Mutations disrupting histone methylation have different effects on replication timing in S. pombe centromere

PLoS One. 2013 May 1;8(5):e61464. doi: 10.1371/journal.pone.0061464. Print 2013.

Abstract

The fission yeast pericentromere comprises repetitive sequence elements packaged into heterchromatin marked by histone H3K9 methylation and Swi6 binding. Transient disruption of Swi6 during S phase allows a period of RNA synthesis which programs the RNAi machinery to maintain histone methylation. However, Swi6 is also required for early replication timing. We show that not only Swi6 but also the chromodomain protein Chp1 are delocalized during S phase. Different from loss of swi6, mutations that disrupt histone methylation in the centromere, chp1Δ and clr4Δ, undergo early DNA replication. However, timing is modestly delayed in RNAi mutants dcr1Δ or rdp1Δ, while hrr1Δ mutants resemble swi6Δ in their replication delay. Finally, we show that recruitment of RNA polymerase II in the centromere occurs independently of replication. These different effects indicate that replication timing is not simply linked to histone methylation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Centromere / metabolism
  • Chromosomal Proteins, Non-Histone / metabolism
  • Chromosomes, Fungal / metabolism
  • DNA Replication*
  • Histones
  • Methylation
  • Methyltransferases / genetics
  • Protein Processing, Post-Translational*
  • Protein Transport
  • RNA Interference
  • RNA Polymerase II / metabolism
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces / metabolism
  • Schizosaccharomyces pombe Proteins / genetics
  • Schizosaccharomyces pombe Proteins / metabolism
  • Sequence Deletion
  • Spindle Apparatus / metabolism

Substances

  • Cell Cycle Proteins
  • Chp1 protein, S pombe
  • Chromosomal Proteins, Non-Histone
  • Histones
  • Schizosaccharomyces pombe Proteins
  • Swi6 protein, S pombe
  • Methyltransferases
  • clr4 protein, S pombe
  • RNA Polymerase II