Mediates heterochromatin assembly by promoting RNAi-mediated heterochromatin silencing and histone deacetylation (PubMed:33693625). Binds pericetromeric transcripts and recruits the RNA-induced transcriptional silencing (RITS) complex to heterochromatin (PubMed:33693625). Recruits sir2 to chromatin to promote deacetylation of 'Lys-9' of histone H3 (PubMed:33693625). Interacts with dpb4 (PubMed:33693625). Interacts with chp1 (PubMed:33693625). Abolishes siRNA production from the centromeric outer repeat region (PubMed:33693625). Decreases H3K9 methylation and impairs heterochromatin silencing; simultaneous disruption of dpb4 exacerbates the effect (PubMed:33693625). Shown to localize to the nucleolus in PMID:16823372 by overexpression of a C-terminally tagged allele, however this allele was subsequently shown to be non-functional in PMID:33693625.