Sclerostin Domain Containing Protein 1 (SOSTDC1)

Sclerostin domain-containing protein 1 is a member of the sclerostin family and encodes an N-glycosylated, secreted protein with a C-terminal cystine knot-like domain. This protein functions as a bone morphogenetic protein (BMP) antagonist. Specifically, it directly associates with BMPs, prohibiting them from binding their receptors, thereby regulating BMP signaling during cellular proliferation, differentiation, and programmed cell death.The deduced 206-amino acid protein has a 22-amino acid N-terminal signal sequence and a core cysteine-rich region. Ectodin has 6 conserved cysteines and a glycine predicted to form a cystine knot with 4 disulfide bridges, and the spacing of cysteines is highly homologous to BMP antagonists in the DAN cerberus  family. Mouse and human ectodin share 95% amino acid identity.