title: Identification of a cAMP-response element in the regulator of G-protein signaling-2 (RGS2) promoter as a key cis-regulatory element for RGS2 transcriptional regulation by angiotensin II in cultured vascular smooth muscles.
abstract: Mice deficient in regulator of G-protein signaling-2 (RGS2) have severe hypertension, and RGS2 genetic variations occur in hypertensive humans. A potentially important negative feedback loop in blood pressure homeostasis is that angiotensin II (Ang II) increases vascular smooth muscle cell (VSMC) RGS2 expression. We reported that Group VIA phospholipase A(2) (iPLA(2)β) is required for this response (Xie, Z., Gong, M. C., Su, W., Turk, J., and Guo, Z. (2007) J. Biol. Chem. 282, 25278-25289), but the specific molecular causes and consequences of iPLA(2)β activation are not known. Here we demonstrate that both protein kinases C (PKC) and A (PKA) participate in Ang II-induced VSMC RGS2 mRNA up-regulation, and that actions of PKC and PKA precede and follow iPLA(2)β activation, respectively. Moreover, we identified a conserved cAMP-response element (CRE) in the murine RGS2 promoter that is critical for cAMP-response element-binding protein (CREB) binding and RGS2 promoter activation. Forskolin-stimulated RGS2 mRNA up-regulation is inhibited by CREB sequestration or specific disruption of the CREB-RGS2 promoter interaction, and Ang II-induced CREB phosphorylation and nuclear localization are blocked by iPLA(2)β pharmacologic inhibition or genetic ablation. Ang II-induced intracellular cyclic AMP accumulation precedes CREB phosphorylation and is diminished by inhibiting iPLA(2), cyclooxygenase, or lipoxygenase. Moreover, three single nucleotide polymorphisms identified in hypertensive patients are located in the human RGS2 promoter CREB binding site. Point mutations corresponding to these single nucleotide polymorphisms interfere with stimulation of human RGS2 promoter activity by forskolin. Our studies thus delineate a negative feedback loop to attenuate Ang II signaling in VSMC with potential importance in blood pressure homeostasis and the pathogenesis of human essential hypertension.
authors: Department of Physiology, University of Kentucky School of Medicine, Lexington, Kentucky 40536, USA.
authors: Zhongwen
authors: Z
authors: Xie
authors: Dexiang
authors: D
authors: Liu
authors: Shu
authors: S
authors: Liu
authors: Lindsay
authors: L
authors: Calderon
authors: Guogang
authors: G
authors: Zhao
authors: John
authors: J
authors: Turk
authors: Zhenheng
authors: Z
authors: Guo
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects / Q000502:physiology; D000804:Angiotensin II / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D050882:CREB-Binding Protein / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000235:genetics / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D020555:GTP-Binding Protein Regulators / Q000096:biosynthesis* / Q000235:genetics; D054522:Group VI Phospholipases A2 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006973:Hypertension / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D020641:Polymorphism, Single Nucleotide; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism; D020710:RGS Proteins / Q000096:biosynthesis* / Q000235:genetics; D011817:Rabbits; D051381:Rats; D020218:Response Elements / Q000502:physiology*; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D014662:Vasoconstrictor Agents / Q000378:metabolism / Q000494:pharmacology
chemical_list: D020555:GTP-Binding Protein Regulators; D020710:RGS Proteins; C087182:RGS2 protein, human; C105345:Rgs2 protein, mouse; C485337:Rgs21 protein, rat; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D005576:Colforsin; D000242:Cyclic AMP; D050882:CREB-Binding Protein; C494363:CREBBP protein, human; C494364:Crebbp protein, mouse; C494365:Crebbp protein, rat; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D054522:Group VI Phospholipases A2; C516476:Pla2g6 protein, mouse