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Sequential recruitment of the repair factors during NER: the role of XPG in initiating the resynthesis step
Author(s) -
Mocquet Vincent,
Lainé Jean Philippe,
Riedl Thilo,
Yajin Zhou,
Lee Marietta Y,
Egly Jean Marc
Publication year - 2008
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7601948
Subject(s) - biology , dna repair , nucleotide excision repair , microbiology and biotechnology , genetics , dna
To address the biochemical mechanisms underlying the coordination between the various proteins required for nucleotide excision repair (NER), we employed the immobilized template system. Using either wild‐type or mutated recombinant proteins, we identified the factors involved in the NER process and showed the sequential comings and goings of these factors to the immobilized damaged DNA. Firstly, we found that PCNA and RF‐C arrival requires XPF 5′ incision. Moreover, the positioning of RF‐C is facilitated by RPA and induces XPF release. Concomitantly, XPG leads to PCNA recruitment and stabilization. Our data strongly suggest that this interaction with XPG protects PCNA and Polδ from the effect of inhibitors such as p21. XPG and RPA are released as soon as Polδ is recruited by the RF‐C/PCNA complex. Finally, a ligation system composed of FEN1 and Ligase I can be recruited to fully restore the DNA. In addition, using XP or trichothiodystrophy patient‐derived cell extracts, we were able to diagnose the biochemical defect that may prove to be important for therapeutic purposes.