Figure 2.

BAF60c and MyoD are recruited to the myogenin promoter in myoblasts prior to the activation of transcription and the recruitment of Brg1-based SWI/SNF complex. (A) ChIP assays were performed in myoblasts and myotubes to monitor the recruitment of MyoD, BAF60c, Brg1, Ini1 and the relative enrichment in H3-K9-18 acetylation at myogenin promoter in proliferating, undifferentiated myoblasts (GM) and differentiating myoblasts (DM) (see Materials and methods for details). (B) Sequential ChIPs (re-ChIPs) were performed by immunoprecipitating the chromatin with antibodies against Flag–BAF60c followed by a second immunoprecipitation using MyoD (left panel) or Brg1 antibodies (right panel) in undifferentiated myoblasts (GM) and differentiating myoblasts (DM). ChIP values are normalized against the input and expressed as relative enrichment of the material precipitated by the indicated antibody on myogenin promoter (relative quantification using the comparative Ct method (2^{−(Ct sample−Ct input)})). Error bars indicate mean±s.d. The graphic shown is representative of at least two independent experiments.