SPTLC3
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:19416851, PubMed:19648650). The SPT complex is composed of SPTLC1, SPTLC2 or SPTLC3 and SPTSSA or SPTSSB. Within this complex, the heterodimer consisting of SPTLC1 and SPTLC2/SPTLC3 forms the catalytic core. The composition of the serine palmitoyltransferase (SPT) complex determines the substrate preference (PubMed:19416851). 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 (PubMed:19416851, PubMed:19648650).
Pathway
Lipid metabolism; sphingolipid metabolism.
Sequence Similarities
Belongs to the class-II pyridoxal-phosphate-dependent aminotransferase family.
Tissue Specificity
Expressed in most tissues, except peripheral blood cells and bone marrow, with highest levels in heart, kidney, liver, uterus and skin.
Cellular localization
- Endoplasmic reticulum membrane
- Single-pass membrane protein
Alternative names
C20orf38, SPTLC2L, SPTLC3, Serine palmitoyltransferase 3, Long chain base biosynthesis protein 2b, Long chain base biosynthesis protein 3, Serine-palmitoyl-CoA transferase 3, LCB2b, LCB 3, SPT 3