%, 9%, 8%, 7%, 5%, 4%, 3%, 2%, or less than 1% of TGF-beta superfamily type I receptor polypeptide homomultimers and less than about 10%, 9%, 8%, 7%, 5%, 4%, 3%, 2%, or less than 1% of TGF-beta superfamily type II receptor polypeptide homomultimers.

In certain embodiments, TGFβ superfamily type I and/or type II receptor polypeptides, as well as heteromultimer complexes thereof, of the disclosure can be produced by a variety of art-known techniques. For example, polypeptides of the disclosure can be synthesized using standard protein chemistry techniques such as those described in Bodansky, M. Principles of Peptide Synthesis, Springer Verlag, Berlin (1993) and Grant G. A. (ed.), Synthetic Peptides: A User's Guide, W. H. Freeman and Company, New York (1992). In addition, automated peptide synthesizers are commercially available (see, e.g., Advanced ChemTech Model 396; Milligen/Biosearch 9600). Alternatively, the polypeptides and complexes of the disclosure, including fragments or variants thereof, may be recombinantly produced using various expression systems [e.g., E. coli , Chinese Hamster Ovary (CHO) cells, COS cells, baculovirus] as is well known in the art. In a further embodiment, the modified or unmodified polypeptides of the disclosure may be produced by digestion of recombinantly produced full-length TGFβ superfamily type I and/or type II receptor polypeptides by using, for example, a protease, e.g., trypsin, thermolysin, chymotrypsin, pepsin, or paired basic amino acid converting enzyme (PACE). Computer analysis (using a commercially available software, e.g., MacVector, Omega, PCGene, Molecular Simulation, Inc.) can be used to identify proteolytic cleavage sites.

›CTAA · 34 of 34

With respect to antibodies that bind to and antagonize ligands that bind to TGF-beta type I receptor polypeptide:TGF-beta type II receptor polypeptide heteromultimers of the disclosure (e.g., BMP2, BMP2/7, BMP3, BMP4, BMP4/7, BMP5, BMP6, BMP7, BMP8a, BMP8b, BMP9, BMP10, GDF3, GDF5, GDF6/BMP13, GDF7, GDF8, GDF9b/BMP15, GDF11/BMP11, GDF15/MIC1, TGF-β1, TGF-β2, TGF-β3, activin A, activin B, activin C, activin E, activin AB, activin AC, activin AE, activin BC, activin BE, nodal, glial cell-derived neurotrophic factor (GDNF), neurturin, artemin, persephin, MIS, and Lefty) it is contemplated that an antibody may be designed as a bispecific antibody comprising a first portion that binds to an epitope of such ligand, such that the first portion of the antibody competes for binding with a type I receptor and comprising a second portion that binds to an epitope of such ligand, such that the second portion of the antibody competes for binding with a type II receptor. In this manner, a bispecific antibody targeting a single ligand can be designed to mimic the dual type I-type II receptor binding blockade that may be conferred by an ALK7:ActRIIB heteromultimer. Similarly it is contemplated that the same effect could be achieved using a combination of two or more antibodies wherein at least a first antibody binds to an epitope of such ligand, such that the first antibody competes for binding with a type I receptor and at least a second antibody binds to an epitope of such ligand, such that the second antibody competes for binding with a type II receptor.

B. Nucleic Acids Encoding TGFβ Superfamily Type I and/or Type II Receptor Polypeptides

In certain embodiments, the present disclosure provides isolated and/or recombinant nucleic acids encoding TGFβ superfamily type I and/or type II receptors (including fragments, functional variants, and fusion proteins thereof) disclosed herein. For example, SEQ ID NO: 12 encodes the naturally occurring human ActRIIA precursor polypeptide, while SEQ ID NO: 13 encodes the mature, extracellular domain of ActRIIA. The subject nucleic acids may be single-stranded or double stranded. Such nucleic acids may be DNA or RNA molecules. These nucleic acids may be used, for example, in methods for making TGF-beta superfamily heteromultimer complexes of the present disclosure.

As used herein, isolated nucleic acid(s) refers to a nucleic acid molecule that has been separated from a component of its natural environment. An isolated nucleic acid includes a nucleic acid molecule contained in cells that ordinarily contain the nucleic acid molecule, but the nucleic acid molecule is present extrachromosomally or at a chromosomal location that is different from its natural chromosomal location.

In certain embodiments, nucleic acids encoding TGFβ superfamily type I and/or type II receptor polypeptides of the present disclosure are understood to include nucleic acids that are variants of any one of SEQ ID NOs: 7, 8, 12, 13, 16, 17, 20, 21, 24, 25, 28, 29, 32, 33, 36, 37, 40, 41, 44, 45, 48, 49, 52, 53, 69, 70, 73, 74, 77, 78, 81, 82, 85, 86, 89, 90, 93, 94, 303, 304, 307, 308, 311, 312, 101, 105, 113, 116, 119, 122, 125, 128, 131, 134, 137, 140, and 143. Variant nucleotide sequences include sequences that differ by one or more nucleotide substitutions, additions, or deletions including allelic variants, and therefore, will include coding sequences that differ from the nucleotide sequence designated in any one of SEQ ID NOs: 7, 8, 12, 13, 16, 17, 20, 21, 24, 25, 28, 29, 32, 33, 36, 37, 40, 41, 44, 45, 48, 49, 52, 53, 69, 70, 73, 74, 77, 78, 81, 82, 85, 86, 89, 90, 93, 94, 303, 304, 307, 308, 311, 312, 101, 105, 113, 116, 119, 122, 125, 128, 131, 134, 137, 140, and 143.

In certain embodiments, TGFβ superfamily type I and/or type II receptor polypeptides of the present disclosure are encoded by isolated or recombinant nucleic acid sequences that are at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NOs: 7, 8, 12, 13, 16, 17, 20, 21, 24, 25, 28, 29, 32, 33, 36, 37, 40, 41, 44, 45, 48, 49, 52, 53, 69, 70, 73, 74, 77, 78, 81, 82, 85, 86, 89, 90, 93, 94, 303, 304, 307, 308, 311, 312, 101, 105, 113, 116, 119, 122, 125, 128, 131, 134, 137, 140, and 143. One of ordinary skill in the art will appreciate that nucleic acid sequences that are at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identical to the sequences complementary to SEQ ID NOs: 7, 8, 12, 13, 16, 17, 20, 21, 24, 25, 28, 29, 32, 33, 36, 37, 40, 41, 44, 45, 48, 49, 52, 53, 69, 70, 73, 74, 77, 78, 81, 82, 85, 86, 89, 90, 93, 94, 303, 304, 307, 308, 311, 312, 101, 105, 113, 116, 119, 122, 125, 128, 131, 134, 137, 140, and 143 are also within the scope of the present disclosure. In further embodiments, the nucleic acid sequences of the disclosure can be isolated, recombinant, and/or fused with a heterologous nucleotide sequence or in a DNA library.

In other embodiments, nucleic acids of the present disclosure also include nucleotide sequences that hybridize under highly stringent conditions to the nucleotide sequence designated in SEQ ID NOs: 7, 8, 12, 13, 16, 17, 20, 21, 24, 25, 28, 29, 32, 33, 36, 37, 40, 41, 44, 45, 48, 49, 52, 53, 69, 70, 73, 74, 77, 78, 81, 82, 85, 86, 89, 90, 93, 94, 303, 304, 307, 308, 311, 312, 101, 105, 113, 116, 119, 122, 125, 128, 131, 134, 137, 140, and 143, the complement sequence of SEQ ID NOs: 7, 8, 12, 13, 16, 17, 20, 21, 24, 25, 28, 29, 32, 33, 36, 37, 40, 41, 44, 45, 48, 49, 52, 53, 69, 70, 73, 74, 77, 78, 81, 82, 85, 86, 89, 90, 93, 94, 303, 304, 307, 308, 311, 312, 101, 105, 113, 116, 119, 122, 125, 128, 131, 134, 137, 140, and 143, or fragments thereof. One of ordinary skill in the art will understand readily that appropriate stringency conditions which promote DNA hybridization can be varied. For example, one could perform the hybridization at 6.0× sodium chloride/sodium citrate (SSC) at about 45° C., followed by a wash of 2.0×SSC at 50° C. For example, the salt concentration in the wash step can be selected from a low stringency of about 2.0×SSC at 50° C. to a high stringency of about 0.2×SSC at 50° C. In addition, the temperature in the wash step can be increased from low stringency conditions at room temperature, about 22° C., to high stringency conditions at about 65° C. Both temperature and salt may be varied, or temper

›Tables in the description — 166

(SEQ ID NO: 1) 1

MTAPWVALAL LWGSLCAGS	G RGEAETRECI YYNANWELER T N QSGLERCE
51
GEQDKRLHCY ASWR N SSGTI ELVKKGCWLD DFNCYDRQEC VATEENPQVY
101	FCCCEGNFCN ERFTHLPEAG GPEVTYEPPP TAPT LLTVLA YSLLPIGGLS
151	LIVLLAFWMY RHRKPPYGHV DIHEDPGPPP PSPLVGLKPL QLLEIKARGR
201	FGCVWKAQLM NDFVAVKIFP LQDKQSWQSE REIFSTPGMK HENLLQFIAA
251	EKRGSNLEVE LWLITAFHDK GSLTDYLKGN IITWNELCHV AETMSRGLSY
301	LHEDVPWCRG EGHKPSIAHR DFKSKNVLLK SDLTAVLADF GLAVRFEPGK
351	PPGDTHGQVG TRRYMAPEVL EGAINFQRDA FLRIDMYAMG LVLWELVSRC
401	KAADGPVDEY MLPFEEEIGQ HPSLEELQEV VVHKKMRPTI KDHWLKHPGL
451	AQLCVTIEEC WDHDAEARLS AGCVEERVSL IRRSVNGTTS DCLVSLVTSV
501	TNVDLPPKES SI

(SEQ ID NO: 4) 1

MTAPWVALAL LWGSLCAGS	G RGEAETRECI YYNANWELER TNQSGLERCE
51
GEQDKRLHCY ASWANSSGTI ELVKKGCWLD DFNCYDRQEC VATEENPQVY
101	FCCCEGNFCN ERFTHLPEAG GPEVTYEPPP TAPT LLTVLA YSLLPIGGLS
151	LIVLLAFWMY RHRKPPYGHV DIHEDPGPPP PSPLVGLKPL QLLEIKARGR
201	FGCVWKAQLM NDFVAVKIFP LQDKQSWQSE REIFSTPGMK HENLLQFIAA
251	EKRGSNLEVE LWLITAFHDK GSLTDYLKGN IITWNELCHV AETMSRGLSY
301	LHEDVPWCRG EGHKPSIAHR DFKSKNVLLK SDLTAVLADF GLAVRFEPGK
351	PPGDTHGQVG TRRYMAPEVL EGAINFQRDA FLRIDMYAMG LVLWELVSRC
401	KAADGPVDEY MLPFEEEIGQ HPSLEELQEV VVHKKMRPTI KDHWLKHPGL
451	AQLCVTIEEC WDHDAEARLS AGCVEERVSL IRRSVNGTTS DCLVSLVTSV
501	TNVDLPPKES SI

(SEQ ID NO: 7) 1 ATGACGGCGC CCTGGGTGGC CCTCGCCCTC CTCTGGGGAT CGCTGTGCGC

51	CGGCTCT GGG CGTGGGGAGG CTGAGACACG GGAGTGCATC TACTACAACG
101	CCAACTGGGA GCTGGAGCGC ACCAACCAGA GCGGCCTGGA GCGCTGCGAA
151	GGCGAGCAGG ACAAGCGGCT GCACTGCTAC GCCTCCTGGC GCAACAGCTC
201	TGGCACCATC GAGCTCGTGA AGAAGGGCTG CTGGCTAGAT GACTTCAACT
251	GCTACGATAG GCAGGAGTGT GTGGCCACTG AGGAGAACCC CCAGGTGTAC
301	TTCTGCTGCT GTGAAGGCAA CTTCTGCAAC GAACGCTTCA CTCATTTGCC
351	AGAGGCTGGG GGCCCGGAAG TCACGTACGA GCCACCCCCG ACAGCCCCCA
401	CCCTGCTCAC GGTGCTGGCC TACTCACTGC TGCCCATCGG GGGCCTTTCC
451	CTCATCGTCC TGCTGGCCTT TTGGATGTAC CGGCATCGCA AGCCCCCCTA
501	CGGTCATGTG GACATCCATG AGGACCCTGG GCCTCCACCA CCATCCCCTC
551	TGGTGGGCCT GAAGCCACTG CAGCTGCTGG AGATCAAGGC TCGGGGGCGC
601	TTTGGCTGTG TCTGGAAGGC CCAGCTCATG AATGACTTTG TAGCTGTCAA
651	GATCTTCCCA CTCCAGGACA AGCAGTCGTG GCAGAGTGAA CGGGAGATCT
701	TCAGCACACC TGGCATGAAG CACGAGAACC TGCTACAGTT CATTGCTGCC
751	GAGAAGCGAG GCTCCAACCT CGAAGTAGAG CTGTGGCTCA TCACGGCCTT
801	CCATGACAAG GGCTCCCTCA CGGATTACCT CAAGGGGAAC ATCATCACAT
851	GGAACGAACT GTGTCATGTA GCAGAGACGA TGTCACGAGG CCTCTCATAC
901	CTGCATGAGG ATGTGCCCTG GTGCCGTGGC GAGGGCCACA AGCCGTCTAT
951	TGCCCACAGG GACTTTAAAA GTAAGAATGT ATTGCTGAAG AGCGACCTCA
1001	CAGCCGTGCT GGCTGACTTT GGCTTGGCTG TTCGATTTGA GCCAGGGAAA
1051	CCTCCAGGGG ACACCCACGG ACAGGTAGGC ACGAGACGGT ACATGGCTCC
1101	TGAGGTGCTC GAGGGAGCCA TCAACTTCCA GAGAGATGCC TTCCTGCGCA
1151	TTGACATGTA TGCCATGGGG TTGGTGCTGT GGGAGCTTGT GTCTCGCTGC
1201	AAGGCTGCAG ACGGACCCGT GGATGAGTAC ATGCTGCCCT TTGAGGAAGA
1251	GATTGGCCAG CACCCTTCGT TGGAGGAGCT GCAGGAGGTG GTGGTGCACA
1301	AGAAGATGAG GCCCACCATT AAAGATCACT GGTTGAAACA CCCGGGCCTG
1351	GCCCAGCTTT GTGTGACCAT CGAGGAGTGC TGGGACCATG ATGCAGAGGC
1401	TCGCTTGTCC GCGGGCTGTG TGGAGGAGCG GGTGTCCCTG ATTCGGAGGT
1451	CGGTCAACGG CACTACCTCG GACTGTCTCG TTTCCCTGGT GACCTCTGTC
1501	ACCAATGTGG ACCTGCCCCC TAAAGAGTCA AGCATC

(SEQ ID NO: 8)

1	GGGCGTGGGG AGGCTGAGAC ACGGGAGTGC ATCTACTACA ACGCCAACTG
51	GGAGCTGGAG CGCACCAACC AGAGCGGCCT GGAGCGCTGC GAAGGCGAGC
101	AGGACAAGCG GCTGCACTGC TACGCCTCCT GGCGCAACAG CTCTGGCACC
151	ATCGAGCTCG TGAAGAAGGG CTGCTGGCTA GATGACTTCA ACTGCTACGA
201	TAGGCAGGAG TGTGTGGCCA CTGAGGAGAA CCCCCAGGTG TACTTCTGCT
251	GCTGTGAAGG CAACTTCTGC AACGAACGCT TCACTCATTT GCCAGAGGCT
301	GGGGGCCCGG AAGTCACGTA CGAGCCACCC CCGACAGCCC CCACC

(SEQ ID NO: 9)

1	MGAAAKLAFA VFLISCSSGA ILGRSETQEC LFFNANWEKD RT N QTGVEPC
51
YGDKDKRRHC FATWK N ISGS IEIVKQGCWL DDINCYDRTD CVEKKDSPEV
101	YFCCCEGNMC NEKFSYFPEM EVTQPTSNPV TPKPP YYNIL LYSLVPLMLI
151	AGIVICAFWV YRHHKMAYPP VLVPTQDPGP PPPSPLLGLK PLQLLEVKAR
201	GRFGCVWKAQ LLNEYVAVKI FPIQDKQSWQ NEYEVYSLPG MKHENILQFI
251	GAEKRGTSVD VDLWLITAFH EKGSLSDFLK ANVVSWNELC HIAETMARGL
301	AYLHEDIPGL KDGHKPAISH RDIKSKNVLL KNNLTACIAD FGLALKFEAG
351	KSAGDTHGQV GTRRYMAPEV LEGAINFQRD AFLRIDMYAM GLVLWELASR
401	CTAADGPVDE YMLPFEEEIG QHPSLEDMQE VVVHKKKRPV LRDYWQKHAG
451	MAMLCETIEE CWDHDAEARL SAGCVGERIT QMQRLTNIIT TEDIVTVVTM
501	VTNVDFPPKE SSL

(SEQ ID NO: 12) 1 ATGGGAGCTG CTGCAAAGTT GGCGTTTGCC GTCTTTCTTA TCTCCTGTTC

51	TTCAGGTGCT ATACTTGGTA GATCAGAAAC TCAGGAGTGT CTTTTCTTTA
101	ATGCTAATTG GGAAAAAGAC AGAACCAATC AAACTGGTGT TGAACCGTGT
151	TATGGTGACA AAGATAAACG GCGGCATTGT TTTGCTACCT GGAAGAATAT
201	TTCTGGTTCC ATTGAAATAG TGAAACAAGG TTGTTGGCTG GATGATATCA
251	ACTGCTATGA CAGGACTGAT TGTGTAGAAA AAAAAGACAG CCCTGAAGTA
301	TATTTTTGTT GCTGTGAGGG CAATATGTGT AATGAAAAGT TTTCTTATTT
351	TCCGGAGATG GAAGTCACAC AGCCCACTTC AAATCCAGTT ACACCTAAGC
401	CACCCTATTA CAACATCCTG CTCTATTCCT TGGTGCCACT TATGTTAATT
451	GCGGGGATTG TCATTTGTGC ATTTTGGGTG TACAGGCATC ACAAGATGGC
501	CTACCCTCCT GTACTTGTTC CAACTCAAGA CCCAGGACCA CCCCCACCTT
551	CTCCATTACT AGGTTTGAAA CCACTGCAGT TATTAGAAGT GAAAGCAAGG
601	GGAAGATTTG GTTGTGTCTG GAAAGCCCAG TTGCTTAACG AATATGTGGC
651	TGTCAAAATA TTTCCAATAC AGGACAAACA GTCATGGCAA AATGAATACG
701	AAGTCTACAG TTTGCCTGGA ATGAAGCATG AGAACATATT ACAGTTCATT
751	GGTGCAGAAA AACGAGGCAC CAGTGTTGAT GTGGATCTTT GGCTGATCAC
801	AGCATTTCAT GAAAAGGGTT CACTATCAGA CTTTCTTAAG GCTAATGTGG
851	TCTCTTGGAA TGAACTGTGT CATATTGCAG AAACCATGGC TAGAGGATTG
901	GCATATTTAC ATGAGGATAT ACCTGGCCTA AAAGATGGCC ACAAACCTGC
951	CATATCTCAC AGGGACATCA AAAGTAAAAA TGTGCTGTTG AAAAACAACC
1001	TGACAGCTTG CATTGCTGAC TTTGGGTTGG CCTTAAAATT TGAGGCTGGC
1051	AAGTCTGCAG GCGATACCCA TGGACAGGTT GGTACCCGGA GGTACATGGC
1101	TCCAGAGGTA TTAGAGGGTG CTATAAACTT CCAAAGGGAT GCATTTTTGA
1151	GGATAGATAT GTATGCCATG GGATTAGTCC TATGGGAACT GGCTTCTCGC
1201	TGTACTGCTG CAGATGGACC TGTAGATGAA TACATGTTGC CATTTGAGGA
1251	GGAAATTGGC CAGCATCCAT CTCTTGAAGA CATGCAGGAA GTTGTTGTGC
1301	ATAAAAAAAA GAGGCCTGTT TTAAGAGATT ATTGGCAGAA ACATGCTGGA
1351	ATGGCAATGC TCTGTGAAAC CATTGAAGAA TGTTGGGATC ACGACGCAGA
1401	AGCCAGGTTA TCAGCTGGAT GTGTAGGTGA AAGAATTACC CAGATGCAGA
1451	GACTAACAAA TATTATTACC ACAGAGGACA TTGTAACAGT GGTCACAATG
1501	GTGACAAATG TTGACTTTCC TCCCAAAGAA TCTAGTCTA

(SEQ ID NO: 13)

1	ATACTTGGTA GATCAGAAAC TCAGGAGTGT CTTTTCTTTA ATGCTAATTG
51	GGAAAAAGAC AGAACCAATC AAACTGGTGT TGAACCGTGT TATGGTGACA
101	AAGATAAACG GCGGCATTGT TTTGCTACCT GGAAGAATAT TTCTGGTTCC
151	ATTGAAATAG TGAAACAAGG TTGTTGGCTG GATGATATCA ACTGCTATGA
201	CAGGACTGAT TGTGTAGAAA AAAAAGACAG CCCTGAAGTA TATTTTTGTT
251	GCTGTGAGGG CAATATGTGT AATGAAAAGT TTTCTTATTT TCCGGAGATG
301	GAAGTCACAC AGCCCACTTC AAATCCAGTT ACACCTAAGC CACCC

(SEQ ID NO: 42) 1

MGRGLLRGLW PLHIVLWTRI AS	TIPPHVQK SVNNDMIVTD NNGAVKFPQL
51
CKFCDVRFST CDNQKSCMSN CSITSICEKP QEVCVAVWRK NDENITLETV
101
CHDPKLPYHD FILEDAASPK CIMKEKKKPG ETFFMCSCSS DECNDNIIFS
151	EEYNTSNPDL LLVIFQ VTGI SLLPPLGVAI SVIIIFYCYR VNRQQKLSST
201	WETGKTRKLM EFSEHCAIIL EDDRSDISST CANNINHNTE LLPIELDTLV
251	GKGRFAEVYK AKLKQNTSEQ FETVAVKIFP YEEYASWKTE KDIFSDINLK
301	HENILQFLTA EERKTELGKQ YWLITAFHAK GNLQEYLTRH VISWEDLRKL
351	GSSLARGIAH LHSDHTPCGR PKMPIVHRDL KSSNILVKND LTCCLCDFGL
401	SLRLDPTLSV DDLANSGQVG TARYMAPEVL ESRMNLENVE SFKQTDVYSM
451	ALVLWEMTSR CNAVGEVKDY EPPFGSKVRE HPCVESMKDN VLRDRGRPEI
501	PSFWLNHQGI QMVCETLTEC WDHDPEARLT AQCVAERFSE LEHLDRLSGR
551	SCSEEKIPED GSLNTTK

(SEQ ID NO: 67) 1

MGRGLLRGLW PLHIVLWTRI AS	TIPPHVQK SDVEMEAQKD EIICPSCNRT
51
AHPLRHINND MIVTDNNGAV KFPQLCKFCD VRFSTCDNQK SCMSNCSITS
101
ICEKPQEVCV AVWRKNDENI TLETVCHDPK LPYHDFILED AASPKCIMKE
151	KKKPGETFFM CSCSSDECND NIIFSEEYNT SNPDLLLVIF Q VTGISLLPP
201	LGVAISVIII FYCYRVNRQQ KLSSTWETGK TRKLMEFSEH CAIILEDDRS
251	DISSTCANNI NHNTELLPIE LDTLVGKGRF AEVYKAKLKQ NTSEQFETVA
301	VKIFPYEEYA SWKTEKDIFS DINLKHENIL QFLTAEERKT ELGKQYWLIT
351	AFHAKGNLQE YLTRHVISWE DLRKLGSSLA RGIAHLHSDH TPCGRPKMPI
401	VHRDLKSSNI LVKNDLTCCL CDFGLSLRLD PTLSVDDLAN SGQVGTARYM
451	APEVLESRMN LENVESFKQT DVYSMALVLW EMTSRCNAVG EVKDYEPPFG
501	SKVREHPCVE SMKDNVLRDR GRPEIPSFWL NHQGIQMVCE TLTECWDHDP
551	EARLTAQCVA ERFSELEHLD RLSGRSCSEE KIPEDGSLNT TK

(SEQ ID NO: 46) 1

MTSSLQRPWR VPWLPWTILL VSTAAA	SQNQ ERLCAFKDPY QQDLGIGESR
51
ISHENGTILC SKGSTCYGLW EKSKGDINLV KQGCWSHIGD PQECHYEECV
101
VTTTPPSIQN GTYRFCCCST DLCNVNFTEN FPPPDTTPLS PPHSFNRDET
151	IIIALASVSV LAVLIVALCF GYRMLTGDRK QGLHSMNMME AAASEPSLDL
201	DNLKLLELIG RGRYGAVYKG SLDERPVAVK VFSFANRQNF INEKNIYRVP
251	LMEHDNIARF IVGDERVTAD GRMEYLLVME YYPNGSLCKY LSLHTSDWVS
301	SCRLAHSVTR GLAYLHTELP RGDHYKPAIS HRDLNSRNVL VKNDGTCVIS
351	DFGLSMRLTG NRLVRPGEED NAAISEVGTI RYMAPEVLEG AVNLRDCESA
401	LKQVDMYALG LIYWEIFMRC TDLFPGESVP EYQMAFQTEV GNHPTFEDMQ
451	VLVSREKQRP KFPEAWKENS LAVRSLKETI EDCWDQDAEA RLTAQCAEER
501	MAELMMIWER NKSVSPTVNP MSTAMQNERN LSHNRRVPKI GPYPDYSSSS
551	YIEDSIHHTD SIVKNISSEH SMSSTPLTIG EKNRNSINYE RQQAQARIPS
601	PETSVTSLST NTTTTNTTGL TPSTGMTTIS EMPYPDETNL HTTNVAQSIG
651	PTPVCLQLTE EDLETNKLDP KEVDKNLKES SDENLMEHSL KQFSGPDPLS
701	STSSSLLYPL IKLAVEATGQ QDFTQTANGQ ACLIPDVLPT QIYPLPKQQN
751	LPKRPTSLPL NTKNSTKEPR LKFGSKHKSN LKQVETGVAK MNTINAAEPH
801	VVTVTMNGVA GRNHSVNSHA ATTQYANGTV LSGQTTNIVT HRAQEMLQNQ
851	FIGEDTRLNI NSSPDEHEPL LRREQQAGHD EGVLDRLVDR RERPLEGGRT
901	NSNNNNSNPC SEQDVLAQGV PSTAADPGPS KPRRAQRPNS LDLSATNVLD
951	GSSIQIGEST QDGKSGSGEK IKKRVKTPYS LKRWRPSTWV ISTESLDCEV
1001	NNNGSNRAVH SKSSTAVYLA EGGTATTMVS KDIGMNCL

