ID:SPTC1_HUMAN DESCRIPTION: RecName: Full=Serine palmitoyltransferase 1; EC=2.3.1.50; AltName: Full=Long chain base biosynthesis protein 1; Short=LCB 1; AltName: Full=Serine-palmitoyl-CoA transferase 1; Short=SPT 1; Short=SPT1; FUNCTION: Serine palmitoyltransferase (SPT). The heterodimer formed with SPTLC2 or SPTLC3 constitutes the catalytic core. The composition of the serine palmitoyltransferase (SPT) complex determines the substrate preference. The SPTLC1-SPTLC2-SPTSSA complex shows a strong preference for C16-CoA substrate, while the SPTLC1-SPTLC3-SPTSSA isozyme uses both C14-CoA and C16-CoA as substrates, with a slight preference for C14-CoA. The SPTLC1- SPTLC2-SPTSSB complex shows a strong preference for C18-CoA substrate, while the SPTLC1-SPTLC3-SPTSSB isozyme displays an ability to use a broader range of acyl-CoAs, without apparent preference. CATALYTIC ACTIVITY: Palmitoyl-CoA + L-serine = CoA + 3-dehydro-D- sphinganine + CO(2). COFACTOR: Pyridoxal phosphate (By similarity). BIOPHYSICOCHEMICAL PROPERTIES: Kinetic parameters: KM=0.75 mM for serine; Vmax=1350 pmol/min/mg enzyme; PATHWAY: Lipid metabolism; sphingolipid metabolism. SUBUNIT: Heterodimer with SPTLC2 or SPTLC3. Component of the serine palmitoyltransferase (SPT) complex, composed of SPTLC1, either SPTLC2 or SPTLC3, and either SSSPTA or SSSPTB. Interacts with SPTSSA and SPTSSB; the interaction is direct. Interacts with ORMDL3. SUBCELLULAR LOCATION: Endoplasmic reticulum membrane; Single-pass membrane protein (By similarity). TISSUE SPECIFICITY: Widely expressed. Not detected in small intestine. DISEASE: Defects in SPTLC1 are the cause of hereditary sensory and autonomic neuropathy type 1A (HSAN1A) [MIM:162400]. The hereditary sensory and autonomic neuropathies are a genetically and clinically heterogeneous group of disorders characterized by degeneration of dorsal root and autonomic ganglion cells, and by sensory and/or autonomic abnormalities. HSAN1A is an autosomal dominant axonal neuropathy with onset in the second or third decades. Initial symptoms are loss of pain, touch, heat, and cold sensation over the feet, followed by distal muscle wasting and weakness. Loss of pain sensation leads to chronic skin ulcers and distal amputations. SIMILARITY: Belongs to the class-II pyridoxal-phosphate-dependent aminotransferase family. CAUTION: Variant Ala-387 has been originally thought to cause HSAN1A (PubMed:15037712). Subsequently, it has been shown to be a rare, benign polymorphism found in homozygous state in a healthy individual (PubMed:19132419). WEB RESOURCE: Name=GeneReviews; URL="http://www.ncbi.nlm.nih.gov/sites/GeneTests/lab/gene/SPTLC1";
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
ModBase Predicted Comparative 3D Structure on O15269
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
Biological Process: GO:0006629 lipid metabolic process GO:0006665 sphingolipid metabolic process GO:0006686 sphingomyelin biosynthetic process GO:0009058 biosynthetic process GO:0030148 sphingolipid biosynthetic process GO:0046511 sphinganine biosynthetic process GO:0046512 sphingosine biosynthetic process GO:0046513 ceramide biosynthetic process GO:1904504 positive regulation of lipophagy
US Server
Sequence and Links to Tools and Databases 
Common Gene Haplotype Alleles 
