title: Coupling between cyclooxygenases and prostaglandin F(2alpha) synthase. Detection of an inducible, glutathione-activated, membrane-bound prostaglandin F(2alpha)-synthetic activity.
abstract: Distinct functional coupling between cyclooxygenases (COXs) and specific terminal prostanoid synthases leads to phase-specific production of particular prostaglandins (PGs). In this study, we examined the coupling between COX isozymes and PGF synthase (PGFS). Co-transfection of COXs with PGFS-I belonging to the aldo-keto reductase family into HEK293 cells resulted in increased production of PGF(2alpha) only when a high concentration of exogenous arachidonic acid (AA) was supplied. However, this enzyme failed to produce PGF(2alpha) from endogenous AA, even though significant increase in PGF(2alpha) production occurred in cells transfected with COX-2 alone. This poor COX/PGFS-I coupling was likely to arise from their distinct subcellular localization. Measurement of PGF(2alpha)-synthetic enzyme activity in homogenates of several cells revealed another type of PGFS activity that was membrane-bound, glutathione (GSH)-activated, and stimulus-inducible. In vivo, membrane-bound PGFS activity was elevated in the lung of lipopolysaccharide-treated mice. Taken together, our results suggest the presence of a novel, membrane-associated form of PGFS that is stimulus-inducible and is likely to be preferentially coupled with COX-2.
authors.affiliation: Department of Health Chemistry, School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan.
authors.forename: Karin
authors.initials: K
authors.lastname: Nakashima
authors.forename: Noriko
authors.initials: N
authors.lastname: Ueno
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kamei
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Tanioka
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Nakatani
authors.forename: Makoto
authors.initials: M
authors.lastname: Murakami
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kudo
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015237:Dinoprost / Q000096:biosynthesis*; D005978:Glutathione / Q000494:pharmacology; D005982:Glutathione Transferase / Q000032:analysis; D006801:Humans; D006911:Hydroxyprostaglandin Dehydrogenases / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism; D019746:Intramolecular Oxidoreductases / Q000032:analysis; D007527:Isoenzymes / Q000737:chemistry* / Q000235:genetics; D008070:Lipopolysaccharides / Q000008:administration & dosage; D008168:Lung / Q000201:enzymology; D017737:Macrophages, Peritoneal / Q000201:enzymology; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D000071876:Prostaglandin-E Synthases; D011451:Prostaglandin-Endoperoxide Synthases / Q000737:chemistry* / Q000235:genetics; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D007527:Isoenzymes; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D016718:Arachidonic Acid; D015237:Dinoprost; D006911:Hydroxyprostaglandin Dehydrogenases; C031051:prostaglandin-F synthase; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; C496512:Ptgs1 protein, mouse; C122107:microsomal glutathione S-transferase-I; D005982:Glutathione Transferase; D019746:Intramolecular Oxidoreductases; D000071876:Prostaglandin-E Synthases; D005978:Glutathione