Sptlc1
Developmental stage
Highly expressed after birth, expression decreases 2 weeks after birth and is maintained until, at least, 18 months.
Domain
The transmembrane domain is involved in the interaction with ORMDL3.
Function
Component of the serine palmitoyltransferase multisubunit enzyme (SPT) that catalyzes the initial and rate-limiting step in sphingolipid biosynthesis by condensing L-serine and activated acyl-CoA (most commonly palmitoyl-CoA) to form long-chain bases (PubMed:28100772). The SPT complex is also composed of SPTLC2 or SPTLC3 and SPTSSA or SPTSSB. Within this complex, the heterodimer with SPTLC2 or SPTLC3 forms 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 (By similarity). Required for adipocyte cell viability and metabolic homeostasis (PubMed:28100772).
Pathway
Lipid metabolism; sphingolipid metabolism.
Post-translational modifications
Phosphorylation at Tyr-164 inhibits activity and promotes cell survival.
Sequence Similarities
Belongs to the class-II pyridoxal-phosphate-dependent aminotransferase family.
Tissue Specificity
Expressed in a variety of tissues. Highest expression in brain, kidney and liver (PubMed:21994399). Expressed in brown and white adipose tissues (PubMed:27818258).
Cellular localization
- Endoplasmic reticulum membrane
- Single-pass membrane protein
Alternative names
Lcb1, Sptlc1, Serine palmitoyltransferase 1, Long chain base biosynthesis protein 1, Serine-palmitoyl-CoA transferase 1, LCB 1, SPT 1, SPT1