Structural and functional insights into the interaction between Ku70/80 and Pol X family polymerases in NHEJ
Non-homologous end joining (NHEJ) is the main repair pathway for double-strand DNA breaks (DSBs) in mammals. DNA polymerases lambda (Pol λ) and mu (Pol μ), members of the Pol X family, play a key role in this process. However, their interaction within the NHEJ complexes is unclear. Here, we present cryo-EM structures of Pol λ in complex with the DNA-PK long-range synaptic complex, and Pol μ bound to Ku70/80-DNA. These structures identify interaction sites between Ku70/80 and Pol X BRCT domains. Using mutants at the proteins interface in functional assays including cell transfection with an original gap-filling reporter, we define the role of the BRCT domain in the recruitment and activity of the two Pol X members in NHEJ and in their contribution to cell survival following DSBs. Finally, we propose a unified model for the interaction of all Pol X members with Ku70/80.
Authors
- Amanda K. Chaplin (ORCID: https://orcid.org/0000-0002-9606-8346)
- Jean‐Baptiste Charbonnier (ORCID: https://orcid.org/0000-0002-5219-1983)
- Virginie Ropars (ORCID: https://orcid.org/0000-0002-3372-6030)
- Sébastien Britton (ORCID: https://orcid.org/0000-0002-7008-5316)
- Dimitri Y. Chirgadze (ORCID: https://orcid.org/0000-0001-9942-0993)
- Himani Amin (ORCID: https://orcid.org/0000-0002-5467-6642)
- Steven W. Hardwick (ORCID: https://orcid.org/0000-0001-9246-1864)
- Sayma Zahid (ORCID: https://orcid.org/0000-0002-1354-9209)
- Philippe Frit (ORCID: https://orcid.org/0000-0002-6571-8860)
- Patrick Calsou (ORCID: https://orcid.org/0000-0001-7951-9806)
- Chloe M. Hall (ORCID: https://orcid.org/0000-0002-8211-6642)
- Jeanne Chauvat (ORCID: https://orcid.org/0000-0002-2409-6874)
- Gurdip Matharu (ORCID: https://orcid.org/0000-0001-6421-5906)
- Nadia Barboule (ORCID: https://orcid.org/0009-0001-5129-8877)
Institutions
- Centre National de la Recherche Scientifique (FR)
- Université Toulouse III - Paul Sabatier (FR)
- University of Leicester (GB)
- University of Cambridge (GB)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Université Paris-Saclay (FR)
- Institut de Pharmacologie et de Biologie Structurale (FR)
- Institut de Biologie Intégrative de la Cellule (FR)
- CEA Paris-Saclay (FR)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-05-06
- DOI
- https://doi.org/10.1038/s41467-025-59133-2
- Citations
- 11
- Primary Topic
- DNA Repair Mechanisms
- Type
- article
- Field-Weighted Citation Impact
- 8.87
Funders
- Biogen
- Lister Institute of Preventive Medicine
- Agence Nationale de la Recherche
- Institut National de la Santé et de la Recherche Médicale
- Fondation ARC pour la Recherche sur le Cancer
- French Infrastructure for Integrated Structural Biology
- Medical Research Council