Figure 5.
Nuclear import enhances E2F-4 transcriptional activity. (A) U20S cells were transfected with 2 μg of E2F-luciferase, 2 μg of pCMV-β-Gal, and 150, 500, or 2,000 ng of either wt-E2F-4 or E2F-4.NLS. The resulting cell extracts were analyzed by luciferase reporter assay and values normalized to β-galactosidase units. Fold-activation over wt-E2F-4 is indicated above the E2F-4.NLS bars. (B) Transcriptional activity 150 ng of wt-E2F-4 alone versus wt-E2F-4 cotransfected with 100, 500, or 1,000 ng of either DP-1 or DP-2. A total of 150 ng of the E2F-4.NLS expression vector induced the transactivation noted in the far right bar of this panel. (C) Luciferase reporter assay using 2 μg of either wt-E2F-4, E2F-4.NES or E2F-4.NLS expression vector, alone, or after cotransfection with 1 μg of DP-1 or DP-2.
