Phosphatidylcholine:ceramide cholinephosphotransferase 1 (Sgms1)

Sphingomyelin synthases synthesize the sphingolipid, sphingomyelin, through transfer of the phosphatidyl head group, phosphatidylcholine, on to the primary hydroxyl of ceramide. The reaction is bidirectional based on the respective heights of the sphingolipid and ceramide.

Golgi apparatus SMS1 directly and specifically recognizes the choline head group on the substrate, requiring two fatty chains on the choline-P donor molecule so as to be recognized efficiently as a substrate. Major form in macrophages.