Coordinated nuclease activities counteract Ku at single-ended DNA double-strand breaks
Publication Date
2016-09-19Journal Title
Nature Communications
ISSN
2041-1723
Publisher
Nature Publishing Group
Volume
7
Number
12889
Language
English
Type
Article
This Version
VoR
Metadata
Show full item recordCitation
Chanut, P., Britton, S., Coates, J., Jackson, S., & Calsou, P. (2016). Coordinated nuclease activities counteract Ku at single-ended DNA double-strand breaks. Nature Communications, 7 (12889)https://doi.org/10.1038/ncomms12889
Abstract
Repair of single-ended DNA double-strand breaks (seDSBs) by homologous recombination (HR) requires the generation of a 3$^\prime$ single-strand DNA overhang by exonuclease activities in a process called DNA resection. However, it is anticipated that the highly abundant DNA end-binding protein Ku sequesters seDSBs and shields them from exonuclease activities. Despite pioneering works in yeast, it is unclear how mammalian cells counteract Ku at seDSBs to allow HR to proceed. Here we show that in human cells, ATM-dependent phosphorylation of CtIP and the epistatic and coordinated actions of MRE11 and CtIP nuclease activities are required to limit the stable loading of Ku on seDSBs. We also provide evidence for a hitherto unsuspected additional mechanism that contributes to prevent Ku accumulation at seDSBs, acting downstream of MRE11 endonuclease activity and in parallel with MRE11 exonuclease activity. Finally, we show that Ku persistence at seDSBs compromises Rad51 focus assembly but not DNA resection.
Keywords
DNA recombination, DNA repair enzymes, double-strand DNA breaks, homologous recombination
Sponsorship
EMBO (long-term fellowship (ALTF 93-2010)), Cancer Research UK (Grant IDs: C6/A11224, C6/A18796, C6946/A14492), La Ligue Nationale Contre le Cancer (senior post-doctoral fellowship, Equipe Labellisée 2013), Wellcome Trust (WT092096), University of Cambridge, INSERM
Funder references
Cancer Research UK (A18796)
Wellcome Trust (092096/Z/10/Z)
Cancer Research UK (A14492)
Embargo Lift Date
2100-01-01
Identifiers
External DOI: https://doi.org/10.1038/ncomms12889
This record's URL: https://www.repository.cam.ac.uk/handle/1810/260373
Rights
Attribution 4.0 International, Attribution 4.0 International, Attribution 4.0 International, Attribution 4.0 International
Recommended or similar items
The following licence files are associated with this item: