title: Two isoforms of prostaglandin EP3 receptor exhibiting constitutive activity and agonist-dependent activity in Rho-mediated stress fiber formation.
abstract: We have cloned two isoforms of the mouse prostaglandin E receptor EP3 subtype, EP3alpha and EP3beta, with different carboxyl-terminal tails, produced through alternative splicing. To determine the functional differences between the two isoforms, we examined the role of the isoforms in regulation of the actin cytoskeleton using Mardin-Darby canine kidney cells expressing these isoforms. The EP3alpha isoform constitutively induced stress fiber formation, independent of an agonist, while the EP3beta isoform agonist-dependently induced stress fiber formation. Pertussis toxin did not prevent stress fiber formation. This signaling pathway is mediated by Rho, because C3 transferase microinjection inhibited stress fiber formation. Therefore, the physiological significance of these isoforms of the EP3 receptor may lie in their different agonist dependency in Rho-mediated stress fiber formation via a pertussis toxin-insensitive G protein.
authors.affiliation: Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hasegawa
authors.forename: M
authors.initials: M
authors.lastname: Negishi
authors.forename: H
authors.initials: H
authors.lastname: Katoh
authors.forename: A
authors.initials: A
authors.lastname: Ichikawa
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D004285:Dogs; D019204:GTP-Binding Proteins / Q000378:metabolism*; D051379:Mice; D037342:Pertussis Toxin; D018078:Receptors, Prostaglandin E / Q000819:agonists / Q000502:physiology*; D058308:Receptors, Prostaglandin E, EP3 Subtype; D011994:Recombinant Proteins / Q000819:agonists / Q000378:metabolism; D015398:Signal Transduction; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
chemical_list: D000199:Actins; C545648:Ptger3 protein, mouse; D018078:Receptors, Prostaglandin E; D058308:Receptors, Prostaglandin E, EP3 Subtype; D011994:Recombinant Proteins; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins