Involvement of SLX4 in interstrand cross-link repair is regulated by the Fanconi anemia pathway

Kimiyo N. Yamamoto, Shunsuke Kobayashi, Masataka Tsuda, Hitoshi Kurumizaka, Minoru Takata, Koichi Kono, Josef Jiricny, Shunichi Takeda, Kouji Hirota*

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    157 Citations (Scopus)


    Interstrand cross-links (ICLs) block replication and transcription and thus are highly cytotoxic. In higher eukaryotes, ICLs processing involves the Fanconi anemia (FA) pathway and homologous recombination. Stalled replication forks activate the eight-subunit FA core complex, which ubiquitylates FANCD2-FANCI. Once it is posttranslationally modi.ed, this heterodimer recruits downstream members of the ICL repairosome, including the FAN1 nuclease. However, ICL processing has been shown to also involve MUS81-EME1 and XPF-ERCC1, nucleases known to interact with SLX4, a docking protein that also can bind another nuclease, SLX1. To investigate the role of SLX4 more closely, we disrupted the SLX4 gene in avian DT40 cells. SLX4 deficiency caused cell death associated with extensive chromosomal aberrations, including a significant fraction of isochromatid-type breaks, with sister chromatids broken at the same site. SLX4 thus appears to play an essential role in cell proliferation, probably by promoting the resolution of interchromatid homologous recombination intermediates. Because ubiquitylation plays a key role in the FA pathway, and because the N-terminal region of SLX4 contains a ubiquitin-binding zinc finger (UBZ) domain, we asked whether this domain is required for ICL processing. We found that SLX4-/- cells expressing UBZ-deficient SLX4 were selectively sensitive to ICL-inducing agents, and that the UBZ domain was required for interaction of SLX4 with ubiquitylated FANCD2 and for its recruitment to DNA-damage foci generated by ICL-inducing agents. Our findings thus suggest that ubiquitylated FANCD2 recruits SLX4 to DNA damage sites, where it mediates the resolution of recombination intermediates generated during the processing of ICLs.

    Original languageEnglish
    Pages (from-to)6492-6496
    Number of pages5
    JournalProceedings of the National Academy of Sciences of the United States of America
    Issue number16
    Publication statusPublished - 2011 Apr 19


    • Cisplatin
    • DNA repair
    • Endonuclease
    • Mitomycin C

    ASJC Scopus subject areas

    • General


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