Cerberus-2 (COCO)

COCO, also known as DAND5, Dante, and CKTSF1B3, is a member of the DAN Domain family of BMP antagonists that includes DAN (DAND1), Gremlin/Drm (DAND2), PRDC (Protein Related to Dan and Cerberus; DAND3), and Cerberus (DAND4) . DAN family members contain a cysteine-knot domain that is homologous to that found in other TGF-beta superfamily ligands. BMPs play important roles in tissue morphogenesis and development processes. The human COCO cDNA encodes a 189 amino acid (aa) precursor with a 22 aa signal sequence. COCO has eight Cys residues in the cysteine-knot which places it in the CAN subfamily of BMP antagonists along with the other DAN family proteins. COCO binds and inhibits Xnr1, BMP-4, Activin, and Wnt-8. In mouse, COCO expression is elevated on the right side of Henson’s node at the early somite stage, in contrast to the left side expression of Nodal (8) . COCO may cooperate with Nodal in gastrulation and embryonic left-right axis formation.