Brother Of CDO Homolog (BOC)

The 1,113-amino acid BOC protein contains 4 Ig repeats, followed by 3 FNIII repeats, a single-pass transmembrane domain, and a 238-residue intracellular region. The domain structure of BOC is similar to that of CDON, and the 2 proteins share 38 to 80% amino acid identity in the individual extracellular domains. The intracellular region of BOC, however, is unrelated to that of CDON. In situ hybridization analysis revealed that, like Cdon, Boc was strongly expressed in dorsal neural tube, somites, and dermomyotomes during murine embryonic development. Northern blot analysis detected a 5-kb transcript in myoblasts in the absence of Ras (190020) transformation. BOC was expressed in most adult human tissues tested, with highest levels in skeletal muscle and small intestine.