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cytosolic phospholipase A2; phospholipase A2 group IVA; includes: phospholipase A2; phosphatidylcholine 2-acylhydrolase; lysophospholipase (PLA2G4A, PLA2G4)

Function: - selectively hydrolyzes arachidonyl phospholipids in the sn-2 position releasing arachidonic acid - together with its lysophospholipid activity, implicated in initiation of the inflammatory response - stimulated by agonists such as ATP, EGF, thrombin & bradykinin as well as by cytosolic Ca+2 - activated by phosphorylation at both Ser-505 & Ser-727 - interacts with KAT5 phosphatidylcholine + H2O = 1-acylglycerophosphocholine + a carboxylate 2-lysophosphatidylcholine + H2O = glycerophosphocholine + a carboxylate Kinetic parameters: - Vmax=2.7 umol/min/mg enzyme for the phospholipase A2 reaction - Vmax=4.6 umol/min/mg enzyme for the lysophosphatase reaction Structure: - the N-terminal C2 domain - associates with lipid membranes upon Ca+2 binding - modulates enzyme activity by presenting the active site to its substrate in response to increases in cytosolic Ca+2 - contains 1 C2 domain - contains 1 PLA2c domain Compartment: - cytoplasm, cytoplasmic vesicle - translocation from cytoplasm to membrane vesicles (Ca+2-dependent) Expression: - expressed in macrophages, platelets, neutrophils, fibroblasts & lung endothelium

General

lysophospholipase phospholipase-A2 [PLA2] type 4; cytoplasmic phospholipase A2 (cPLA2)

Properties

SIZE: entity length = 749 aa MW = 85 kD COMPARTMENT: cytoplasm MOTIF: Phospholipid binding {1-178} MOTIF: C2 domain {5-106} MOTIF: binding site FOR-BINDING-OF: phospholipid Ca+2-binding site Ca+2-binding site SITE: 40-40 Ca+2-binding site SITE: 41-41 Ca+2-binding site SITE: 43-43 Ca+2-binding site SITE: 65-65 Ca+2-binding site SITE: 93-93 Ca+2-binding site SITE: 94-94 Ca+2-binding site SITE: 95-95 PLA2c {140-740} MOTIF: serine residue {S228} Thr phosphorylation site {T268} Ser phosphorylation site {S434} Ser phosphorylation site {S435} Ser phosphorylation site {S437} Ser phosphorylation site {S505} Tyr phosphorylation site {Y535} aspartate residue {D549} Ser phosphorylation site {S727} Ser phosphorylation site {S729}

Database Correlations

OMIM 600522 MORBIDMAP 600522 UniProt P47712 PFAM correlations Entrez Gene 5321 KEGG correlations ENZYME correlations

References

  1. UniProt :accession P47712
  2. NIEHS-SNPs http://egp.gs.washington.edu/data/pla2g4a/