Phospholipase A2, Group IVB (PLA2G4B)

Cytosolic phospholipase A2 (CPLA2) initiates the production of inflammatory mediators by hydrolyzing the sn-2 bond of phospholipids, releasing arachidonic acid.The PLA2G4B protein contains a C2 calcium- and lipid-binding domain and shares approximately 30% sequence identity with PLA2G4A and PLA2G4C, including total conservation of 4 catalytically essential residues. Using a baculovirus system, Pickard et al. (1999) demonstrated calcium-dependent enzymatic activity. Northern blot analysis detected low level expression of an unspliced 8.5-kb PLA2G4B mRNA in a broad range of human tissues, with strongest expression in cerebellum and pancreas. RT-PCR analysis detected a spliced 3-kb transcript in brain.