Figure 1.

(A) MCF-7 cells were grown in the presence or absence (Ō) of TOT and forskolin, and whole-cell extracts were immunoprecipitated with anti-N-CoR IgG and detected by using antibodies against the estrogen receptor (Left). ER-transfected HeLa cells were cotreated with EGF and TOT, followed by immunoprecipitation with anti-N-CoR as above. Forskolin treatment for HeLa cells is shown as a control (Lower Right). HeLa cells were transfected with a mutant estrogen receptor (Ser-118 → Ala), treated with the indicated combination of agents, and immunoprecipitations with N-CoR were performed as above (Right). (B) Microinjection of anti-N-CoR, anti-Sin3 (A+B), and anti-HDAC2 IgG (αN-CoR, αSin3A/B, αHDAC2) into MCF-7 cells with a LacZ reporter containing two estrogen receptor-binding elements controlling a minimal p36 promoter, in the presence or absence of 17β-estradiol or TOT. The last two columns compare these effects with those of forskolin and EGF.