(SEQ ID NO: 71) 1

MTSSLQRPWR VPWLPWTILL VSTAAA	SQNQ ERLCAFKDPY QQDLGIGESR
51
ISHENGTILC SKGSTCYGLW EKSKGDINLV KQGCWSHIGD PQECHYEECV
101
VTTTPPSIQN GTYRFCCCST DLCNVNFTEN FPPPDTTPLS PPHSFNRDET
151	IIIALASVSV LAVLIVALCF GYRMLTGDRK QGLHSMNMME AAASEPSLDL
201	DNLKLLELIG RGRYGAVYKG SLDERPVAVK VFSFANRQNF INEKNIYRVP
251	LMEHDNIARF IVGDERVTAD GRMEYLLVME YYPNGSLCKY LSLHTSDWVS
301	SCRLAHSVTR GLAYLHTELP RGDHYKPAIS HRDLNSRNVL VKNDGTCVIS
351	DFGLSMRLTG NRLVRPGEED NAAISEVGTI RYMAPEVLEG AVNLRDCESA
401	LKQVDMYALG LIYWEIFMRC TDLFPGESVP EYQMAFQTEV GNHPTFEDMQ
451	VLVSREKQRP KFPEAWKENS LAVRSLKETI EDCWDQDAEA RLTAQCAEER
501	MAELMMIWER NKSVSPTVNP MSTAMQNERR

(SEQ ID NO: 50) 1

MLGSLGLWAL LPTAVEA	PPN RRTCVFFEAP GVRGSTKTLG ELLDTGTELP
51
RAIRCLYSRC CFGIWNLTQD RAQVEMQGCR DSDEPGCESL HCDPSPRAHP
101	SPGSTLFTCS CGTDFCNANY SHLPPPGSPG TPGSQGPQAA PGESIWMAL V
151	LLGLFLLLLL LLGSIILALL QRKNYRVRGE PVPEPRPDSG RDWSVELQEL
201	PELCFSQVIR EGGHAVVWAG QLQGKLVAIK AFPPRSVAQF QAERALYELP
251	GLQHDHIVRF ITASRGGPGR LLSGPLLVLE LHPKGSLCHY LTQYTSDWGS
301	SLRMALSLAQ GLAFLHEERW QNGQYKPGIA HRDLSSQNVL IREDGSCAIG
351	DLGLALVLPG LTQPPAWTPT QPQGPAAIME AGTQRYMAPE LLDKTLDLQD
401	WGMALRRADI YSLALLLWEI LSRCPDLRPD SSPPPFQLAY EAELGNTPTS
451	DELWALAVQE RRRPYIPSTW RCFATDPDGL RELLEDCWDA DPEARLTAEC
501	VQQRLAALAH PQESHPFPES CPRGCPPLCP EDCTSIPAPT ILPCRPQRSA
551	CHFSVQQGPC SRNPQPACTL SPV

(SEQ ID NO: 75) 1

MLGSLGLWAL LPTAVEA	PPN RRTCVFFEAP GVRGSTKTLG ELLDTGTELP
051
RAIRCLYSRC CFGIWNLTQD RAQVEMQGCR DSDEPGCESL HCDPSPRAHP
101	SPGSTLFTCS CGTDFCNANY SHLPPPGSPG TPGSQGPQAA PGESIWMAL V
151	LLGLFLLLLL LLGSIILALL QRKNYRVRGE PVPEPRPDSG RDWSVELQEL
201	PELCFSQVIR EGGHAVVWAG QLQGKLVAIK AFPPRSVAQF QAERALYELP
251	GLQHDHIVRF ITASRGGPGR LLSGPLLVLE LHPKGSLCHY LTQYTSDWGS
301	SLRMALSLAQ GLAFLHEERW QNGQYKPGIA HRDLSSQNVL IREDGSCAIG
351	DLGLALVLPG LTQPPAWTPT QPQGPAAIME AGTQRYMAPE LLDKTLDLQD
401	WGMALRRADI YSLALLLWEI LSRCPDLRPA VHHPSNWPMR QNWAIPLPLM
451	SYGPWQCRRG GVPTSHPPGA ALPQTLMG

(SEQ ID NO: 79) 1

MLGSLGLWAL LPTAVEA	PPN RRTCVFFEAP GVRGSTKTLG ELLDTGTELP
51
RAIRCLYSRC CFGIWNLTQD RAQVEMQGCR DSDEPGCESL HCDPSPRAHP
101	SPGSTLFTCS CGTDFCNANY SHLPPPGSPG TPGSQGPQAA PGESIWMAL V
151	LLGLFLLLLL LLGSIILALL QRKNYRVRGE PVPEPRPDSG RDWSVELQEL
201	PELCFSQVIR EGGHAVVWAG QLQGKLVAIK AFPPRSVAQF QAERALYELP
251	GLQHDHIVRF ITASRGGPGR LLSGPLLVLE LHPKGSLCHY LTQYTSDWGS
301	SLRMALSLAQ GLAFLHEERW QNGQYKPGIA HRDLSSQNVL IREDGSCAIG
351	DLGLALVLPG LTQPPAWTPT QPQGPAAIME DPDGLRELLE DCWDADPEAR
401	LTAECVQQRL AALAHPQESH PFPESCPRGC PPLCPEDCTS IPAPTILPCR
451	PQRSACHFSV QQGPCSRNPQ PACTLSPV

(SEQ ID NO: 14) 1

MTLGSPRKGL LMLLMALVTQ G	DPVKPSRGP LVTCTCESPH CKGPTCRGAW
51
CTVVLVREEG RHPQEHRGCG NLHRELCRGR PTEFVNHYCC DSHLCNHNVS
101	LVLEATQPPS EQPGTDGQ LA LILGPVLALL ALVALGVLGL WHVRRRQEKQ
151	RGLHSELGES SLILKASEQG DSMLGDLLDS DCTTGSGSGL PFLVQRTVAR
201	QVALVECVGK GRYGEVWRGL WHGESVAVKI FSSRDEQSWF RETEIYNTVL
251	LRHDNILGFI ASDMTSRNSS TQLWLITHYH EHGSLYDFLQ RQTLEPHLAL
301	RLAVSAACGL AHLHVEIFGT QGKPAIAHRD FKSRNVLVKS NLQCCIADLG
351	LAVMHSQGSD YLDIGNNPRV GTKRYMAPEV LDEQIRTDCF ESYKWTDIWA
401	FGLVLWEIAR RTIVNGIVED YRPPFYDVVP NDPSFEDMKK VVCVDQQTPT
451	IPNRLAADPV LSGLAQMMRE CWYPNPSARL TALRIKKTLQ KISNSPEKPK
501	VIQ

(SEQ ID NO: 18)

1	MVDGVMILPV LIMIALPSPS MEDEKPKVNP KLYMCVCEGL SCGNEDHCEG
51
QQCFSSLSIN DGFHVYQKGC FQVYEQGKMT CKTPPSPGQA VECCQGDWCN
101	RNITAQLPTK GKSFPGTQNF HLE VGLIILS VVFAVCLLAC LLGVALRKFK
151	RRNQERLNPR DVEYGTIEGL ITTNVGDSTL ADLLDHSCTS GSGSGLPFLV
201	QRTVARQITL LECVGKGRYG EVWRGSWQGE NVAVKIFSSR DEKSWFRETE
251	LYNTVMLRHE NILGFIASDM TSRHSSTQLW LITHYHEMGS LYDYLQLTTL
301	DTVSCLRIVL SIASGLAHLH IEIFGTQGKP AIAHRDLKSK NILVKKNGQC
351	CIADLGLAVM HSQSTNQLDV GNNPRVGTKR YMAPEVLDET IQVDCFDSYK
401	RVDIWAFGLV LWEVARRMVS NGIVEDYKPP FYDVVPNDPS FEDMRKVVCV
451	DQQRPNIPNR WFSDPTLTSL AKLMKECWYQ NPSARLTALR IKKTLTKIDN
501	SLDKLKTDC

(SEQ ID NO: 22) 1

MPQLYIYIRL LGAYLFIISR VQG	QNLDSML HGTGMKSDSD QKKSENGVTL APEDTLPFLK
61
CYCSGHCPDD AINNTCITNG HCFAIIEEDD QGETTLASGC MKYEGSDFQC KDSPKAQLRR
121	TIECCRTNLC NQYLQPTLPP VVIGPFFDGS IR WLVLLISM AVCIIAMIIF SSCFCYKHYC
181	KSISSRRRYN RDLEQDEAFI PVGESLKDLI DQSQSSGSGS GLPLLVQRTI AKQIQMVRQV
241	GKGRYGEVWM GKWRGEKVAV KVFFTTEEAS WFRETEIYQT VLMRHENILG FIAADIKGTG
301	SWTQLYLITD YHENGSLYDF LKCATLDTRA LLKLAYSAAC GLCHLHTEIY GTQGKPAIAH
361	RDLKSKNILI KKNGSCCIAD LGLAVKFNSD TNEVDVPLNT RVGTKRYMAP EVLDESLNKN
421	HFQPYIMADI YSFGLIIWEM ARRCITGGIV EEYQLPYYNM VPSDPSYEDM REVVCVKRLR
481	PIVSNRWNSD ECLRAVLKLM SECWAHNPAS RLTALRIKKT LAKMVESQDV KI

(SEQ ID NO: 23)

1	QNLDSMLHGT GMKSDSDQKK SENGVTLAPE DTLPFLKCYC
	SGHCPDDAIN NTCITNGHCF
61	AIIEEDDQGE TTLASGCMKY EGSDFQCKDS PKAQLRRTIE
	CCRTNLCNQY LQPTLPPVVI
121	GPFFDGSIR

(SEQ ID NO: 24) 1 ATGCCTCAGC TATACATTTA CATCAGATTA TTGGGAGCCT ATTTGTTCAT CATTTCTCGT 61

GTTCAAGGA	C AGAATCTGGA TAGTATGCTT CATGGCACTG GGATGAAATC AGACTCCGAC
121
CAGAAAAAGT CAGAAAATGG AGTAACCTTA GCACCAGAGG ATACCTTGCC TTTTTTAAAG
181
TGCTATTGCT CAGGGCACTG TCCAGATGAT GCTATTAATA ACACATGCAT AACTAATGGA
241
CATTGCTTTG CCATCATAGA AGAAGATGAC CAGGGAGAAA CCACATTAGC TTCAGGGTGT
301
ATGAAATATG AAGGATCTGA TTTTCAGTGC AAAGATTCTC CAAAAGCCCA GCTACGCCGG
361
ACAATAGAAT GTTGTCGGAC CAATTTATGT AACCAGTATT TGCAACCCAC ACTGCCCCCT
421	GTTGTCATAG GTCCGTTTTT TGATGGCAGC ATTCGA TGGC TGGTTTTGCT CATTTCTATG
481	GCTGTCTGCA TAATTGCTAT GATCATCTTC TCCAGCTGCT TTTGTTACAA ACATTATTGC
541	AAGAGCATCT CAAGCAGACG TCGTTACAAT CGTGATTTGG AACAGGATGA AGCATTTATT
601	CCAGTTGGAG AATCACTAAA AGACCTTATT GACCAGTCAC AAAGTTCTGG TAGTGGGTCT
661	GGACTACCTT TATTGGTTCA GCGAACTATT GCCAAACAGA TTCAGATGGT CCGGCAAGTT
721	GGTAAAGGCC GATATGGAGA AGTATGGATG GGCAAATGGC GTGGCGAAAA AGTGGCGGTG
781	AAAGTATTCT TTACCACTGA AGAAGCCAGC TGGTTTCGAG AAACAGAAAT CTACCAAACT
841	GTGCTAATGC GCCATGAAAA CATACTTGGT TTCATAGCGG CAGACATTAA AGGTACAGGT
901	TCCTGGACTC AGCTCTATTT GATTACTGAT TACCATGAAA ATGGATCTCT CTATGACTTC
961	CTGAAATGTG CTACACTGGA CACCAGAGCC CTGCTTAAAT TGGCTTATTC AGCTGCCTGT
1021	GGTCTGTGCC ACCTGCACAC AGAAATTTAT GGCACCCAAG GAAAGCCCGC AATTGCTCAT
1081	CGAGACCTAA AGAGCAAAAA CATCCTCATC AAGAAAAATG GGAGTTGCTG CATTGCTGAC
1141	CTGGGCCTTG CTGTTAAATT CAACAGTGAC ACAAATGAAG TTGATGTGCC CTTGAATACC
1201	AGGGTGGGCA CCAAACGCTA CATGGCTCCC GAAGTGCTGG ACGAAAGCCT GAACAAAAAC
1261	CACTTCCAGC CCTACATCAT GGCTGACATC TACAGCTTCG GCCTAATCAT TTGGGAGATG
1321	GCTCGTCGTT GTATCACAGG AGGGATCGTG GAAGAATACC AATTGCCATA TTACAACATG
1381	GTACCGAGTG ATCCGTCATA CGAAGATATG CGTGAGGTTG TGTGTGTCAA ACGTTTGCGG
1441	CCAATTGTGT CTAATCGGTG GAACAGTGAT GAATGTCTAC GAGCAGTTTT GAAGCTAATG
1501	TCAGAATGCT GGGCCCACAA TCCAGCCTCC AGACTCACAG CATTGAGAAT TAAGAAGACG
1561	CTTGCCAAGA TGGTTGAATC CCAAGATGTA AAAATC

(SEQ ID NO: 25)

1	CAGAATCTGG ATAGTATGCT TCATGGCACT GGGATGAAAT CAGACTCCGA CCAGAAAAAG
61	TCAGAAAATG GAGTAACCTT AGCACCAGAG GATACCTTGC CTTTTTTAAA GTGCTATTGC
121	TCAGGGCACT GTCCAGATGA TGCTATTAAT AACACATGCA TAACTAATGG ACATTGCTTT
181	GCCATCATAG AAGAAGATGA CCAGGGAGAA ACCACATTAG CTTCAGGGTG TATGAAATAT
241	GAAGGATCTG ATTTTCAGTG CAAAGATTCT CCAAAAGCCC AGCTACGCCG GACAATAGAA
301	TGTTGTCGGA CCAATTTATG TAACCAGTAT TTGCAACCCA CACTGCCCCC TGTTGTCATA
361	GGTCCGTTTT TTGATGGCAG CATTCGA

(SEQ ID NO: 26) 1

MAESAGASSF FPLVVLLLAG SGG	SGPRGVQ ALLCACTSCL QANYTCETDG ACMVSIFNLD
61
GMEHHVRTCI PKVELVPAGK PFYCLSSEDL RNTHCCYTDY CNRIDLRVPS GHLKEPEHPS
121	MWGPVE LVGI IAGPVFLLFL IIIIVFLVIN YHQRVYHNRQ RLDMEDPSCE MCLSKDKTLQ
181	DLVYDLSTSG SGSGLPLFVQ RTVARTIVLQ EIIGKGRFGE VWRGRWRGGD VAVKIFSSRE
241	ERSWFREAEI YQTVMLRHEN ILGFIAADNK DNGTWTQLWL VSDYHEHGSL FDYLNRYTVT
301	IEGMIKLALS AASGLAHLHM EIVGTQGKPG IAHRDLKSKN ILVKKNGMCA IADLGLAVRH
361	DAVTDTIDIA PNQRVGTKRY MAPEVLDETI NMKHFDSFKC ADIYALGLVY WEIARRCNSG
421	GVHEEYQLPY YDLVPSDPSI EEMRKVVCDQ KLRPNIPNWW QSYEALRVMG KMMRECWYAN
481	GAARLTALRI KKTLSQLSVQ EDVKI

(SEQ ID NO: 83) 1

MAESAGASSF FPLVVLLLAG SGG	SGPRGVQ ALLCACTSCL QANYTCETDG ACMVSIFNLD
61
GMEHHVRTCI PKVELVPAGK PFYCLSSEDL RNTHCCYTDY CNRIDLRVPS GHLKEPEHPS
121	MWGPVE LVGI IAGPVFLLFL IIIIVFLVIN YHQRVYHNRQ RLDMEDPSCE MCLSKDKTLQ
181	DLVYDLSTSG SGSGLPLFVQ RTVARTIVLQ EIIGKGRFGE VWRGRWRGGD VAVKIFSSRE
241	ERSWFREAEI YQTVMLRHEN ILGFIAADNK ADCSFLTLPW EVVMVSAAPK LRSLRLQYKG
301	GRGRARFLFP LNNGTWTQLW LVSDYHEHGS LFDYLNRYTV TIEGMIKLAL SAASGLAHLH
361	MEIVGTQGKP GIAHRDLKSK NILVKKNGMC AIADLGLAVR HDAVTDTIDI APNQRVGTKR
421	YMAPEVLDET INMKHFDSFK CADIYALGLV YWEIARRCNS GGVHEEYQLP YYDLVPSDPS
481	IEEMRKVVCD QKLRPNIPNW WQSYEALRVM GKMMRECWYA NGAARLTALR IKKTLSQLSV
541	QEDVKI

(SEQ ID NO: 30) 1

MEAAVAAPRP RLLLLVLAAA AAAA	ALLPG ATALQCFCHL CTKDNFTCVT DGLCFVSVTE
61
TTDKVIHNSM CIAEIDLIPR DRPFVCAPSS KTGSVTTTYC CNQDHCNKIE LPTTVKSSPG
121	LGPVEL AAVI AGPVCFVCIS LMLMVYICHN RTVIHHRVPN EEDPSLDRPF ISEGTTLKDL
181	IYDMTTSGSG SGLPLLVQRT IARTIVLQES IGKGRFGEVW RGKWRGEEVA VKIFSSREER
241	SWFREAEIYQ TVMLRHENIL GFIAADNKDN GTWTQLWLVS DYHEHGSLFD YLNRYTVTVE
301	GMIKLALSTA SGLAHLHMEI VGTQGKPAIA HRDLKSKNIL VKKNGTCCIA DLGLAVRHDS
361	ATDTIDIAPN HRVGTKRYMA PEVLDDSINM KHFESFKRAD IYAMGLVFWE IARRCSIGGI
421	HEDYQLPYYD LVPSDPSVEE MRKVVCEQKL RPNIPNRWQS CEALRVMAKI MRECWYANGA
481	ARLTALRIKK TLSQLSQQEG IKM

(SEQ ID NO: 87) 1

MEAAVAAPRP RLLLLVLAAA AAAA	AALLPG ATALQCFCHL CTKDNFTCVT DGLCFVSVTE
61
TTDKVIHNSM CIAEIDLIPR DRPFVCAPSS KTGSVTTTYC CNQDHCNKIE LPTTGPFSVK
121	SSPGLGPVEL AAVIAGPVCF VCISLMLMVY ICHNRTVIHH RVPNEEDPSL DRPFISEGTT
181	LKDLIYDMTT SGSGSGLPLL VQRTIARTIV LQESIGKGRF GEVWRGKWRG EEVAVKIFSS
241	REERSWFREA EIYQTVMLRH ENILGFIAAD NKDNGTWTQL WLVSDYHEHG SLFDYLNRYT
301	VTVEGMIKLA LSTASGLAHL HMEIVGTQGK PAIAHRDLKS KNILVKKNGT CCIADLGLAV
361	RHDSATDTID IAPNHRVGTK RYMAPEVLDD SINMKHFESF KRADIYAMGL VFWEIARRCS
421	IGGIHEDYQL PYYDLVPSDP SVEEMRKVVC EQKLRPNIPN RWQSCEALRV MAKIMRECWY
481	ANGAARLTAL RIKKTLSQLS QQEGIKM

(SEQ ID NO: 34) 1

MLLRSAGKLN VGT	KKEDGES TAPTPRPKVL RCKCHHHCPE DSVNNICSTD GYCFTMIEED
61
DSGLPVVTSG CLGLEGSDFQ CRDTPIPHQR RSIECCTERN ECNKDLHPTL PPLKNRDFVD
121	GPIHHR ALLI SVTVCSLLLV LIILFCYFRY KRQETRPRYS IGLEQDETYI PPGESLRDLI
181	EQSQSSGSGS GLPLLVQRTI AKQIQMVKQI GKGRYGEVWM GKWRGEKVAV KVFFTTEEAS
241	WFRETEIYQT VLMRHENILG FIAADIKGTG SWTQLYLITD YHENGSLYDY LKSTTLDAKS
301	MLKLAYSSVS GLCHLHTEIF STQGKPAIAH RDLKSKNILV KKNGTCCIAD LGLAVKFISD
361	TNEVDIPPNT RVGTKRYMPP EVLDESLNRN HFQSYIMADM YSFGLILWEV ARRCVSGGIV
421	EEYQLPYHDL VPSDPSYEDM REIVCIKKLR PSFPNRWSSD ECLRQMGKLM TECWAHNPAS
481	RLTALRVKKT LAKMSESQDI KL

(SEQ ID NO: 91) 1

MGWLEELNWQ LHIFLLILLS MHTRA	NFLDN MLLRSAGKLN VGTKKEDGES TAPTPRPKVL
61
RCKCHHHCPE DSVNNICSTD GYCFTMIEED DSGLPVVTSG CLGLEGSDFQ CRDTPIPHQR
121	RSIECCTERN ECNKDLHPTL PPLKNRDFVD GPIHHR ALLI SVTVCSLLLV LIILFCYFRY
181	KRQETRPRYS IGLEQDETYI PPGESLRDLI EQSQSSGSGS GLPLLVQRTI AKQIQMVKQI
241	GKGRYGEVWM GKWRGEKVAV KVFFTTEEAS WFRETEIYQT VLMRHENILG FIAADIKGTG
301	SWTQLYLITD YHENGSLYDY LKSTTLDAKS MLKLAYSSVS GLCHLHTEIF STQGKPAIAH
361	RDLKSKNILV KKNGTCCIAD LGLAVKFISD TNEVDIPPNT RVGTKRYMPP EVLDESLNRN
421	HFQSYIMADM YSFGLILWEV ARRCVSGGIV EEYQLPYHDL VPSDPSYEDM REIVCIKKLR
481	PSFPNRWSSD ECLRQMGKLM TECWAHNPAS RLTALRVKKT LAKMSESQDI KL

(SEQ ID NO: 38)

1	MTRALCSALR QALLLLAAAA ELSPGLKCVC LLCDSSNFTC QTEGACWASV MLTNGKEQVI
61	KSCVSLPELN AQVFCHSSNN VTKTECCFTD FCNNITLHLP TASPNAPKLG PME LAIIITV
121	PVCLLSIAAM LTVWACQGRQ CSYRKKKRPN VEEPLSECNL VNAGKTLKDL IYDVTASGSG
181	SGLPLLVQRT IARTIVLQEI VGKGRFGEVW HGRWCGEDVA VKIFSSRDER SWFREAEIYQ
241	TVMLRHENIL GFIAADNKDN GTWTQLWLVS EYHEQGSLYD YLNRNIVTVA GMIKLALSIA
301	SGLAHLHMEI VGTQGKPAIA HRDIKSKNIL VKKCETCAIA DLGLAVKHDS ILNTIDIPQN
361	PKVGTKRYMA PEMLDDTMNV NIFESFKRAD IYSVGLVYWE IARRCSVGGI VEEYQLPYYD
421	MVPSDPSIEE MRKVVCDQKF RPSIPNQWQS CEALRVMGRI MRECWYANGA ARLTALRIKK
481	TISQLCVKED CKA

(SEQ ID NO: 301) 1 MLTNGKEQVI KSCVSLPELN AQVFCHSSNN VTKTECCFTD FCNNITLHLP TASPNAPKLG

61	PME LAIIITV PVCLLSIAAM LTVWACQGRQ CSYRKKKRPN VEEPLSECNL VNAGKTLKDL
121	IYDVTASGSG SGLPLLVQRT IARTIVLQEI VGKGRFGEVW HGRWCGEDVA VKIFSSRDER
181	SWFREAEIYQ TVMLRHENIL GFIAADNKDN GTWTQLWLVS EYHEQGSLYD YLNRNIVTVA
241	GMIKLALSIA SGLAHLHMEI VGTQGKPAIA HRDIKSKNIL VKKCETCAIA DLGLAVKHDS
301	ILNTIDIPQN PKVGTKRYMA PEMLDDTMNV NIFESFKRAD IYSVGLVYWE IARRCSVGGI
361	VEEYQLPYYD MVPSDPSIEE MRKVVCDQKF RPSIPNQWQS CEALRVMGRI MRECWYANGA
421	ARLTALRIKK TISQLCVKED CKA

(SEQ ID NO: 305)

1	MTRALCSALR QALLLLAAAA ELSPGLKCVC LLCDSSNFTC QTEGACWASV MLTNGKEQVI
61	KSCVSLPELN AQVFCHSSNN VTKTECCFTD FCNNITLHLP TGLPLLVQRT IARTIVLQEI
121	VGKGRFGEVW HGRWCGEDVA VKIFSSRDER SWFREAEIYQ TVMLRHENIL GFIAADNKDN
181	GTWTQLWLVS EYHEQGSLYD YLNRNIVTVA GMIKLALSIA SGLAHLHMEI VGTQGKPAIA
241	HRDIKSKNIL VKKCETCAIA DLGLAVKHDS ILNTIDIPQN PKVGTKRYMA PEMLDDTMNV
301	NIFESFKRAD IYSVGLVYWE IARRCSVGGI VEEYQLPYYD MVPSDPSIEE MRKVVCDQKF
361	RPSIPNQWQS CEALRVMGRI MRECWYANGA ARLTALRIKK TISQLCVKED CKA

