Smad Nuclear Interacting Protein 1 (SNIP1)

The deduced 396-amino acid protein has a calculated molecular mass of about 50 kD. SNIP1 contains an N-terminal bipartite nuclear localization signal and a C-terminal forkhead-associated domain. Northern blot analysis detected transcripts of 4.4, 2.4, and 1.5 kb in all tissues examined, with highest expression in heart and skeletal muscle. Western blot analysis of several cell lines showed that SNIP1 has an apparent molecular mass of about 50 kD. Western blot analysis of multiple adult mouse tissues detected Snip1 in all tissues examined. Immunohistochemical analysis of rat kidney sections detected Snip1 localized specifically to epithelial elements. Indirect immunofluorescence demonstrated that mouse Snip1 localized to the nucleus in a mouse mammary cell line.