LMPD Database

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LMP001377

UniProt Annotations

Entry Information
Gene Namesphingomyelin synthase 1
Protein EntryQ8VCQ6_MOUSE
UniProt IDQ8VCQ6
SpeciesMouse
Comments
Comment typeDescription
Alternative ProductsEvent=Alternative splicing; Named isoforms=3; Name=1; Synonyms=SMS1-alpha; IsoId=Q8VCQ6-1; Sequence=Displayed; Name=2; Synonyms=SMS1-beta; IsoId=Q8VCQ6-2; Sequence=VSP_050673; Name=3; Synonyms=SMS1-gamma; IsoId=Q8VCQ6-3; Sequence=VSP_027225, VSP_027226;
Catalytic ActivityA ceramide + a phosphatidylcholine = a sphingomyelin + a 1,2-diacyl-sn-glycerol.
Disruption PhenotypeNull mice have hearing impairments with stria vascularis (SV) in these mice exhibiting atrophy and disorganized marginal cells resulting in significantly smaller endocochlear potentials (EPs). These decreased EPs, together with abnormal KCNQ1 expression patterns, increase with age. There is a decrease in plasma, liver, and macrophage sphingomyelin (59%, 45%, and 54%, respectively) and a dramatic increase in glycosphingolipids. No change in ceramide, total cholesterol, phospholipids nor triglycerides levels. Diminished macrophage MAP kinase and NFKB1 activation is observed. Atherosclerosis in SMS1(-/-)/LDLR(-/-) mice is significantly decreased.
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 (By similarity). 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:0000250, ECO:0000269|PubMed:16879426, ECO:0000269|PubMed:22580896}.
InductionIsoform 1 and isoform 2 are induced by TNF-alpha.
SimilarityBelongs to the sphingomyelin synthase family.
SimilarityContains 1 SAM (sterile alpha motif) domain.
Subcellular LocationGolgi apparatus membrane ; Multi-pass membrane protein .
Tissue SpecificityIsoform 1 is widely expressed, isoform 2 shows a more narrow distribution and isoform 3 is detected only in testis and heart.