Background：Functions as a histone acetyltransferase （HAT） to promote transcriptional activation. Has significant histone acetyltransferase activity with core histones （H3 and H4）, and also with nucleosome core particles. Inhibits cell-cycle progression and counteracts the mitogenic activity of the adenoviral oncoprotein E1A. In case of HIV-1 infection, it is recruited by the viral protein Tat. Regulates Tat's transactivating activity and may help inducing chromatin remodeling of proviral genes.
