Skip to main content
. Author manuscript; available in PMC: 2011 Aug 1.
Published in final edited form as: Exp Cell Res. 2010 May 7;316(13):2123–2135. doi: 10.1016/j.yexcr.2010.05.003

Fig. 1.

Fig. 1

Lack of hyperacetylation of histone H4 following treatment of metaphase-arrested HeLa cells with HDAC inhibitors. (A), (B) Time course of treatment of (A) metaphase-arrested and (B) interphase (unsynchronized) HeLa cell cultures with 10 mM sodium butyrate. Histones were extracted from isolated chromosomes or nuclei at the indicated times after treatment, separated by acid-urea polyacrylamide gel electrophoresis [54] and stained with Coomassie blue. Note that H4 is highly acetylated in interphase cells after one or more hours with butyrate, but no increase in H4 acetylation is seen in metaphase-arrested cells even after five hours of treatment. (C), (D) Effects of other HDAC inhibitors on histone H4 acetylation. Aliquots of (C) metaphase-arrested and (D) interphase (unsynchronized) cultures were treated in parallel for 4 hrs with 1.0 Φg/mL trichostatin A (lanes 1), 2.0 Φg/mL apicidin (lanes 2), 2.0 Φg/mL oxamflatin (lanes 3), or 10 mM sodium butyrate (lanes 4), or incubated for 4 hrs with no treatment (Ctrl). Histones were extracted and analyzed as in (A) and (B). All four inhibitors induce extensive acetylation of histone H4 in interphase but not in metaphase-arrested cells. The positions of histone H4 and its acetylated forms, as well as mitotic (phosphorylated) and interphase histone H1 (H1M and H1I, respectively) are indicated at the right. The abundances of H1M and H1I verify that the cells were indeed predominantly mitotic in (A) and (C) and interphase in (B) and (D). Only the portions of the gels containing the histones are shown.