FIG. 3.

p300 HAT activity is required for full activation of SF-1. Expression plasmids for SF-1-HA (0.2 μg) and increasing amounts of p300 WT (0.1, 0.5, and 1 μg) or p300 DY were cotransfected with 0.3 μg SF-1-dependent reporter gene phscc-2.3K-LacZ into NIH 3T3 cells. (A) The specific activity of each transfectant consisted of the β-galactosidase (β-gal) activity normalized with the SF-1 expression level. The specific activity of SF-1-HA alone was set to 1. All values represent the results of at least three separate transfection experiments, with error bars representing standard deviations. *, P of <0.05, and **, P of <0.01, compared with wild-type SF-1-HA transfection only, by Student's t test. (B) Immunoblotting (IB) for expression of SF-1-HA (top) and c-Myc-tagged p300 (bottom; transfection with 1μg plasmid) of cell lysate from panel A. WT, wild type. Triangles and trapezoids denote increasing amounts of p300.