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MGP006897

UniProt Annotations

Entry Information
Gene Namesphingomyelin synthase 1
Protein EntrySMS1_HUMAN
UniProt IDQ86VZ5
SpeciesHuman
Comments
Comment typeDescription
Alternative ProductsEvent=Alternative splicing; Named isoforms=2; Name=1; IsoId=Q86VZ5-1; Sequence=Displayed; Name=2; IsoId=Q86VZ5-2; Sequence=VSP_027223, VSP_027224;
Catalytic ActivityA ceramide + a phosphatidylcholine = a sphingomyelin + a 1,2-diacyl-sn-glycerol.
Enzyme RegulationInhibited by bacterial PC-phospholipase C inhibitor D609. {ECO:0000269|PubMed:14685263}.
FunctionSphingomyelin synthases synthesize the sphingolipid, sphingomyelin, through transfer of the phosphatidyl head group, phosphatidylcholine, on to the primary hydroxyl of ceramide. The reaction is bidirectional depending on the respective levels 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 in order to be recognized efficiently as a substrate. Major form in macrophages. Required for cell growth in certain cell types such as HeLa cells. Suppresses BAX-mediated apoptosis and also prevents cell death in response to stimuli such as hydrogen peroxide, osmotic stress, elevated temperature and exogenously supplied sphingolipids. May protect against cell death by reversing the stress-inducible increase in levels of proapoptotic ceramide. {ECO:0000269|PubMed:14685263, ECO:0000269|PubMed:17449912}.
MiscellaneousOverexpression of the human protein in mouse causes increased non-HDL-sphingomyelin and non-HDL cholesterol levels, decreased HDL-sphingomyelin and HDL-cholesterol levels and increases lipoprotein atherogenic potential.
Sequence CautionSequence=AAH42899.1; Type=Miscellaneous discrepancy; Note=Unusual initiator. The initiator methionine is coded by a non-canonical CTG leucine codon.; Evidence={ECO:0000305}; Sequence=AAP37279.1; Type=Miscellaneous discrepancy; Note=Unusual initiator. The initiator methionine is coded by a non-canonical CTG leucine codon.; Evidence={ECO:0000305}; Sequence=AAQ22363.1; Type=Miscellaneous discrepancy; Note=Unusual initiator. The initiator methionine is coded by a non-canonical CTG leucine codon.; Evidence={ECO:0000305}; Sequence=AAQ82051.1; Type=Miscellaneous discrepancy; Note=Unusual initiator. The initiator methionine is coded by a non-canonical CTG leucine codon.; Evidence={ECO:0000305}; Sequence=AK026683; Type=Miscellaneous discrepancy; Note=Unusual initiator. The initiator methionine is coded by a non-canonical CTG leucine codon.; Evidence={ECO:0000305}; Sequence=BAD16809.1; Type=Miscellaneous discrepancy; Note=Unusual initiator. The initiator methionine is coded by a non-canonical CTG leucine codon.; Evidence={ECO:0000305}; Sequence=CAD79708.1; Type=Miscellaneous discrepancy; Note=Unusual initiator. The initiator methionine is coded by a non-canonical CTG leucine codon.; Evidence={ECO:0000305};
SimilarityBelongs to the sphingomyelin synthase family. {ECO:0000305}.
SimilarityContains 1 SAM (sterile alpha motif) domain. {ECO:0000255|PROSITE-ProRule:PRU00184}.
Subcellular LocationGolgi apparatus membrane {ECO:0000269|PubMed:14685263, ECO:0000269|PubMed:17449912, ECO:0000269|PubMed:18694848}; Multi-pass membrane protein {ECO:0000269|PubMed:14685263, ECO:0000269|PubMed:17449912, ECO:0000269|PubMed:18694848}.
Tissue SpecificityBrain, heart, kidney, liver, muscle and stomach. {ECO:0000269|PubMed:11841947, ECO:0000269|PubMed:14685263, ECO:0000269|PubMed:15315829}.
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