Figure 4.

Release of cyclin C from promoters does not require Med13/Med13L degradation. A and B, RT-qPCR (A) and ChIP analysis (B) for the cyclin C–repressed genes indicated following H₂O₂/MG-132 treatment. ChIP data are shown as percentages of input DNA compared with a nonspecific control (GFP antibody). H₂O₂-treated WT control is from Fig. 1 to aid in comparing results. C, Med13 and Med13L levels were determined by Western blotting analysis in extracts prepared from MEF cultures following exposure to H₂O₂ and/or MG-132 as indicated. The β-actin concentrations were obtained using separate blots. The same β-actin blots are reproduced in both panels to allow easy comparison. D, the ratios of Med13 and Med13L signals to the β-actin internal control were calculated then compared to WT untreated control (n = 3). Statistical significance is indicated by the following: *, p < 0.05; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001.