FIGURE 3.

UV radiation augments TIP60 autoacetylation. A, autoacetylation of TIP60 is induced by UV radiation. U2OS cells stably expressing TIP60 were irradiated with 50 J/m² UV and then incubated for the indicated period of time. Cells were harvested, lysed, and subjected to precipitation (IP) and immunoblotting (WB) as indicated. B, dose-dependent induction of TIP60 autoacetylation following UV radiation. U2OS cells stably expressing TIP60 were UV-irradiated with the indicated dosages. Cells were collected at 12 h. Precipitation and immunoblotting were performed as indicated. C, caffeine blocks UV-induced TIP60 autoacetylation. U2OS cells stably expressing TIP60 were preincubated with 1 mm caffeine for 1 h before they were irradiated (40 J/m²). Precipitation and immunoblotting were performed as outlined in B.