Coupling between cyclooxygenases and prostaglandin F(2alpha) synthase. Detection of an inducible, glutathione-activated, membrane-bound prostaglandin F(2alpha)-synthetic activity.
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.
Nakashima
Karin
K
Department of Health Chemistry, School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan.
Ueno
Noriko
N
Kamei
Daisuke
D
Tanioka
Toshihiro
T
Nakatani
Yoshihito
Y
Murakami
Makoto
M
Kudo
Ichiro
I
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
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