Prevents gene silencing by suppressing CHG methylation as well as histone H3 lysine 9 dimethylation (H3K9me2) status at target loci. Collaboratively with ASI1 and EDM2, the AAE complex regulates alternative RNA processing (e.g. alternative splicing) and epigenetic silencing (e.g. H3K9me2) of intronic heterochromatin-containing genes as well as genic heterochromatin-containing genes by promoting distal 3' polyadenylation, thus being required for the accumulation of their full-length transcripts. May also modulate transposable elements (TE) expression. Mediates RPP7-dependent race-specific disease resistance by promoting histone H3 lysine 9 dimethylation (H3K9me2) at the proximal RPP7 polyadenylation site, thus controlling alternative polyadenylation of RPP7 immune receptor transcripts and facilitating 2-phosphoserine RNAPII occupancy. In cv. Columbia, required for RPP7-dependent disease resistance against the Hyaloperonospora arabidopsidis isolate Hiks1