Figure 6

Recruitment of ERα and Pol II to the pS2 promoter in MCF-7 cells. ChIP-kinetic experiments were performed using anti ERα antibody (HC-20) (A) or anti-Pol II antibody (B). Cells were cultured in 10% FCS and then in 3% dextran-charcoal treated FCS for three days. Twenty four hours before experiment, cells were deprived of serum and subsequently treated for 2 hr with 2.5 μM α-amanitin, and then with 10 nM E2 during 8 hours. Chromatin was prepared as in Figure 4 or 5. Values are mean ± SD of two independent immunoprecipitation assays of the same chromatin, and expressed as in Figure 4. ERα (A) protein levels were analyzed by Western blot experiments. MCF-7 treatments for ChiP assays and Western blot experiments were identical. Extracts were prepared at indicated times, and Western blotted with antibodies for ERα (HC-20) or actin.