TGF-beta superfamily type I and type II receptor heteromultimers and uses thereof
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.
1. A soluble recombinant heteromultimer comprising an ALK3 polypeptide and an ActRIIB polypeptide, wherein the ALK3 polypeptide is a fusion protein comprising an ALK3 domain and a heterologous domain, wherein the ALK3 domain comprises an amino acid sequence that is at least 90% identical to amino acids 61-130 of SEQ ID NO: 22, and wherein the ActRIIB polypeptide is a fusion protein comprising an ActRIIB domain and a heterologous domain, wherein the ActRIIB domain comprises an amino acid sequence that is at least 90% identical to amino acids 29-109 of SEQ ID NO: 1, wherein the amino acid position in the ActRIIB polypeptide corresponding to L79 of SEQ ID NO: 1 is not an aspartic acid (D); and wherein the heteromultimer binds to BMP2 and/or BMP4.
2. The heteromultimer of claim 1 , wherein the heteromultimer is an ALK3:ActRIIB heterodimer.
3. The heteromultimer of claim 1 , wherein the heterologous domain of the ALK3 polypeptide comprises a constant region from an IgG heavy chain, and wherein the heterologous domain of the ActRIIB polypeptide comprises a constant region from an IgG heavy chain.
4. The heteromultimer of claim 3 , wherein one or both of the constant regions from the IgG heavy chain is an immunoglobulin Fc domain of IgG1 immunoglobulin.
5. The heteromultimer of claim 4 , wherein the immunoglobulin Fc domain comprises one or more amino acid mutations that promote heterodimer formation.
6. The heteromultimer of claim 4 , wherein the immunoglobulin Fc domain comprises one or more amino acid mutations that inhibit homodimer formation.
7. The heteromultimer of claim 1 , wherein the ALK3 polypeptide and/or ActRIIB polypeptide comprises one or more modified amino acid residues selected from the group consisting of: a glycosylated amino acid, a PEGylated amino acid, a farnesylated amino acid, an acetylated amino acid, a biotinylated amino acid, and an amino acid conjugated to a lipid moiety.
8. The heteromultimer of claim 7 , wherein the ALK3 polypeptide and/or ActRIIB polypeptide is glycosylated and has a glycosylation pattern obtainable from expression of the type I receptor polypeptide in a CHO cell.
9. A pharmaceutical preparation comprising the heteromultimer of claim 1 and a pharmaceutically acceptable carrier.
10. The heteromultimer of claim 1 , wherein the ALK3 polypeptide comprises an amino acid sequence that is at least 90% identical to amino acids 24-152 of SEQ ID NO: 22.
11. The heteromultimer of claim 1 , wherein the ALK3 polypeptide comprises an amino acid sequence that is at least 90% identical to a polypeptide that:
a) begins at any one of amino acids 24-61 of SEQ ID NO: 22, and
b) ends at any one of amino acids 130-152 of SEQ ID NO: 22.
12. The heteromultimer of claim 1 , wherein the ALK3 polypeptide comprises an amino acid sequence that is at least 90% identical to any one of SEQ ID Nos: 22, 23, 115, 117, 175, 176, 407, 408, 467, and 468.
13. The heteromultimer of claim 1 , wherein the ActRIIB polypeptide comprises an amino acid sequence that is at least 90% identical to a polypeptide that:
a) begins at any one of amino acids 20-29 of SEQ ID NO: 1, and
b) ends at any one of amino acids 109-134 of SEQ ID NO: 1.
14. The heteromultimer of claim 1 , wherein the ActRIIB polypeptide comprises an amino acid sequence that is at least 90% identical to any one of SEQ ID Nos: 1, 2, 3, 4, 5, 6, 100, 102, 153, 154, 401, 402, 453, and 454.
15. The heteromultimer of claim 1 , wherein the ALK3 polypeptide comprises an amino acid sequence that is at least 95% identical to amino acids 61-130 of SEQ ID NO: 22, and wherein the ActRIIB polypeptide comprises an amino acid sequence that is at least 95% identical to amino acids 29-109 of SEQ ID NO: 1.
16. The heteromultimer of claim 1 , wherein the ALK3 polypeptide comprises the amino acid sequence corresponding to amino acids 61-130 of SEQ ID NO: 22, and wherein the ActRIIB polypeptide comprises the amino acid sequence corresponding to amino acids 29-109 of SEQ ID NO: 1.
17. The heteromultimer of claim 1 , wherein the ALK3 polypeptide comprises an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 23, and wherein the ActRIIB polypeptide comprises an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 2.
18. The heteromultimer of claim 1 , wherein the ALK3 polypeptide comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 23, and wherein the ActRIIB polypeptide comprises an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 2.
19. The heteromultimer of claim 1 , wherein the ALK3 polypeptide comprises the amino acid sequence of SEQ ID NO: 23, and wherein the ActRIIB polypeptide comprises the amino acid sequence of SEQ ID NO: 2.
20. The heteromultimer of claim 15 , wherein the heterologous domain of the ALK3 polypeptide and the heterologous domain of the ActRIIB polypeptide each comprises an Fc immunoglobulin domain, wherein the Fc immunoglobulin domain is an IgG1 immunoglobulin domain.
21. The heteromultimer of claim 16 , wherein the heterologous domain of the ALK3 polypeptide and the heterologous domain of the ActRIIB polypeptide each comprises an Fc immunoglobulin domain, wherein the Fc immunoglobulin domain is an IgG1 immunoglobulin domain.
22. The heteromultimer of claim 18 , wherein the heterologous domain of the ALK3 polypeptide and the heterologous domain of the ActRIIB polypeptide each comprises an Fc immunoglobulin domain, wherein the Fc immunoglobulin domain is an IgG1 immunoglobulin domain.
23. The heteromultimer of claim 19 , wherein the heterologous domain of the ALK3 polypeptide and the heterologous domain of the ActRIIB polypeptide each comprises an Fc immunoglobulin domain, wherein the Fc immunoglobulin domain is an IgG1 immunoglobulin domain.
24. The heteromultimer of claim 15 , wherein a linker domain is positioned between the ALK3 domain and the heterologous domain and/or a linker domain is positioned between the ActRIIB domain and the heterologous domain.
25. The heteromultimer of claim 16 , wherein a linker domain is positioned between the ALK3 domain and the heterologous domain and/or a linker domain is positioned between the ActRIIB domain and the heterologous domain.
26. The heteromultimer of claim 18 , wherein a linker domain is positioned between the ALK3 domain and the heterologous domain and/or a linker domain is positioned between the ActRIIB domain and the heterologous domain.
27. The heteromultimer of claim 19 , wherein a linker domain is positioned between the ALK3 domain and the heterologous domain and/or a linker domain is positioned between the ActRIIB domain and the heterologous domain.