a calcium-dependent phospholipase A2 that catalyzes the release of arachidonic acid from membrane phospholipids. Selectively hydrolyzes arachidonyl phospholipids in the sn-2 position releasing arachidonic acid. Arachidonic acid is a precursor for the eicosanoids that are involved in hemodynamic regulation, inflammatory responses, and other cellular processes. Promotes cerebellar long-term depression and motor learning. Translocates to the Golgi and endoplasmic reticulum in a calcium-dependent fashion. Translocation and activation of at the ER facilitates the process of ER stress. Regulates the biogenesis of lipid droplets, a process dependent on JNK and ceramide kinase. Stimulated by agonists such as ATP, EGF, thrombin and bradykinin as well as by cytosolic Ca2+. The N-terminal C2 domain, by its association with lipid membranes, mediates the regulation of CPLA2 by presenting the active site to its substrate in response to elevations of cytosolic Ca2+. Inhibited when in trimolecular complex with ANXA2 and S100A10. Phosphorylation of S727 relieves this inhibitory interaction, thus activating PLA2G4A. Note: This description may include information from UniProtKB.