Figure 3

Stat6 interacts directly with progesterone-bound PR via its LTKLL in the TAD domain. A. Coimmunoprecipitation assays. T47D cells were treated with progesterone (30 nM) and RU486 (10 nM) for 12 h, or untreated. Total protein extracts (50 μg) were then subjected to Western blotting using a PR antibody either after immunoprecipitation with anti-Stat6 or nonimmune rabbit IgG (negative control) antibodies (upper panel) or directly for control of the in-cell PR levels (lower panel). B. as in A, coimmunoprecipitation assays were conducted on cells with the indicated treatment. C, flag–Stat6, either wild type or mutated in the LTKLL (flag-Stat6m) motif, was assayed for interaction with PR as described above in the presence of progesterone (10 nM).