FIG. 8.

Loss of SUMOylation, but not phosphorylation, enhances SF-1 promoter occupancy. (A) Diagram of the mouse StAR promoter showing the two SF-1 response elements. The primer pairs indicated by the arrows were used for ChIP analysis and amplified the proximal element. (B) ChIP assays were performed on HIS-FLAG-tagged SF-1 stable Y1 cell lines (1 × 10⁶; serum deprived for 48 h and synchronized with α-amanitin) using anti-FLAG antibodies. The immunoprecipitates were analyzed by quantitative PCR using primers designed against the proximal mouse StAR promoter. The data were normalized to values obtained for 1% input controls, and the results are presented as percentage of baseline values. The error bars indicate standard errors. (C) ChIP assays were performed on HIS-FLAG-tagged WT and K194R SF-1 stable Y1 cell lines (1 × 10⁶; serum deprived for 48 h and synchronized with α-amanitin) after ACTH (10 nM) treatment at specific time points using anti-FLAG antibodies. Anti-FLAG-immunoprecipitated lysates were re-ChIPed with anti-polymerase II or anti-SRC-1 antibodies as a function of time. The immunoprecipitates were analyzed by quantitative PCR using primers designed against the proximal mouse StAR promoter. The data were normalized to values obtained for 1% input controls, and the results are presented as percentages of baseline values.