Multiple forms of histone acetyltransferases in the cytosol of calf endometrium.
The histone acetyltransferase (EC 2.3.1.-) activity of calf endometrium cytosol has been separated into three separate activities by stepwise chromatography on DEAE-cellulose. In addition to differential elution from the DEAE-cellulose, the three activities are differentiated by their pH optima, preferences for histone subfractions as substrates, and stability to heat denaturation. Peak I has an optimum of pH 8.7 and preferentially acetylates histones F2b and F3; Peak II has an optimum of pH 8.5, and preferentially acetylates histone F2al followed by histone F2b; Peak III has an optimum of pH 9.5, and had similar specificity to Peak II. Peak III is appreciably more stable at 60 degrees C than is Peak II. None of the peaks transferred acetate to other proteins tested or to tRNA. These studies suggest the presence of multiple histone acetyltransferases in tissue cytosols.
Multiple forms of histone acetyltransferases in the cytosol of calf endometrium. The histone acetyltransferase (EC 2.3.1.-) activity of calf endometrium cytosol has been separated into three separate activities by stepwise chromatography on DEAE-cellulose. In addition to differential elution from the DEAE-cellulose, the three activities are differentiated by their pH optima, preferences for histone subfractions as substrates, and stability to heat denaturation. Peak I has an optimum of pH 8.7 and preferentially acetylates histones F2b and F3; Peak II has an optimum of pH 8.5, and preferentially acetylates histone F2al followed by histone F2b; Peak III has an optimum of pH 9.5, and had similar specificity to Peak II. Peak III is appreciably more stable at 60 degrees C than is Peak II. None of the peaks transferred acetate to other proteins tested or to tRNA. These studies suggest the presence of multiple histone acetyltransferases in tissue cytosols.