Figure 2

Progesterone enhances Stat6 recruitment at multiprotein complexes formed with PR and CBP/p300 at proximal Sp1 elements of the p21 and p27 promoters. Chromatin was prepared from T47D cells incubated with progesterone (30nM) or ethanol (vehicle) (A) or with progesterone (30 nM) alone (B) for 4 h before lysis. Immunoprecipitations were then performed using antibodies as indicated (top). Controls included PCRs done without DNA (H₂O) or with nonprecipitated genomic DNA (input) or immunoprecipitation assays performed without antibody (no Ab) or with an irrelevant antibody (anti-flag). The extracted DNA was amplified using the primer pairs covering either the progesterone-responsive Sp1-binding region of the p21 gene promoter (upper panel), a distal region of the p21 gene located ~1 kb from this element, the 544/533 progesterone-responsive Sp1-binding region of the p27 gene promoter, a distal region of the p27 gene located ~1 kb from this element, or a β-actin gene region (lower panel).