Structural basis of phosphatidylcholine recognition by the C2-domain of cytosolic phospholipase A2alpha.Hirano, Y., Gao, Y.G., Stephenson, D.J., Vu, N.T., Malinina, L., Simanshu, D.K., Chalfant, C.E., Patel, D.J., Brown, R.E.
(2019) Elife 8: --
- PubMed: 31050338
- DOI: 10.7554/eLife.44760
- PubMed Abstract:
Ca <sup>2+ </sup>-stimulated translocation of cytosolic phospholipase A <sub>2 </sub>α (cPLA <sub>2 </sub>α) to the Golgi induces arachidonic acid production, the rate-limiting step in pro-inflammatory eicosanoid synthesis. Structural insights into t ...
Ca 2+ -stimulated translocation of cytosolic phospholipase A 2 α (cPLA 2 α) to the Golgi induces arachidonic acid production, the rate-limiting step in pro-inflammatory eicosanoid synthesis. Structural insights into the cPLA 2 α preference for phosphatidylcholine (PC)-enriched membranes have remained elusive. Here, we report cPLA 2 α C2-domain structure (2.2Å resolution) containing bound 1,2-dihexanoyl- sn -glycero-3-phosphocholine (DHPC) and Ca 2+ ions. Two Ca 2+ are complexed at locations previously reported for lipid-free C2-domain. One of these Ca 2+ along with a third Ca 2+ bridge the C2-domain to the DHPC phosphate group, which also interacts with Asn65. Tyr96 plays a key role in lipid headgroup recognition via cation-π interaction with the PC trimethylammonium group. Mutagenesis analyses confirm Tyr96 and Asn65 function in PC binding selectivity by C2-domain and regulation of cPLA 2 α activity. The differing DHPC-binding mode of cPLA 2 α C2-domain, compared to phosphatidylserine or phosphatidylinositol 4,5-bisphosphate binding by other C2-domains, expands and deepens knowledge of lipid-binding mechanisms mediated by C2-domains.
Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, United States.,Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, United States.,Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, United States.,Hormel Institute, University of Minnesota, Austin, United States.