(SEQ ID NO: 306)

1	ELSPGLKCVC LLCDSSNFTC QTEGACWASV MLTNGKEQVI KSCVSLPELN AQVFCHSSNN
61	VTKTECCFTD FCNNITLHLP TGLPLLVQRT IARTIVLQEI VGKGRFGEVW HGRWCGEDVA
121	VKIFSSRDER SWFREAEIYQ TVMLRHENIL GFIAADNKDN GTWTQLWLVS EYHEQGSLYD
181	YLNRNIVTVA GMIKLALSIA SGLAHLHMEI VGTQGKPAIA HRDIKSKNIL VKKCETCAIA
241	DLGLAVKHDS ILNTIDIPQN PKVGTKRYMA PEMLDDTMNV NIFESFKRAD IYSVGLVYWE
301	IARRCSVGGI VEEYQLPYYD MVPSDPSIEE MRKVVCDQKF RPSIPNQWQS CEALRVMGRI
361	MRECWYANGA ARLTALRIKK TISQLCVKED CKA

(SEQ ID NO: 309)

1	MTRALCSALR QALLLLAAAA ELSPGLKCVC LLCDSSNFTC QTEGACWASV MLTNGKEQVI
61	KSCVSLPELN AQVFCHSSNN VTKTECCFTD FCNNITLHLP TDNGTWTQLW LVSEYHEQGS
121	LYDYLNRNIV TVAGMIKLAL SIASGLAHLH MEIVGTQGKP AIAHRDIKSK NILVKKCETC
181	AIADLGLAVK HDSILNTIDI PQNPKVGTKR YMAPEMLDDT MNVNIFESFK RADIYSVGLV
241	YWEIARRCSV GGIVEEYQLP YYDMVPSDPS IEEMRKVVCD QKFRPSIPNQ WQSCEALRVM
301	GRIMRECWYA NGAARLTALR IKKTISQLCV KEDCKA

(SEQ ID NO: 310)

1	ELSPGLKCVC LLCDSSNFTC QTEGACWASV MLTNGKEQVI KSCVSLPELN AQVFCHSSNN
61	VTKTECCFTD FCNNITLHLP TDNGTWTQLW LVSEYHEQGS LYDYLNRNIV TVAGMIKLAL
121	SIASGLAHLH MEIVGTQGKP AIAHRDIKSK NILVKKCETC AIADLGLAVK HDSILNTIDI
181	PQNPKVGTKR YMAPEMLDDT MNVNIFESFK RADIYSVGLV YWEIARRCSV GGIVEEYQLP
240	YYDMVPSDPS IEEMRKVVCD QKFRPSIPNQ WQSCEALRVM GRIMRECWYA NGAARLTALR
301	IKKTISQLCV KEDCKA

(SEQ ID NO: 313)

1	LKCVCLLCDS SNFTCQTEGA CWASVMLTNG KEQVIKSCVS
	LPELNAQVFC HSSNNVTKTE
61	CCFTDFCNNI TLHLPTASPN APKLGPME

(SEQ ID NO: 208) 1

51	VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK
101	VSNKALPAPI EKTISKAKGQ PREPQVYTLP PSR E E M TKNQ VSLTCLVKGF
151	YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFLYSKLTV DKSRWQQGNV
201	FSCSVMHEAL HNHYTQKSLS LSPGK

(SEQ ID NO: 209) 1

51	FNWYVDGVEV HNAKTKPREE QFNSTFRVVS VLTVVHQDWL NGKEYKCKVS
101	NKGLPAPIEK TISKTKGQPR EPQVYTLPPS REEMTKNQVS LTCLVKGFYP
151	SDI A VEWESN GQPENNYKTT PPMLDSDGSF FLYSKLTVDK SRWQQGNVFS
201	CSVMHEALHN HYTQKSLSLS PGK

(SEQ ID NO: 210) 1

51	VSHEDPEVQF KWYVDGV E VH NAKTK P RE E Q Y NSTFRVVSV LTVLHQ D WL N
101	GKEYKCKVSN KALPAPIEKT ISK T KGQPRE PQVYTLPPSR EEMTKNQVSL
151	TCLVKGFYPS DIAVEWES S G QPENNYNTTP PMLDSDGSFF LYSKLTVDKS
201	RWQQGNIFSC SVMHEALHNR F TQKSLSLSP GK
(SEQ ID NO: 211)
1
51
101	EDPEVQFKWY VDGV E VHNAK TK P RE E Q Y NS TFRVVSVLTV LHQ D WL N GKE
151	YKCKVSNKAL PAPIEKTISK T KGQPREPQV YTLPPSREEM TKNQVSLTCL
201	VKGFYPSDIA VEWES S GQPE NNYNTTPPML DSDGSFFLYS KLTVDKSRWQ
251	QGNIFSCSVM HEALHNR F TQ KSLSLSPGK

(SEQ ID NO: 212) 1

51	EDPEVQFNWY VDGVEVHNAK TKPREEQFNS TYRVVSVLTV LHQDWLNGKE
101	YKCKVSNKGL PSSIEKTISK AKGQPREPQV YTLPPSQEEM TKNQVSLTCL
151	VKGFYPSDIA VEWESNGQPE NNYKTTPPVL DSDGSFFLYS RLTVDKSRWQ
201	EGNVFSCSVM HEALHNHYTQ KSLSLSLGK

Correspondence of C H 3 Positions in Different Numbering Systems *Kabat et al. (eds) 1991; pp. 688-696 in Sequences of Proteins of Immunological Interest , 5 th ed., Vol. 1, NIH, Bethesda, MD.

G1Fc	IgG1 heavy chain
(Numbering begins	constant domain	IgG1 heavy chain
at first threonine	(Numbering	(EU numbering scheme
in hinge region)	begins at C H 1)	of Kabat et al., 1991*)
Y127	Y232	Y349
S132	S237	S354
E134	E239	E356
T144	T249	T366
L146	L251	L368
K170	K275	K392
D177	D282	D399
Y185	Y290	Y407
K187	K292	K409

Examples of Pair-Wise Charged Residue Mutations to Enhance Heterodimer Formation Corresponding

Position in	Mutation in	Interacting position in	mutation in second
first chain	first chain	second chain	chain
Lys409	Asp or Glu	Asp399′	Lys, Arg, or His
Lys392	Asp or Glu	Asp399′	Lys, Arg, or His
Lys439	Asp or Glu	Asp356′	Lys, Arg, or His
Lys370	Asp or Glu	Glu357′	Lys, Arg, or His
Asp399	Lys, Arg, or His	Lys409′	Asp or Glu
Asp399	Lys, Arg, or His	Lys392′	Asp or Glu
Asp356	Lys, Arg, or His	Lys439′	Asp or Glu
Glu357	Lys, Arg, or His	Lys370′	Asp or Glu

(SEQ ID NO: 200)

1	THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE
51	VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK
101	VSNKALPAPI EKTISKAKGQ PREPQVYTLP PSR K EMTKNQ VSLTCLVKGF
151	YPSDIAVEWE SNGQPENNYK TTPPVL K SDG SFFLYSKLTV DKSRWQQGNV
201	FSCSVMHEAL HNHYTQKSLS LSPGK
(SEQ ID NO: 201)
1	THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE
51	VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK
101	VSNKALPAPI EKTISKAKGQ PREPQVYTLP PSREEMTKNQ VSLTCLVKGF
151	YPSDIAVEWE SNGQPENNY D TTPPVLDSDG SFFLYS D LTV DKSRWQQGNV
201	FSCSVMHEAL HNHYTQKSLS LSPGK

(SEQ ID NO: 202)

1	THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE
51	VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK
101	VSNKALPAPI EKTISKAKGQ PREPQVYTLP PSREEMTKNQ VSL Y CLVKGF
151	YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFLYSKLTV DKSRWQQGNV
201	FSCSVMHEAL HNHYTQKSLS LSPGK
(SEQ ID NO: 203)
1	THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE
51	VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK
101	VSNKALPAPI EKTISKAKGQ PREPQVYTLP PSREEMTKNQ VSLTCLVKGF
151	YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFL T SKLTV DKSRWQQGNV
201	FSCSVMHEAL HNHYTQKSLS LSPGK

(SEQ ID NO: 204)

1	THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE
51	VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK
101	VSNKALPAPI EKTISKAKGQ PREPQVYTLP P C REEMTKNQ VSL W CLVKGF
151	YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFLYSKLTV DKSRWQQGNV
201	FSCSVMHEAL HNHYTQKSLS LSPGK
(SEQ ID NO: 205)
1	THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE
51	VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK
101	VSNKALPAPI EKTISKAKGQ PREPQV C TLP PSREEMTKNQ VSL S C A VKGF
151	YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFL V SKLTV DKSRWQQGNV
201	FSCSVMHEAL HNHYTQKSLS LSPGK

(SEQ ID NO: 206)

1	THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE
51	VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK
101	VSNKALPAPI EKTISKAKGQ P FR P E V HL LP PSREEMTKNQ VSLTCL AR GF
151	YP K DIAVEWE SNGQPENNYK TIP SRQEPSQ GTTT F AVT SK LTVDKSRWQQ
201	GNVFSCSVMH EALHNHYTQK TI SLSPGK
(SEQ ID NO: 207)
1	THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE
51	VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK
101	VSNKALPAPI EKTISKAKGQ PREPQVYTLP P PS EE LALNE L V T LTCLVKG
151	FYPSDIAVEW ESNG Q ELPRE K Y L T WA PVLD SDGSFFLYS I L R V AAED W KK
201	G DT FSCSVMH EALHNHYTQK SL DR SPGK

(SEQ ID NO: 213)

1	THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE
51	VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK
101	VSNKALPAPI EKTISKAKGQ PREPQVYTLP PSREEMTKNQ VSLTCLVKGF
151	YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFLYSKLTV DKSRWQQGNV
201	FSCSVMHEAL HNHYTQKSLS LSPGK GGSAQ LEKELQALEK ENAQLEWELQ
251
ALEKELAQGA T
(SEQ ID NO: 214)
1	THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE
51	VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK
101	VSNKALPAPI EKTISKAKGQ PREPQVYTLP PSREEMTKNQ VSLTCLVKGF
151	YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFLYSKLTV DKSRWQQGNV
201	FSCSVMHEAL HNHYTQKSLS LSPGK GGSAQ LKKKLQALKK KNAQLKWKLQ
251
ALKKKLAQGA T

(SEQ ID NO: 100)

1	MDAMKRGLCC VLLLCGAVFV SPGAS GRGEA ETRECIYYNA NWELERTNQS
51	GLERCEGEQD KRLHCYASWR NSSGTIELVK KGCWLDDFNC YDRQECVATE
101	ENPQVYFCCC EGNFCNERFT HLPEAGGPEV TYEPPPTAP T GGG THTCPPC
151	PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE DPEVKFNWYV
201	DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY KCKVSNKALP
251	APIEKTISKA KGQPREPQVY TLPPSR K EMT KNQVSLTCLV KGFYPSDIAV
301	EWESNGQPEN NYKTTPPVL K SDGSFFLYSK LTVDKSRWQQ GNVFSCSVMH
351	EALHNHYTQK SLSLSPGK

(SEQ ID NO: 101)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCTCTGGGCG TGGGGAGGCT GAGACACGGG
101	AGTGCATCTA CTACAACGCC AACTGGGAGC TGGAGCGCAC CAACCAGAGC
151	GGCCTGGAGC GCTGCGAAGG CGAGCAGGAC AAGCGGCTGC ACTGCTACGC
201	CTCCTGGCGC AACAGCTCTG GCACCATCGA GCTCGTGAAG AAGGGCTGCT
251	GGCTAGATGA CTTCAACTGC TACGATAGGC AGGAGTGTGT GGCCACTGAG
301	GAGAACCCCC AGGTGTACTT CTGCTGCTGT GAAGGCAACT TCTGCAACGA
351	GCGCTTCACT CATTTGCCAG AGGCTGGGGG CCCGGAAGTC ACGTACGAGC
401	CACCCCCGAC AGCCCCCACC GGTGGTGGAA CTCACACATG CCCACCGTGC
451	CCAGCACCTG AACTCCTGGG GGGACCGTCA GTCTTCCTCT TCCCCCCAAA
501	ACCCAAGGAC ACCCTCATGA TCTCCCGGAC CCCTGAGGTC ACATGCGTGG
551	TGGTGGACGT GAGCCACGAA GACCCTGAGG TCAAGTTCAA CTGGTACGTG
601	GACGGCGTGG AGGTGCATAA TGCCAAGACA AAGCCGCGGG AGGAGCAGTA
651	CAACAGCACG TACCGTGTGG TCAGCGTCCT CACCGTCCTG CACCAGGACT
701	GGCTGAATGG CAAGGAGTAC AAGTGCAAGG TCTCCAACAA AGCCCTCCCA
751	GCCCCCATCG AGAAAACCAT CTCCAAAGCC AAAGGGCAGC CCCGAGAACC
801	ACAGGTGTAC ACCCTGCCCC CATCCCGGAA GGAGATGACC AAGAACCAGG
851	TCAGCCTGAC CTGCCTGGTC AAAGGCTTCT ATCCCAGCGA CATCGCCGTG
901	GAGTGGGAGA GCAATGGGCA GCCGGAGAAC AACTACAAGA CCACGCCTCC
951	CGTGCTGAAG TCCGACGGCT CCTTCTTCCT CTATAGCAAG CTCACCGTGG
1001	ACAAGAGCAG GTGGCAGCAG GGGAACGTCT TCTCATGCTC CGTGATGCAT
1051	GAGGCTCTGC ACAACCACTA CACGCAGAAG AGCCTCTCCC TGTCTCCGGG
1101	TAAA

(SEQ ID NO: 102)

1	GRGEAETREC IYYNANWELE RTNQSGLERC EGEQDKRLHC YASWRNSSGT
51	IELVKKGCWL DDFNCYDRQE CVATEENPQV YFCCCEGNFC NERFTHLPEA
101	GGPEVTYEPP PTAPTGGGTH TCPPCPAPEL LGGPSVFLFP PKPKDTLMIS
151	RTPEVTCVVV DVSHEDPEVK FNWYVDGVEV HNAKTKPREE QYNSTYRVVS
201	VLTVLHQDWL NGKEYKCKVS NKALPAPIEK TISKAKGQPR EPQVYTLPPS
251	RKEMTKNQVS LTCLVKGFYP SDIAVEWESN GQPENNYKTT PPVLKSDGSF
301	FLYSKLTVDK SRWQQGNVFS CSVMHEALHN HYTQKSLSLS PGK

(SEQ ID NO: 104)

1	MDAMKRGLCC VLLLCGAVFV SPGA SGPRGV QALLCACTSC LQANYTCETD
51	GACMVSIFNL DGMEHHVRTC IPKVELVPAG KPFYCLSSED LRNTHCCYTD
101	YCNRIDLRVP SGHLKEPEHP SMWGPVE TGG G THTCPPCPA PELLGGPSVF
151	LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG VEVHNAKTKP
201	REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP IEKTISKAKG
251	QPREPQVYTL PPSREEMTKN QVSLTCLVKG FYPSDIAVEW ESNGQPENNY
301	D TTPPVLDSD GSFFLYS D LT VDKSRWQQGN VFSCSVMHEA LHNHYTQKSL
351	SLSPG

(SEQ ID NO: 105)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCTCCGGGCC CCGGGGGGTC CAGGCTCTGC
101	TGTGTGCGTG CACCAGCTGC CTCCAGGCCA ACTACACGTG TGAGACAGAT
151	GGGGCCTGCA TGGTTTCCAT TTTCAATCTG GATGGGATGG AGCACCATGT
201	GCGCACCTGC ATCCCCAAAG TGGAGCTGGT CCCTGCCGGG AAGCCCTTCT
251	ACTGCCTGAG CTCGGAGGAC CTGCGCAACA CCCACTGCTG CTACACTGAC
301	TACTGCAACA GGATCGACTT GAGGGTGCCC AGTGGTCACC TCAAGGAGCC
351	TGAGCACCCG TCCATGTGGG GCCCGGTGGA GACCGGTGGT GGAACTCACA
401	CATGCCCACC GTGCCCAGCA CCTGAACTCC TGGGGGGACC GTCAGTCTTC
451	CTCTTCCCCC CAAAACCCAA GGACACCCTC ATGATCTCCC GGACCCCTGA
501	GGTCACATGC GTGGTGGTGG ACGTGAGCCA CGAAGACCCT GAGGTCAAGT
551	TCAACTGGTA CGTGGACGGC GTGGAGGTGC ATAATGCCAA GACAAAGCCG
601	CGGGAGGAGC AGTACAACAG CACGTACCGT GTGGTCAGCG TCCTCACCGT
651	CCTGCACCAG GACTGGCTGA ATGGCAAGGA GTACAAGTGC AAGGTCTCCA
701	ACAAAGCCCT CCCAGCCCCC ATCGAGAAAA CCATCTCCAA AGCCAAAGGG
751	CAGCCCCGAG AACCACAGGT GTACACCCTG CCCCCATCCC GGGAGGAGAT
801	GACCAAGAAC CAGGTCAGCC TGACCTGCCT GGTCAAAGGC TTCTATCCCA
851	GCGACATCGC CGTGGAGTGG GAGAGCAATG GGCAGCCGGA GAACAACTAC
901	GACACCACGC CTCCCGTGCT GGACTCCGAC GGCTCCTTCT TCCTCTATAG
951	CGACCTCACC GTGGACAAGA GCAGGTGGCA GCAGGGGAAC GTCTTCTCAT
1001	GCTCCGTGAT GCATGAGGCT CTGCACAACC ACTACACGCA GAAGAGCCTC
1051	TCCCTGTCTC CGGGT

(SEQ ID NO: 106)

1	SGPRGVQALL CACTSCLQAN YTCETDGACM VSIFNLDGME HHVRTCIPKV
51	ELVPAGKPFY CLSSEDLRNT HCCYTDYCNR IDLRVPSGHL KEPEHPSMWG
101	PVETGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
151	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
201	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPSR EEMTKNQVSL
251	TCLVKGFYPS DIAVEWESNG QPENNYDTTP PVLDSDGSFF LYSDLTVDKS
301	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP G

(SEQ ID NO: 401)

1	MDAMKRGLCC VLLLCGAVFV SPGAS GRGEA ETRECIYYNA NWELERTNQS
51	GLERCEGEQD KRLHCYASWR NSSGTIELVK KGCWLDDFNC YDRQECVATE
101	ENPQVYFCCC EGNFCNERFT HLPEAGGPEV TYEPPPTAP T GGG THTCPPC
151	PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE DPEVKFNWYV
201	DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY KCKVSNKALP
251	APIEKTISKA KGQPREPQVY TLPP C REEMT KNQVSL W CLV KGFYPSDIAV
301	EWESNGQPEN NYKTTPPVLD SDGSFFLYSK LTVDKSRWQQ GNVFSCSVMH
351	EALHNHYTQK SLSLSPGK

(SEQ ID NO: 402)

1	GRGEAETREC IYYNANWELE RTNQSGLERC EGEQDKRLHC YASWRNSSGT
51	IELVKKGCWL DDFNCYDRQE CVATEENPQV YFCCCEGNFC NERFTHLPEA
101	GGPEVTYEPP PTAPTGGGTH TCPPCPAPEL LGGPSVFLFP PKPKDTLMIS
151	RTPEVTCVVV DVSHEDPEVK FNWYVDGVEV HNAKTKPREE QYNSTYRVVS
201	VLTVLHQDWL NGKEYKCKVS NKALPAPIEK TISKAKGQPR EPQVYTLPPC
251	REEMTKNQVS LWCLVKGFYP SDIAVEWESN GQPENNYKTT PPVLDSDGSF
301	FLYSKLTVDK SRWQQGNVFS CSVMHEALHN HYTQKSLSLS PGK

(SEQ ID NO: 403)

1	MDAMKRGLCC VLLLCGAVFV SPGA SGPRGV QALLCACTSC LQANYTCETD
51	GACMVSIFNL DGMEHHVRTC IPKVELVPAG KPFYCLSSED LRNTHCCYTD
101	YCNRIDLRVP SGHLKEPEHP SMWGPVE TGG G THTCPPCPA PELLGGPSVF
151	LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG VEVHNAKTKP
201	REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP IEKTISKAKG
251	QPREPQV C TL PPSREEMTKN QVSL S C A VKG FYPSDIAVEW ESNGQPENNY
301	KTTPPVLDSD GSFFLVSKLT VDKSRWQQGN VFSCSVMHEA LHNHYTQKSL
351	SLSPGK

(SEQ ID NO: 404)

1	SGPRGVQALL CACTSCLQAN YTCETDGACM VSIFNLDGME HHVRTCIPKV
51	ELVPAGKPFY CLSSEDLRNT HCCYTDYCNR IDLRVPSGHL KEPEHPSMWG
101	PVETGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
151	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
201	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVCTLPPSR EEMTKNQVSL
251	SCAVKGFYPS DIAVEWESNG QPENNYKTTP PVLDSDGSFF LVSKLTVDKS
301	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP GK

Activity of ActRIIB-Fc and ALK4-Fc Complexes in Wild-Type Mice

			ActRIIB-Fc	ActRIIB-Fc:ALK4-Fc
Endpoint		homodimer	heterodimer
(4 wk)	Vehicle	10 mg/kg	10 mg/kg	3 mg/kg
Change in body weight from	↑ 15%	↑ 38% **	↑ 41% **	↑ 33% **
baseline
Change in total lean mass	↓ 1%	↑ 5% **	↑ 5% **	↑ 5% **
from baseline
Change in total adipose	↑ 5%	↓ 36% **	↓ 35% **	↓ 35% **
mass from baseline
Change in total bone mineral	↑ 8%	↑ 14% *	↑ 12% *	↑ 11%
density from baseline
Gastrocnemius weight †	23	36 **	35 **	30 **
Femoris weight †	11.5	17 **	16 **	14 **
Pectoralis weight †	15	23 **	28 **	23 **
* P < 0.05 vs. vehicle
** P < 0.01 vs. vehicle
† Combined left and right muscle weights normalized to femur length (mg/mm) to control for body size

(SEQ ID NO: 115)

1	MDAMKRGLCC VLLLCGAVFV SPGA QNLDSM LHGTGMKSDS DQKKSENGVT
51	LAPEDTLPFL KCYCSGHCPD DAINNTCITN GHCFAIIEED DQGETTLASG
101	CMKYEGSDFQ CKDSPKAQLR RTIECCRTNL CNQYLQPTLP PVVIGPFFDG
151	SIR TGGG THT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
201	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
251	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPSR EEMTKNQVSL
301	TCLVKGFYPS DIAVEWESNG QPENNY D TTP PVLDSDGSFF LYS D LTVDKS
351	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP G

(SEQ ID NO: 116)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCCAGAATCT GGATAGTATG CTTCATGGCA
101	CTGGGATGAA ATCAGACTCC GACCAGAAAA AGTCAGAAAA TGGAGTAACC
151	TTAGCACCAG AGGATACCTT GCCTTTTTTA AAGTGCTATT GCTCAGGGCA
201	CTGTCCAGAT GATGCTATTA ATAACACATG CATAACTAAT GGACATTGCT
251	TTGCCATCAT AGAAGAAGAT GACCAGGGAG AAACCACATT AGCTTCAGGG
301	TGTATGAAAT ATGAAGGATC TGATTTTCAG TGCAAAGATT CTCCAAAAGC
351	CCAGCTACGC CGGACAATAG AATGTTGTCG GACCAATTTA TGTAACCAGT
401	ATTTGCAACC CACACTGCCC CCTGTTGTCA TAGGTCCGTT TTTTGATGGC
451	AGCATTCGAA CCGGTGGTGG AACTCACACA TGCCCACCGT GCCCAGCACC
501	TGAACTCCTG GGGGGACCGT CAGTCTTCCT CTTCCCCCCA AAACCCAAGG
551	ACACCCTCAT GATCTCCCGG ACCCCTGAGG TCACATGCGT GGTGGTGGAC
601	GTGAGCCACG AAGACCCTGA GGTCAAGTTC AACTGGTACG TGGACGGCGT
651	GGAGGTGCAT AATGCCAAGA CAAAGCCGCG GGAGGAGCAG TACAACAGCA
701	CGTACCGTGT GGTCAGCGTC CTCACCGTCC TGCACCAGGA CTGGCTGAAT
751	GGCAAGGAGT ACAAGTGCAA GGTCTCCAAC AAAGCCCTCC CAGCCCCCAT
801	CGAGAAAACC ATCTCCAAAG CCAAAGGGCA GCCCCGAGAA CCACAGGTGT
851	ACACCCTGCC CCCATCCCGG GAGGAGATGA CCAAGAACCA GGTCAGCCTG
901	ACCTGCCTGG TCAAAGGCTT CTATCCCAGC GACATCGCCG TGGAGTGGGA
951	GAGCAATGGG CAGCCGGAGA ACAACTACGA CACCACGCCT CCCGTGCTGG
1001	ACTCCGACGG CTCCTTCTTC CTCTATAGCG ACCTCACCGT GGACAAGAGC
1051	AGGTGGCAGC AGGGGAACGT CTTCTCATGC TCCGTGATGC ATGAGGCTCT
1101	GCACAACCAC TACACGCAGA AGAGCCTCTC CCTGTCTCCG GGT

(SEQ ID NO: 117)

