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 126.96.36.199, 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
1. Ullman, M.D. and Radin, N.S. The enzymatic formation of sphingomyelin from ceramide and lecithin in mouse liver. J. Biol. Chem. 249 (1974) 1506-1512. [PMID: 4817756]
2. Voelker, D.R. and Kennedy, E.P. Cellular and enzymic synthesis of sphingomyelin. Biochemistry 21 (1982) 2753-2759. [PMID: 7093220]
3. Huitema, K., van den Dikkenberg, J., Brouwers, J.F. and Holthuis, J.C. Identification of a family of animal sphingomyelin synthases. EMBO J. 23 (2004) 33-44. [PMID: 14685263]
4. Tafesse, F.G., Ternes, P. and Holthuis, J.C. The multigenic sphingomyelin synthase family. J. Biol. Chem. 281 (2006) 29421-29425. [PMID: 16905542]
5. Yamaoka, S., Miyaji, M., Kitano, T., Umehara, H. and Okazaki, T. Expression cloning of a human cDNA restoring sphingomyelin synthesis and cell growth in sphingomyelin synthase-defective lymphoid cells. J. Biol. Chem. 279 (2004) 18688-18693. [PMID: 14976195]