The molecular basis of ceramide-1-phosphate recognition by C2 domains[S]

• Published in: Journal of lipid research Vol. 54; no. 3; pp. 636 - 648
• Main Authors: Ward, Katherine E., Bhardwaj, Nitin, Vora, Mohsin, Chalfant, Charles E., Lu, Hui, Stahelin, Robert V.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2013; The American Society for Biochemistry and Molecular Biology; Elsevier
• Subjects: calcium; Calcium - metabolism; Ceramides - metabolism; cytosolic phospholipase A2α; eicosanoids; Eicosanoids - metabolism; Group IV Phospholipases A2 - chemistry; Group IV Phospholipases A2 - metabolism; lipid binding; membrane binding; Molecular Dynamics Simulation; Protein Binding; eicosanoids; cytosolic phospholipase A2α; calcium; lipid binding; membrane binding
• ISSN: 0022-2275; 1539-7262
• DOI: 10.1194/jlr.M031088

Group IVA cytosolic phospholipase A2 (cPLA2α), which harbors an N-terminal lipid binding C2 domain and a C-terminal lipase domain, produces arachidonic acid from the sn-2 position of zwitterionic lipids such as phosphatidylcholine. The C2 domain has been shown to bind zwitterionic lipids, but more recently, the anionic phosphomonoester sphingolipid metabolite ceramide-1-phosphate (C1P) has emerged as a potent bioactive lipid with high affinity for a cationic patch in the C2 domain β-groove. To systematically analyze the role that C1P plays in promoting the binding of cPLA2α-C2 to biological membranes, we employed biophysical measurements and cellular translocation studies along with mutagenesis. Biophysical and cellular translocation studies demonstrate that C1P specificity is mediated by Arg59, Arg61, and His62 (an RxRH sequence) in the C2 domain. Computational studies using molecular dynamics simulations confirm the origin of C1P specificity, which results in a spatial shift of the C2 domain upon membrane docking to coordinate the small C1P headgroup. Additionally, the hydroxyl group on the sphingosine backbone plays an important role in the interaction with the C2 domain, further demonstrating the selectivity of the C2 domain for C1P over phosphatidic acid. Taken together, this is the first study demonstrating the molecular origin of C1P recognition.