FIG. 5.

H89 inhibits the induction of the HDAC1 gene during combinatorial TSA and anisomycin treatment. (A) Northern blot analysis of resting Swiss 3T3 cells left untreated or pretreated with 10 μM H89 for 15 min. Cells were then left untreated (−) or stimulated (+) for the indicated time periods with 50 ng of anisomycin (sAn)/ml alone or with anisomycin in combination with TSA (sAn+TSA). The Northern blot was hybridized with the radiolabeled HDAC1 cDNA (HDAC1). Transferred 18S rRNA was stained with methylene blue to confirm loading and transfer of similar amounts of RNA. (B) Phosphoacetylation of histone H3 is inhibited by H89. Western blot analysis of core histones isolated from cells treated as described for panel A was performed with a phosphoacetyl-H3 antibody. To confirm equal loading, a duplicate gel was stained with Coomassie blue.