Rad52-Rad51 association is essential to protect Rad51 filaments against Srs2, but facultative for filament formation
Abstract
Homology search and strand exchange mediated by Rad51 nucleoprotein filaments are key steps of the homologous recombination process. In budding yeast, Rad52 is the main mediator of Rad51 filament formation, thereby playing an essential role. The current model assumes that Rad51 filament formation requires the interaction between Rad52 and Rad51. However, we report here that Rad52 mutations that disrupt this interaction do not affect γ-ray- or HO endonuclease-induced gene conversion frequencies. In vivo and in vitro studies confirmed that Rad51 filaments formation is not affected by these mutations. Instead, we found that Rad52-Rad51 association makes Rad51 filaments toxic in Srs2-deficient cells after exposure to DNA damaging agents, independently of Rad52 role in Rad51 filament assembly. Importantly, we also demonstrated that Rad52 is essential for protecting Rad51 filaments against dissociation by the Srs2 DNA translocase. Our findings open new perspectives in the understanding of the role of Rad52 in eukaryotes.
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All data generated or analysed during this study are included in the manuscript and supporting files.
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Funding
Commissariat à l'Énergie Atomique et aux Énergies Alternatives (Recurrent funding)
- Raphaël Guerois
- Eric Coïc
Centre National de la Recherche Scientifique (Recurrent funding)
- Eric Le Cam
Fondation ARC pour la Recherche sur le Cancer (SFI20121205689)
- Eric Coïc
Ligue Contre le Cancer (2015-16)
- Eric Coïc
Agence Nationale de la Recherche (ANR-15-CE11-0008-01)
- Raphaël Guerois
Region Ile-de-France (DIM Nano-K No F13012333)
- Eric Le Cam
Fondation ARC pour la Recherche sur le Cancer (PJA 20141201772)
- Eric Coïc
Ligue Contre le Cancer (2016-2017)
- Eric Le Cam
Agence Nationale de la Recherche (ANR-13-BSV8-0022)
- Eric Le Cam
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2018, Ma et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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