ChIP-seq profiling of transcriptional co-activator p300 during early myogenic differentiation

Molecular regulation of stem cell differentiation is exerted through both genetic and epigenetic determinants over distal regulatory or enhancer regions. Understanding the mechanistic action of active or poised enhancers is thus imperative for control of stem cell differentiation. Based on a genome-wide co-occurrence of different epigenetic marks in committed proliferating myoblasts, we have previously generated a 14-state chromatin state model to profile residue-specific histone acetylation in early myoblast differentiation. Here, we use genome-wide chromatin state association to delineate the functional mode of transcription regulators in early myogenic differentiation. We define a role of transcriptional coactivator p300, when recruited by master muscle regulator MyoD, in the establishment and regulation of myogenic loci at the onset of terminal differentiation. In addition, we reveal an enrichment of residue- and loci-specific histone acetylation at p300 associated active or poised enhancers, particularly when enlisted by MyoD. We provide novel molecular insights into the regulation of myogenic enhancers by p300 in concert with MyoD. Our studies present a valuable aptitude for driving stage specific chromatin state or enhancers pharmacologically to treat muscle related diseases and for the identification of additional myogenic targets and molecular interactions for therapeutic development.