1	GAQNLDSMLH GTGMKSDSDQ KKSENGVTLA PEDTLPFLKC YCSGHCPDDA
51	INNTCITNGH CFAIIEEDDQ GETTLASGCM KYEGSDFQCK DSPKAQLRRT
101	IECCRTNLCN QYLQPTLPPV VIGPFFDGSI RTGGGTHTCP PCPAPELLGG
151	PSVFLFPPKP KDTLMISRTP EVTCVVVDVS HEDPEVKFNW YVDGVEVHNA
201	KTKPREEQYN STYRVVSVLT VLHQDWLNGK EYKCKVSNKA LPAPIEKTIS
251	KAKGQPREPQ VYTLPPSREE MTKNQVSLTC LVKGFYPSDI AVEWESNGQP
301	ENNYDTTPPV LDSDGSFFLY SDLTVDKSRW QQGNVFSCSV MHEALHNHYT
351	QKSLSLSPG

(SEQ ID NO: 407)

1	MDAMKRGLCC VLLLCGAVFV SPGA QNLDSM LHGTGMKSDS DQKKSENGVT
51	LAPEDTLPFL KCYCSGHCPD DAINNTCITN GHCFAIIEED DQGETTLASG
101	CMKYEGSDFQ CKDSPKAQLR RTIECCRTNL CNQYLQPTLP PVVIGPFFDG
151	SIR TGGG THT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
201	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
251	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQV C TLPPSR EEMTKNQVSL
301	S C A VKGFYPS DIAVEWESNG QPENNYKTTP PVLDSDGSFF L V SKLTVDKS
351	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP GK

(SEQ ID NO: 408)

1	GAQNLDSMLH GTGMKSDSDQ KKSENGVTLA PEDTLPFLKC YCSGHCPDDA
51	INNTCITNGH CFAIIEEDDQ GETTLASGCM KYEGSDFQCK DSPKAQLRRT
101	IECCRTNLCN QYLQPTLPPV VIGPFFDGSI RTGGGTHTCP PCPAPELLGG
151	PSVFLFPPKP KDTLMISRTP EVTCVVVDVS HEDPEVKFNW YVDGVEVHNA
201	KTKPREEQYN STYRVVSVLT VLHQDWLNGK EYKCKVSNKA LPAPIEKTIS
251	KAKGQPREPQ VCTLPPSREE MTKNQVSLSC AVKGFYPSDI AVEWESNGQP
301	ENNYKTTPPV LDSDGSFFLV SKLTVDKSRW QQGNVFSCSV MHEALHNHYT
351	QKSLSLSPGK

Activity of ActRIIB-Fc and ALK3-Fc Complexes in Wild-Type Mice Compared to Vehicle

		ActRIIB-Fc	ALK3-Fc	ActRIIB-Fc:ALK3-Fc
Endpoint	homodimer	homodimer	heterodimer
6.5 wk	10 mg/kg	10 mg/kg	10 mg/kg	3 mg/kg
Body weight	↑ 23% *	↓ 3%	↓ 0.5%	↓ 1%
Total adipose mass	↓ 41% *	↓ 12%	↓ 14% *	↓ 18% *
Total bone mineral	↑ 8% *	↑ 6% *	↑ 9% *	↑ 10% *
density
* P < 0.05 vs. vehicle

(SEQ ID NO: 112)

1	MDAMKRGLCC VLLLCGAVFV SPGA GLKCVC LLCDSSNFTC QTEGACWASV
51	MLTNGKEQVI KSCVSLPELN AQVFCHSSNN VTKTECCFTD FCNNITLHLP
101	TASPNAPKLG PME TGGG THT CPPCPAPELL GGPSVFLFPP KPKDTLMISR
151	TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV
201	LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPSR
251	EEMTKNQVSL TCLVKGFYPS DIAVEWESNG QPENNY D TTP PVLDSDGSFF
301	LYS D LTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP G

(SEQ ID NO: 113)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCGGACTGAA GTGTGTATGT CTTTTGTGTG
101	ATTCTTCAAA CTTTACCTGC CAAACAGAAG GAGCATGTTG GGCATCAGTC
151	ATGCTAACCA ATGGAAAAGA GCAGGTGATC AAATCCTGTG TCTCCCTTCC
201	AGAACTGAAT GCTCAAGTCT TCTGTCATAG TTCCAACAAT GTTACCAAAA
251	CCGAATGCTG CTTCACAGAT TTTTGCAACA ACATAACACT GCACCTTCCA
301	ACAGCATCAC CAAATGCCCC AAAACTTGGA CCCATGGAGA CCGGTGGTGG
351	AACTCACACA TGCCCACCGT GCCCAGCACC TGAACTCCTG GGGGGACCGT
401	CAGTCTTCCT CTTCCCCCCA AAACCCAAGG ACACCCTCAT GATCTCCCGG
451	ACCCCTGAGG TCACATGCGT GGTGGTGGAC GTGAGCCACG AAGACCCTGA
501	GGTCAAGTTC AACTGGTACG TGGACGGCGT GGAGGTGCAT AATGCCAAGA
551	CAAAGCCGCG GGAGGAGCAG TACAACAGCA CGTACCGTGT GGTCAGCGTC
601	CTCACCGTCC TGCACCAGGA CTGGCTGAAT GGCAAGGAGT ACAAGTGCAA
651	GGTCTCCAAC AAAGCCCTCC CAGCCCCCAT CGAGAAAACC ATCTCCAAAG
701	CCAAAGGGCA GCCCCGAGAA CCACAGGTGT ACACCCTGCC CCCATCCCGG
751	GAGGAGATGA CCAAGAACCA GGTCAGCCTG ACCTGCCTGG TCAAAGGCTT
801	CTATCCCAGC GACATCGCCG TGGAGTGGGA GAGCAATGGG CAGCCGGAGA
851	ACAACTACGA CACCACGCCT CCCGTGCTGG ACTCCGACGG CTCCTTCTTC
901	CTCTATAGCG ACCTCACCGT GGACAAGAGC AGGTGGCAGC AGGGGAACGT
951	CTTCTCATGC TCCGTGATGC ATGAGGCTCT GCACAACCAC TACACGCAGA
1001	AGAGCCTCTC CCTGTCTCCG GGT

(SEQ ID NO: 114)

1	GLKCVCLLCD SSNFTCQTEG ACWASVMLTN GKEQVIKSCV SLPELNAQVF
51	CHSSNNVTKT ECCFTDFCNN ITLHLPTASP NAPKLGPMET GGGTHTCPPC
101	PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE DPEVKFNWYV
151	DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY KCKVSNKALP
201	APIEKTISKA KGQPREPQVY TLPPSREEMT KNQVSLTCLV KGFYPSDIAV
251	EWESNGQPEN NYDTTPPVLD SDGSFFLYSD LTVDKSRWQQ GNVFSCSVMH
301	EALHNHYTQK SLSLSPG

(SEQ ID NO: 405)

1	MDAMKRGLCC VLLLCGAVFV SPGA GLKCVC LLCDSSNFTC QTEGACWASV
51	MLTNGKEQVI KSCVSLPELN AQVFCHSSNN VTKTECCFTD FCNNITLHLP
101	TASPNAPKLG PME TGGG THT CPPCPAPELL GGPSVFLFPP KPKDTLMISR
151	TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV
201	LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQV C TLPPSR
251	EEMTKNQVSL S C A VKGFYPS DIAVEWESNG QPENNYKTTP PVLDSDGSFF
301	L V SKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP GK

(SEQ ID NO: 406)

1	GLKCVCLLCD SSNFTCQTEG ACWASVMLTN GKEQVIKSCV SLPELNAQVF
51	CHSSNNVTKT ECCFTDFCNN ITLHLPTASP NAPKLGPMET GGGTHTCPPC
101	PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE DPEVKFNWYV
151	DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY KCKVSNKALP
201	APIEKTISKA KGQPREPQVC TLPPSREEMT KNQVSLSCAV KGFYPSDIAV
251	EWESNGQPEN NYKTTPPVLD SDGSFFLVSK LTVDKSRWQQ GNVFSCSVMH
301	EALHNHYTQK SLSLSPGK

(SEQ ID NO: 136)

1	MDAMKRGLCC VLLLCGAVFV SPGA MEDEKP KVNPKLYMCV CEGLSCGNED
51	HCEGQQCFSS LSINDGFHVY QKGCFQVYEQ GKMTCKTPPS PGQAVECCQG
101	DWCNRNITAQ LPTKGKSFPG TQNFHLE TGG G THTCPPCPA PELLGGPSVF
151	LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG VEVHNAKTKP
201	REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP IEKTISKAKG
251	QPREPQVYTL PPSREEMTKN QVSLTCLVKG FYPSDIAVEW ESNGQPENNY
301	D TTPPVLDSD GSFFLYS D LT VDKSRWQQGN VFSCSVMHEA LHNHYTQKSL
351	SLSPG

(SEQ ID NO: 137)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCATGGAAGA TGAGAAGCCC AAGGTCAACC
101	CCAAACTCTA CATGTGTGTG TGTGAAGGTC TCTCCTGCGG TAATGAGGAC
151	CACTGTGAAG GCCAGCAGTG CTTTTCCTCA CTGAGCATCA ACGATGGCTT
201	CCACGTCTAC CAGAAAGGCT GCTTCCAGGT TTATGAGCAG GGAAAGATGA
251	CCTGTAAGAC CCCGCCGTCC CCTGGCCAAG CTGTGGAGTG CTGCCAAGGG
301	GACTGGTGTA ACAGGAACAT CACGGCCCAG CTGCCCACTA AAGGAAAATC
351	CTTCCCTGGA ACACAGAATT TCCACTTGGA GACCGGTGGT GGAACTCACA
401	CATGCCCACC GTGCCCAGCA CCTGAACTCC TGGGGGGACC GTCAGTCTTC
451	CTCTTCCCCC CAAAACCCAA GGACACCCTC ATGATCTCCC GGACCCCTGA
501	GGTCACATGC GTGGTGGTGG ACGTGAGCCA CGAAGACCCT GAGGTCAAGT
551	TCAACTGGTA CGTGGACGGC GTGGAGGTGC ATAATGCCAA GACAAAGCCG
601	CGGGAGGAGC AGTACAACAG CACGTACCGT GTGGTCAGCG TCCTCACCGT
651	CCTGCACCAG GACTGGCTGA ATGGCAAGGA GTACAAGTGC AAGGTCTCCA
701	ACAAAGCCCT CCCAGCCCCC ATCGAGAAAA CCATCTCCAA AGCCAAAGGG
751	CAGCCCCGAG AACCACAGGT GTACACCCTG CCCCCATCCC GGGAGGAGAT
801	GACCAAGAAC CAGGTCAGCC TGACCTGCCT GGTCAAAGGC TTCTATCCCA
851	GCGACATCGC CGTGGAGTGG GAGAGCAATG GGCAGCCGGA GAACAACTAC
901	GACACCACGC CTCCCGTGCT GGACTCCGAC GGCTCCTTCT TCCTCTATAG
951	CGACCTCACC GTGGACAAGA GCAGGTGGCA GCAGGGGAAC GTCTTCTCAT
1001	GCTCCGTGAT GCATGAGGCT CTGCACAACC ACTACACGCA GAAGAGCCTC
1051	TCCCTGTCTC CGGGT

(SEQ ID NO: 138)

1	MEDEKPKVNP KLYMCVCEGL SCGNEDHCEG QQCFSSLSIN DGFHVYQKGC
51	FQVYEQGKMT CKTPPSPGQA VECCQGDWCN RNITAQLPTK GKSFPGTQNF
101	HLETGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
151	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
201	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPSR EEMTKNQVSL
251	TCLVKGFYPS DIAVEWESNG QPENNYDTTP PVLDSDGSFF LYSDLTVDKS
301	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP G

(SEQ ID NO: 421)

1	MDAMKRGLCC VLLLCGAVFV SPGA MEDEKP KVNPKLYMCV CEGLSCGNED
51	HCEGQQCFSS LSINDGFHVY QKGCFQVYEQ GKMTCKTPPS PGQAVECCQG
101	DWCNRNITAQ LPTKGKSFPG TQNFHLE TGG G THTCPPCPA PELLGGPSVF
151	LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG VEVHNAKTKP
201	REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP IEKTISKAKG
251	QPREPQV C TL PPSREEMTKN QVSL S C A VKG FYPSDIAVEW ESNGQPENNY
301	KTTPPVLDSD GSFFL V SKLT VDKSRWQQGN VFSCSVMHEA LHNHYTQKSL
351	SLSPGK

(SEQ ID NO: 422)

1	MEDEKPKVNP KLYMCVCEGL SCGNEDHCEG QQCFSSLSIN DGFHVYQKGC
51	FQVYEQGKMT CKTPPSPGQA VECCQGDWCN RNITAQLPTK GKSFPGTQNF
101	HLETGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
151	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
201	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVCTLPPSR EEMTKNQVSL
251	SCAVKGFYPS DIAVEWESNG QPENNYKTTP PVLDSDGSFF LVSKLTVDKS
301	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP GK

(SEQ ID NO: 139)

1	MDAMKRGLCC VLLLCGAVFV SPGA ALLPGA TALQCFCHLC TKDNFTCVTD
51	GLCFVSVTET TDKVIHNSMC IAEIDLIPRD RPFVCAPSSK TGSVTTTYCC
101	NQDHCNKIEL PTTVKSSPGL GPVE TGGG TH TCPPCPAPEL LGGPSVFLFP
151	PKPKDTLMIS RTPEVTCVVV DVSHEDPEVK FNWYVDGVEV HNAKTKPREE
201	QYNSTYRVVS VLTVLHQDWL NGKEYKCKVS NKALPAPIEK TISKAKGQPR
251	EPQVYTLPPS REEMTKNQVS LTCLVKGFYP SDIAVEWESN GQPENNY D TT
301	PPVLDSDGSF FLYS D LTVDK SRWQQGNVFS CSVMHEALHN HYTQKSLSLS
351	PG

(SEQ ID NO: 140)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCGCGCTGCT CCCGGGGGCG ACGGCGTTAC
101	AGTGTTTCTG CCACCTCTGT ACAAAAGACA ATTTTACTTG TGTGACAGAT
151	GGGCTCTGCT TTGTCTCTGT CACAGAGACC ACAGACAAAG TTATACACAA
201	CAGCATGTGT ATAGCTGAAA TTGACTTAAT TCCTCGAGAT AGGCCGTTTG
251	TATGTGCACC CTCTTCAAAA ACTGGGTCTG TGACTACAAC ATATTGCTGC
301	AATCAGGACC ATTGCAATAA AATAGAACTT CCAACTACTG TAAAGTCATC
351	ACCTGGCCTT GGTCCTGTGG AAACCGGTGG TGGAACTCAC ACATGCCCAC
401	CGTGCCCAGC ACCTGAACTC CTGGGGGGAC CGTCAGTCTT CCTCTTCCCC
451	CCAAAACCCA AGGACACCCT CATGATCTCC CGGACCCCTG AGGTCACATG
501	CGTGGTGGTG GACGTGAGCC ACGAAGACCC TGAGGTCAAG TTCAACTGGT
551	ACGTGGACGG CGTGGAGGTG CATAATGCCA AGACAAAGCC GCGGGAGGAG
601	CAGTACAACA GCACGTACCG TGTGGTCAGC GTCCTCACCG TCCTGCACCA
651	GGACTGGCTG AATGGCAAGG AGTACAAGTG CAAGGTCTCC AACAAAGCCC
701	TCCCAGCCCC CATCGAGAAA ACCATCTCCA AAGCCAAAGG GCAGCCCCGA
751	GAACCACAGG TGTACACCCT GCCCCCATCC CGGGAGGAGA TGACCAAGAA
801	CCAGGTCAGC CTGACCTGCC TGGTCAAAGG CTTCTATCCC AGCGACATCG
851	CCGTGGAGTG GGAGAGCAAT GGGCAGCCGG AGAACAACTA CGACACCACG
901	CCTCCCGTGC TGGACTCCGA CGGCTCCTTC TTCCTCTATA GCGACCTCAC
951	CGTGGACAAG AGCAGGTGGC AGCAGGGGAA CGTCTTCTCA TGCTCCGTGA
1001	TGCATGAGGC TCTGCACAAC CACTACACGC AGAAGAGCCT CTCCCTGTCT
1051	CCGGGT

(SEQ ID NO: 141)

1	ALLPGATALQ CFCHLCTKDN FTCVTDGLCF VSVTETTDKV IHNSMCIAEI
51	DLIPRDRPFV CAPSSKTGSV TTTYCCNQDH CNKIELPTTV KSSPGLGPVE
101	TGGGTHTCPP CPAPELLGGP SVFLFPPKPK DTLMISRTPE VTCVVVDVSH
151	EDPEVKFNWY VDGVEVHNAK TKPREEQYNS TYRVVSVLTV LHQDWLNGKE
201	YKCKVSNKAL PAPIEKTISK AKGQPREPQV YTLPPSREEM TKNQVSLTCL
251	VKGFYPSDIA VEWESNGQPE NNYDTTPPVL DSDGSFFLYS DLTVDKSRWQ
301	QGNVFSCSVM HEALHNHYTQ KSLSLSPG

(SEQ ID NO: 423)

1	MDAMKRGLCC VLLLCGAVFV SPGA ALLPGA TALQCFCHLC TKDNFTCVTD
51	GLCFVSVTET TDKVIHNSMC IAEIDLIPRD RPFVCAPSSK TGSVTTTYCC
101	NQDHCNKIEL PTTVKSSPGL GPVE TGGG TH TCPPCPAPEL LGGPSVFLFP
151	PKPKDTLMIS RTPEVTCVVV DVSHEDPEVK FNWYVDGVEV HNAKTKPREE
201	QYNSTYRVVS VLTVLHQDWL NGKEYKCKVS NKALPAPIEK TISKAKGQPR
251	EPQV C TLPPS REEMTKNQVS L S C A VKGFYP SDIAVEWESN GQPENNYKTT
301	PPVLDSDGSF FL V SKLTVDK SRWQQGNVFS CSVMHEALHN HYTQKSLSLS
351	PGK

(SEQ ID NO: 424)

1	ALLPGATALQ CFCHLCTKDN FTCVTDGLCF VSVTETTDKV IHNSMCIAEI
51	DLIPRDRPFV CAPSSKTGSV TTTYCCNQDH CNKIELPTTV KSSPGLGPVE
101	TGGGTHTCPP CPAPELLGGP SVFLFPPKPK DTLMISRTPE VTCVVVDVSH
151	EDPEVKFNWY VDGVEVHNAK TKPREEQYNS TYRVVSVLTV LHQDWLNGKE
201	YKCKVSNKAL PAPIEKTISK AKGQPREPQV CTLPPSREEM TKNQVSLSCA
251	VKGFYPSDIA VEWESNGQPE NNYKTTPPVL DSDGSFFLVS KLTVDKSRWQ
301	QGNVFSCSVM HEALHNHYTQ KSLSLSPGK

(SEQ ID NO: 142)

1	MDAMKRGLCC VLLLCGAVFV SPGA KKEDGE STAPTPRPKV LRCKCHHHCP
51	EDSVNNICST DGYCFTMIEE DDSGLPVVTS GCLGLEGSDF QCRDTPIPHQ
101	RRSIECCTER NECNKDLHPT LPPLKNRDFV DGPIHHR TGG G THTCPPCPA
151	PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG
201	VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP
251	IEKTISKAKG QPREPQVYTL PPSREEMTKN QVSLTCLVKG FYPSDIAVEW
301	ESNGQPENNY D TTPPVLDSD GSFFLYS D LT VDKSRWQQGN VFSCSVMHEA
351	LHNHYTQKSL SLSPG

(SEQ ID NO: 143)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCAAGAAAGA GGATGGTGAG AGTACAGCCC
101	CCACCCCCCG TCCAAAGGTC TTGCGTTGTA AATGCCACCA CCATTGTCCA
151	GAAGACTCAG TCAACAATAT TTGCAGCACA GACGGATATT GTTTCACGAT
201	GATAGAAGAG GATGACTCTG GGTTGCCTGT GGTCACTTCT GGTTGCCTAG
251	GACTAGAAGG CTCAGATTTT CAGTGTCGGG ACACTCCCAT TCCTCATCAA
301	AGAAGATCAA TTGAATGCTG CACAGAAAGG AACGAATGTA ATAAAGACCT
351	ACACCCTACA CTGCCTCCAT TGAAAAACAG AGATTTTGTT GATGGACCTA
401	TACACCACAG GACCGGTGGT GGAACTCACA CATGCCCACC GTGCCCAGCA
451	CCTGAACTCC TGGGGGGACC GTCAGTCTTC CTCTTCCCCC CAAAACCCAA
501	GGACACCCTC ATGATCTCCC GGACCCCTGA GGTCACATGC GTGGTGGTGG
551	ACGTGAGCCA CGAAGACCCT GAGGTCAAGT TCAACTGGTA CGTGGACGGC
601	GTGGAGGTGC ATAATGCCAA GACAAAGCCG CGGGAGGAGC AGTACAACAG
651	CACGTACCGT GTGGTCAGCG TCCTCACCGT CCTGCACCAG GACTGGCTGA
701	ATGGCAAGGA GTACAAGTGC AAGGTCTCCA ACAAAGCCCT CCCAGCCCCC
751	ATCGAGAAAA CCATCTCCAA AGCCAAAGGG CAGCCCCGAG AACCACAGGT
801	GTACACCCTG CCCCCATCCC GGGAGGAGAT GACCAAGAAC CAGGTCAGCC
851	TGACCTGCCT GGTCAAAGGC TTCTATCCCA GCGACATCGC CGTGGAGTGG
901	GAGAGCAATG GGCAGCCGGA GAACAACTAC GACACCACGC CTCCCGTGCT
951	GGACTCCGAC GGCTCCTTCT TCCTCTATAG CGACCTCACC GTGGACAAGA
1001	GCAGGTGGCA GCAGGGGAAC GTCTTCTCAT GCTCCGTGAT GCATGAGGCT
1051	CTGCACAACC ACTACACGCA GAAGAGCCTC TCCCTGTCTC CGGGT

(SEQ ID NO: 144)

1	KKEDGESTAP TPRPKVLRCK CHHHCPEDSV NNICSTDGYC FTMIEEDDSG
51	LPVVTSGCLG LEGSDFQCRD TPIPHQRRSI ECCTERNECN KDLHPTLPPL
101	KNRDFVDGPI HHRTGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR
151	TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV
201	LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPSR
251	EEMTKNQVSL TCLVKGFYPS DIAVEWESNG QPENNYDTTP PVLDSDGSFF
301	LYSDLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP G

(SEQ ID NO: 425)

1	MDAMKRGLCC VLLLCGAVFV SPGA KKEDGE STAPTPRPKV LRCKCHHHCP
51	EDSVNNICST DGYCFTMIEE DDSGLPVVTS GCLGLEGSDF QCRDTPIPHQ
101	RRSIECCTER NECNKDLHPT LPPLKNRDFV DGPIHHR TGG G THTCPPCPA
151	PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG
201	VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP
251	IEKTISKAKG QPREPQV C TL PPSREEMTKN QVSL S C A VKG FYPSDIAVEW
301	ESNGQPENNY KTTPPVLDSD GSFFL V SKLT VDKSRWQQGN VFSCSVMHEA
351	LHNHYTQKSL SLSPGK

(SEQ ID NO: 426)

1	KKEDGESTAP TPRPKVLRCK CHHHCPEDSV NNICSTDGYC FTMIEEDDSG
51	LPVVTSGCLG LEGSDFQCRD TPIPHQRRSI ECCTERNECN KDLHPTLPPL
101	KNRDFVDGPI HHRTGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR
151	TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV
201	LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVCTLPPSR
251	EEMTKNQVSL SCAVKGFYPS DIAVEWESNG QPENNYKTTP PVLDSDGSFF
301	LVSKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP GK

(SEQ ID NO: 118)

1	MDAMKRGLCC VLLLCGAVFV SPGA AILGRS ETQECLFFNA NWEKDRTNQT
51	GVEPCYGDKD KRRHCFATWK NISGSIEIVK QGCWLDDINC YDRTDCVEKK
101	DSPEVYFCCC EGNMCNEKFS YFPEMEVTQP TSNPVTPKPP TGGG THTCPP
151	CPAPELLGGP SVFLFPPKPK DTLMISRTPE VTCVVVDVSH EDPEVKFNWY
201	VDGVEVHNAK TKPREEQYNS TYRVVSVLTV LHQDWLNGKE YKCKVSNKAL
251	PAPIEKTISK AKGQPREPQV YTLPPSR K EM TKNQVSLTCL VKGFYPSDIA
301	VEWESNGQPE NNYKTTPPVL K SDGSFFLYS KLTVDKSRWQ QGNVFSCSVM
351	HEALHNHYTQ KSLSLSPGK

(SEQ ID NO: 119)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCGCTATACT TGGTAGATCA GAAACTCAGG
101	AGTGTCTTTT CTTTAATGCT AATTGGGAAA AAGACAGAAC CAATCAAACT
151	GGTGTTGAAC CGTGTTATGG TGACAAAGAT AAACGGCGGC ATTGTTTTGC
201	TACCTGGAAG AATATTTCTG GTTCCATTGA AATAGTGAAA CAAGGTTGTT
251	GGCTGGATGA TATCAACTGC TATGACAGGA CTGATTGTGT AGAAAAAAAA
301	GACAGCCCTG AAGTATATTT CTGTTGCTGT GAGGGCAATA TGTGTAATGA
351	AAAGTTTTCT TATTTTCCGG AGATGGAAGT CACACAGCCC ACTTCAAATC
401	CAGTTACACC TAAGCCACCC ACCGGTGGTG GAACTCACAC ATGCCCACCG
451	TGCCCAGCAC CTGAACTCCT GGGGGGACCG TCAGTCTTCC TCTTCCCCCC
501	AAAACCCAAG GACACCCTCA TGATCTCCCG GACCCCTGAG GTCACATGCG
551	TGGTGGTGGA CGTGAGCCAC GAAGACCCTG AGGTCAAGTT CAACTGGTAC
601	GTGGACGGCG TGGAGGTGCA TAATGCCAAG ACAAAGCCGC GGGAGGAGCA
651	GTACAACAGC ACGTACCGTG TGGTCAGCGT CCTCACCGTC CTGCACCAGG
701	ACTGGCTGAA TGGCAAGGAG TACAAGTGCA AGGTCTCCAA CAAAGCCCTC
751	CCAGCCCCCA TCGAGAAAAC CATCTCCAAA GCCAAAGGGC AGCCCCGAGA
801	ACCACAGGTG TACACCCTGC CCCCATCCCG GAAGGAGATG ACCAAGAACC
851	AGGTCAGCCT GACCTGCCTG GTCAAAGGCT TCTATCCCAG CGACATCGCC
901	GTGGAGTGGG AGAGCAATGG GCAGCCGGAG AACAACTACA AGACCACGCC
951	TCCCGTGCTG AAGTCCGACG GCTCCTTCTT CCTCTATAGC AAGCTCACCG
1001	TGGACAAGAG CAGGTGGCAG CAGGGGAACG TCTTCTCATG CTCCGTGATG
1051	CATGAGGCTC TGCACAACCA CTACACGCAG AAGAGCCTCT CCCTGTCTCC
1101	GGGTAAA

