Sphingomyelin Synthase 1 (SGMS1)

Sphingomyelin (SM) is a major component of plasma membranes. It is preferentially concentrated in the outer leaflet and has a role in the formation of lipid rafts. SM synthases, such as SGMS1, produce SM through the transfer of phosphocholine from phosphatidylcholine onto ceramide, yielding diacylglycerol as a side prod. The deduced 413-amino acid protein has an N-terminal SAM domain, 5 transmembrane domains, and an acid phosphatase-like domain that overlaps transmembrane domains 4 and 5. The N terminus, including the SAM domain, is predicted to be oriented into the cytoplasm. Northern blot analysis detected a transcript of over 3 kb highly expressed in cerebellum and forebrain cortex. EST database analysis suggested that MOB has more widespread expression.