DNA damage triggers increased mobility of chromosomes in G1-phase cells

Mol Biol Cell. 2019 Oct 1;30(21):2620-2625. doi: 10.1091/mbc.E19-08-0469. Epub 2019 Sep 4.

Abstract

During S phase in Saccharomyces cerevisiae, chromosomal loci become mobile in response to DNA double-strand breaks both at the break site (local mobility) and throughout the nucleus (global mobility). Increased nuclear exploration is regulated by the recombination machinery and the DNA damage checkpoint and is likely an important aspect of homology search. While mobility in response to DNA damage has been studied extensively in S phase, the response in interphase has not, and the question of whether homologous recombination proceeds to completion in G1 phase remains controversial. Here, we find that global mobility is triggered in G1 phase. As in S phase, global mobility in G1 phase is controlled by the DNA damage checkpoint and the Rad51 recombinase. Interestingly, despite the restriction of Rad52 mediator foci to S phase, Rad51 foci form at high levels in G1 phase. Together, these observations indicate that the recombination and checkpoint machineries promote global mobility in G1 phase, supporting the notion that recombination can occur in interphase diploids.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Cell Nucleus / genetics*
  • Cell Nucleus / metabolism
  • Chromosomes, Fungal / genetics*
  • DNA Breaks, Double-Stranded
  • DNA Damage*
  • DNA Repair / genetics
  • G1 Phase / genetics*
  • Homologous Recombination
  • Rad51 Recombinase / genetics
  • Rad51 Recombinase / metabolism
  • Rad52 DNA Repair and Recombination Protein / genetics
  • Rad52 DNA Repair and Recombination Protein / metabolism
  • S Phase / genetics
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism

Substances

  • RAD52 protein, S cerevisiae
  • Rad52 DNA Repair and Recombination Protein
  • Saccharomyces cerevisiae Proteins
  • RAD51 protein, S cerevisiae
  • Rad51 Recombinase