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

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    30 Citations (Scopus)

    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 - 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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