Fig 2.

RVB1 relieves p400-mediated inhibition of TIP60's activity in vivo. (A) Codepletion of p400 bypasses the requirement of RVB1 for TIP60.com's HAT activity. 293T cells were cotransfected with Flag-TIP60 or shControl/shRVB1-A/shp400-A-expressing plasmids. Flag-TIP60 complex was immunoprecipitated (IP) from the lysate and assayed for HAT activity as described in Materials and Methods. Depletion of RVB1 was detected using anti-RVB1 antibody. Immunoblotting (IB) with anti-Flag antibody shows the amounts of TIP60 in the lanes. Actin and IgG served as loading controls for input and immunoprecipitation, respectively. (B) p400 is depleted in cells expressing shp400-A plasmid. Total RNA was isolated, and the relative p400 mRNA measured by quantitative reverse transcription-PCR (Q-RT-PCR) and normalized to actin mRNA is shown. Results are means ± standard deviations (SD) from three experiments.