Augmentation of receptor-mediated adenylyl cyclase activity by Gi-coupled prostaglandin receptor subtype EP3 in a Gbetagamma subunit-independent manner.
We previously demonstrated that the mouse EP3beta receptor and its C-terminal tail-truncated receptor (abbreviated T-335) expressed in Chinese hamster ovary cells showed agonist-dependent and fully constitutive Gi activity in forskolin-stimulated cAMP accumulation, respectively. Here we examined the effect of the EP3beta receptor or T-335 receptor on adenylyl cyclase activity stimulated by the Gs-coupled EP2 subtype receptor in COS-7 cells. As a result, sulprostone, a selective EP3 agonist, dose dependently augmented butaprost-stimulated adenylyl cyclase activity in EP3beta receptor- or T-335 receptor-expressing COS-7 cells. However, such adenylyl cyclase augmentation was not attenuated by either pertussis toxin treatment or expression of the PH domain of rat betaARK1, which serves as a scavenger of Gbetagamma subunits, but was partially attenuated by treatment with either 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra(acetoxymethyl)ester, an intracellular Ca(2+) chelator, or W-7, a calmodulin inhibitor. These findings suggest that the C-terminal tail of the EP3beta receptor is not essentially involved in activation of EP2 receptor-stimulated adenylyl cyclase in a Ca(2+)/calmodulin-dependent but Gbetagamma subunit-independent manner.
Hatae
Noriyuki
N
Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606, Japan.
Yamaoka
Kumiko
K
Sugimoto
Yukihiko
Y
Negishi
Manabu
M
Ichikawa
Atsushi
A
D000244:Adenosine Diphosphate / Q000378:metabolism; D037361:Adenylate Cyclase Toxin; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000527:Alprostadil / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D019556:COS Cells; D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002614:Chelating Agents / Q000494:pharmacology; D003001:Cloning, Molecular; D000242:Cyclic AMP / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D015232:Dinoprostone / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism*; D037342:Pertussis Toxin; D011453:Prostaglandins / Q000378:metabolism*; D011459:Prostaglandins E, Synthetic / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D051381:Rats; D018078:Receptors, Prostaglandin E / Q000378:metabolism*; D058308:Receptors, Prostaglandin E, EP3 Subtype; D013449:Sulfonamides / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D037361:Adenylate Cyclase Toxin; D002147:Calmodulin; D002614:Chelating Agents; D018076:DNA, Complementary; D004791:Enzyme Inhibitors; D011453:Prostaglandins; D011459:Prostaglandins E, Synthetic; C545648:Ptger3 protein, mouse; C545649:Ptger3 protein, rat; D018078:Receptors, Prostaglandin E; D058308:Receptors, Prostaglandin E, EP3 Subtype; D013449:Sulfonamides; D010566:Virulence Factors, Bordetella; C016767:sulprostone; D004533:Egtazic Acid; D000244:Adenosine Diphosphate; C017967:W 7; D000242:Cyclic AMP; D037342:Pertussis Toxin; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D000262:Adenylyl Cyclases; D000527:Alprostadil; C048491:butaprost; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D015232:Dinoprostone; D002118:Calcium