Fig 6.

Recombinant RVB interacts with p400 fragment and neutralizes its inhibitory effect on rTIP60. (A and B) p400(949-1372) interacts with rRVB1 and rRVB2 in a GST pulldown assay. Glutathione-agarose-bound proteins were immunoblotted with the indicated antibodies. (C) p400-mediated inhibition of rTIP60's HAT activity (as measured by an ELISA) can be reversed by both rRVB1 and rRVB2. Means ± SD of six measurements are shown. (D) GST-p400 fragment inhibits rTIP60's HAT activity and rRVB1 antagonizes its effect in the presence of nonhydrolyzable ATP or with a Walker B mutation. The indicated proteins [GST, GST-p400(949-1372), RVB1-WT (wild type), or RVB1-WB (Walker B mutant)] were incubated in an in vitro ELISA-HAT assay. A 10 μM concentration of either ATP or ATPγS was added where indicated. Means ± SD of four measurements are shown.