RNA interference is essential for cellular quiescence

B. Roche (1, 2) , Benoît Arcangioli (3) , R. Martienssen (1, 2)

1 CSHL - Cold Spring Harbor Laboratory
2 HHMI - Howard Hughes Medical Institute
3 Dynamique du Génome - Dynamics of the genome

Quiescent cells play a predominant role in most organisms. Here we identify RNA interference (RNAi) as a major requirement for quiescence (G0 phase of the cell cycle) in Schizosaccharomyces pombe RNAi mutants lose viability at G0 entry and are unable to maintain long-term quiescence. We identified suppressors of G0 defects in cells lacking Dicer (dcr1Δ), which mapped to genes involved in chromosome segregation, RNA polymerase-associated factors, and heterochromatin formation. We propose a model in which RNAi promotes the release of RNA polymerase in cycling and quiescent cells: (i) RNA polymerase II release mediates heterochromatin formation at centromeres, allowing proper chromosome segregation during mitotic growth and G0 entry, and (ii) RNA polymerase I release prevents heterochromatin formation at ribosomal DNA during quiescence maintenance. Our model may account for the codependency of RNAi and histone H3 lysine 9 methylation throughout eukaryotic evolution.

Domains: Genomics [q-bio.GN]

B. Roche, Benoît Arcangioli, R. Martienssen. RNA interference is essential for cellular quiescence. Science, 2016, 354 (6313), ⟨10.1126/science.aah5651⟩. ⟨pasteur-01868276⟩