(SEQ ID NO: 120)

1	ILGRSETQEC LFFNANWEKD RTNQTGVEPC YGDKDKRRHC FATWKNISGS
51	IEIVKQGCWL DDINCYDRTD CVEKKDSPEV YFCCCEGNMC NEKFSYFPEM
101	EVTQPTSNPV TPKPPTGGGT HTCPPCPAPE LLGGPSVFLF PPKPKDTLMI
151	SRTPEVTCVV VDVSHEDPEV KFNWYVDGVE VHNAKTKPRE EQYNSTYRVV
201	SVLTVLHQDW LNGKEYKCKV SNKALPAPIE KTISKAKGQP REPQVYTLPP
251	SRKEMTKNQV SLTCLVKGFY PSDIAVEWES NGQPENNYKT TPPVLKSDGS
301	FFLYSKLTVD KSRWQQGNVF SCSVMHEALH NHYTQKSLSL SPGK

(SEQ ID NO: 409)

1	MDAMKRGLCC VLLLCGAVFV SPGA AILGRS ETQECLFFNA NWEKDRTNQT
51	GVEPCYGDKD KRRHCFATWK NISGSIEIVK QGCWLDDINC YDRTDCVEKK
101	DSPEVYFCCC EGNMCNEKFS YFPEMEVTQP TSNPVTPKPP TGGG THTCPP
151	CPAPELLGGP SVFLFPPKPK DTLMISRTPE VTCVVVDVSH EDPEVKFNWY
201	VDGVEVHNAK TKPREEQYNS TYRVVSVLTV LHQDWLNGKE YKCKVSNKAL
251	PAPIEKTISK AKGQPREPQV YTLPP C REEM TKNQVSL W CL VKGFYPSDIA
301	VEWESNGQPE NNYKTTPPVL DSDGSFFLYS KLTVDKSRWQ QGNVFSCSVM
351	HEALHNHYTQ KSLSLSPGK

(SEQ ID NO: 410)

1	ILGRSETQEC LFFNANWEKD RTNQTGVEPC YGDKDKRRHC FATWKNISGS
51	IEIVKQGCWL DDINCYDRTD CVEKKDSPEV YFCCCEGNMC NEKFSYFPEM
101	EVTQPTSNPV TPKPPTGGGT HTCPPCPAPE LLGGPSVFLF PPKPKDTLMI
151	SRTPEVTCVV VDVSHEDPEV KFNWYVDGVE VHNAKTKPRE EQYNSTYRVV
201	SVLTVLHQDW LNGKEYKCKV SNKALPAPIE KTISKAKGQP REPQVYTLPP
251	CREEMTKNQV SLWCLVKGFY PSDIAVEWES NGQPENNYKT TPPVLDSDGS
301	FFLYSKLTVD KSRWQQGNVF SCSVMHEALH NHYTQKSLSL SPGK

(SEQ ID NO: 121)

1	MDAMKRGLCC VLLLCGAVFV SPGA SQNQER LCAFKDPYQQ DLGIGESRIS
51	HENGTILCSK GSTCYGLWEK SKGDINLVKQ GCWSHIGDPQ ECHYEECVVT
101	TTPPSIQNGT YRFCCCSTDL CNVNFTENFP PPDTTPLSPP HSFNRDE TGG
151	G THTCPPCPA PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP
201	EVKFNWYVDG VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC
251	KVSNKALPAP IEKTISKAKG QPREPQVYTL PPSR K EMTKN QVSLTCLVKG
301	FYPSDIAVEW ESNGQPENNY KTTPPVL K SD GSFFLYSKLT VDKSRWQQGN
351	VFSCSVMHEA LHNHYTQKSL SLSPGK

(SEQ ID NO: 122)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCTCGCAGAA TCAAGAACGC CTATGTGCGT
101	TTAAAGATCC GTATCAGCAA GACCTTGGGA TAGGTGAGAG TAGAATCTCT
151	CATGAAAATG GGACAATATT ATGCTCGAAA GGTAGCACCT GCTATGGCCT
201	TTGGGAGAAA TCAAAAGGGG ACATAAATCT TGTAAAACAA GGATGTTGGT
251	CTCACATTGG AGATCCCCAA GAGTGTCACT ATGAAGAATG TGTAGTAACT
301	ACCACTCCTC CCTCAATTCA GAATGGAACA TACCGTTTCT GCTGTTGTAG
351	CACAGATTTA TGTAATGTCA ACTTTACTGA GAATTTTCCA CCTCCTGACA
401	CAACACCACT CAGTCCACCT CATTCATTTA ACCGAGATGA GACCGGTGGT
451	GGAACTCACA CATGCCCACC GTGCCCAGCA CCTGAACTCC TGGGGGGACC
501	GTCAGTCTTC CTCTTCCCCC CAAAACCCAA GGACACCCTC ATGATCTCCC
551	GGACCCCTGA GGTCACATGC GTGGTGGTGG ACGTGAGCCA CGAAGACCCT
601	GAGGTCAAGT TCAACTGGTA CGTGGACGGC GTGGAGGTGC ATAATGCCAA
651	GACAAAGCCG CGGGAGGAGC AGTACAACAG CACGTACCGT GTGGTCAGCG
701	TCCTCACCGT CCTGCACCAG GACTGGCTGA ATGGCAAGGA GTACAAGTGC
751	AAGGTCTCCA ACAAAGCCCT CCCAGCCCCC ATCGAGAAAA CCATCTCCAA
801	AGCCAAAGGG CAGCCCCGAG AACCACAGGT GTACACCCTG CCCCCATCCC
851	GGAAGGAGAT GACCAAGAAC CAGGTCAGCC TGACCTGCCT GGTCAAAGGC
901	TTCTATCCCA GCGACATCGC CGTGGAGTGG GAGAGCAATG GGCAGCCGGA
951	GAACAACTAC AAGACCACGC CTCCCGTGCT GAAGTCCGAC GGCTCCTTCT
1001	TCCTCTATAG CAAGCTCACC GTGGACAAGA GCAGGTGGCA GCAGGGGAAC
1051	GTCTTCTCAT GCTCCGTGAT GCATGAGGCT CTGCACAACC ACTACACGCA
1101	GAAGAGCCTC TCCCTGTCTC CGGGTAAA

(SEQ ID NO: 123)

1	SQNQERLCAF KDPYQQDLGI GESRISHENG TILCSKGSTC YGLWEKSKGD
51	INLVKQGCWS HIGDPQECHY EECVVTTTPP SIQNGTYRFC CCSTDLCNVN
101	FTENFPPPDT TPLSPPHSFN RDETGGGTHT CPPCPAPELL GGPSVFLFPP
151	KPKDTLMISR TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ
201	YNSTYRVVSV LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE
251	PQVYTLPPSR KEMTKNQVSL TCLVKGFYPS DIAVEWESNG QPENNYKTTP
301	PVLKSDGSFF LYSKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP
351	GK

(SEQ ID NO: 124)

1	MDAMKRGLCC VLLLCGAVFV SPGA DPVKPS RGPLVTCTCE SPHCKGPTCR
51	GAWCTVVLVR EEGRHPQEHR GCGNLHRELC RGRPTEFVNH YCCDSHLCNH
101	NVSLVLEATQ PPSEQPGTDG QLA TGGG THT CPPCPAPELL GGPSVFLFPP
151	KPKDTLMISR TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ
201	YNSTYRVVSV LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE
251	PQVYTLPPSR EEMTKNQVSL TCLVKGFYPS DIAVEWESNG QPENNY D TTP
301	PVLDSDGSFF LYS D LTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP
351	G

(SEQ ID NO: 125)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCGACCCTGT GAAGCCGTCT CGGGGCCCGC
101	TGGTGACCTG CACGTGTGAG AGCCCACATT GCAAGGGGCC TACCTGCCGG
151	GGGGCCTGGT GCACAGTAGT GCTGGTGCGG GAGGAGGGGA GGCACCCCCA
201	GGAACATCGG GGCTGCGGGA ACTTGCACAG GGAGCTCTGC AGGGGCCGCC
251	CCACCGAGTT CGTCAACCAC TACTGCTGCG ACAGCCACCT CTGCAACCAC
301	AACGTGTCCC TGGTGCTGGA GGCCACCCAA CCTCCTTCGG AGCAGCCGGG
351	AACAGATGGC CAGCTGGCCA CCGGTGGTGG AACTCACACA TGCCCACCGT
401	GCCCAGCACC TGAACTCCTG GGGGGACCGT CAGTCTTCCT CTTCCCCCCA
451	AAACCCAAGG ACACCCTCAT GATCTCCCGG ACCCCTGAGG TCACATGCGT
501	GGTGGTGGAC GTGAGCCACG AAGACCCTGA GGTCAAGTTC AACTGGTACG
551	TGGACGGCGT GGAGGTGCAT AATGCCAAGA CAAAGCCGCG GGAGGAGCAG
601	TACAACAGCA CGTACCGTGT GGTCAGCGTC CTCACCGTCC TGCACCAGGA
651	CTGGCTGAAT GGCAAGGAGT ACAAGTGCAA GGTCTCCAAC AAAGCCCTCC
701	CAGCCCCCAT CGAGAAAACC ATCTCCAAAG CCAAAGGGCA GCCCCGAGAA
751	CCACAGGTGT ACACCCTGCC CCCATCCCGG GAGGAGATGA CCAAGAACCA
801	GGTCAGCCTG ACCTGCCTGG TCAAAGGCTT CTATCCCAGC GACATCGCCG
851	TGGAGTGGGA GAGCAATGGG CAGCCGGAGA ACAACTACGA CACCACGCCT
901	CCCGTGCTGG ACTCCGACGG CTCCTTCTTC CTCTATAGCG ACCTCACCGT
951	GGACAAGAGC AGGTGGCAGC AGGGGAACGT CTTCTCATGC TCCGTGATGC
1001	ATGAGGCTCT GCACAACCAC TACACGCAGA AGAGCCTCTC CCTGTCTCCG
1051	GGT

(SEQ ID NO: 126)

1	DPVKPSRGPL VTCTCESPHC KGPTCRGAWC TVVLVREEGR HPQEHRGCGN
51	LHRELCRGRP TEFVNHYCCD SHLCNHNVSL VLEATQPPSE QPGTDGQLA T
101	GGG THTCPPC PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE
151	DPEVKFNWYV DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY
201	KCKVSNKALP APIEKTISKA KGQPREPQVY TLPPSREEMT KNQVSLTCLV
251	KGFYPSDIAV EWESNGQPEN NY D TTPPVLD SDGSFFLYS D LTVDKSRWQQ
301	GNVFSCSVMH EALHNHYTQK SLSLSPG

(SEQ ID NO: 411)

1	MDAMKRGLCC VLLLCGAVFV SPGA SQNQER LCAFKDPYQQ DLGIGESRIS
51	HENGTILCSK GSTCYGLWEK SKGDINLVKQ GCWSHIGDPQ ECHYEECVVT
101	TTPPSIQNGT YRFCCCSTDL CNVNFTENFP PPDTTPLSPP HSFNRDE TGG
151	G THTCPPCPA PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP
201	EVKFNWYVDG VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC
251	KVSNKALPAP IEKTISKAKG QPREPQVYTL PP C REEMTKN QVSL W CLVKG
301	FYPSDIAVEW ESNGQPENNY KTTPPVLDSD GSFFLYSKLT VDKSRWQQGN
351	VFSCSVMHEA LHNHYTQKSL SLSPGK

(SEQ ID NO: 412)

1	SQNQERLCAF KDPYQQDLGI GESRISHENG TILCSKGSTC YGLWEKSKGD
51	INLVKQGCWS HIGDPQECHY EECVVTTTPP SIQNGTYRFC CCSTDLCNVN
101	FTENFPPPDT TPLSPPHSFN RDE TGGG THT CPPCPAPELL GGPSVFLFPP
151	KPKDTLMISR TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ
201	YNSTYRVVSV LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE
251	PQVYTLPP C R EEMTKNQVSL W CLVKGFYPS DIAVEWESNG QPENNYKTTP
301	PVLDSDGSFF LYSKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP
351	GK

(SEQ ID NO: 413)

1	MDAMKRGLCC VLLLCGAVFV SPGA DPVKPS RGPLVTCTCE SPHCKGPTCR
51	GAWCTVVLVR EEGRHPQEHR GCGNLHRELC RGRPTEFVNH YCCDSHLCNH
101	NVSLVLEATQ PPSEQPGTDG QLA TGGG THT CPPCPAPELL GGPSVFLFPP
151	KPKDTLMISR TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ
201	YNSTYRVVSV LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE
251	PQV C TLPPSR EEMTKNQVSL S C A VKGFYPS DIAVEWESNG QPENNYKTTP
301	PVLDSDGSFF L V SKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP
351	GK

(SEQ ID NO: 414)

1	DPVKPSRGPL VTCTCESPHC KGPTCRGAWC TVVLVREEGR HPQEHRGCGN
51	LHRELCRGRP TEFVNHYCCD SHLCNHNVSL VLEATQPPSE QPGTDGQLA T
101	GGG THTCPPC PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE
151	DPEVKFNWYV DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY
201	KCKVSNKALP APIEKTISKA KGQPREPQV C TLPPSREEMT KNQVSL S C A V
251	KGFYPSDIAV EWESNGQPEN NYKTTPPVLD SDGSFFL V SK LTVDKSRWQQ
301	GNVFSCSVMH EALHNHYTQK SLSLSPGK

(SEQ ID NO: 127)

1	MDAMKRGLCC VLLLCGAVFV SPGA TIPPHV QKSVNNDMIV TDNNGAVKFP
51	QLCKFCDVRF STCDNQKSCM SNCSITSICE KPQEVCVAVW RKNDENITLE
101	TVCHDPKLPY HDFILEDAAS PKCIMKEKKK PGETFFMCSC SSDECNDNII
151	FSEEYNTSNP D TGGG THTCP PCPAPELLGG PSVFLFPPKP KDTLMISRTP
201	EVTCVVVDVS HEDPEVKFNW YVDGVEVHNA KTKPREEQYN STYRVVSVLT
251	VLHQDWLNGK EYKCKVSNKA LPAPIEKTIS KAKGQPREPQ VYTLPPSR K E
301	MTKNQVSLTC LVKGFYPSDI AVEWESNGQP ENNYKTTPPV L K SDGSFFLY
351	SKLTVDKSRW QQGNVFSCSV MHEALHNHYT QKSLSLSPGK

(SEQ ID NO: 128)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCACGATCCC ACCGCACGTT CAGAAGTCGG
101	TTAATAACGA CATGATAGTC ACTGACAACA ACGGTGCAGT CAAGTTTCCA
151	CAACTGTGTA AATTTTGTGA TGTGAGATTT TCCACCTGTG ACAACCAGAA
201	ATCCTGCATG AGCAACTGCA GCATCACCTC CATCTGTGAG AAGCCACAGG
251	AAGTCTGTGT GGCTGTATGG AGAAAGAATG ACGAGAACAT AACACTAGAG
301	ACAGTTTGCC ATGACCCCAA GCTCCCCTAC CATGACTTTA TTCTGGAAGA
351	TGCTGCTTCT CCAAAGTGCA TTATGAAGGA AAAAAAAAAG CCTGGTGAGA
401	CTTTCTTCAT GTGTTCCTGT AGCTCTGATG AGTGCAATGA CAACATCATC
451	TTCTCAGAAG AATATAACAC CAGCAATCCT GACACCGGTG GTGGAACTCA
501	CACATGCCCA CCGTGCCCAG CACCTGAACT CCTGGGGGGA CCGTCAGTCT
551	TCCTCTTCCC CCCAAAACCC AAGGACACCC TCATGATCTC CCGGACCCCT
601	GAGGTCACAT GCGTGGTGGT GGACGTGAGC CACGAAGACC CTGAGGTCAA
651	GTTCAACTGG TACGTGGACG GCGTGGAGGT GCATAATGCC AAGACAAAGC
701	CGCGGGAGGA GCAGTACAAC AGCACGTACC GTGTGGTCAG CGTCCTCACC
751	GTCCTGCACC AGGACTGGCT GAATGGCAAG GAGTACAAGT GCAAGGTCTC
801	CAACAAAGCC CTCCCAGCCC CCATCGAGAA AACCATCTCC AAAGCCAAAG
851	GGCAGCCCCG AGAACCACAG GTGTACACCC TGCCCCCATC CCGGAAGGAG
901	ATGACCAAGA ACCAGGTCAG CCTGACCTGC CTGGTCAAAG GCTTCTATCC
951	CAGCGACATC GCCGTGGAGT GGGAGAGCAA TGGGCAGCCG GAGAACAACT
1001	ACAAGACCAC GCCTCCCGTG CTGAAGTCCG ACGGCTCCTT CTTCCTCTAT
1051	AGCAAGCTCA CCGTGGACAA GAGCAGGTGG CAGCAGGGGA ACGTCTTCTC
1101	ATGCTCCGTG ATGCATGAGG CTCTGCACAA CCACTACACG CAGAAGAGCC
1151	TCTCCCTGTC TCCGGGTAAA

(SEQ ID NO: 129)

1	TIPPHVQKSV NNDMIVTDNN GAVKFPQLCK FCDVRFSTCD NQKSCMSNCS
51	ITSICEKPQE VCVAVWRKND ENITLETVCH DPKLPYHDFI LEDAASPKCI
101	MKEKKKPGET FFMCSCSSDE CNDNIIFSEE YNTSNPDTGG GTHTCPPCPA
151	PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG
201	VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP
251	IEKTISKAKG QPREPQVYTL PPSRKEMTKN QVSLTCLVKG FYPSDIAVEW
301	ESNGQPENNY KTTPPVLKSD GSFFLYSKLT VDKSRWQQGN VFSCSVMHEA
351	LHNHYTQKSL SLSPGK

(SEQ ID NO: 130)

1	MDAMKRGLCC VLLLCGAVFV SPGA TIPPHV QKSDVEMEAQ KDEIICPSCN
51	RTAHPLRHIN NDMIVTDNNG AVKFPQLCKF CDVRFSTCDN QKSCMSNCSI
101	TSICEKPQEV CVAVWRKNDE NITLETVCHD PKLPYHDFIL EDAASPKCIM
151	KEKKKPGETF FMCSCSSDEC NDNIIFSEEY NTSNPD TGGG THTCPPCPAP
201	ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE VKFNWYVDGV
251	EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK VSNKALPAPI
301	EKTISKAKGQ PREPQVYTLP PSR K EMTKNQ VSLTCLVKGF YPSDIAVEWE
351	SNGQPENNYK TTPPVL K SDG SFFLYSKLTV DKSRWQQGNV FSCSVMHEAL
401	HNHYTQKSLS LSPGK

(SEQ ID NO: 131)

1	ATGGATGCAA TGAAGAGAGG GCTCTGCTGT GTGCTGCTGC TGTGTGGAGC
51	AGTCTTCGTT TCGCCCGGCG CCACGATCCC ACCGCACGTT CAGAAGTCGG
101	ATGTGGAAAT GGAGGCCCAG AAAGATGAAA TCATCTGCCC CAGCTGTAAT
151	AGGACTGCCC ATCCACTGAG ACATATTAAT AACGACATGA TAGTCACTGA
201	CAACAACGGT GCAGTCAAGT TTCCACAACT GTGTAAATTT TGTGATGTGA
251	GATTTTCCAC CTGTGACAAC CAGAAATCCT GCATGAGCAA CTGCAGCATC
301	ACCTCCATCT GTGAGAAGCC ACAGGAAGTC TGTGTGGCTG TATGGAGAAA
351	GAATGACGAG AACATAACAC TAGAGACAGT TTGCCATGAC CCCAAGCTCC
401	CCTACCATGA CTTTATTCTG GAAGATGCTG CTTCTCCAAA GTGCATTATG
451	AAGGAAAAAA AAAAGCCTGG TGAGACTTTC TTCATGTGTT CCTGTAGCTC
501	TGATGAGTGC AATGACAACA TCATCTTCTC AGAAGAATAT AACACCAGCA
551	ATCCTGACAC CGGTGGTGGA ACTCACACAT GCCCACCGTG CCCAGCACCT
601	GAACTCCTGG GGGGACCGTC AGTCTTCCTC TTCCCCCCAA AACCCAAGGA
651	CACCCTCATG ATCTCCCGGA CCCCTGAGGT CACATGCGTG GTGGTGGACG
701	TGAGCCACGA AGACCCTGAG GTCAAGTTCA ACTGGTACGT GGACGGCGTG
751	GAGGTGCATA ATGCCAAGAC AAAGCCGCGG GAGGAGCAGT ACAACAGCAC
801	GTACCGTGTG GTCAGCGTCC TCACCGTCCT GCACCAGGAC TGGCTGAATG
851	GCAAGGAGTA CAAGTGCAAG GTCTCCAACA AAGCCCTCCC AGCCCCCATC
901	GAGAAAACCA TCTCCAAAGC CAAAGGGCAG CCCCGAGAAC CACAGGTGTA
951	CACCCTGCCC CCATCCCGGA AGGAGATGAC CAAGAACCAG GTCAGCCTGA
1001	CCTGCCTGGT CAAAGGCTTC TATCCCAGCG ACATCGCCGT GGAGTGGGAG
1051	AGCAATGGGC AGCCGGAGAA CAACTACAAG ACCACGCCTC CCGTGCTGAA
1101	GTCCGACGGC TCCTTCTTCC TCTATAGCAA GCTCACCGTG GACAAGAGCA
1151	GGTGGCAGCA GGGGAACGTC TTCTCATGCT CCGTGATGCA TGAGGCTCTG
1201	CACAACCACT ACACGCAGAA GAGCCTCTCC CTGTCTCCGG GTAAA

(SEQ ID NO: 132)

1	TIPPHVQKSD VEMEAQKDEI ICPSCNRTAH PLRHINNDMI VTDNNGAVKF
51	PQLCKFCDVR FSTCDNQKSC MSNCSITSIC EKPQEVCVAV WRKNDENITL
101	ETVCHDPKLP YHDFILEDAA SPKCIMKEKK KPGETFFMCS CSSDECNDNI
151	IFSEEYNTSN PDTGGGTHTC PPCPAPELLG GPSVFLFPPK PKDTLMISRT
201	PEVTCVVVDV SHEDPEVKFN WYVDGVEVHN AKTKPREEQY NSTYRVVSVL
251	TVLHQDWLNG KEYKCKVSNK ALPAPIEKTI SKAKGQPREP QVYTLPPSRK
301	EMTKNQVSLT CLVKGFYPSD IAVEWESNGQ PENNYKTTPP VLKSDGSFFL
351	YS K LTVDKSR WQQGNVFSCS VMHEALHNHY TQKSLSLSPG K

(SEQ ID NO: 415)

1	MDAMKRGLCC VLLLCGAVFV SPGA TIPPHV QKSVNNDMIV TDNNGAVKFP
51	QLCKFCDVRF STCDNQKSCM SNCSITSICE KPQEVCVAVW RKNDENITLE
101	TVCHDPKLPY HDFILEDAAS PKCIMKEKKK PGETFFMCSC SSDECNDNII
151	FSEEYNTSNP D TGGG THTCP PCPAPELLGG PSVFLFPPKP KDTLMISRTP
201	EVTCVVVDVS HEDPEVKFNW YVDGVEVHNA KTKPREEQYN STYRVVSVLT
251	VLHQDWLNGK EYKCKVSNKA LPAPIEKTIS KAKGQPREPQ VYTLPP C REE
301	MTKNQVSL W C LVKGFYPSDI AVEWESNGQP ENNYKTTPPV LDSDGSFFLY
351	SKLTVDKSRW QQGNVFSCSV MHEALHNHYT QKSLSLSPGK

(SEQ ID NO: 416)

1	TIPPHVQKSV NNDMIVTDNN GAVKFPQLCK FCDVRFSTCD NQKSCMSNCS
51	ITSICEKPQE VCVAVWRKND ENITLETVCH DPKLPYHDFI LEDAASPKCI
101	MKEKKKPGET FFMCSCSSDE CNDNIIFSEE YNTSNPDTGG GTHTCPPCPA
151	PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG
201	VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP
251	IEKTISKAKG QPREPQVYTL PPCREEMTKN QVSLWCLVKG FYPSDIAVEW
301	ESNGQPENNY KTTPPVLDSD GSFFLYSKLT VDKSRWQQGN VFSCSVMHEA
351	LHNHYTQKSL SLSPGK

(SEQ ID NO: 417)

