Cytosolic phospholipase A2
https://www.uniprot.org/uniprot/P47712
Has primarily calcium-dependent phospholipase and lysophospholipase activities, with a major role in membrane lipid remodeling and biosynthesis of lipid mediators of the inflammatory response (PubMed:7794891, PubMed:8619991, PubMed:8702602, PubMed:9425121, PubMed:10358058, PubMed:14709560, PubMed:16617059, PubMed:17472963, PubMed:27642067, PubMed:18451993).
Plays an important role in embryo implantation and parturition through its ability to trigger prostanoid production (By similarity).
Preferentially hydrolyzes the ester bond of the fatty acyl group attached at sn-2 position of phospholipids (phospholipase A2 activity) (PubMed:7794891, PubMed:8619991, PubMed:9425121, PubMed:10358058, PubMed:17472963, PubMed:18451993).
Selectively hydrolyzes sn-2 arachidonoyl group from membrane phospholipids, providing the precursor for eicosanoid biosynthesis via the cyclooxygenase pathway (PubMed:18451993, PubMed:7794891, PubMed:9425121, PubMed:10358058, PubMed:17472963).
In an alternative pathway of eicosanoid biosynthesis, hydrolyzes sn-2 fatty acyl chain of eicosanoid lysophopholipids to release free bioactive eicosanoids (PubMed:27642067).
Hydrolyzes the ester bond of the fatty acyl group attached at sn-1 position of phospholipids (phospholipase A1 activity) only if an ether linkage rather than an ester linkage is present at the sn-2 position. This hydrolysis is not stereospecific (PubMed:7794891).
Has calcium-independent phospholipase A2 and lysophospholipase activities in the presence of phosphoinositides (PubMed:12672805).
Has O-acyltransferase activity. Catalyzes the transfer of fatty acyl chains from phospholipids to a primary hydroxyl group of glycerol (sn-1 or sn-3), potentially contributing to monoacylglycerol synthesis (PubMed:7794891).
Activity regulation
Activated by cytosolic calcium, which is necessary for binding to membrane lipids (PubMed:12672805). Activated by phosphorylation in response to mitogenic stimuli (PubMed:8381049). Activated by ceramide-1-phosphate. Binding (via C2 domain) to ceramide-1-phosphate increases the affinity for membrane lipids (PubMed:17472963). Can be activated by phosphoinositides in the absence of calcium (PubMed:12672805). Inhibited by ANXA5 in a calcium- and substrate-dependent way (PubMed:9425121).
Tissue specificity
Expressed in various cells and tissues such as macrophages, neutrophils, fibroblasts and lung endothelium. Expressed in platelets (at protein level) (PubMed:25102815).
85/88 kDa calcium-independent phospholipase A2
https://www.uniprot.org/uniprot/O60733
Calcium-independent phospholipase involved in phospholipid remodeling with implications in cellular membrane homeostasis, mitochondrial integrity and signal transduction. Hydrolyzes the ester bond of the fatty acyl group attached at sn-1 or sn-2 position of phospholipids (phospholipase A1 and A2 activity respectively), producing lysophospholipids that are used in deacylation-reacylation cycles (PubMed:9417066, PubMed:10092647, PubMed:10336645, PubMed:20886109).
Hydrolyzes both saturated and unsaturated long fatty acyl chains in various glycerophospholipid classes such as phosphatidylcholines, phosphatidylethanolamines and phosphatidates, with a preference for hydrolysis at sn-2 position (PubMed:10092647, PubMed:10336645, PubMed:20886109).
Can further hydrolyze lysophospholipids carrying saturated fatty acyl chains (lysophospholipase activity) (PubMed:20886109).
Upon oxidative stress, contributes to remodeling of mitochondrial phospholipids in pancreatic beta cells, in a repair mechanism to reduce oxidized lipid content (PubMed:23533611).
Preferentially hydrolyzes oxidized polyunsaturated fatty acyl chains from cardiolipins, yielding monolysocardiolipins that can be reacylated with unoxidized fatty acyls to regenerate native cardiolipin species (By similarity).
Hydrolyzes oxidized glycerophosphoethanolamines present in pancreatic islets, releasing oxidized polyunsaturated fatty acids such as hydroxyeicosatetraenoates (HETEs) (By similarity).
Has thioesterase activity toward fatty-acyl CoA releasing CoA-SH known to facilitate fatty acid transport and beta-oxidation in mitochondria particularly in skeletal muscle (PubMed:20886109).
Plays a role in regulation of membrane dynamics and homeostasis. Selectively hydrolyzes sn-2 arachidonoyl group in plasmalogen phospholipids, structural components of lipid rafts and myelin (By similarity).
Regulates F-actin polymerization at the pseudopods, which is required for both speed and directionality of MCP1/CCL2-induced monocyte chemotaxis (PubMed:18208975).
Targets membrane phospholipids to produce potent lipid signaling messengers. Generates lysophosphatidate (LPA, 1-acyl-glycerol-3-phosphate), which acts via G-protein receptors in various cell types (By similarity).
Has phospholipase A2 activity toward platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine), likely playing a role in inactivation of this potent proinflammatory signaling lipid (By similarity).
In response to glucose, amplifies calcium influx in pancreatic beta cells to promote INS secretion (By similarity).
Activity regulation
Activated by ATP (PubMed:10092647). Inhibited by calcium-activated calmodulin (By similarity). Inhibited by bromoenol lactone (BEL) (By similarity).
Phospholipase A2
https://www.uniprot.org/uniprot/P04054
Secretory calcium-dependent phospholipase A2 that primarily targets dietary phospholipids in the intestinal tract (PubMed:1420353, PubMed:10681567, PubMed:17603006).
Hydrolyzes the ester bond of the fatty acyl group attached at sn-2 position of phospholipids (phospholipase A2 activity) with preference for phosphatidylethanolamines and phosphatidylglycerols over phosphatidylcholines (PubMed:1420353, PubMed:10681567, PubMed:17603006).
May play a role in the biosynthesis of N-acyl ethanolamines that regulate energy metabolism and inflammation in the intestinal tract. Hydrolyzes N-acyl phosphatidylethanolamines to N-acyl lysophosphatidylethanolamines, which are further cleaved by a lysophospholipase D to release N-acyl ethanolamines (By similarity).
May act in an autocrine and paracrine manner (PubMed:7721806, PubMed:25335547).
Upon binding to the PLA2R1 receptor can regulate podocyte survival and glomerular homeostasis (PubMed:25335547).
Has anti-helminth activity in a process regulated by gut microbiota. Upon helminth infection of intestinal epithelia, directly affects phosphatidylethanolamine contents in the membrane of helminth larvae, likely controlling an array of phospholipid-mediated cellular processes such as membrane fusion and cell division while providing for better immune recognition, ultimately reducing larvae integrity and infectivity (By similarity).
Activity regulationi
Regulated by bile acid salts. Up-regulated by cholate and down-regulated by taurochenodeoxycholate. Cholate-activated rate of hydrolysis is lowered by hypolipidemic drug ezetimibe.
