Abstract
Mutations in the tumour suppressor gene BRCA2 are associated with predisposition to breast and ovarian cancers. BRCA2 has a central role in maintaining genome integrity by facilitating the repair of toxic DNA double-strand breaks (DSBs) by homologous recombination (HR). BRCA2 acts by controlling RAD51 nucleoprotein filament formation on resected single-stranded DNA, but how BRCA2 activity is regulated during HR is not fully understood. Here, we delineate a pathway where ATM and ATR kinases phosphorylate a highly conserved region in BRCA2 in response to DSBs. These phosphorylations stimulate the binding of the protein phosphatase PP2A-B56 to BRCA2 through a conserved binding motif. We show that the phosphorylation-dependent formation of the BRCA2-PP2A-B56 complex is required for efficient RAD51 filament formation at sites of DNA damage and HR-mediated DNA repair. Moreover, we find that several cancer-associated mutations in BRCA2 deregulate the BRCA2-PP2A-B56 interaction and sensitize cells to PARP inhibition. Collectively, our work uncovers PP2A-B56 as a positive regulator of BRCA2 function in HR with clinical implications for BRCA2 and PP2A-B56 mutated cancers.
BRCA2 plays a central role in facilitating DNA repair by homologous recombination (HR). Here the authors describe how BRCA2 forms a complex with the protein phosphatase PP2A-B56 in response to DNA damage, which is required for HR.
Original language | English |
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Article number | 5748 |
Journal | Nature Communications |
Volume | 12 |
Issue number | 1 |
Number of pages | 11 |
ISSN | 2041-1723 |
DOIs | |
Publication status | Published - 2021 |
Keywords
- CROSS-LINK
- GENOME INTEGRITY
- DIRECTED REPAIR
- REPLICATION
- RAD51
- BREAST
- PROMOTES
- MECHANISM
- PHOSPHORYLATION
- DEGRADATION