Figure 7.

HBZ is a potent inhibitor of p300/CBP HAT activity in vitro. HAT assays were performed using recombinant histones (2 µM, lanes 1–7), p300 (4 nM, lanes 2–7) and increasing concentrations of GST-HBZ [(A), HBZ-bZIP (B), or curcumin (C)]. Reactions were analyzed by western blot using the antibodies indicated. In each lower panel, the membrane showing acetylated histones was reprobed for histone H3. (D) The graph shows the decrease in histone acetylation in response to increasing concentrations of GST-HBZ, HBZ-bZIP or curcumin. Western blot data were used to quantify levels of histone acetylation and data were plotted relative to the concentration of the inhibitor. The graph shows data averaged from two independent experiments.