MRE11–RAD50–NBS1 is a critical regulator of FANCD2 stability and function during DNA double-strand break repair

Céline Roques (1) , Yan Coulombe (1) , Mathieu Delannoy (2) , Julien Vignard (1) , Simona Grossi (2) , Isabelle Brodeur (1) , Amélie Rodrigue (1) , Jean Gautier (3) , Alicja Z Stasiak (4) , Andrzej Stasiak (4) , Angelos Constantinou (2) , Jean-Yves Masson (5)

1 Laval University Cancer Research Center - Genome Stability Laboratory
2 BIL Biomedical Research Center
3 Columbia University [New York]
4 Faculty of Biology and Medicine, Center for Integrative Genomics
5 Hôpital Hôtel-Dieu

Monoubiquitination of the Fanconi anaemia protein FANCD2 is a key event leading to repair of interstrand cross-links. It was reported earlier that FANCD2 co-localizes with NBS1. However, the functional connection between FANCD2 and MRE11 is poorly understood. In this study, we show that inhibition of MRE11, NBS1 or RAD50 leads to a destabilization of FANCD2. FANCD2 accumulated from mid-S to G2 phase within sites containing single-stranded DNA (ssDNA) intermediates, or at sites of DNA damage, such as those created by restriction endonucleases and laser irradiation. Purified FANCD2, a ring-like particle by electron microscopy, preferentially bound ssDNA over various DNA substrates. Inhibition of MRE11 nuclease activity by Mirin decreased the number of FANCD2 foci formed in vivo. We propose that FANCD2 binds to ssDNA arising from MRE11-processed DNA double-strand breaks. Our data establish MRN as a crucial regulator of FANCD2 stability and function in the DNA damage response.

Mots clés: DNA metabolism; homologous recombination; mirin

Mots clés: fanconi anaemia

Domaines: Sciences du Vivant [q-bio]

Céline Roques, Yan Coulombe, Mathieu Delannoy, Julien Vignard, Simona Grossi, et al.. MRE11–RAD50–NBS1 is a critical regulator of FANCD2 stability and function during DNA double-strand break repair. EMBO Journal, 2009, 28 (16), pp.2400-2413. ⟨10.1038/emboj.2009.193⟩. ⟨hal-02662125⟩