Figure 6.

The effect of p300, CBP, or PCAF overexpression on GAL4-EBNA2 (GE) or GAL4-VP16 (GV) acidic domain-mediated transactivation of a GAL4-dependent promoter in 293 T cells. Various amounts of p300 expression vector (A) or 3.5 μg of CBP expression vector (B) was transfected into 293 T cell with 0.2 μg of GAL4-EBNA2 or 0.01 μg of GAL4-VP16 expression plasmids and 0.5 μg of reporter plasmid. The amount of cotransfected p300 DNA is indicated (in μg) in the figure. The fold activation induced by p300/CBP is relative to that induced by GAL4-EBNA2 or GAL4-VP16 alone. In C, the effect of 4 μg of p300 expression vector on coexpressed GAL4-EBNA2 acidic domain-mediated transactivation is compared with that of p300 HAT-negative mutants p300Δ1472–1522 or Δ1603–1653 in 293 T cells. The extent of cotransactivation by p300 mutants is shown relative to that by wild-type p300. In D, the effect of PCAF on GAL4-EBNA2- or GAL4-VP16-mediated activation of a GAL4-responsive promoter is assayed as described in A above. For all experiments in this figure, vector DNA was used to balance the different amounts of DNA used in different transfections. Luciferase activity was adjusted to the transfection efficiency represented by β-galactosidase activity. The results shown are the average of four to five independent experiments, with error bars representing SE.