Figure 6.
A component of the DRIP complex contains HAT activity. The indicated fractions were incubated with either free histones or BSA, together with 3H-labeled acetyl-CoA, and assayed for HAT activity in a filter-binding assay as described by (Brownell and Allis 1995). The amount of HAT activity is quantitated as cpm 3H-labeled acetate transferred from acetyl CoA to histones. GST–VDR LBD + DRIPs are the glutathione-eluted complex used in the transcription experiments described in Fig. 5B. [DRIPs (Sark.)] represent DRIPs eluted from GST–VDR LBD beads with the detergent Sarkosyl. CV-1 extract, extract + GRIP-1, and extract + CBP represent nuclear extracts from untransfected cells, or GRIP-1 or CBP-transfected CV-1 cells, respectively.