ID   2.7.8.27
DE   sphingomyelin synthase.
AN   phosphatidylcholine:ceramide cholinephosphotransferase.
AN   SM synthase.
CA   a 1,2-diacyl-sn-glycero-3-phosphocholine + an N-acylsphing-4-enine =
CA   a 1,2-diacyl-sn-glycerol + a sphingomyelin.
CC   -!- The reaction can occur in both directions.
CC   -!- Occupies a central position in sphingolipid and glycerophospholipid
CC       metabolism.
CC   -!- Up- and down-regulation of its activity has been linked to mitogenic
CC       and pro-apoptotic signaling in a variety of mammalian cell types.
CC   -!- Unlike EC 2.7.8.3 CDP-choline cannot replace phosphatidylcholine as
CC       the donor of the phosphocholine moiety of sphingomyelin.
DR   B3A0L9, SLS1_TRYBB ;  Q38E55, SLS3_TRYB2 ;  B3A0M1, SLS3_TRYBB ;
DR   Q38E56, SLS4_TRYB2 ;  B3A0M2, SLS4_TRYBB ;  Q9U3D4, SMS1_CAEEL ;
DR   Q7T3T4, SMS1_CHICK ;  Q86VZ5, SMS1_HUMAN ;  Q8VCQ6, SMS1_MOUSE ;
DR   A0AAS4, SMS1_PIG   ;  Q7TSX5, SMS1_RAT   ;  Q20735, SMS2_CAEEL ;
DR   Q8NHU3, SMS2_HUMAN ;  Q4R763, SMS2_MACFA ;  Q9D4B1, SMS2_MOUSE ;
DR   Q4JM44, SMS2_RAT   ;  Q965Q4, SMS3_CAEEL ;
//