Isolated nucleotide sequences encoding GDF traps
In certain aspects, the present invention provides compositions and methods for increasing red blood cell and/or hemoglobin levels in vertebrates, including rodents and primates, and particularly in humans.
1. A method for producing a variant ActRIIB polypeptide, comprising:
a) culturing a cell under conditions suitable for expression of the polypeptide, and
b) recovering the polypeptide expressed by the cell;
wherein the cell comprises a nucleic acid; wherein the nucleic acid comprises a nucleic acid sequence that hybridizes to the complement of nucleotides 76-396 of SEQ ID NO: 30 in the presence of 6.0× sodium chloride/sodium citrate (SSC) at 45° C. followed by a wash in 0.2× SSC at 65° C., wherein the nucleic acid sequence encodes a polypeptide that comprises an acidic amino acid at the position corresponding to position 79 of SEQ ID NO: 1.
2. The method of claim 1 , wherein the nucleic acid hybridizes to the complement of the nucleotide sequence of SEQ ID NO: 30 in the presence of 6.0× sodium chloride/sodium citrate (SSC) at 45° C. followed by a wash in 0.2× SSC at 65° C.
3. The method of claim 1 , wherein the nucleic acid comprises nucleotides 76-396 of SEQ ID NO: 30.
4. The method of claim 1 , wherein the nucleic acid comprises the nucleotide sequence of SEQ ID NO: 30.
5. The method of claim 1 , wherein the nucleic acid comprises a nucleotide sequence encoding a polypeptide comprising amino acids 26-132 of SEQ ID NO: 26.
6. The method of claim 1 , wherein the nucleic acid comprises a nucleotide sequence encoding a polypeptide comprising the amino acid sequence of SEQ ID NO: 26.
7. The method of claim 1 , wherein the nucleic acid further comprises a nucleotide sequence encoding a tissue plasminogen activator (TPA) leader sequence.
8. The method of claim 1 , wherein the nucleic acid is operably linked to one or more regulatory sequences.
9. The method of claim 1 , wherein the variant polypeptide comprises the amino acid sequence of SEQ ID NO: 28.
10. The method of claim 1 , wherein the cell is a mammalian cell.
11. The method of claim 1 , wherein the cell is a CHO cell.
12. The method of claim 1 , wherein the variant polypeptide comprises an amino acid sequence consisting of SEQ ID NO: 28.