Polyubiquitinated PCNA recruits the ZRANB3 translocase to maintain genomic integrity after replication stress

Mol Cell. 2012 Aug 10;47(3):396-409. doi: 10.1016/j.molcel.2012.05.024. Epub 2012 Jun 14.


Completion of DNA replication after replication stress depends on PCNA, which undergoes monoubiquitination to stimulate direct bypass of DNA lesions by specialized DNA polymerases or is polyubiquitinated to promote recombination-dependent DNA synthesis across DNA lesions by template switching mechanisms. Here we report that the ZRANB3 translocase, a SNF2 family member related to the SIOD disorder SMARCAL1 protein, is recruited by polyubiquitinated PCNA to promote fork restart following replication arrest. ZRANB3 depletion in mammalian cells results in an increased frequency of sister chromatid exchange and DNA damage sensitivity after treatment with agents that cause replication stress. Using in vitro biochemical assays, we show that recombinant ZRANB3 remodels DNA structures mimicking stalled replication forks and disassembles recombination intermediates. We therefore propose that ZRANB3 maintains genomic stability at stalled or collapsed replication forks by facilitating fork restart and limiting inappropriate recombination that could occur during template switching events.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Cell Line, Tumor
  • DNA Damage / physiology
  • DNA Helicases / genetics
  • DNA Helicases / metabolism*
  • DNA Replication / physiology*
  • Genomic Instability / physiology*
  • Green Fluorescent Proteins / genetics
  • Humans
  • Molecular Sequence Data
  • Osteosarcoma
  • Polyubiquitin / metabolism*
  • Proliferating Cell Nuclear Antigen / metabolism*
  • Protein Binding / physiology
  • Recombination, Genetic / physiology
  • Sister Chromatid Exchange / physiology
  • Stress, Physiological / genetics*
  • Ubiquitination / physiology


  • Proliferating Cell Nuclear Antigen
  • Polyubiquitin
  • Green Fluorescent Proteins
  • SMARCAL1 protein, human
  • DNA Helicases
  • ZRANB3 protein, human