ERβ Binds N-CoR in the Presence of Agonists in Mammalian Cells. (A) Two-hybrid assays. Components of the two-hybrid assay are shown in schematic at top. Results of a representative assay are shown below (with error bars representing the standard error of values determined from three separate wells). Ligand concentrations were: ICI, raloxifene, Genistein, Coumestrol; 1 uM, Tamoxifen; 5 uM, estradiol DES 100 nM. (B) Estradiol dependence of ERβ interactions with N-CoR and GRIP1 fusion proteins in mammalian cells. A representative experiment is shown. Error bars represent standard deviations from four wells.