DNA polymerase κ-dependent DNA synthesis at stalled replication forks is important for CHK1 activation

EMBO J. 2013 Jul 31;32(15):2172-85. doi: 10.1038/emboj.2013.148. Epub 2013 Jun 25.


Formation of primed single-stranded DNA at stalled replication forks triggers activation of the replication checkpoint signalling cascade resulting in the ATR-mediated phosphorylation of the Chk1 protein kinase, thus preventing genomic instability. By using siRNA-mediated depletion in human cells and immunodepletion and reconstitution experiments in Xenopus egg extracts, we report that the Y-family translesion (TLS) DNA polymerase kappa (Pol κ) contributes to the replication checkpoint response and is required for recovery after replication stress. We found that Pol κ is implicated in the synthesis of short DNA intermediates at stalled forks, facilitating the recruitment of the 9-1-1 checkpoint clamp. Furthermore, we show that Pol κ interacts with the Rad9 subunit of the 9-1-1 complex. Finally, we show that this novel checkpoint function of Pol κ is required for the maintenance of genomic stability and cell proliferation in unstressed human cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cell Proliferation
  • Checkpoint Kinase 1
  • DNA Replication / physiology*
  • DNA-Directed DNA Polymerase / genetics
  • DNA-Directed DNA Polymerase / metabolism*
  • Genomic Instability / physiology*
  • HeLa Cells
  • Humans
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Xenopus Proteins / genetics
  • Xenopus Proteins / metabolism*
  • Xenopus laevis


  • Cell Cycle Proteins
  • Xenopus Proteins
  • rad9 protein
  • Protein Kinases
  • CHEK1 protein, human
  • Checkpoint Kinase 1
  • Chek1 protein, Xenopus
  • DNA-Directed DNA Polymerase
  • POLK protein, human
  • Polk protein, Xenopus