FIGURE 5:

The histone deacetylase HDAC3 activity opposes Tip60 activity to relocalize Aurora B from chromatin to inner centromeres. Cells treated to reduce HDAC3 by shRNA had reduced amounts of Aurora B but this was rescued by concurrent inhibition of Tip60 acetyltransferase activity. (A) Immunofluorescence images showing Aurora B inner centromeric localization in prometaphase cells treated with shHDAC3 knockdown with and without Tip60 inhibition. Note that most of the Aurora B remains on noninner centromeric (chromosome arm) regions after HDAC3 depletion. However, if Tip60 was inhibited in the previous S/G2 phase then HDAC3 is not required to localize Aurora B to inner centromeres; scale bar, 5 µm. (B) Quantification of Aurora B signal at centromeres after the indicated treatment: shCtrl n = (11, 13); shHDAC3 n = (13, 10); shHDAC3+Nu9056 n = (11, 5); p value_{shCtrl-shHDAC3} = (0.0211, 0.0046); p value_{shCtrl-shHDAC3+Nu9056} (0.49, 0.63). (C) Quantification of chromatin bound Aurora B signal after the centromeric signals have been subtracted to measure the amount of Aurora B on chromosome arms after the indicated treatments. shCtrl n = (11, 13); shHDAC3 n = (13, 10); shHDAC3+Nu9056 n = (11, 5); p value_{shCtrl-shHDAC3} = (0.02678, 0.00065); p value_{shCtrl-shHDAC3+Nu9056} (0.25, 0.41). For statistical analysis Welch’s t test was applied; ns > 0.05, *P < 0.05. Light and dark blue dots indicate two independent experimental replicates.