Structure of Human GIVD Cytosolic Phospholipase A2 Reveals Insights into Substrate Recognition. Issue 13 (3rd July 2016)

• Record Type: Journal Article
• Authors: Wang, Hui; Klein, Michael G.; Snell, Gyorgy; Lane, Weston; Zou, Hua; Levin, Irena; Li, Ke; Sang, Bi-Ching
• Is Part Of: Journal of molecular biology. Volume 428:Issue 13(2016:Jul. 01)
• Page Start: 2769
• Page End: 2779
• Publication Date: 2016-07-03
• Subjects: cPLA2 cytosolic phospholipase A2 -- GIV group IV -- MγLnFP methyl γ-linolenyl fluorophosphonate -- MAFP methyl arachidonyl fluorophosphonate -- MGLP methyl γ-linolenylphosphonate -- SAD single-wavelength anomalous diffraction -- SeMet selenomethionine -- CBL calcium-binding loop; cPLA2 -- α/β hydrolase -- inhibitor -- C2 domain -- calcium binding; Molecular biology -- Periodicals; Biology -- Periodicals; Biochemistry -- Periodicals; Bacteriology -- Periodicals; Molecular Biology -- Periodicals; Biochemistry -- Periodicals; Biologie moléculaire -- Périodiques; Biologie -- Périodiques; Biochimie -- Périodiques; Moleculaire biologie; Biochemistry; Biology; Molecular biology; Periodicals; 572.805
• DOI: 10.1016/j.jmb.2016.05.012
• Languages: English
• ISSNs: 0022-2836

Abstract

Abstract: Cytosolic phospholipases A2 (cPLA2 s) consist of a family of calcium-sensitive enzymes that function to generate lipid second messengers through hydrolysis of membrane-associated glycerophospholipids. The GIVD cPLA2 (cPLA2 δ) is a potential drug target for developing a selective therapeutic agent for the treatment of psoriasis. Here, we present two X-ray structures of human cPLA2 δ, capturing an apo state, and in complex with a substrate-like inhibitor. Comparison of the apo and inhibitor-bound structures reveals conformational changes in a flexible cap that allows the substrate to access the relatively buried active site, providing new insight into the mechanism for substrate recognition. The cPLA2 δ structure reveals an unexpected second C2 domain that was previously unrecognized from sequence alignments, placing cPLA2 δ into the class of membrane-associated proteins that contain a tandem pair of C2 domains. Furthermore, our structures elucidate novel inter-domain interactions and define three potential calcium-binding sites that are likely important for regulation and activation of enzymatic activity. These findings provide novel insights into the molecular mechanisms governing cPLA2 's function in signal transduction. Graphical Abstract: Highlights: The first crystal structure of cytosolic phospholipase A2 bound to an inhibitor The first crystal structure of GIVD cytosolic phospholipase A2 An unexpected three-domain architecture consisting of two C2 domains and one catalytic domain Unique inhibitor-binding or substrate-binding pocket Striking inhibitor-induced conformational changes Novel inter-domain interface between the C2 domains and the catalytic domain