title: Signal-dependent activation of the MEF2 transcription factor by dissociation from histone deacetylases.
abstract: Myocyte enhancer factor-2 (MEF2) transcription factors control muscle-specific and growth factor-inducible genes. We show that hypertrophic growth of cardiomyocytes in response to phenylephrine and serum is accompanied by activation of MEF2 through a posttranslational mechanism mediated by calcium, calmodulin-dependent protein kinase (CaMK), and mitogen-activated protein kinase (MAPK) signaling. CaMK stimulates MEF2 activity by dissociating class II histone deacetylases (HDACs) from the DNA-binding domain. MAPKs, which activate MEF2 by phosphorylation of the transcription activation domain, maximally stimulate MEF2 activity only when repression by HDACs is relieved by CaMK signaling to the DNA-binding domain. These findings identify MEF2 as an endpoint for hypertrophic stimuli in cardiomyocytes and demonstrate that MEF2 mediates synergistic transcriptional responses to the CaMK and MAPK signaling pathways by signal-dependent dissociation from HDACs.
authors.affiliation: Department of Molecular Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75235-9148, USA.
authors.forename: J
authors.initials: J
authors.lastname: Lu
authors.forename: T A
authors.initials: TA
authors.lastname: McKinsey
authors.forename: R L
authors.initials: RL
authors.lastname: Nicol
authors.forename: E N
authors.initials: EN
authors.lastname: Olson
mesh_terms: D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006655:Histone Deacetylases / Q000378:metabolism*; D064326:MEF2 Transcription Factors; D051379:Mice; D018006:Myogenic Regulatory Factors; D051381:Rats; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; D064326:MEF2 Transcription Factors; D018006:Myogenic Regulatory Factors; D014157:Transcription Factors; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D006655:Histone Deacetylases