FIGURE 6.

Model for functional effects of activator-dependent p300 histone acetylation. Based on our data, promoter-proximal p300 histone acetylation is proposed to perform two functions. One antagonizes histone methylation-dependent transduction pathways via acetylation of H3K9, H3K27, and H3K36, whereas the other destabilizes higher order structure via acetylation-dependent disruption of both secondary and tertiary chromatin structures leading to subsequent primary structure changes of the chromatin fiber and fine-tuned regulation of gene expression.