Involved in post-transcriptional regulation of gene expression by 3'-UTR-mediated RNA regulation (PubMed:31822915). Promotes interactions between mRNA and poly(A)-binding protein (PubMed:31822915). Binds the 3' UTR of mRNAs, centromeric transcripts and antisense-rDNA (PubMed:31822915). Required for the establishment but not the maintenance of heterochromatin at pericentromeres, and for the maintenance of small domains of facultative heterochromatin known as HOODs (PubMed:31822915). Interacts with pab1 binding protein ath1. Abnormal establishment of heterochromatin (PubMed:31822915). Increased level of RNA-DNA hybrids (PubMed:31822915). Belongs to the XPG/RAD2 endonuclease family. Although it belongs to the XPG/RAD2 endonuclease family, only two of the seven Asp residues involved in Mg(2+) binding are conserved suggesting that it has no nuclease activity.