The mammalian INO80 chromatin remodeling complex is required for replication stress recovery

Nucleic Acids Res. 2014 Aug;42(14):9074-86. doi: 10.1093/nar/gku605. Epub 2014 Jul 12.


A number of studies have implicated the yeast INO80 chromatin remodeling complex in DNA replication, but the function of the human INO80 complex during S phase remains poorly understood. Here, we have systematically investigated the involvement of the catalytic subunit of the human INO80 complex during unchallenged replication and under replication stress by following the effects of its depletion on cell survival, S-phase checkpoint activation, the fate of individual replication forks, and the consequences of fork collapse. We report that INO80 was specifically needed for efficient replication elongation, while it was not required for initiation of replication. In the absence of the Ino80 protein, cells became hypersensitive to hydroxyurea and displayed hyperactive ATR-Chk1 signaling. Using bulk and fiber labeling of DNA, we found that cells deficient for Ino80 and Arp8 had impaired replication restart after treatment with replication inhibitors and accumulated double-strand breaks as evidenced by the formation of γ-H2AX and Rad51 foci. These data indicate that under conditions of replication stress mammalian INO80 protects stalled forks from collapsing and allows their subsequent restart.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATPases Associated with Diverse Cellular Activities
  • Cell Cycle
  • Cell Line
  • Chromatin / metabolism
  • DNA Helicases / antagonists & inhibitors
  • DNA Helicases / physiology*
  • DNA Replication* / drug effects
  • DNA-Binding Proteins
  • Humans
  • Hydroxyurea / toxicity
  • Microfilament Proteins / antagonists & inhibitors
  • Replication Origin
  • S Phase / drug effects
  • S Phase / genetics
  • Stress, Physiological / genetics*


  • ACTR8 protein, human
  • Chromatin
  • DNA-Binding Proteins
  • Microfilament Proteins
  • ATPases Associated with Diverse Cellular Activities
  • DNA Helicases
  • INO80 protein, human
  • Hydroxyurea