Comparative expression profiling identifies differential roles for Myogenin and p38 MAPK signaling in myogenesis

Mitogen activated protein kinase (MAPK) signaling regulates differentiation of many cell types. During myogenesis in particular, p38a MAPK (MAPK14) phosphorylates multiple transcriptional regulators to modulate muscle-specific gene expression. Among the p38a MAPK modulated genes is the muscle-specific transcriptional regulator Myogenin (Myog) that is also essential to complete the muscle differentiation program, and while it is known that both p38a MAPK and Myog are critically required for myogenesis, the individual contribution of each of these proteins is poorly defined. Here we show that Myog expression (in the absence of p38a MAPK signaling) is sufficient to establish expression of many late markers of muscle differentiation and to mediate cell migration. However, Myog expression alone did not led to the formation of multinucleated muscle cells, highlighting a critical role for p38a MAPK in myoblast fusion. Using comparative microarray analysis we identified p38a MAPK-dependent genes that are not regulated by Myog

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Liu QC, Zha XH, Faralli H, Yin H, Louis-Jeune C, Perdiguero E, Pranckeviciene E, Muñoz-Cànoves P, Rudnicki MA, Brand M, Perez-Iratxeta C, Dilworth FJ