title: Adrenocorticotropin hormone (ACTH) effects on MAPK phosphorylation in human fasciculata cells and in embryonic kidney 293 cells expressing human melanocortin 2 receptor (MC2R) and MC2R accessory protein (MRAP)β.
abstract: Adrenocorticotropin hormone (ACTH) exerts trophic effects on adrenocortical cells. We studied the phosphorylation of mitogen-activated proteins kinases (MAPKs) in human embryonic kidney cells stably expressing the ACTH receptor, MC2R, and its accessory protein MRAPβ and in primary cultures of human adrenal fasciculata cells. ACTH induced a maximal increase in p44/p42(mapk) and of p38 MAPK phosphorylation after 5min. Neither the overexpression of wild-type arrestin2, arrestin3 or their respective dominant negative forms affected p44/p42(mapk) phosphorylation. However, preincubation with the recycling inhibitors brefeldin A and monensin attenuated both cAMP accumulation and p44/p42(mapk) phosphorylation proportionally. Cyclic AMP-related PKA inhibitors (H89, KI(6-22)) and Rp-cAMPS decreased p44/p42(mapk) phosphorylation but not ACTH-mediated cAMP production. The selective Epac1/2 activator, 8-pCPT-2'-O-MecAMP, did not modify the effect of ACTH. Thus, cAMP/PKA, but not cAMP/Epac1/2 pathways, or arrestin-coupled internalization of MC2R is involved in ACTH-induced p44/p42(mapk) phosphorylation by human MC2R. Together, ACTH binding to MC2R stimulates PKA-dependent p44/p42(mapk) phosphorylation.
authors.affiliation: Service d'Endocrinologie, Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4.
authors.forename: Simon
authors.initials: S
authors.lastname: Roy
authors.forename: Sandra
authors.initials: S
authors.lastname: Pinard
authors.forename: Lucie
authors.initials: L
authors.lastname: Chouinard
authors.forename: Nicole
authors.initials: N
authors.lastname: Gallo-Payet
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects; D020536:Enzyme Activators / Q000494:pharmacology; D057809:HEK293 Cells; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008954:Models, Biological; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D044103:Receptor, Melanocortin, Type 2 / Q000378:metabolism*; D013449:Sulfonamides / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013997:Time Factors; D015383:Zona Fasciculata / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D020536:Enzyme Activators; D007546:Isoquinolines; C458099:MRAP protein, human; D008565:Membrane Proteins; D047428:Protein Kinase Inhibitors; D044103:Receptor, Melanocortin, Type 2; D013449:Sulfonamides; D000324:Adrenocorticotropic Hormone; D000242:Cyclic AMP; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide; D013755:Tetradecanoylphorbol Acetate