Nephronectin (NPNT)

Nephronectin contains 561 amino acids. In situ hybridization detected nephronectin in the developing mouse kidney and in several other tissues and organs. Expression appeared particularly prominent at epithelial-mesenchymal interfaces in tissues undergoing morphogenesis.

The deduced 565- and 582-amino acid proteins have calculated molecular masses of 61.9 and 64.0 kD, respectively. Both proteins contain an N-terminal signal sequence, followed by 5 EGF domains, and a C-terminal MAM domain. They also contain an RGD integrin-binding site, a potential glycosylation site, and a potential tyrosine phosphorylation site. EGF repeats 2, 4, and 5 contain Ca(2+)-binding EGF domains. In the longer variant, the 17 additional amino acids are inserted N-terminal to the first EGF domain.