RAD51 protects against nonconservative DNA double-strand break repair through a nonenzymatic function

Autor: Ayeong So, Elodie Dardillac, Ali Muhammad, Catherine Chailleux, Laura Sesma-Sanz, Sandrine Ragu, Eric Le Cam, Yvan Canitrot, Jean Yves Masson, Pauline Dupaigne, Bernard S Lopez, Josée Guirouilh-Barbat
Přispěvatelé: [Institut Cochin] Département Développement, Reproduction et Cancer (DRC), Institut Cochin (IC UM3 (UMR 8104 / U1016)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut Gustave Roussy (IGR), Intégrité du génome et cancers (IGC), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut Gustave Roussy (IGR)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centre de Biologie Intégrative (CBI), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Axe Oncologie [CRCHU de Québec], Centre de recherche du CHU de Québec-Université Laval (CRCHUQ), CHU de Québec–Université Laval, Université Laval [Québec] (ULaval)-Université Laval [Québec] (ULaval)-CHU de Québec–Université Laval, Université Laval [Québec] (ULaval)-Université Laval [Québec] (ULaval), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Guirouilh-Barbat, Josée
Rok vydání: 2022
Předmět:
Zdroj: Nucleic Acids Research
Nucleic Acids Research, 2022, 50 (5), pp.2651-2666. ⟨10.1093/nar/gkac073⟩
ISSN: 1362-4962
0305-1048
DOI: 10.1093/nar/gkac073
Popis: Selection of the appropriate DNA double-strand break (DSB) repair pathway is decisive for genetic stability. It is proposed to act according to two steps: 1-canonical nonhomologous end-joining (C-NHEJ) versus resection that generates single-stranded DNA (ssDNA) stretches; 2-on ssDNA, gene conversion (GC) versus nonconservative single-strand annealing (SSA) or alternative end-joining (A-EJ). Here, we addressed the mechanisms by which RAD51 regulates this second step, preventing nonconservative repair in human cells. Silencing RAD51 or BRCA2 stimulated both SSA and A-EJ, but not C-NHEJ, validating the two-step model. Three different RAD51 dominant-negative forms (DN-RAD51s) repressed GC and stimulated SSA/A-EJ. However, a fourth DN-RAD51 repressed SSA/A-EJ, although it efficiently represses GC. In living cells, the three DN-RAD51s that stimulate SSA/A-EJ failed to load efficiently onto damaged chromatin and inhibited the binding of endogenous RAD51, while the fourth DN-RAD51, which inhibits SSA/A-EJ, efficiently loads on damaged chromatin. Therefore, the binding of RAD51 to DNA, rather than its ability to promote GC, is required for SSA/A-EJ inhibition by RAD51. We showed that RAD51 did not limit resection of endonuclease-induced DSBs, but prevented spontaneous and RAD52-induced annealing of complementary ssDNA in vitro. Therefore, RAD51 controls the selection of the DSB repair pathway, protecting genome integrity from nonconservative DSB repair through ssDNA occupancy, independently of the promotion of CG.
Databáze: OpenAIRE