| abstract |
Compositions and methods to modulate (promote or inhibit) the growth of a tissue, such as bone, cartilaginous, muscular, adipose and / or neuronal tissue. Also methods for sweeping compounds that modulate the activity of an ActRIIB protein and / or an ActRIIB ligand. The compositions and methods are useful in the treatment of diseases associated with an abnormal activity of an ActRIIB protein and / or an ActRIIB ligand. Claim 1: A variant of the ActRIIB fusion protein characterized in that it comprises a portion derived from the ActRIIB sequence of SEQ ID N °: 4 and a second polypeptide portion, wherein the portion derived from SEQ ID N °: 4 corresponds to a sequence that begins at any of amino acids 21-29 of SEQ ID N °: 4 and that ends at any of amino acids 109-134 of SEQ ID N °: 4, and where the ActRIIB fusion protein has an arginine (R), lysine (K) or histidine (H) at position 64 of SEQ ID N °: 4 and inhibits signaling by activin, myostatin and / or GDF11 in a cell-based assay. |