Reaction: a ceramide + a phosphatidylcholine = a sphingomyelin + a 1,2-diacyl-sn-glycerol
For diagram click here.
Glossary: sphingomyelin = a ceramide-1-phosphocholine
ceramide = an N-acylsphingoid. The fatty acids of naturally occurring ceramides range in chain length from about C16 to about C26 and may contain one or more double bonds and/or hydroxy substituents at C-2
sphingoid = sphinganine, i.e. D-erythro-2-aminooctadecane-1,3-diol, and its homologues and stereoisomers (see also Lip-1.4)
Other name(s): SM synthase; SMS1; SMS2
Systematic name: ceramide:phosphatidylcholine cholinephosphotransferase
Comments: The reaction can occur in both directions . This enzyme occupies a central position in sphingolipid and glycerophospholipid metabolism . Up- and down-regulation of its activity has been linked to mitogenic and pro-apoptotic signalling in a variety of mammalian cell types . Unlike EC 18.104.22.168, ceramide cholinephosphotransferase, CDP-choline cannot replace phosphatidylcholine as the donor of the phosphocholine moiety of sphingomyelin .
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 58703-97-2
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