The serine C-palmitoyltransferase complex catalyses the condensation of L-serine with palmitoyl-CoA to form 3-ketosphinganine, the sphingoid base which is the starting point for all sphingolipids. The eukaryotic complex consists of catalytic components (SPTLC1, SPTLC2 and SPTLC3 in humans) and regulatory components, which include activators (SPTSSA/SPTSSB in humans) and negative regulators (ORMDL1/ORMDL2/ORMDL3 in humans). (Adapted from
PMID:29863195,
PMID:33558761.)