title: Extracellular signal-regulated kinase 1/2-mediated transcriptional regulation of G-protein-coupled receptor kinase 3 expression in neuronal cells.
abstract: Relatively small changes in G-protein-coupled receptor kinase (GRK) 3 expression (approximately 2-fold) profoundly affect alpha2-adrenergic receptor (AR) function and preferentially regulate neuronal alpha2A- and alpha2B-AR signaling. In the present study, we provide evidence that epinephrine (EPI)-induced up-regulation of GRK3 protein expression in two neuronal cell lines, BE(2)-C cells (endogenously express alpha2A- and beta2AR) and BN17 cells [endogenously express alpha2B (NG108) and transfected to express beta2-AR] is due in part to increased GRK3 gene expression. In both cell lines, the increase in GRK3 transcription occurred via an extracellular signal-regulated kinase (ERK) 1/2-dependent mechanism because the increase in GRK3 mRNA is eliminated in the presence of the mitogen-activated protein kinase/ERK kinase 1/2 inhibitor, U0126 [1,4-diamino-2,3-dicyano-1,4-bis (2-amino phenylthiobutadiene)]. EPI-induced GRK3 mRNA up-regulation also is prevented in the presence of propranolol or phentolamine. Moreover, GRK3 mRNA did not increase in response to EPI treatment in NG108 cells (endogenously express alpha2B-AR with no beta2-AR). Both these results suggest that simultaneous activation of alpha2- and beta2-AR by EPI is required for the ERK1/2-dependent increase in GRK3 mRNA. The EPI-induced increase in GRK3 mRNA was unaffected in the presence of the protein kinase C inhibitor, chelerythrine chloride. Finally, EPI treatment resulted in increased nuclear translocation and accumulation of the transcription factors, Sp-1 and Ap-2, in BE(2)-C cells. Taken together, our results demonstrate the involvement of the ERK1/2 pathway in selective up-regulation of GRK3 mRNA expression, possibly via activation of Sp-1 and Ap-2 transcription factors in neuronal cells.
authors.affiliation: Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204-5037, USA.
authors.forename: Samina
authors.initials: S
authors.lastname: Salim
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Standifer
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Eikenburg
mesh_terms: D058647:Adrenergic alpha-2 Receptor Agonists; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D058666:Adrenergic beta-2 Receptor Agonists; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000470:Alkaloids / Q000494:pharmacology; D053119:Benzophenanthridines / Q000494:pharmacology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004837:Epinephrine / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D054770:G-Protein-Coupled Receptor Kinase 3; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000502:physiology*; D048052:Mitogen-Activated Protein Kinase 3 / Q000502:physiology*; D009474:Neurons / Q000201:enzymology* / Q000502:physiology; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation / Q000502:physiology; D051552:beta-Adrenergic Receptor Kinases / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D058666:Adrenergic beta-2 Receptor Agonists; D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D000470:Alkaloids; D053119:Benzophenanthridines; D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D011433:Propranolol; C016299:chelerythrine; D054770:G-Protein-Coupled Receptor Kinase 3; C517848:GRK3 protein, human; D051552:beta-Adrenergic Receptor Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D004837:Epinephrine; D010646:Phentolamine