1	MDAMKRGLCC VLLLCGAVFV SPGA TIPPHV QKSDVEMEAQ KDEIICPSCN
51	RTAHPLRHIN NDMIVTDNNG AVKFPQLCKF CDVRFSTCDN QKSCMSNCSI
101	TSICEKPQEV CVAVWRKNDE NITLETVCHD PKLPYHDFIL EDAASPKCIM
151	KEKKKPGETF FMCSCSSDEC NDNIIFSEEY NTSNPD TGGG THTCPPCPAP
201	ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE VKFNWYVDGV
251	EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK VSNKALPAPI
301	EKTISKAKGQ PREPQVYTLP P C REEMTKNQ VSL W CLVKGF YPSDIAVEWE
351	SNGQPENNYK TTPPVLDSDG SFFLYSKLTV DKSRWQQGNV FSCSVMHEAL
401	HNHYTQKSLS LSPGK

(SEQ ID NO: 418)

1	TIPPHVQKSD VEMEAQKDEI ICPSCNRTAH PLRHINNDMI VTDNNGAVKF
51	PQLCKFCDVR FSTCDNQKSC MSNCSITSIC EKPQEVCVAV WRKNDENITL
101	ETVCHDPKLP YHDFILEDAA SPKCIMKEKK KPGETFFMCS CSSDECNDNI
151	IFSEEYNTSN PDTGGGTHTC PPCPAPELLG GPSVFLFPPK PKDTLMISRT
201	PEVTCVVVDV SHEDPEVKFN WYVDGVEVHN AKTKPREEQY NSTYRVVSVL
251	TVLHQDWLNG KEYKCKVSNK ALPAPIEKTI SKAKGQPREP QVYTLPPCRE
301	EMTKNQVSLW CLVKGFYPSD IAVEWESNGQ PENNYKTTPP VLDSDGSFFL
351	YSKLTVDKSR WQQGNVFSCS VMHEALHNHY TQKSLSLSPG K

Inhibitory Activity of TGFβRII Fusion Proteins in A549 Cells IC 50 (pM)

	TGFβ1	TGFβ2	TGFβ3
Construct	(640 pg/mL)	(480 pg/mL)	(270 pg/mL)
TGFβRII SHORT -Fc homodimer	90	—	9
TGFβRII SHORT -Fc:	<350*	~200*	<90*
ALK5-Fc heterodimer*
TGFβRII LONG -Fc:	204	154	35
ALK5-Fc heterodimer
— No inhibition (tested at concentrations up to 10 nM)
*Value imprecise due to range of concentrations tested

(SEQ ID NO: 133)

1	MDAMKRGLCC VLLLCGAVFV SPGA PPNRRT CVFFEAPGVR GSTKTLGELL
51	DTGTELPRAI RCLYSRCCFG IWNLTQDRAQ VEMQGCRDSD EPGCESLHCD
101	PSPRAHPSPG STLFTCSCGT DFCNANYSHL PPPGSPGTPG SQGPQAAPGE
151	SIWMAL TGGG THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV
201	VVDVSHEDPE VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD
251	WLNGKEYKCK VSNKALPAPI EKTISKAKGQ PREPQVYTLP PSR K EMTKNQ
301	VSLTCLVKGF YPSDIAVEWE SNGQPENNYK TTPPVL K SDG SFFLYSKLTV
351	DKSRWQQGNV FSCSVMHEAL HNHYTQKSLS LSPGK

(SEQ ID NO: 135)

1	PPNRRTCVFF EAPGVRGSTK TLGELLDTGT ELPRAIRCLY SRCCFGIWNL
51	TQDRAQVEMQ GCRDSDEPGC ESLHCDPSPR AHPSPGSTLF TCSCGTDFCN
101	ANYSHLPPPG SPGTPGSQGP QAAPGESIWM ALTGGGTHTC PPCPAPELLG
151	GPSVFLFPPK PKDTLMISRT PEVTCVVVDV SHEDPEVKFN WYVDGVEVHN
201	AKTKPREEQY NSTYRVVSVL TVLHQDWLNG KEYKCKVSNK ALPAPIEKTI
251	SKAKGQPREP QVYTLPPSRK EMTKNQVSLT CLVKGFYPSD IAVEWESNGQ
301	PENNYKTTPP VLKSDGSFFL YSKLTVDKSR WQQGNVFSCS VMHEALHNHY
351	TQKSLSLSPG K

(SEQ ID NO: 419)

1	MDAMKRGLCC VLLLCGAVFV SPGA PPNRRT CVFFEAPGVR GSTKTLGELL
51	DTGTELPRAI RCLYSRCCFG IWNLTQDRAQ VEMQGCRDSD EPGCESLHCD
101	PSPRAHPSPG STLFTCSCGT DFCNANYSHL PPPGSPGTPG SQGPQAAPGE
151	SIWMAL TGGG THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV
201	VVDVSHEDPE VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD
251	WLNGKEYKCK VSNKALPAPI EKTISKAKGQ PREPQVYTLP P C REEMTKNQ
301	VSL W CLVKGF YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFLYSKLTV
351	DKSRWQQGNV FSCSVMHEAL HNHYTQKSLS LSPGK

(SEQ ID NO: 420)

1	PPNRRTCVFF EAPGVRGSTK TLGELLDTGT ELPRAIRCLY SRCCFGIWNL
51	TQDRAQVEMQ GCRDSDEPGC ESLHCDPSPR AHPSPGSTLF TCSCGTDFCN
101	ANYSHLPPPG SPGTPGSQGP QAAPGESIWM ALTGGGTHTC PPCPAPELLG
151	GPSVFLFPPK PKDTLMISRT PEVTCVVVDV SHEDPEVKFN WYVDGVEVHN
201	AKTKPREEQY NSTYRVVSVL TVLHQDWLNG KEYKCKVSNK ALPAPIEKTI
251	SKAKGQPREP QVYTLPPCRE EMTKNQVSLW CLVKGFYPSD IAVEWESNGQ
301	PENNYKTTPP VLDSDGSFFL YSKLTVDKSR WQQGNVFSCS VMHEALHNHY
351	TQKSLSLSPG K

(SEQ ID NO: 153)

1	MDAMKRGLCC VLLLCGAVFV SPGAS GRGEA ETRECIYYNA NWELERTNQS
51	GLERCEGEQD KRLHCYASWR NSSGTIELVK KGCWLDDFNC YDRQECVATE
101	ENPQVYFCCC EGNFCNERFT HLPEAGGPEV TYEPPPTAP T GGG THTCPPC
151	PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE DPEVKFNWYV
201	DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY KCKVSNKALP
251	APIEKTISKA KGQPREPQVY TLPPSREEMT KNQVSLTCLV KGFYPSDIAV
301	EWESNGQPEN NY D TTPPVLD SDGSFFLYS D LTVDKSRWQQ GNVFSCSVMH
351	EALHNHYTQK SLSLSPGK

(SEQ ID NO: 154)

1	GRGEAETREC IYYNANWELE RTNQSGLERC EGEQDKRLHC YASWRNSSGT
51	IELVKKGCWL DDFNCYDRQE CVATEENPQV YFCCCEGNFC NERFTHLPEA
101	GGPEVTYEPP PTAPTGGGTH TCPPCPAPEL LGGPSVFLFP PKPKDTLMIS
151	RTPEVTCVVV DVSHEDPEVK FNWYVDGVEV HNAKTKPREE QYNSTYRVVS
201	VLTVLHQDWL NGKEYKCKVS NKALPAPIEK TISKAKGQPR EPQVYTLPPS
251	REEMTKNQVS LTCLVKGFYP SDIAVEWESN GQPENNYDTT PPVLDSDGSF
301	FLYSDLTVDK SRWQQGNVFS CSVMHEALHN HYTQKSLSLS PGK

(SEQ ID NO: 151)

1	MDAMKRGLCC VLLLCGAVFV SPGA AILGRS ETQECLFFNA NWEKDRTNQT
51	GVEPCYGDKD KRRHCFATWK NISGSIEIVK QGCWLDDINC YDRTDCVEKK
101	DSPEVYFCCC EGNMCNEKFS YFPEMEVTQP TSNPVTPKPP TGGG THTCPP
151	CPAPELLGGP SVFLFPPKPK DTLMISRTPE VTCVVVDVSH EDPEVKFNWY
201	VDGVEVHNAK TKPREEQYNS TYRVVSVLTV LHQDWLNGKE YKCKVSNKAL
251	PAPIEKTISK AKGQPREPQV YTLPPSREEM TKNQVSLTCL VKGFYPSDIA
301	VEWESNGQPE NNY D TTPPVL DSDGSFFLYS D LTVDKSRWQ QGNVFSCSVM
351	HEALHNHYTQ KSLSLSPGK

(SEQ ID NO: 152)

1	ILGRSETQEC LFFNANWEKD RTNQTGVEPC YGDKDKRRHC FATWKNISGS
51	IEIVKQGCWL DDINCYDRTD CVEKKDSPEV YFCCCEGNMC NEKFSYFPEM
101	EVTQPTSNPV TPKPPTGGGT HTCPPCPAPE LLGGPSVFLF PPKPKDTLMI
151	SRTPEVTCVV VDVSHEDPEV KFNWYVDGVE VHNAKTKPRE EQYNSTYRVV
201	SVLTVLHQDW LNGKEYKCKV SNKALPAPIE KTISKAKGQP REPQVYTLPP
251	SREEMTKNQV SLTCLVKGFY PSDIAVEWES NGQPENNYDT TPPVLDSDGS
301	FFLYSDLTVD KSRWQQGNVF SCSVMHEALH NHYTQKSLSL SPGK

(SEQ ID NO: 453)

1	MDAMKRGLCC VLLLCGAVFV SPGAS GRGEA ETRECIYYNA NWELERTNQS
51	GLERCEGEQD KRLHCYASWR NSSGTIELVK KGCWLDDFNC YDRQECVATE
101	ENPQVYFCCC EGNFCNERFT HLPEAGGPEV TYEPPPTAP T GGG THTCPPC
151	PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE DPEVKFNWYV
201	DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY KCKVSNKALP
251	APIEKTISKA KGQPREPQV C TLPPSREEMT KNQVSL S C A V KGFYPSDIAV
301	EWESNGQPEN NYKTTPPVLD SDGSFFL V SK LTVDKSRWQQ GNVFSCSVMH
351	EALHNHYTQK SLSLSPGK

(SEQ ID NO: 454)

1	GRGEAETREC IYYNANWELE RTNQSGLERC EGEQDKRLHC YASWRNSSGT
51	IELVKKGCWL DDFNCYDRQE CVATEENPQV YFCCCEGNFC NERFTHLPEA
101	GGPEVTYEPP PTAPTGGGTH TCPPCPAPEL LGGPSVFLFP PKPKDTLMIS
151	RTPEVTCVVV DVSHEDPEVK FNWYVDGVEV HNAKTKPREE QYNSTYRVVS
201	VLTVLHQDWL NGKEYKCKVS NKALPAPIEK TISKAKGQPR EPQVCTLPPS
251	REEMTKNQVS LSCAVKGFYP SDIAVEWESN GQPENNYKTT PPVLDSDGSF
301	FLVSKLTVDK SRWQQGNVFS CSVMHEALHN HYTQKSLSLS PGK

(SEQ ID NO: 451)

1	MDAMKRGLCC VLLLCGAVFV SPGA AILGRS ETQECLFFNA NWEKDRTNQT
51	GVEPCYGDKD KRRHCFATWK NISGSIEIVK QGCWLDDINC YDRTDCVEKK
101	DSPEVYFCCC EGNMCNEKFS YFPEMEVTQP TSNPVTPKPP TGGG THTCPP
151	CPAPELLGGP SVFLFPPKPK DTLMISRTPE VTCVVVDVSH EDPEVKFNWY
201	VDGVEVHNAK TKPREEQYNS TYRVVSVLTV LHQDWLNGKE YKCKVSNKAL
251	PAPIEKTISK AKGQPREPQV C TLPPSREEM TKNQVSL S C A VKGFYPSDIA
301	VEWESNGQPE NNYKTTPPVL DSDGSFFL V S KLTVDKSRWQ QGNVFSCSVM
351	HEALHNHYTQ KSLSLSPGK

(SEQ ID NO: 452)

1	ILGRSETQEC LFFNANWEKD RTNQTGVEPC YGDKDKRRHC FATWKNISGS
51	IEIVKQGCWL DDINCYDRTD CVEKKDSPEV YFCCCEGNMC NEKFSYFPEM
101	EVTQPTSNPV TPKPPTGGGT HTCPPCPAPE LLGGPSVFLF PPKPKDTLMI
151	SRTPEVTCVV VDVSHEDPEV KFNWYVDGVE VHNAKTKPRE EQYNSTYRVV
201	SVLTVLHQDW LNGKEYKCKV SNKALPAPIE KTISKAKGQP REPQVCTLPP
251	SREEMTKNQV SLSCAVKGFY PSDIAVEWES NGQPENNYKT TPPVLDSDGS
301	FFLVSKLTVD KSRWQQGNVF SCSVMHEALH NHYTQKSLSL SPGK

(SEQ ID NO: 155)

1	MDAMKRGLCC VLLLCGAVFV SPGA SQNQER LCAFKDPYQQ DLGIGESRIS
51	HENGTILCSK GSTCYGLWEK SKGDINLVKQ GCWSHIGDPQ ECHYEECVVT
101	TTPPSIQNGT YRFCCCSTDL CNVNFTENFP PPDTTPLSPP HSFNRDE TGG
151	G THTCPPCPA PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP
201	EVKFNWYVDG VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC
251	KVSNKALPAP IEKTISKAKG QPREPQVYTL PPSREEMTKN QVSLTCLVKG
301	FYPSDIAVEW ESNGQPENNY D TTPPVLDSD GSFFLYS D LT VDKSRWQQGN
351	VFSCSVMHEA LHNHYTQKSL SLSPGK

(SEQ ID NO: 156)

1	SQNQERLCAF KDPYQQDLGI GESRISHENG TILCSKGSTC YGLWEKSKGD
51	INLVKQGCWS HIGDPQECHY EECVVTTTPP SIQNGTYRFC CCSTDLCNVN
101	FTENFPPPDT TPLSPPHSFN RDETGGGTHT CPPCPAPELL GGPSVFLFPP
151	KPKDTLMISR TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ
201	YNSTYRVVSV LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE
251	PQVYTLPPSR EEMTKNQVSL TCLVKGFYPS DIAVEWESNG QPENNYDTTP
301	PVLDSDGSFF LYSDLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP
351	GK

(SEQ ID NO: 455)

1	MDAMKRGLCC VLLLCGAVFV SPGA SQNQER LCAFKDPYQQ DLGIGESRIS
51	HENGTILCSK GSTCYGLWEK SKGDINLVKQ GCWSHIGDPQ ECHYEECVVT
101	TTPPSIQNGT YRFCCCSTDL CNVNFTENFP PPDTTPLSPP HSFNRDE TGG
151	G THTCPPCPA PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP
201	EVKFNWYVDG VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC
251	KVSNKALPAP IEKTISKAKG QPREPQV C TL PPSREEMTKN QVSL S C A VKG
301	FYPSDIAVEW ESNGQPENNY KTTPPVLDSD GSFFL V SKLT VDKSRWQQGN
351	VFSCSVMHEA LHNHYTQKSL SLSPGK

(SEQ ID NO: 456)

1	SQNQERLCAF KDPYQQDLGI GESRISHENG TILCSKGSTC YGLWEKSKGD
51	INLVKQGCWS HIGDPQECHY EECVVTTTPP SIQNGTYRFC CCSTDLCNVN
101	FTENFPPPDT TPLSPPHSFN RDETGGGTHT CPPCPAPELL GGPSVFLFPP
151	KPKDTLMISR TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ
201	YNSTYRVVSV LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE
251	PQVCTLPPSR EEMTKNQVSL SCAVKGFYPS DIAVEWESNG QPENNYKTTP
301	PVLDSDGSFF LVSKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP
351	GK

(SEQ ID NO: 161)

1	MDAMKRGLCC VLLLCGAVFV SPGA PPNRRT CVFFEAPGVR GSTKTLGELL
51	DTGTELPRAI RCLYSRCCFG IWNLTQDRAQ VEMQGCRDSD EPGCESLHCD
101	PSPRAHPSPG STLFTCSCGT DFCNANYSHL PPPGSPGTPG SQGPQAAPGE
151	SIWMAL TGGG THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV
201	VVDVSHEDPE VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD
251	WLNGKEYKCK VSNKALPAPI EKTISKAKGQ PREPQVYTLP PSREEMTKNQ
301	VSLTCLVKGF YPSDIAVEWE SNGQPENNY D TTPPVLDSDG SFFLYS D LTV
351	DKSRWQQGNV FSCSVMHEAL HNHYTQKSLS LSPGK

(SEQ ID NO: 162)

1	PPNRRTCVFF EAPGVRGSTK TLGELLDTGT ELPRAIRCLY SRCCFGIWNL
51	TQDRAQVEMQ GCRDSDEPGC ESLHCDPSPR AHPSPGSTLF TCSCGTDFCN
101	ANYSHLPPPG SPGTPGSQGP QAAPGESIWM ALTGGGTHTC PPCPAPELLG
151	GPSVFLFPPK PKDTLMISRT PEVTCVVVDV SHEDPEVKFN WYVDGVEVHN
201	AKTKPREEQY NSTYRVVSVL TVLHQDWLNG KEYKCKVSNK ALPAPIEKTI
251	SKAKGQPREP QVYTLPPSRE EMTKNQVSLT CLVKGFYPSD IAVEWESNGQ
301	PENNYDTTPP VLDSDGSFFL YSDLTVDKSR WQQGNVFSCS VMHEALHNHY
351	TQKSLSLSPG K

(SEQ ID NO: 457)

1	MDAMKRGLCC VLLLCGAVFV SPGA PPNRRT CVFFEAPGVR GSTKTLGELL
51	DTGTELPRAI RCLYSRCCFG IWNLTQDRAQ VEMQGCRDSD EPGCESLHCD
101	PSPRAHPSPG STLFTCSCGT DFCNANYSHL PPPGSPGTPG SQGPQAAPGE
151	SIWMAL TGGG THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV
201	VVDVSHEDPE VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD
251	WLNGKEYKCK VSNKALPAPI EKTISKAKGQ PREPQV C TLP PSREEMTKNQ
301	VSL S C A VKGF YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFL V SKLTV
351	DKSRWQQGNV FSCSVMHEAL HNHYTQKSLS LSPGK

(SEQ ID NO: 458)

1	PPNRRTCVFF EAPGVRGSTK TLGELLDTGT ELPRAIRCLY SRCCFGIWNL
51	TQDRAQVEMQ GCRDSDEPGC ESLHCDPSPR AHPSPGSTLF TCSCGTDFCN
101	ANYSHLPPPG SPGTPGSQGP QAAPGESIWM ALTGGGTHTC PPCPAPELLG
151	GPSVFLFPPK PKDTLMISRT PEVTCVVVDV SHEDPEVKFN WYVDGVEVHN
201	AKTKPREEQY NSTYRVVSVL TVLHQDWLNG KEYKCKVSNK ALPAPIEKTI
251	SKAKGQPREP QVCTLPPSRE EMTKNQVSLS CAVKGFYPSD IAVEWESNGQ
301	PENNYKTTPP VLDSDGSFFL VSKLTVDKSR WQQGNVFSCS VMHEALHNHY
351	TQKSLSLSPG K

(SEQ ID NO: 157)

1	MDAMKRGLCC VLLLCGAVFV SPGA TIPPHV QKSVNNDMIV TDNNGAVKFP
51	QLCKFCDVRF STCDNQKSCM SNCSITSICE KPQEVCVAVW RKNDENITLE
101	TVCHDPKLPY HDFILEDAAS PKCIMKEKKK PGETFFMCSC SSDECNDNII
151	FSEEYNTSNP D TGGG THTCP PCPAPELLGG PSVFLFPPKP KDTLMISRTP
201	EVTCVVVDVS HEDPEVKFNW YVDGVEVHNA KTKPREEQYN STYRVVSVLT
251	VLHQDWLNGK EYKCKVSNKA LPAPIEKTIS KAKGQPREPQ VYTLPPSREE
301	MTKNQVSLTC LVKGFYPSDI AVEWESNGQP ENNY D TTPPV LDSDGSFFLY
351	S D LTVDKSRW QQGNVFSCSV MHEALHNHYT QKSLSLSPGK

(SEQ ID NO: 158)

1	TIPPHVQKSV NNDMIVTDNN GAVKFPQLCK FCDVRFSTCD NQKSCMSNCS
51	ITSICEKPQE VCVAVWRKND ENITLETVCH DPKLPYHDFI LEDAASPKCI
101	MKEKKKPGET FFMCSCSSDE CNDNIIFSEE YNTSNPDTGG GTHTCPPCPA
151	PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG
201	VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP
251	IEKTISKAKG QPREPQVYTL PPSREEMTKN QVSLTCLVKG FYPSDIAVEW
301	ESNGQPENNY DTTPPVLDSD GSFFLYSDLT VDKSRWQQGN VFSCSVMHEA
351	LHNHYTQKSL SLSPGK

(SEQ ID NO: 459)

1	MDAMKRGLCC VLLLCGAVFV SPGA TIPPHV QKSVNNDMIV TDNNGAVKFP
51	QLCKFCDVRF STCDNQKSCM SNCSITSICE KPQEVCVAVW RKNDENITLE
101	TVCHDPKLPY HDFILEDAAS PKCIMKEKKK PGETFFMCSC SSDECNDNII
151	FSEEYNTSNP D TGGG THTCP PCPAPELLGG PSVFLFPPKP KDTLMISRTP
201	EVTCVVVDVS HEDPEVKFNW YVDGVEVHNA KTKPREEQYN STYRVVSVLT
251	VLHQDWLNGK EYKCKVSNKA LPAPIEKTIS KAKGQPREPQ V C TLPPSREE
301	MTKNQVSL S C A VKGFYPSDI AVEWESNGQP ENNYKTTPPV LDSDGSFFL V
351	SKLTVDKSRW QQGNVFSCSV MHEALHNHYT QKSLSLSPGK

(SEQ ID NO: 460)

1	TIPPHVQKSV NNDMIVTDNN GAVKFPQLCK FCDVRFSTCD NQKSCMSNCS
51	ITSICEKPQE VCVAVWRKND ENITLETVCH DPKLPYHDFI LEDAASPKCI
101	MKEKKKPGET FFMCSCSSDE CNDNIIFSEE YNTSNPDTGG GTHTCPPCPA
151	PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG
201	VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP
251	IEKTISKAKG QPREPQVCTL PPSREEMTKN QVSLSCAVKG FYPSDIAVEW
301	ESNGQPENNY KTTPPVLDSD GSFFLVSKLT VDKSRWQQGN VFSCSVMHEA
351	LHNHYTQKSL SLSPGK

(SEQ ID NO: 159)

1	MDAMKRGLCC VLLLCGAVFV SPGA TIPPHV QKSDVEMEAQ KDEIICPSCN
51	RTAHPLRHIN NDMIVTDNNG AVKFPQLCKF CDVRFSTCDN QKSCMSNCSI
101	TSICEKPQEV CVAVWRKNDE NITLETVCHD PKLPYHDFIL EDAASPKCIM
151	KEKKKPGETF FMCSCSSDEC NDNIIFSEEY NTSNPD TGGG THTCPPCPAP
201	ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE VKFNWYVDGV
251	EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK VSNKALPAPI
301	EKTISKAKGQ PREPQVYTLP PSREEMTKNQ VSLTCLVKGF YPSDIAVEWE
351	SNGQPENNY D TTPPVLDSDG SFFLYS D LTV DKSRWQQGNV FSCSVMHEAL
401	HNHYTQKSLS LSPGK

(SEQ ID NO: 160)

1	TIPPHVQKSD VEMEAQKDEI ICPSCNRTAH PLRHINNDMI VTDNNGAVKF
51	PQLCKFCDVR FSTCDNQKSC MSNCSITSIC EKPQEVCVAV WRKNDENITL
101	ETVCHDPKLP YHDFILEDAA SPKCIMKEKK KPGETFFMCS CSSDECNDNI
151	IFSEEYNTSN PDTGGGTHTC PPCPAPELLG GPSVFLFPPK PKDTLMISRT
201	PEVTCVVVDV SHEDPEVKFN WYVDGVEVHN AKTKPREEQY NSTYRVVSVL
251	TVLHQDWLNG KEYKCKVSNK ALPAPIEKTI SKAKGQPREP QVYTLPPSRE
301	EMTKNQVSLT CLVKGFYPSD IAVEWESNGQ PENNYDTTPP VLDSDGSFFL
351	YSDLTVDKSR WQQGNVFSCS VMHEALHNHY TQKSLSLSPG K

(SEQ ID NO: 461)

1	MDAMKRGLCC VLLLCGAVFV SPGA TIPPHV QKSDVEMEAQ KDEIICPSCN
51	RTAHPLRHIN NDMIVTDNNG AVKFPQLCKF CDVRFSTCDN QKSCMSNCSI
101	TSICEKPQEV CVAVWRKNDE NITLETVCHD PKLPYHDFIL EDAASPKCIM
151	KEKKKPGETF FMCSCSSDEC NDNIIFSEEY NTSNPD TGGG THTCPPCPAP
201	ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE VKFNWYVDGV
251	EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK VSNKALPAPI
301	EKTISKAKGQ PREPQV C TLP PSREEMTKNQ VSL S C A VKGF YPSDIAVEWE
351	SNGQPENNYK TTPPVLDSDG SFFL V SKLTV DKSRWQQGNV FSCSVMHEAL
401	HNHYTQKSLS LSPGK

(SEQ ID NO: 462)

1	TIPPHVQKSD VEMEAQKDEI ICPSCNRTAH PLRHINNDMI VTDNNGAVKF
51	PQLCKFCDVR FSTCDNQKSC MSNCSITSIC EKPQEVCVAV WRKNDENITL
101	ETVCHDPKLP YHDFILEDAA SPKCIMKEKK KPGETFFMCS CSSDECNDNI
151	IFSEEYNTSN PDTGGGTHTC PPCPAPELLG GPSVFLFPPK PKDTLMISRT
201	PEVTCVVVDV SHEDPEVKFN WYVDGVEVHN AKTKPREEQY NSTYRVVSVL
251	TVLHQDWLNG KEYKCKVSNK ALPAPIEKTI SKAKGQPREP QVCTLPPSRE
301	EMTKNQVSLS CAVKGFYPSD IAVEWESNGQ PENNYKTTPP VLDSDGSFFL
351	VSKLTVDKSR WQQGNVFSCS VMHEALHNHY TQKSLSLSPG K

