Fig. 8

BRD4 and BRD2 occupancy at MITF-binding sites is associated with chromatin accessibility in Meb-a cells. a, b Melb-a cells were differentiated for 24 h in the presence of vehicle (VC) or 500 nM (+)JQ1. Cells were cross-linked and control IgG or an antibody to BRD4 or BRD2 was used for ChIP. BRD4 and BRD2 binding to the MITF-binding sites to the promoter regions of Tyr and Tyrp1 was assayed by qPCR. BRD4 and BRD2 enrichment is shown relative to IgG enrichment and normalized to a non-specific region (IgH enhancer). The data are the average of three independent experiments. Standard error bars are shown statistically significant differences between VC and (+)JQ1 treated samples are shown (*< 0.05, **p < 0.01, ***p < 0.001). c Melb-a cells were differentiated as described in a, b. FAIRE enrichment at the MITF-binding sites in the Tyr and Tyrp1 promoters was determined by qPCR. Enrichment at the IgH enhancer is shown as a negative control. The data are the average of two independent experiments performed in triplicate Statistically significant differences between VC and (+)JQ1-treated samples are shown (*< 0.05, **p < 0.01, ***p < 0.001). D. NHEMs were treated with 500 nM inactive (−)JQ1 or 500 nM active (+)JQ1 for 48 h, then harvested for FAIRE. FAIRE enrichment at the MITF-binding site in the TYRP1 promoter was determined by qPCR. FAIRE enrichment at the CD25 promoter is shown as a negative control. The data is the average of two independent experiments performed in triplicate Statistically significant differences between (−)JQ1 and (+)JQ1-treated samples are shown (*< 0.05, **p < 0.01, ***p < 0.001)