title: Identification of the major prostaglandin glycerol ester hydrolase in human cancer cells.
abstract: Prostaglandin glycerol esters (PG-Gs) are produced as a result of the oxygenation of the endocannabinoid, 2-arachidonoylglycerol, by cyclooxygenase 2. Understanding the role that PG-Gs play in a biological setting has been difficult because of their sensitivity to enzymatic hydrolysis. By comparing PG-G hydrolysis across human cancer cell lines to serine hydrolase activities determined by activity-based protein profiling, we identified lysophospholipase A2 (LYPLA2) as a major enzyme responsible for PG-G hydrolysis. The principal role played by LYPLA2 in PGE2-G hydrolysis was confirmed by siRNA knockdown. Purified recombinant LYPLA2 hydrolyzed PG-Gs in the following order of activity: PGE2-G > PGF2α-G > PGD2-G; LYPLA2 hydrolyzed 1- but not 2-arachidonoylglycerol or arachidonoylethanolamide. Chemical inhibition of LYPLA2 in the mouse macrophage-like cell line, RAW264.7, elicited an increase in PG-G production. Our data indicate that LYPLA2 serves as a major PG-G hydrolase in human cells. Perturbation of this enzyme should enable selective modulation of PG-Gs without alterations in endocannabinoids, thereby providing a means to decipher the unique functions of PG-Gs in biology and disease.
authors.affiliation: From the A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 and.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Manna
authors.affiliation: From the A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 and.
authors.forename: James A
authors.initials: JA
authors.lastname: Wepy
authors.affiliation: the Skaggs Institute for Chemical Biology and the Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California 92037.
authors.forename: Ku-Lung
authors.initials: KL
authors.lastname: Hsu
authors.affiliation: the Skaggs Institute for Chemical Biology and the Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California 92037.
authors.forename: Jae Won
authors.initials: JW
authors.lastname: Chang
authors.affiliation: the Skaggs Institute for Chemical Biology and the Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California 92037.
authors.forename: Benjamin F
authors.initials: BF
authors.lastname: Cravatt
authors.affiliation: From the A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 and larry.marnett@vanderbilt.edu.
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Marnett
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism; D045744:Cell Line, Tumor; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D063388:Endocannabinoids / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D004952:Esters; D015972:Gene Expression Regulation, Neoplastic; D005989:Glycerides / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D008264:Macrophages / Q000166:cytology / Q000201:enzymology*; D051379:Mice; D053284:Polyunsaturated Alkamides / Q000378:metabolism; D011453:Prostaglandins / Q000737:chemistry / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013379:Substrate Specificity; D013869:Thiolester Hydrolases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001095:Arachidonic Acids; D063388:Endocannabinoids; D004952:Esters; D005989:Glycerides; D053284:Polyunsaturated Alkamides; D011453:Prostaglandins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; C094503:glyceryl 2-arachidonate; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; C581317:LYPLA2 protein, human; D013869:Thiolester Hydrolases; D005990:Glycerol; C078814:anandamide
keywords: Activity-based Protein Profiling; Cancer; Chemical Biology; Endocannabinoids; Enzyme Kinetics; Lipid Metabolism; Prostaglandin; Prostaglandin Glycerol Esters; Serine Hydrolase