Figure 5

MOZ-TIF2 inhibition of ER-mediated transcription was not antagonized by increased expression of CBP and expression of MOZ-TIF2 competed with wild type TIF2 in ER signaling. CV-1 cells were co-transfected with pVit-TKSL containing MOZ-TIF2 or MOZ-TIF2 plus CBP or TIF2. The cells were lysed and luciferase activity was measured as described after incubation of the transfected cells for 36 hours of cells with 50 nM estradiol. A. The forced expression of CBP does not antagonize MOZ-TIF2 inhibition of ER-mediated transcription. B. The inhibition of ER-mediated transcription by MOZ-TIF2 was partially released by increased expression of wild type of TIF2. Open bars, the presence of 50 nM estradiol; dark bars, without estradiol. Double stars represent a significant difference at P < 0.01 by the two tailed Student T- test compared to the transfection with MOZ-TIF2 in the ligand added condition. Dark circles represent a significant difference at P < 0.05 compared to the transfection with TIF2 alone in the ligand added condition. The numbers on top of the open bars indicate the ratio of light units as described in Figure 3.