Required for G1 arrest and mating in response to nitrogen starvation. Ago1 regulation of cytokinesis and cell cycle checkpoints occurs downstream of dcr1. Required, indirectly, for regulated hyperphosphorylation of cdc2. Has a role in the RNA interference (RNAi) pathway which is important for heterochromatin formation, accurate chromosome segregation, centromere cohesion and telomere function during mitosis and meiosis. Digests double-stranded RNA (dsRNA) producing 21 to 23 bp dsRNAs, so-called interfering RNAs (siRNA). Required for both post-transcriptional and transcriptional gene silencing. Required for silencing at the centromeres and for initiation of transcriptionally silent heterochromatin at the mating type locus. Promotes histone H3 'Lys-10' methylation necessary for centromere function. Required for recruitment of swi6 and cohesin to an ectopic dg repeat. The C-terminal dsRNA-binding fold contains a bound zinc ion and is important for normal nuclear retention and function in RNAi-dependent heterochromatin assembly. It binds double-stranded DNA and RNA (in vitro). Belongs to the helicase family. Dicer subfamily.