Histone hypoacetylation following release of HTC cells from butyrate

Exposure of HTC cells to 6 mM sodium butyrate for 20 h results in significantly reduced amounts of nuclear histone acetyltransferase. While the direct butyrate inhibition of histone deacetylases is rapidly reversed upon removal of cells from butyrate, histone acetyltransferase activity increases only gradually following release of cells from butyrate, requiring several hours to regain control cell levels. As a result, HTC cells released from a 20-h exposure to butyrate display normal kinetics of histone acetate turnover but markedly reduced rates of histone acetylation, the imbalance in these two processes produces histone hypoacetylation.