title: Extracellular signal-regulated kinase 1/2-mediated phosphorylation of p300 enhances myosin heavy chain I/beta gene expression via acetylation of nuclear factor of activated T cells c1.
abstract: The nuclear factor of activated T-cells (NFAT) c1 has been shown to be essential for Ca(2+)-dependent upregulation of myosin heavy chain (MyHC) I/β expression during skeletal muscle fiber type transformation. Here, we report activation of extracellular signal-regulated kinase (ERK) 1/2 in Ca(2+)-ionophore-treated C2C12 myotubes and electrostimulated soleus muscle. Activated ERK1/2 enhanced NFATc1-dependent upregulation of a -2.4 kb MyHCI/β promoter construct without affecting subcellular localization of endogenous NFATc1. Instead, ERK1/2-augmented phosphorylation of transcriptional coactivator p300, promoted its recruitment to NFATc1 and increased NFATc1-DNA binding to a NFAT site of the MyHCI/β promoter. In line, inhibition of ERK1/2 signaling abolished the effects of p300. Comparison between wild-type p300 and an acetyltransferase-deficient mutant (p300DY) indicated increased NFATc1-DNA binding as a consequence of p300-mediated acetylation of NFATc1. Activation of the MyHCI/β promoter by p300 depends on two conserved acetylation sites in NFATc1, which affect DNA binding and transcriptional stimulation. NFATc1 acetylation occurred in Ca(2+)-ionophore treated C2C12 myotubes or electrostimulated soleus. Finally, endogenous MyHCI/β gene expression in C2C12 myotubes was strongly inhibited by p300DY and a mutant deficient in ERK phosphorylation sites. In conclusion, ERK1/2-mediated phosphorylation of p300 is crucial for enhancing NFATc1 transactivation function by acetylation, which is essential for Ca(2+)-induced MyHCI/β expression.
authors.affiliation: Department of Vegetative Physiology, Institute of Biochemistry, Hannover Medical School, D-30625 Hannover, Germany.
authors.forename: Joachim D
authors.initials: JD
authors.lastname: Meissner
authors.forename: Robert
authors.initials: R
authors.lastname: Freund
authors.forename: Dorothee
authors.initials: D
authors.lastname: Krone
authors.forename: Patrick K
authors.initials: PK
authors.lastname: Umeda
authors.forename: Kin-Chow
authors.initials: KC
authors.lastname: Chang
authors.forename: Gerolf
authors.initials: G
authors.lastname: Gros
authors.forename: Renate J
authors.initials: RJ
authors.lastname: Scheibe
mesh_terms: D000107:Acetylation; D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D004247:DNA / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D007476:Ionophores / Q000494:pharmacology; D048369:MAP Kinase Kinase 1 / Q000378:metabolism; D020935:MAP Kinase Signaling System; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D018485:Muscle Fibers, Skeletal / Q000201:enzymology / Q000378:metabolism; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000235:genetics*; D050778:NFATC Transcription Factors / Q000378:metabolism*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D015533:Transcriptional Activation; D050880:p300-CBP Transcription Factors / Q000378:metabolism*; D000099224:p300-CBP-Associated Factor
chemical_list: D004247:DNA; D007476:Ionophores; D048369:MAP Kinase Kinase 1; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D018995:Myosin Heavy Chains; D050778:NFATC Transcription Factors; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor; C551613:Myh7 protein, mouse