CUB And Sushi Multiple Domains Protein 1 (CSMD1)

The deduced 3,508-amino acid protein has a calculated molecular mass of 383 kD. It has an extracellular N terminus, which contains a signal peptide, followed by 14 alternating CUB and sushi domains, 13 additional tandem sushi domains, a transmembrane region, and a 63-amino acid C-terminal cytoplasmic tail, which contains several phosphorylation sites. CUB and sushi domains commonly have a multiple beta-strand structure held together in part by 2 conserved disulfide bonds. The CUB domains of CSMD1 depart from this model by having only 2 or 3 cysteines each instead of the canonical 4. The deduced 1,048-amino acid protein shares 33% identity with SEZ6L. Low expression was detected in testis, and little to no expression was detected in the other tissues examined.