Phospholipase A2 group XIIB (PLA2G12B)

Phospholipase A2 group XIIB (PLA2G12B) is a member of the secreted phospholipase A2 (sPLA2) gene family but has evolved a distinct, non-catalytic role in regulating triglyceride-rich lipoprotein (TRL) expansion. PLA2G12B is tightly associated with the endoplasmic reticulum (ER) membrane and facilitates the loading of triglycerides into nascent apolipoprotein B-containing lipoproteins, thereby promoting efficient lipid secretion and maintaining cellular lipid homeostasis. Unlike other sPLA2s, PLA2G12B is not actively secreted into the extracellular space but is retained within the ER where it interacts with the membrane and proteins involved in lipoprotein assembly, such as the lipid transfer protein MTP. PLA2G12B is calcium-dependent and contains functional domains including a signal peptide, an ER-retention motif, hydrophobic membrane anchor sequences, and a calcium-binding domain. Mutations disrupting PLA2G12B lead to reduced secretion of triglyceride-rich lipoproteins, excess intracellular lipid accumulation, profound hypolipidemia, and resistance to atherosclerosis in animal models, highlighting its significance in preventing cardiovascular disease and metabolic disorders.

Other names

Group XIIB secretory phospholipase A2-like proteinPLA2G12BPLA2G13FKSG71GXIII sPLA2-likeGXIIBGroup XIII secretory phospholipase A2-like proteinsPLA2-GXIIBGXIIIsPLA2group XIIB secretory phospholipase A2-like proteingroup XIII secreted phospholipase A2phospholipase A2, group XIII