PTIP/Swift is required for efficient PCNA ubiquitination in response to DNA damage

Thomas Göhler, Ivan M. Munoz, John Rouse, J. Julian Blow

Research output: Contribution to journalArticlepeer-review

Abstract

Monoubiquitination of proliferating cell nuclear antigen (PCNA) enables translesion synthesis (TLS) by specialized DNA polymerases to replicate past damaged DNA. We have studied PCNA modification and chromatin recruitment of TLS polymerases in Xenopus egg extracts and mammalian cells. We show that Xenopus PCNA becomes ubiquitinated and sumoylated after replication stress induced by UV or aphidicolin. Under these conditions the TLS polymerase eta was recruited to chromatin and also became monoubiquitinated. PTIP/Swift is an adaptor protein for the ATM/ATR kinases. Immunodepletion of PTIP/Swift from Xenopus extracts prevented efficient PCNA ubiquitination and polymerase eta recruitment to chromatin during replicative stress. In addition to PCNA ubiquitination, efficient polymerase eta recruitment to chromatin also required ATR kinase activity. We also show that PTIP depletion from mammalian cells by RNAi reduced PCNA ubiquitination in response to DNA damage, and also decreased the recruitment to chromatin of polymerase eta and the recombination protein Rad51. Our results suggest that PTIP/Swift is an important new regulator of DNA damage avoidance in metazoans. (c) 2008 Elsevier B.V. All rights reserved.
Original languageEnglish
Pages (from-to)775-787
Number of pages13
JournalDNA Repair
Volume7
Issue number5
DOIs
Publication statusPublished - 3 May 2008

Keywords

  • PTIP
  • PCNA
  • ubiquitination
  • sumoylation
  • translesion synthesis
  • Swift
  • CELL NUCLEAR ANTIGEN
  • WERNER-SYNDROME PROTEIN
  • DOUBLE-STRAND BREAK
  • TRANSLESION SYNTHESIS
  • POLYMERASE-ETA
  • S-PHASE
  • REPLICATION
  • REPAIR
  • SUMO
  • DOMAINS

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