Function
Involved in dorsal-ventral patterning, permitting peak BMP signaling by antagonizing the residual anti-BMP activity of the cleavage products of chrd. Functions to promote the formation of ventral mesoderm by increasing the activity of bmp7 and other BMPS. Seems to antagonize BMP signaling by forming ternary complexes with chrd and BMPs, thereby preventing BMPs from binding to their receptors. In addition to the anti-BMP function, also has pro-BMP activity, partly mediated by cleavage and degradation of chrd, which releases BMPs from ternary complexes. May be an important modulator of BMP-regulated cartilage development and chondrocyte differentiation (By similarity).