title: Cell condition-dependent regulation of ERK5 by cAMP.
abstract: ERK5 activity is increased by agents known to activate receptor tyrosine kinases, G-protein coupled receptors, and stress response pathways. We now find a role for cAMP in the regulation of ERK5. ERK5 is activated by forskolin, isoproterenol, and epinephrine in NIH3T3 cells and C2C12 myoblasts. ERK1/2 are also activated by cAMP in NIH3T3 cells, but not in C2C12 myoblasts, demonstrating differential regulation of ERK5 and ERK1/2 by cAMP. We examined the effect of cell context on activation of ERK5 and discovered ERK5 activity is inhibited, rather than activated, by cAMP in confluent, serum-deprived NIH3T3 cells and C2C12 myoblasts. Our results suggest that regulation of MAP kinase pathways by cAMP is not only dictated by cell type, but also by cell context.
authors.affiliation: Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75390-9041, USA.
authors.forename: Gray W
authors.initials: GW
authors.lastname: Pearson
authors.forename: Melanie H
authors.initials: MH
authors.lastname: Cobb
mesh_terms: D016475:3T3 Cells; D000818:Animals; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000502:physiology*; D004789:Enzyme Activation; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D048054:Mitogen-Activated Protein Kinase 7; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016716:PC12 Cells; D051381:Rats
chemical_list: D005576:Colforsin; D000242:Cyclic AMP; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048054:Mitogen-Activated Protein Kinase 7; D020928:Mitogen-Activated Protein Kinases