TABLE “Type II:Type II Receptor Heterodimers” Amino Acid SEQ ID NOs for Type II:Type II Receptor Heterodimers Amino Acid

Heteromeric		ECD		SEQ ID NO
Fusion Protein		Correspondence	Receptor-Fc	With
Complex	Fc Pair Type	to Fc Pair	Fusion Protein	Leader	Mature
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
ActRIIB-Fc			ActRIIB-Fc	153	154
		B	ActRIIA-Fc	151	152
			ActRIIB-Fc	100	102
	Hydrophobic	A	ActRIIA-Fc	409	410
			ActRIIB-Fc	453	454
		B	ActRIIA-Fc	451	452
			ActRIIB-Fc	401	402
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
BMPRII-Fc			BMPRII-Fc	155	156
		B	ActRIIA-Fc	151	152
			BMPRII-Fc	121	123
	Hydrophobic	A	ActRIIA-Fc	409	410
			BMPRII-Fc	455	456
		B	ActRIIA-Fc	451	452
			BMPRII-Fc	411	412
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
MISRII-Fc			MISRII-Fc	161	162
		B	ActRIIA-Fc	151	152
			MISRII-Fc	133	135
	Hydrophobic	A	ActRIIA-Fc	409	410
			MISRII-Fc	457	458
		B	ActRIIA-Fc	451	452
			MISRII-Fc	419	420
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
TGFβRII SHORT -Fc			TGFβRII SHORT -Fc	157	158
		B	ActRIIA-Fc	151	152
			TGFβRII SHORT -Fc	127	129
	Hydrophobic	A	ActRIIA-Fc	409	410
			TGFβRII SHORT -Fc	459	460
		B	ActRIIA-Fc	451	452
			TGFβRII SHORT -Fc	415	416
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
TGFβRII LONG -Fc			TGFβRII LONG -Fc	159	160
		B	ActRIIA-Fc	151	152
			TGFβRII LONG -Fc	130	132
	Hydrophobic	A	ActRIIA-Fc	409	410
			TGFβRII LONG -Fc	461	462
		B	ActRIIA-Fc	451	452
			TGFβRII LONG -Fc	417	418
ActRIIB-Fc:	Electrostatic	A	ActRIIB-Fc	100	102
BMPRII-Fc			BMPRII-Fc	155	156
		B	ActRIIB-Fc	153	154
			BMPRII-Fc	121	123
	Hydrophobic	A	ActRIIB-Fc	401	402
			BMPRII-Fc	455	456
		B	ActRIIB-Fc	453	454
			BMPRII-Fc	411	412
ActRIIB-Fc:	Electrostatic	A	ActRIIB-Fc	100	102
MISRII-Fc			MISRII-Fc	161	162
		B	ActRIIB-Fc	153	154
			MISRII-Fc	133	135
	Hydrophobic	A	ActRIIB-Fc	401	402
			MISRII-Fc	457	458
		B	ActRIIB-Fc	453	454
			MISRII-Fc	419	420
ActRIIB-Fc:	Electrostatic	A	ActRIIB-Fc	100	102
TGFβRII SHORT -Fc			TGFβRII SHORT -Fc	157	158
		B	ActRIIB-Fc	153	154
			TGFβRII SHORT -Fc	127	129
	Hydrophobic	A	ActRIIB-Fc	401	402
			TGFβRII SHORT -Fc	459	460
		B	ActRIIB-Fc	453	454
			TGFβRII SHORT -Fc	415	416
ActRIIB-Fc:	Electrostatic	A	ActRIIB-Fc	100	102
TGFβRII LONG -Fc			TGFβRII LONG -Fc	159	160
		B	ActRIIB-Fc	153	154
			TGFβRII LONG -Fc	130	132
	Hydrophobic	A	ActRIIB-Fc	401	402
			TGFβRII LONG -Fc	461	462
		B	ActRIIB-Fc	453	454
			TGFβRII LONG -Fc	417	418
BMPRII-Fc:	Electrostatic	A	BMPRII-Fc	121	123
MISRII-Fc			MISRII-Fc	161	162
		B	BMPRII-Fc	155	156
			MISRII-Fc	133	135
	Hydrophobic	A	BMPRII-Fc	411	412
			MISRII-Fc	457	458
		B	BMPRII-Fc	455	456
			MISRII-Fc	419	420
BMPRII-Fc:	Electrostatic	A	BMPRII-Fc	121	123
TGFβRII SHORT -Fc			TGFβRII SHORT -Fc	157	158
		B	BMPRII-Fc	155	156
			TGFβRII SHORT -Fc	127	129
	Hydrophobic	A	BMPRII-Fc	411	412
			TGFβRII SHORT -Fc	459	460
		B	BMPRII-Fc	455	456
			TGFβRII SHORT -Fc	415	416
BMPRII-Fc:	Electrostatic	A	BMPRII-Fc	121	123
TGFβRII LONG -Fc			TGFβRII LONG -Fc	159	160
		B	BMPRII-Fc	155	156
			TGFβRII LONG -Fc	130	132
	Hydrophobic	A	BMPRII-Fc	411	412
			TGFβRII LONG -Fc	461	462
		B	BMPRII-Fc	455	456
			TGFβRII LONG -Fc	417	418
MISRII-Fc:	Electrostatic	A	MISRII-Fc	133	135
TGFβRII SHORT -Fc			TGFβRII SHORT -Fc	157	158
		B	MISRII-Fc	161	162
			TGFβRII SHORT -Fc	127	129
	Hydrophobic	A	MISRII-Fc	419	420
			TGFβRII SHORT -Fc	459	460
		B	MISRII-Fc	457	458
			TGFβRII SHORT -Fc	415	416
MISRII-Fc:	Electrostatic	A	MISRII-Fc	133	135
TGFβRII LONG -Fc			TGFβRII LONG -Fc	159	160
		B	MISRII-Fc	161	162
			TGFβRII LONG -Fc	130	132
	Hydrophobic	A	MISRII-Fc	419	420
			TGFβRII LONG -Fc	461	462
		B	MISRII-Fc	457	458
			TGFβRII LONG -Fc	417	418
TGFβRII SHORT -Fc:	Electrostatic	A	TGFβRII SHORT -Fc	127	129
TGFβRII LONG -Fc			TGFβRII LONG -Fc	159	160
		B	TGFβRII SHORT -Fc	157	158
			TGFβRII LONG -Fc	130	132
	Hydrophobic	A	TGFβRII SHORT -Fc	415	416
			TGFβRII LONG -Fc	461	462
		B	TGFβRII SHORT -Fc	459	460
			TGFβRII LONG -Fc	417	418

(SEQ ID NO: 173)

1	MDAMKRGLCC VLLLCGAVFV SPGA MEDEKP KVNPKLYMCV CEGLSCGNED
51	HCEGQQCFSS LSINDGFHVY QKGCFQVYEQ GKMTCKTPPS PGQAVECCQG
101	DWCNRNITAQ LPTKGKSFPG TQNFHLE TGG G THTCPPCPA PELLGGPSVF
151	LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG VEVHNAKTKP
201	REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP IEKTISKAKG
251	QPREPQVYTL PPSR K EMTKN QVSLTCLVKG FYPSDIAVEW ESNGQPENNY
301	KTTPPVL K SD GSFFLYSKLT VDKSRWQQGN VFSCSVMHEA LHNHYTQKSL
351	SLSPG

(SEQ ID NO: 174)

1	MEDEKPKVNP KLYMCVCEGL SCGNEDHCEG QQCFSSLSIN DGFHVYQKGC
51	FQVYEQGKMT CKTPPSPGQA VECCQGDWCN RNITAQLPTK GKSFPGTQNF
101	HLETGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
151	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
201	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPSR KEMTKNQVSL
251	TCLVKGFYPS DIAVEWESNG QPENNYKTTP PVLKSDGSFF LYSKLTVDKS
301	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP G

(SEQ ID NO: 171)

1	MDAMKRGLCC VLLLCGAVFV SPGA DPVKPS RGPLVTCTCE SPHCKGPTCR
51	GAWCTVVLVR EEGRHPQEHR GCGNLHRELC RGRPTEFVNH YCCDSHLCNH
101	NVSLVLEATQ PPSEQPGTDG QLA TGGG THT CPPCPAPELL GGPSVFLFPP
151	KPKDTLMISR TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ
201	YNSTYRVVSV LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE
251	PQVYTLPPSR K EMTKNQVSL TCLVKGFYPS DIAVEWESNG QPENNYKTTP
301	PVL K SDGSFF LYSKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP
351	G

(SEQ ID NO: 172)

1	DPVKPSRGPL VTCTCESPHC KGPTCRGAWC TVVLVREEGR HPQEHRGCGN
51	LHRELCRGRP TEFVNHYCCD SHLCNHNVSL VLEATQPPSE QPGTDGQLAT
101	GGGTHTCPPC PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE
151	DPEVKFNWYV DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY
201	KCKVSNKALP APIEKTISKA KGQPREPQVY TLPPSRKEMT KNQVSLTCLV
251	KGFYPSDIAV EWESNGQPEN NYKTTPPVLK SDGSFFLYSK LTVDKSRWQQ
301	GNVFSCSVMH EALHNHYTQK SLSLSPG

(SEQ ID NO: 465)

1	MDAMKRGLCC VLLLCGAVFV SPGA MEDEKP KVNPKLYMCV CEGLSCGNED
51	HCEGQQCFSS LSINDGFHVY QKGCFQVYEQ GKMTCKTPPS PGQAVECCQG
101	DWCNRNITAQ LPTKGKSFPG TQNFHLE TGG G THTCPPCPA PELLGGPSVF
151	LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG VEVHNAKTKP
201	REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP IEKTISKAKG
251	QPREPQVYTL PP C REEMTKN QVSL W CLVKG FYPSDIAVEW ESNGQPENNY
301	KTTPPVLDSD GSFFLYSKLT VDKSRWQQGN VFSCSVMHEA LHNHYTQKSL
351	SLSPGK

(SEQ ID NO: 466)

1	MEDEKPKVNP KLYMCVCEGL SCGNEDHCEG QQCFSSLSIN DGFHVYQKGC
51	FQVYEQGKMT CKTPPSPGQA VECCQGDWCN RNITAQLPTK GKSFPGTQNF
101	HLETGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
151	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
201	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPCR EEMTKNQVSL
251	WCLVKGFYPS DIAVEWESNG QPENNYKTTP PVLDSDGSFF LYSKLTVDKS
301	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP GK

(SEQ ID NO: 463)

1	MDAMKRGLCC VLLLCGAVFV SPGA DPVKPS RGPLVTCTCE SPHCKGPTCR
51	GAWCTVVLVR EEGRHPQEHR GCGNLHRELC RGRPTEFVNH YCCDSHLCNH
101	NVSLVLEATQ PPSEQPGTDG QLA TGGG THT CPPCPAPELL GGPSVFLFPP
151	KPKDTLMISR TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ
201	YNSTYRVVSV LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE
251	PQVYTLPP C R EEMTKNQVSL W CLVKGFYPS DIAVEWESNG QPENNYKTTP
301	PVLDSDGSFF LYSKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP
351	GK

(SEQ ID NO: 464)

1	DPVKPSRGPL VTCTCESPHC KGPTCRGAWC TVVLVREEGR HPQEHRGCGN
51	LHRELCRGRP TEFVNHYCCD SHLCNHNVSL VLEATQPPSE QPGTDGQLAT
101	GGGTHTCPPC PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE
151	DPEVKFNWYV DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY
201	KCKVSNKALP APIEKTISKA KGQPREPQVY TLPPCREEMT KNQVSLWCLV
251	KGFYPSDIAV EWESNGQPEN NYKTTPPVLD SDGSFFLYSK LTVDKSRWQQ
301	GNVFSCSVMH EALHNHYTQK SLSLSPGK

(SEQ ID NO: 175)

1	MDAMKRGLCC VLLLCGAVFV SPGA QNLDSM LHGTGMKSDS DQKKSENGVT
51	LAPEDTLPFL KCYCSGHCPD DAINNTCITN GHCFAIIEED DQGETTLASG
101	CMKYEGSDFQ CKDSPKAQLR RTIECCRTNL CNQYLQPTLP PVVIGPFFDG
151	SIR TGGG THT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
201	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
251	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPSR K EMTKNQVSL
301	TCLVKGFYPS DIAVEWESNG QPENNYKTTP PVL K SDGSFF LYSKLTVDKS
351	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP G

(SEQ ID NO: 176)

1	GAQNLDSMLH GTGMKSDSDQ KKSENGVTLA PEDTLPFLKC YCSGHCPDDA
51	INNTCITNGH CFAIIEEDDQ GETTLASGCM KYEGSDFQCK DSPKAQLRRT
101	IECCRTNLCN QYLQPTLPPV VIGPFFDGSI RTGGGTHTCP PCPAPELLGG
151	PSVFLFPPKP KDTLMISRTP EVTCVVVDVS HEDPEVKFNW YVDGVEVHNA
201	KTKPREEQYN STYRVVSVLT VLHQDWLNGK EYKCKVSNKA LPAPIEKTIS
251	KAKGQPREPQ VYTLPPSRKE MTKNQVSLTC LVKGFYPSDI AVEWESNGQP
301	ENNYKTTPPV LKSDGSFFLY SKLTVDKSRW QQGNVFSCSV MHEALHNHYT
351	QKSLSLSPG

(SEQ ID NO: 467)

1	MDAMKRGLCC VLLLCGAVFV SPGA QNLDSM LHGTGMKSDS DQKKSENGVT
51	LAPEDTLPFL KCYCSGHCPD DAINNTCITN GHCFAIIEED DQGETTLASG
101	CMKYEGSDFQ CKDSPKAQLR RTIECCRTNL CNQYLQPTLP PVVIGPFFDG
151	SIR TGGG THT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
201	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
251	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPP C R EEMTKNQVSL
301	W CLVKGFYPS DIAVEWESNG QPENNYKTTP PVLDSDGSFF LYSKLTVDKS
351	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP GK

(SEQ ID NO: 468)

1	GAQNLDSMLH GTGMKSDSDQ KKSENGVTLA PEDTLPFLKC YCSGHCPDDA
51	INNTCITNGH CFAIIEEDDQ GETTLASGCM KYEGSDFQCK DSPKAQLRRT
101	IECCRTNLCN QYLQPTLPPV VIGPFFDGSI RTGGGTHTCP PCPAPELLGG
151	PSVFLFPPKP KDTLMISRTP EVTCVVVDVS HEDPEVKFNW YVDGVEVHNA
201	KTKPREEQYN STYRVVSVLT VLHQDWLNGK EYKCKVSNKA LPAPIEKTIS
251	KAKGQPREPQ VYTLPPCREE MTKNQVSLWC LVKGFYPSDI AVEWESNGQP
301	ENNYKTTPPV LDSDGSFFLY SKLTVDKSRW QQGNVFSCSV MHEALHNHYT
351	QKSLSLSPGK

(SEQ ID NO: 177)

1	MDAMKRGLCC VLLLCGAVFV SPGA SGPRGV QALLCACTSC LQANYTCETD
51	GACMVSIFNL DGMEHHVRTC IPKVELVPAG KPFYCLSSED LRNTHCCYTD
101	YCNRIDLRVP SGHLKEPEHP SMWGPVE TGG G THTCPPCPA PELLGGPSVF
151	LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG VEVHNAKTKP
201	REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP IEKTISKAKG
251	QPREPQVYTL PPSR K EMTKN QVSLTCLVKG FYPSDIAVEW ESNGQPENNY
301	KTTPPVL K SD GSFFLYSKLT VDKSRWQQGN VFSCSVMHEA LHNHYTQKSL
351	SLSPG

(SEQ ID NO: 178)

1	SGPRGVQALL CACTSCLQAN YTCETDGACM VSIFNLDGME HHVRTCIPKV
51	ELVPAGKPFY CLSSEDLRNT HCCYTDYCNR IDLRVPSGHL KEPEHPSMWG
101	PVETGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
151	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
201	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPSR KEMTKNQVSL
251	TCLVKGFYPS DIAVEWESNG QPENNYKTTP PVLKSDGSFF LYS K LTVDKS
301	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP G

(SEQ ID NO: 469)

1	MDAMKRGLCC VLLLCGAVFV SPGA SGPRGV QALLCACTSC LQANYTCETD
51	GACMVSIFNL DGMEHHVRTC IPKVELVPAG KPFYCLSSED LRNTHCCYTD
101	YCNRIDLRVP SGHLKEPEHP SMWGPVE TGG G THTCPPCPA PELLGGPSVF
151	LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG VEVHNAKTKP
201	REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP IEKTISKAKG
251	QPREPQVYTL PP C REEMTKN QVSL W CLVKG FYPSDIAVEW ESNGQPENNY
301	KTTPPVLDSD GSFFLYSKLT VDKSRWQQGN VFSCSVMHEA LHNHYTQKSL
351	SLSPGK

(SEQ ID NO: 470)

1	SGPRGVQALL CACTSCLQAN YTCETDGACM VSIFNLDGME HHVRTCIPKV
51	ELVPAGKPFY CLSSEDLRNT HCCYTDYCNR IDLRVPSGHL KEPEHPSMWG
101	PVETGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR TPEVTCVVVD
151	VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV LTVLHQDWLN
201	GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPCR EEMTKNQVSL
251	WCLVKGFYPS DIAVEWESNG QPENNYKTTP PVLDSDGSFF LYSKLTVDKS
301	RWQQGNVFSC SVMHEALHNH YTQKSLSLSP GK

(SEQ ID NO: 179)

1	MDAMKRGLCC VLLLCGAVFV SPGA ALLPGA TALQCFCHLC TKDNFTCVTD
51	GLCFVSVTET TDKVIHNSMC IAEIDLIPRD RPFVCAPSSK TGSVTTTYCC
101	NQDHCNKIEL PTTVKSSPGL GPVE TGGG TH TCPPCPAPEL LGGPSVFLFP
151	PKPKDTLMIS RTPEVTCVVV DVSHEDPEVK FNWYVDGVEV HNAKTKPREE
201	QYNSTYRVVS VLTVLHQDWL NGKEYKCKVS NKALPAPIEK TISKAKGQPR
251	EPQVYTLPPS R K EMTKNQVS LTCLVKGFYP SDIAVEWESN GQPENNYKTT
301	PPVL K SDGSF FLYSKLTVDK SRWQQGNVFS CSVMHEALHN HYTQKSLSLS
351	PG

(SEQ ID NO: 180)

1	ALLPGATALQ CFCHLCTKDN FTCVTDGLCF VSVTETTDKV IHNSMCIAEI
51	DLIPRDRPFV CAPSSKTGSV TTTYCCNQDH CNKIELPTTV KSSPGLGPVE
101	TGGGTHTCPP CPAPELLGGP SVFLFPPKPK DTLMISRTPE VTCVVVDVSH
151	EDPEVKFNWY VDGVEVHNAK TKPREEQYNS TYRVVSVLTV LHQDWLNGKE
201	YKCKVSNKAL PAPIEKTISK AKGQPREPQV YTLPPSRKEM TKNQVSLTCL
251	VKGFYPSDIA VEWESNGQPE NNYKTTPPVL KSDGSFFLYS KLTVDKSRWQ
301	QGNVFSCSVM HEALHNHYTQ KSLSLSPG

(SEQ ID NO: 471)

1	MDAMKRGLCC VLLLCGAVFV SPGA ALLPGA TALQCFCHLC TKDNFTCVTD
51	GLCFVSVTET TDKVIHNSMC IAEIDLIPRD RPFVCAPSSK TGSVTTTYCC
101	NQDHCNKIEL PTTVKSSPGL GPVE TGGG TH TCPPCPAPEL LGGPSVFLFP
151	PKPKDTLMIS RTPEVTCVVV DVSHEDPEVK FNWYVDGVEV HNAKTKPREE
201	QYNSTYRVVS VLTVLHQDWL NGKEYKCKVS NKALPAPIEK TISKAKGQPR
251	EPQVYTLPP C REEMTKNQVS L W CLVKGFYP SDIAVEWESN GQPENNYKTT
301	PPVLDSDGSF FLYSKLTVDK SRWQQGNVFS CSVMHEALHN HYTQKSLSLS
351	PGK

(SEQ ID NO: 472)

1	ALLPGATALQ CFCHLCTKDN FTCVTDGLCF VSVTETTDKV IHNSMCIAEI
51	DLIPRDRPFV CAPSSKTGSV TTTYCCNQDH CNKIELPTTV KSSPGLGPVE
101	TGGGTHTCPP CPAPELLGGP SVFLFPPKPK DTLMISRTPE VTCVVVDVSH
151	EDPEVKFNWY VDGVEVHNAK TKPREEQYNS TYRVVSVLTV LHQDWLNGKE
201	YKCKVSNKAL PAPIEKTISK AKGQPREPQV YTLPPCREEM TKNQVSLWCL
251	VKGFYPSDIA VEWESNGQPE NNYKTTPPVL DSDGSFFLYS KLTVDKSRWQ
301	QGNVFSCSVM HEALHNHYTQ KSLSLSPGK

(SEQ ID NO: 181)

1	MDAMKRGLCC VLLLCGAVFV SPGA KKEDGE STAPTPRPKV LRCKCHHHCP
51	EDSVNNICST DGYCFTMIEE DDSGLPVVTS GCLGLEGSDF QCRDTPIPHQ
101	RRSIECCTER NECNKDLHPT LPPLKNRDFV DGPIHHR TGG G THTCPPCPA
151	PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG
201	VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP
251	IEKTISKAKG QPREPQVYTL PPSR K EMTKN QVSLTCLVKG FYPSDIAVEW
301	ESNGQPENNY KTTPPVL K SD GSFFLYSKLT VDKSRWQQGN VFSCSVMHEA
351	LHNHYTQKSL SLSPG

(SEQ ID NO: 182)

1	KKEDGESTAP TPRPKVLRCK CHHHCPEDSV NNICSTDGYC FTMIEEDDSG
51	LPVVTSGCLG LEGSDFQCRD TPIPHQRRSI ECCTERNECN KDLHPTLPPL
101	KNRDFVDGPI HHRTGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR
151	TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV
201	LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPSR
251	KEMTKNQVSL TCLVKGFYPS DIAVEWESNG QPENNYKTTP PVLKSDGSFF
301	LYSKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP G

(SEQ ID NO: 473)

1	MDAMKRGLCC VLLLCGAVFV SPGA KKEDGE STAPTPRPKV LRCKCHHHCP
51	EDSVNNICST DGYCFTMIEE DDSGLPVVTS GCLGLEGSDF QCRDTPIPHQ
101	RRSIECCTER NECNKDLHPT LPPLKNRDFV DGPIHHR TGG G THTCPPCPA
151	PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG
201	VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP
251	IEKTISKAKG QPREPQVYTL PP C REEMTKN QVSL W CLVKG FYPSDIAVEW
301	ESNGQPENNY KTTPPVLDSD GSFFLYSKLT VDKSRWQQGN VFSCSVMHEA
351	LHNHYTQKSL SLSPGK

(SEQ ID NO: 474)

1	KKEDGESTAP TPRPKVLRCK CHHHCPEDSV NNICSTDGYC FTMIEEDDSG
51	LPVVTSGCLG LEGSDFQCRD TPIPHQRRSI ECCTERNECN KDLHPTLPPL
101	KNRDFVDGPI HHRTGGGTHT CPPCPAPELL GGPSVFLFPP KPKDTLMISR
151	TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV
201	LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPCR
251	EEMTKNQVSL WCLVKGFYPS DIAVEWESNG QPENNYKTTP PVLDSDGSFF
301	LYSKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP GK

(SEQ ID NO: 183)

1	MDAMKRGLCC VLLLCGAVFV SPGA GLKCVC LLCDSSNFTC QTEGACWASV
51	MLTNGKEQVI KSCVSLPELN AQVFCHSSNN VTKTECCFTD FCNNITLHLP
101	TASPNAPKLG PME TGGG THT CPPCPAPELL GGPSVFLFPP KPKDTLMISR
151	TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV
201	LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPPSR
251	K EMTKNQVSL TCLVKGFYPS DIAVEWESNG QPENNYKTTP PVL K SDGSFF
301	LYSKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP G

(SEQ ID NO: 184)

1	GLKCVCLLCD SSNFTCQTEG ACWASVMLTN GKEQVIKSCV SLPELNAQVF
51	CHSSNNVTKT ECCFTDFCNN ITLHLPTASP NAPKLGPMET GGGTHTCPPC
101	PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE DPEVKFNWYV
151	DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY KCKVSNKALP
201	APIEKTISKA KGQPREPQVY TLPPSRKEMT KNQVSLTCLV KGFYPSDIAV
251	EWESNGQPEN NYKTTPPVLK SDGSFFLYSK LTVDKSRWQQ GNVFSCSVMH
301	EALHNHYTQK SLSLSPG

(SEQ ID NO: 475)

1	MDAMKRGLCC VLLLCGAVFV SPGA GLKCVC LLCDSSNFTC QTEGACWASV
51	MLTNGKEQVI KSCVSLPELN AQVFCHSSNN VTKTECCFTD FCNNITLHLP
101	TASPNAPKLG PME TGGG THT CPPCPAPELL GGPSVFLFPP KPKDTLMISR
151	TPEVTCVVVD VSHEDPEVKF NWYVDGVEVH NAKTKPREEQ YNSTYRVVSV
201	LTVLHQDWLN GKEYKCKVSN KALPAPIEKT ISKAKGQPRE PQVYTLPP C R
251	EEMTKNQVSL W CLVKGFYPS DIAVEWESNG QPENNYKTTP PVLDSDGSFF
301	LYSKLTVDKS RWQQGNVFSC SVMHEALHNH YTQKSLSLSP GK

(SEQ ID NO: 476)

