Figure 5.

Effect of C3 exoenzyme on estrogen response element-dependent luciferase activity in MCF-7 cells. Cells, deprived of estradiol (E2) for 4 days, were treated with C3 exoenzyme as described in Materials and methods. Twenty-four hours later the cells were stimulated with E2 (5 nM) or ethanol. Luciferase activities were quantified 16 hours after E2 addition, as described in Material and methods. Results are expressed in arbitrary units after protein normalization. Error bars indicate the mean values ± standard deviation from triplicate experiments, and the results are representative of two independent experiments.