The nuclear factor of activated T-cells (NFAT) c1 has been shown to be essential for @entity141 -dependent upregulation of @entity9740 ( @entity9740 ) I/b expression during skeletal muscle fiber type transformation. Here, we report activation of @entity3962 in @entity141 -ionophore-treated C2C12 myotubes and electrostimulated soleus muscle. Activated @entity1366 enhanced @entity9889 -dependent upregulation of a -2.4 kb MyHCI/b promoter construct without affecting subcellular localization of endogenous @entity9889 . Instead, @entity1366 -augmented phosphorylation of transcriptional coactivator @entity3493 , promoted its recruitment to @entity9889 and increased @entity9889 -DNA binding to a NFAT site of the MyHCI/b promoter. In line, inhibition of @entity1366 signaling abolished the effects of @entity3493 . Comparison between wild-type @entity3493 and an acetyltransferase-deficient mutant (p300DY) indicated increased @entity9889 -DNA binding as a consequence of @entity3493 -mediated acetylation of @entity9889 . Activation of the MyHCI/b promoter by @entity3493 depends on two conserved acetylation sites in @entity9889 , which affect DNA binding and transcriptional stimulation. @entity9889 acetylation occurred in @entity141 -ionophore treated C2C12 myotubes or electrostimulated soleus. Finally, endogenous MyHCI/b gene expression in C2C12 myotubes was strongly inhibited by p300DY and a mutant deficient in ERK phosphorylation sites. In conclusion, @entity1366 -mediated phosphorylation of @entity3493 is crucial for enhancing @entity9889 transactivation function by acetylation, which is essential for @entity141 -induced MyHCI/b expression.

Extracellular signal-regulated kinase 1/2-mediated phosphorylation of @entity3493 enhances XXXX I/beta gene expression via acetylation of nuclear factor of activated T cells c1.

@entity9889 :: ('4772', 'Gene') :: ['NFATc1'] @entity9740 :: ('4624', 'Gene') :: ['myosin heavy chain', 'MyHC'] @entity3962 :: ('5594;5595', 'Gene') :: ['extracellular signal-regulated kinase (ERK) 1/2'] @entity3493 :: ('2033', 'Gene') :: ['p300'] @entity141 :: ('CHEBI:29108', 'Chemical') :: ['Ca(2+)'] @entity1366 :: ('5595;5594', 'Gene') :: ['ERK1/2']
@entity9740 :: (4624,Gene) :: ['myosin heavy chain']