1	GLKCVCLLCD SSNFTCQTEG ACWASVMLTN GKEQVIKSCV SLPELNAQVF
51	CHSSNNVTKT ECCFTDFCNN ITLHLPTASP NAPKLGPMET GGGTHTCPPC
101	PAPELLGGPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE DPEVKFNWYV
151	DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY KCKVSNKALP
201	APIEKTISKA KGQPREPQVY TLPPCREEMT KNQVSLWCLV KGFYPSDIAV
251	EWESNGQPEN NYKTTPPVLD SDGSFFLYSK LTVDKSRWQQ GNVFSCSVMH
301	EALHNHYTQK SLSLSPGK

TABLE “Type I:Type I Receptor Heterodimers” Amino Acid SEQ ID NOs for Type I:Type I Receptor Heterodimers

		ECD		Amino Acid
Heteromeric		Corre-	Receptor-	SEQ ID NO
Fusion Protein		spondence	Fc Fusion	With
Complex	Fc Pair Type	to Fc Pair	Protein	Leader	Mature
ALK1-Fc:	Electrostatic	A	ALK1-Fc	124	126
ALK2-Fc			ALK2-Fc	173	174
		B	ALK1-Fc	171	172
			ALK2-Fc	136	138
	Hydrophobic	A	ALK1-Fc	413	414
			ALK2-Fc	465	466
		B	ALK1-Fc	463	464
			ALK2-Fc	421	422
ALK1-Fc:	Electrostatic	A	ALK1-Fc	124	126
ALK3-Fc			ALK3-Fc	175	176
		B	ALK1-Fc	171	172
			ALK3-Fc	115	117
	Hydrophobic	A	ALK1-Fc	413	414
			ALK3-Fc	467	468
		B	ALK1-Fc	463	464
			ALK3-Fc	407	408
ALK1-Fc:	Electrostatic	A	ALK1-Fc	124	126
ALK4-Fc			ALK4-Fc	177	178
		B	ALK1-Fc	171	172
			ALK4-Fc	104	106
	Hydrophobic	A	ALK1-Fc	413	414
			ALK4-Fc	469	470
		B	ALK1-Fc	463	464
			ALK4-Fc	403	404
ALK1-Fc:	Electrostatic	A	ALK1-Fc	124	126
ALK5-Fc			ALK5-Fc	179	180
		B	ALK1-Fc	171	172
			ALK5-Fc	139	141
	Hydrophobic	A	ALK1-Fc	413	414
			ALK5-Fc	471	472
		B	ALK1-Fc	463	464
			ALK5-Fc	423	424
ALK1-Fc:	Electrostatic	A	ALK1-Fc	124	126
ALK6-Fc			ALK6-Fc	181	182
		B	ALK1-Fc	171	172
			ALK6-Fc	142	144
	Hydrophobic	A	ALK1-Fc	413	414
			ALK6-Fc	473	474
		B	ALK1-Fc	463	464
			ALK6-Fc	425	426
ALK1-Fc:	Electrostatic	A	ALK1-Fc	124	126
ALK7-Fc			ALK7-Fc	183	184
		B	ALK1-Fc	171	172
			ALK7-Fc	112	114
	Hydrophobic	A	ALK1-Fc	413	414
			ALK7-Fc	475	476
		B	ALK1-Fc	463	464
			ALK7-Fc	405	406
ALK2-Fc:	Electrostatic	A	ALK2-Fc	136	138
ALK3-Fc			ALK3-Fc	175	176
		B	ALK2-Fc	173	174
			ALK3-Fc	115	117
	Hydrophobic	A	ALK2-Fc	421	422
			ALK3-Fc	467	468
		B	ALK2-Fc	465	466
			ALK3-Fc	407	408
ALK2-Fc:	Electrostatic	A	ALK2-Fc	136	138
ALK4-Fc			ALK4-Fc	177	178
		B	ALK2-Fc	173	174
			ALK4-Fc	104	106
	Hydrophobic	A	ALK2-Fc	421	422
			ALK4-Fc	469	470
		B	ALK2-Fc	465	466
			ALK4-Fc	403	404
ALK2-Fc:	Electrostatic	A	ALK2-Fc	136	138
ALK5-Fc			ALK5-Fc	179	180
		B	ALK2-Fc	173	174
			ALK5-Fc	139	141
	Hydrophobic	A	ALK2-Fc	421	422
			ALK5-Fc	471	472
		B	ALK2-Fc	465	466
			ALK5-Fc	423	424
ALK2-Fc:	Electrostatic	A	ALK2-Fc	136	138
ALK6-Fc			ALK6-Fc	181	182
		B	ALK2-Fc	173	174
			ALK6-Fc	142	144
	Hydrophobic	A	ALK2-Fc	421	422
			ALK6-Fc	473	474
		B	ALK2-Fc	465	466
			ALK6-Fc	425	426
ALK2-Fc:	Electrostatic	A	ALK2-Fc	136	138
ALK7-Fc			ALK7-Fc	183	184
		B	ALK2-Fc	173	174
			ALK7-Fc	112	114
	Hydrophobic	A	ALK2-Fc	421	422
			ALK7-Fc	475	476
		B	ALK2-Fc	465	466
			ALK7-Fc	405	406
ALK3-Fc:	Electrostatic	A	ALK3-Fc	115	117
ALK4-Fc			ALK4-Fc	177	178
		B	ALK3-Fc	175	176
			ALK4-Fc	104	106
	Hydrophobic	A	ALK3-Fc	407	408
			ALK4-Fc	469	470
		B	ALK3-Fc	467	468
			ALK4-Fc	403	404
ALK3-Fc:	Electrostatic	A	ALK3-Fc	115	117
ALK5-Fc			ALK5-Fc	179	180
		B	ALK3-Fc	175	176
			ALK5-Fc	139	141
	Hydrophobic	A	ALK3-Fc	407	408
			ALK5-Fc	471	472
		B	ALK3-Fc	467	468
			ALK5-Fc	423	424
ALK3-Fc:	Electrostatic	A	ALK3-Fc	115	117
ALK6-Fc			ALK6-Fc	181	182
		B	ALK3-Fc	175	176
			ALK6-Fc	142	144
	Hydrophobic	A	ALK3-Fc	407	408
			ALK6-Fc	473	474
		B	ALK3-Fc	467	468
			ALK6-Fc	425	426
ALK3-Fc:	Electrostatic	A	ALK3-Fc	115	117
ALK7-Fc			ALK7-Fc	183	184
		B	ALK3-Fc	175	176
			ALK7-Fc	112	114
	Hydrophobic	A	ALK3-Fc	407	408
			ALK7-Fc	475	476
		B	ALK3-Fc	467	468
			ALK7-Fc	405	406
ALK4-Fc:	Electrostatic	A	ALK4-Fc	104	106
ALK5-Fc			ALK5-Fc	179	180
		B	ALK4-Fc	177	178
			ALK5-Fc	139	141
	Hydrophobic	A	ALK4-Fc	403	404
			ALK5-Fc	471	472
		B	ALK4-Fc	469	470
			ALK5-Fc	423	424
ALK4-Fc:	Electrostatic	A	ALK4-Fc	104	106
ALK6-Fc			ALK6-Fc	181	182
		B	ALK4-Fc	177	178
			ALK6-Fc	142	144
	Hydrophobic	A	ALK4-Fc	403	404
			ALK6-Fc	473	474
		B	ALK4-Fc	469	470
			ALK6-Fc	425	426
ALK4-Fc:	Electrostatic	A	ALK4-Fc	104	106
ALK7-Fc			ALK7-Fc	183	184
		B	ALK4-Fc	177	178
			ALK7-Fc	112	114
	Hydrophobic	A	ALK4-Fc	403	404
			ALK7-Fc	475	476
		B	ALK4-Fc	469	470
			ALK7-Fc	405	406
ALK5-Fc:	Electrostatic	A	ALK5-Fc	139	141
ALK6-Fc			ALK6-Fc	181	182
		B	ALK5-Fc	179	180
			ALK6-Fc	142	144
	Hydrophobic	A	ALK5-Fc	423	424
			ALK6-Fc	473	474
		B	ALK5-Fc	471	472
			ALK6-Fc	425	426
ALK5-Fc:	Electrostatic	A	ALK5-Fc	139	141
ALK7-Fc			ALK7-Fc	183	184
		B	ALK5-Fc	179	180
			ALK7-Fc	112	114
	Hydrophobic	A	ALK5-Fc	423	424
			ALK7-Fc	475	476
		B	ALK5-Fc	471	472
			ALK7-Fc	405	406
ALK6-Fc:	Electrostatic	A	ALK6-Fc	142	144
ALK7-Fc			ALK7-Fc	183	184
		B	ALK6-Fc	181	182
			A LK7-Fc	112	114
	Hydrophobic	A	ALK6-Fc	425	426
			ALK7-Fc	475	476
		B	ALK6-Fc	473	474
			ALK7-Fc	405	406

TABLE “Type I:Type II Receptor Heterodimers” Amino Acid SEQ ID NOs for Type I:Type II Receptor Heterodimers Amino Acid

Heteromeric		ECD		SEQ ID NO
Fusion Protein		Correspondence	Receptor-Fc	With
Complex	Fc Pair Type	to Fc Pair	Fusion Protein	Leader	Mature
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
ALK1-Fc			ALK1-Fc	124	126
		B	ActRIIA-Fc	151	152
			ALK1-Fc	171	172
	Hydrophobic	A	ActRIIA-Fc	409	410
			ALK1-Fc	413	414
		B	ActRIIA-Fc	451	452
			ALK1-Fc	463	464
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
ALK2-Fc			ALK2-Fc	136	138
		B	ActRIIA-Fc	151	152
			ALK2-Fc	173	174
	Hydrophobic	A	ActRIIA-Fc	409	410
			ALK2-Fc	421	422
		B	ActRIIA-Fc	451	452
			ALK2-Fc	465	466
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
ALK3-Fc			ALK3-Fc	115	117
		B	ActRIIA-Fc	151	152
			ALK3-Fc	175	176
	Hydrophobic	A	ActRIIA-Fc	409	410
			ALK3-Fc	407	408
		B	ActRIIA-Fc	451	452
			ALK3-Fc	467	468
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
ALK4-Fc			ALK4-Fc	104	106
		B	ActRIIA-Fc	151	152
			ALK4-Fc	177	178
	Hydrophobic	A	ActRIIA-Fc	409	410
			ALK4-Fc	403	404
		B	ActRIIA-Fc	451	452
			ALK4-Fc	469	470
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
ALK5-Fc			ALK5-Fc	139	141
		B	ActRIIA-Fc	151	152
			ALK5-Fc	179	180
	Hydrophobic	A	ActRIIA-Fc	409	410
			ALK5-Fc	423	424
		B	ActRIIA-Fc	451	452
			ALK5-Fc	471	472
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
ALK6-Fc			ALK6-Fc	142	144
		B	ActRIIA-Fc	151	152
			ALK6-Fc	181	182
	Hydrophobic	A	ActRIIA-Fc	409	410
			ALK6-Fc	425	426
		B	ActRIIA-Fc	451	452
			ALK6-Fc	473	474
ActRIIA-Fc:	Electrostatic	A	ActRIIA-Fc	118	120
ALK7-Fc			ALK7-Fc	112	114
		B	ActRIIA-Fc	151	152
			ALK7-Fc	183	184
	Hydrophobic	A	ActRIIA-Fc	409	410
			ALK7-Fc	405	406
		B	ActRIIA-Fc	451	452
			ALK7-Fc	475	476
ActRIIB-Fc:	Electrostatic	A	ActRIIB-Fc	100	102
ALK1-Fc			ALK1-Fc	124	126
		B	ActRIIB-Fc	153	154
			ALK1-Fc	171	172
	Hydrophobic	A	ActRIIB-Fc	401	402
			ALK1-Fc	413	414
		B	ActRIIB-Fc	453	454
			ALK1-Fc	463	464
ActRIIB-Fc:	Electrostatic	A	ActRIIB-Fc	100	102
ALK2-Fc			ALK2-Fc	136	138
		B	ActRIIB-Fc	153	154
			ALK2-Fc	173	174
	Hydrophobic	A	ActRIIB-Fc	401	402
			ALK2-Fc	421	422
		B	ActRIIB-Fc	453	454
			ALK2-Fc	465	466
ActRIIB-Fc:	Electrostatic	A	ActRIIB-Fc	100	102
ALK3-Fc			ALK3-Fc	115	117
		B	ActRIIB-Fc	153	154
			ALK3-Fc	175	176
	Hydrophobic	A	ActRIIB-Fc	401	402
			ALK3-Fc	407	408
		B	ActRIIB-Fc	453	454
			ALK3-Fc	467	468
ActRIIB-Fc:	Electrostatic	A	ActRIIB-Fc	100	102
ALK4-Fc			ALK4-Fc	104	106
		B	ActRIIB-Fc	153	154
			ALK4-Fc	177	178
	Hydrophobic	A	ActRIIB-Fc	401	402
			ALK4-Fc	403	404
		B	ActRIIB-Fc	453	454
			ALK4-Fc	469	470
ActRIIB-Fc:	Electrostatic	A	ActRIIB-Fc	100	102
ALK5-Fc			ALK5-Fc	139	141
		B	ActRIIB-Fc	153	154
			ALK5-Fc	179	180
	Hydrophobic	A	ActRIIB-Fc	401	402
			ALK5-Fc	423	424
		B	ActRIIB-Fc	453	454
			ALK5-Fc	471	472
ActRIIB-Fc:	Electrostatic	A	ActRIIB-Fc	100	102
ALK6-Fc			ALK6-Fc	142	144
		B	ActRIIB-Fc	153	154
			ALK6-Fc	181	182
	Hydrophobic	A	ActRIIB-Fc	401	402
			ALK6-Fc	425	426
		B	ActRIIB-Fc	453	454
			ALK6-Fc	473	474
ActRIIB-Fc:	Electrostatic	A	ActRIIB-Fc	100	102
ALK7-Fc			ALK7-Fc	112	114
		B	ActRIIB-Fc	153	154
			ALK7-Fc	183	184
	Hydrophobic	A	ActRIIB-Fc	401	402
			ALK7-Fc	405	406
		B	ActRIIB-Fc	453	454
			ALK7-Fc	475	476
BMPRII-Fc:	Electrostatic	A	BMPRII-Fc	121	123
ALK1-Fc			ALK1-Fc	124	126
		B	BMPRII-Fc	155	156
			ALK1-Fc	171	172
	Hydrophobic	A	BMPRII-Fc	411	412
			ALK1-Fc	413	414
		B	BMPRII-Fc	455	456
			ALK1-Fc	463	464
BMPRII-Fc:	Electrostatic	A	BMPRII-Fc	121	123
ALK2-Fc			ALK2-Fc	136	138
		B	BMPRII-Fc	155	156
			ALK2-Fc	173	174
	Hydrophobic	A	BMPRII-Fc	411	412
			ALK2-Fc	421	422
		B	BMPRII-Fc	455	456
			ALK2-Fc	465	466
BMPRII-Fc:	Electrostatic	A	BMPRII-Fc	121	123
ALK3-Fc			ALK3-Fc	115	117
		B	BMPRII-Fc	155	156
			ALK3-Fc	175	176
	Hydrophobic	A	BMPRII-Fc	411	412
			ALK3-Fc	407	408
		B	BMPRII-Fc	455	456
			ALK3-Fc	467	468
BMPRII-Fc:	Electrostatic	A	BMPRII-Fc	121	123
ALK4-Fc			ALK4-Fc	104	106
		B	BMPRII-Fc	155	156
			ALK4-Fc	177	178
	Hydrophobic	A	BMPRII-Fc	411	412
			ALK4-Fc	403	404
		B	BMPRII-Fc	455	456
			ALK4-Fc	469	470
BMPRII-Fc:	Electrostatic	A	BMPRII-Fc	121	123
ALK5-Fc			ALK5-Fc	139	141
		B	BMPRII-Fc	155	156
			ALK5-Fc	179	180
	Hydrophobic	A	BMPRII-Fc	411	412
			ALK5-Fc	423	424
		B	BMPRII-Fc	455	456
			ALK5-Fc	471	472
BMPRII-Fc:	Electrostatic	A	BMPRII-Fc	121	123
ALK6-Fc			ALK6-Fc	142	144
		B	BMPRII-Fc	155	156
			ALK6-Fc	181	182
	Hydrophobic	A	BMPRII-Fc	411	412
			ALK6-Fc	425	426
		B	BMPRII-Fc	455	456
			ALK6-Fc	473	474
BMPRII-Fc:	Electrostatic	A	BMPRII-Fc	121	123
ALK7-Fc			ALK7-Fc	112	114
		B	BMPRII-Fc	155	156
			ALK7-Fc	183	184
	Hydrophobic	A	BMPRII-Fc	411	412
			ALK7-Fc	405	406
		B	BMPRII-Fc	455	456
			ALK7-Fc	475	476
MISRII-Fc:	Electrostatic	A	MISRII-Fc	133	135
ALK1-Fc			ALK1-Fc	124	126
		B	MISRII-Fc	161	162
			ALK1-Fc	171	172
	Hydrophobic	A	MISRII-Fc	419	420
			ALK1-Fc	413	414
		B	MISRII-Fc	457	458
			ALK1-Fc	463	464
MISRII-Fc:	Electrostatic	A	MISRII-Fc	133	135
ALK2-Fc			ALK2-Fc	136	138
		B	MISRII-Fc	161	162
			ALK2-Fc	173	174
	Hydrophobic	A	MISRII-Fc	419	420
			ALK2-Fc	421	422
		B	MISRII-Fc	457	458
			ALK2-Fc	465	466
MISRII-Fc:	Electrostatic	A	MISRII-Fc	133	135
ALK3-Fc			ALK3-Fc	115	117
		B	MISRII-Fc	161	162
			ALK3-Fc	175	176
	Hydrophobic	A	MISRII-Fc	419	420
			ALK3-Fc	407	408
		B	MISRII-Fc	457	458
			ALK3-Fc	467	468
MISRII-Fc:	Electrostatic	A	MISRII-Fc	133	135
ALK4-Fc			ALK4-Fc	104	106
		B	MISRII-Fc	161	162
			ALK4-Fc	177	178
	Hydrophobic	A	MISRII-Fc	419	420
			ALK4-Fc	403	404
		B	MISRII-Fc	457	458
			ALK4-Fc	469	470
MISRII-Fc:	Electrostatic	A	MISRII-Fc	133	135
ALK5-Fc			ALK5-Fc	139	141
		B	MISRII-Fc	161	162
			ALK5-Fc	179	180
	Hydrophobic	A	MISRII-Fc	419	420
			ALK5-Fc	423	424
		B	MISRII-Fc	457	458
			ALK5-Fc	471	472
MISRII-Fc:	Electrostatic	A	MISRII-Fc	133	135
ALK6-Fc			ALK6-Fc	142	144
		B	MISRII-Fc	161	162
			ALK6-Fc	181	182
	Hydrophobic	A	MISRII-Fc	419	420
			ALK6-Fc	425	426
		B	MISRII-Fc	457	458
			ALK6-Fc	473	474
MISRII-Fc:	Electrostatic	A	MISRII-Fc	133	135
ALK7-Fc			ALK7-Fc	112	114
		B	MISRII-Fc	161	162
			ALK7-Fc	183	184
	Hydrophobic	A	MISRII-Fc	419	420
			ALK7-Fc	405	406
		B	MISRII-Fc	457	458
			ALK7-Fc	475	476
TGFβRII SHORT -Fc:	Electrostatic	A	TGFβRII SHORT -Fc	127	129
ALK1-Fc			ALK1-Fc	124	126
		B	TGFβRII SHORT -Fc	157	158
			ALK1-Fc	171	172
	Hydrophobic	A	TGFβRII SHORT -Fc	415	416
			ALK1-Fc	413	414
		B	TGFβRII SHORT -Fc	459	460
			ALK1-Fc	463	464
TGFβRII SHORT -Fc:	Electrostatic	A	TGFβRII SHORT -Fc	127	129
ALK2-Fc			ALK2-Fc	136	138
		B	TGFβRII SHORT -Fc	157	158
			ALK2-Fc	173	174
	Hydrophobic	A	TGFβRII SHORT -Fc	415	416
			ALK2-Fc	421	422
		B	TGFβRII SHORT -Fc	459	460
			ALK2-Fc	465	466
TGFβRII SHORT -Fc:	Electrostatic	A	TGFβRII SHORT -Fc	127	129
ALK3-Fc			ALK3-Fc	115	117
		B	TGFβRII SHORT -Fc	157	158
			ALK3-Fc	175	176
	Hydrophobic	A	TGFβRII SHORT -Fc	415	416
			ALK3-Fc	407	408
		B	TGFβRII SHORT -Fc	459	460
			ALK3-Fc	467	468
TG9βRII SHORT -Fc:	Electrostatic	A	TGFβRII SHORT -Fc	127	129
ALK4-Fc			ALK4-Fc	104	106
		B	TGFβRII SHORT -Fc	157	158
			ALK4-Fc	177	178
	Hydrophobic	A	TGFβRII SHORT -Fc	415	416
			ALK4-Fc	403	404
		B	TGFβRII SHORT -Fc	459	460
			ALK4-Fc	469	470
TGFβRII SHORT -Fc:	Electrostatic	A	TGFβRII SHORT -Fc	127	129
ALK5-Fc			ALK5-Fc	139	141
		B	TGFβRII SHORT -Fc	157	158
			ALK5-Fc	179	180
	Hydrophobic	A	TGFβRII SHORT -Fc	415	416
			ALK5-Fc	423	424
		B	TGFβRII SHORT -Fc	459	460
			ALK5-Fc	471	472
TGFβRII SHORT -Fc:	Electrostatic	A	TGFβRII SHORT -Fc	127	129
ALK6-Fc			ALK6-Fc	142	144
		B	TGFβRII SHORT -Fc	157	158
			ALK6-Fc	181	182
	Hydrophobic	A	TGFβRII SHORT -Fc	415	416
			ALK6-Fc	425	426
		B	TGFβRII SHORT -Fc	459	460
			ALK6-Fc	473	474
TGFβRII SHORT -Fc:	Electrostatic	A	TGFβRII SHORT -Fc	127	129
ALK7-Fc			ALK7-Fc	112	114
		B	TGFβRII SHORT -Fc	157	158
			ALK7-Fc	183	184
	Hydrophobic	A	TGFβRII SHORT -Fc	415	416
			ALK7-Fc	405	406
		B	TGFβRII SHORT -Fc	459	460
			ALK7-Fc	475	476
TGFβRII LONG -Fc:	Electrostatic	A	TGFβRII LONG -Fc	130	132
ALK1-Fc			ALK1-Fc	124	126
		B	TGFβRII LONG -Fc	159	160
			ALK1-Fc	171	172
	Hydrophobic	A	TGFβRII LONG -Fc	417	418
			ALK1-Fc	413	414
		B	TGFβRII LONG -Fc	461	462
			ALK1-Fc	463	464
TGFβRII LONG -Fc:	Electrostatic	A	TGFβRII LONG -Fc	130	132
ALK2-Fc			ALK2-Fc	136	138
		B	TGFβRII LONG -Fc	159	160
			ALK2-Fc	173	174
	Hydrophobic	A	TGFβRII LONG -Fc	417	418
			ALK2-Fc	421	422
		B	TGFβRII LONG -Fc	461	462
			ALK2-Fc	465	466
TGFβRII LONG -Fc:	Electrostatic	A	TGFβRII LONG -Fc	130	132
ALK3-Fc			ALK3-Fc	115	117
		B	TGFβRII LONG -Fc	159	160
			ALK3-Fc	175	176
	Hydrophobic	A	TGFβRII LONG -Fc	417	418
			ALK3-Fc	407	408
		B	TGFβRII LONG -Fc	461	462
			ALK3-Fc	467	468
TGFβRII LONG -Fc:	Electrostatic	A	TGFβRII LONG -Fc	130	132
ALK4-Fc			ALK4-Fc	104	106
		B	TGFβRII LONG -Fc	159	160
			ALK4-Fc	177	178
	Hydrophobic	A	TGFβRII LONG -Fc	417	418
			ALK4-Fc	403	404
		B	TGFβRII LONG -Fc	461	462
			ALK4-Fc	469	470
TGFβRII LONG -Fc:	Electrostatic	A	TGFβRII LONG -Fc	130	132
ALK5-Fc			ALK5-Fc	139	141
		B	TGFβRII LONG -Fc	159	160
			ALK5-Fc	179	180
	Hydrophobic	A	TGFβRII LONG -Fc	417	418
			ALK5-Fc	423	424
		B	TGFβRII LONG -Fc	461	462
			ALK5-Fc	471	472
TGFβRII LONG -Fc:	Electrostatic	A	TGFβRII LONG -Fc	130	132
ALK6-Fc			ALK6-Fc	142	144
		B	TGFβRII LONG -Fc	159	160
			ALK6-Fc	181	182
	Hydrophobic	A	TGFβRII LONG -Fc	417	418
			ALK6-Fc	425	426
		B	TGFβRII LONG -Fc	461	462
			ALK6-Fc	473	474
TGFβRII LONG -Fc:	Electrostatic	A	TGFβRII LONG -Fc	130	132
ALK7-Fc			ALK7-Fc	112	114
		B	TGFβRII LONG -Fc	159	160
			ALK7-Fc	183	184
	Hydrophobic	A	TGFβRII LONG -Fc	417	418
			ALK7-Fc	405	406
		B	TGFβRII LONG -Fc	461	462
			ALK7-Fc	475	476

description truncated at 500,000 characters

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Claims as granted

4 claims

Classifications

4 codes

IPC · International Patent Classification

Section A — Human necessities

A61K38/45
A61K38/00

Section C — Chemistry; metallurgy

C07K14/71
C12N9/12

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Pendency

2.0 y

746 days filing → grant

Office actions

after a restriction

Responses

no RCE

Examiner

Ruixiang Li

art unit 1646 · TC 1600

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Citations: 160 back · 2 forward

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Chain of title

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