Fig 7. An overall model of the two classes of HDAC2-target genes.

HDAC2-repressed gene targets require the presence of HDAC2 for both HDAC2 and HDAC1 binding at gene targets as evident by the loss of enrichment of both with disruption of HDAC2. In the second class, novel HDAC2-activated target genes, HDAC2 is not necessary for the recruitment of HDAC1 to target genes. In both classes of gene targets, SIN3 enrichment is variably altered but not completely disrupted. Varying degrees of increases in histone acetylation, mainly at H3K9, at gene targets is observed with loss of HDAC2.