Homology-Directed Repair and the Role of BRCA1, BRCA2, and Related Proteins in Genome Integrity and Cancer

Chen, Chun-Chin; Feng, Weiran; Lim, Pei Xin; Kass, Elizabeth M.; Jasin, Maria

doi:10.1146/annurev-cancerbio-030617-050502

Cited by 257 publications

(243 citation statements)

References 206 publications

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“…While yeast do not possess obvious homologs of BRCA1, BRCA1 has a well-described function in supporting the resection of DSBs in somatic mammalian cells 33 . Surprisingly, we find that BRCA1 does not similarly promote resection during meiotic recombination.…”

Section: Discussionmentioning

confidence: 99%

“…One principle role of BRCA1 is to counteract 53BP1's block to resection in S phase, possibly by excluding it from chromatin proximal to DNA damage sites 32 . In addition, BRCA1 acts post-resection to load the RAD51 recombinase onto 3' ssDNA 33 . Despite these extensive studies demonstrating their importance in somatic cells, the roles of 53BP1 and BRCA1 in regulating meiotic resection are unknown.…”

Section: Minimal Roles Of Exo1 Brca1 and 53bp1 In Long-range Resectionmentioning

confidence: 99%

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ATM and PRDM9 Regulate SPO11-bound Recombination Intermediates During Meiosis

Paiano

Yamada

et al. 2019

Preprint

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Meiotic recombination is initiated by genome-wide SPO11-induced double-strand breaks (DSBs) that are processed by MRE11-mediated release of SPO11. The DSB is then resected and loaded with DMC1/RAD51 filaments that invade homologous chromosome templates. In most mammals, DSB locations ("hotspots") are determined by the DNA sequence specificity of PRDM9. Here, we demonstrate the first direct detection of meiotic DSBs and resection in vertebrates by performing END-seq on mouse spermatocytes using low sample input. We find that DMC1 limits both the minimum and maximum lengths of resected DNA, whereas 53BP1, BRCA1 and EXO1 play surprisingly minimal roles in meiotic resection. Through enzymatic modifications to the END-seq protocol that mimic the in vivo processing of SPO11, we identify a novel meiotic recombination intermediate ("SPO11-RI") present at all hotspots. The SPO11-bound intermediate is dependent on PRDM9 and caps the 3' resected end during engagement with the homologous template. We propose that SPO11-RI is generated because chromatin-bound PRDM9 asymmetrically blocks MRE11 from releasing SPO11. In Atm -/spermatocytes, SPO11-RI is reduced while unresected DNA-bound SPO11 accumulate because of defective MRE11 initiation. Thus in addition to their global roles in governing SPO11 breakage, ATM and PRDM9 are critical local regulators of mammalian SPO11 processing. MainRecombination between homologous chromosomes during meiosis requires DNA double-strand break (DSB) formation by the topoisomerase-like protein SPO11 1 . After cutting, SPO11 remains covalently bound to a two-nucleotide, 5' overhang at both ends of the DNA via phosphotyrosyl linkage. Recombination then begins with the processing of SPO11-bound DSBs into resected 3' single-stranded DNA (ssDNA) tails that preferentially invade the homologous chromosome by the recombinases DMC1 and RAD51. Studies in budding yeast Saccharomyces cerevisiae determined that the MRE11/RAD50/NBS1 (MRN) complex detects SPO11 and cooperates with Sae2 to produce a nick on the SPO11-bound strand via MRE11 endonuclease activity 2 . The nick serves as an entry point for both short-range MRE11 3'-5' exonuclease activity to degrade back to the DSB, thereby removing covalently bound SPO11 attached to a ssDNA oligonucleotide, as well as for more extensive long-range processing of 5' strands (Extended Data Fig. 1a) 2 . In budding yeast, Exo1 nuclease is uniquely responsible for this long-range 5'-3' resection 3 .Moreover, short-and long-range resection are tightly coupled in a single processive reaction (Extended Data Fig. 1a). As a result, meiotic DSBs are maximally resected as soon as they appear and unresected SPO11-bound DSBs are extremely rare 4-6 . While ATM has been shown to regulate DSB numbers and locations 7,8 , its remains unclear whether it also functions downstream in regulating SPO11 processing and resection.Distinct from yeast, DSB hotspots in mice and humans are determined by the DNA binding specificity of the PRDM9 methyltransferase 9 . Besides positioning DSBs, PRDM9...

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Section: Discussionmentioning

confidence: 99%

Section: Minimal Roles Of Exo1 Brca1 and 53bp1 In Long-range Resectionmentioning

confidence: 99%

ATM and PRDM9 Regulate SPO11-bound Recombination Intermediates During Meiosis

Paiano

Yamada

et al. 2019

Preprint

View full text Add to dashboard Cite

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“…These defects are caused by mutations in genes involved in maintaining the integrity of the genome. For example, the loss of function mutations in BRCA1 and BRCA2 , two genes important for the repair of double‐strand breaks (DSBs) through homologous recombination (HR), accounts for a large fraction of hereditary breast and ovarian cancers . On the other hand, genome instability has also been exploited for cancer therapy with the idea that additional instability brought about by chemotherapy agents or radiation would push cancer cells into death or senescence due to the accumulation of excessive DNA damages.…”

Section: Introductionmentioning

confidence: 99%

RECQL5 plays an essential role in maintaining genome stability and viability of triple‐negative breast cancer cells

et al. 2019

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Triple‐negative breast cancer (TNBC) is a malignancy that currently lacks targeted therapies. The majority of TNBCs can be characterized as basal‐like and has an expression profile enriched with genes involved in DNA damage repair and checkpoint response. Here, we report that TNBC cells are under replication stress and are constantly generating DNA double‐strand breaks, which is not seen in non‐TNBC cells. Consequently, we found that RECQL5 , which encodes a RecQ family DNA helicase involved in many aspects of DNA metabolism including replication and repair, was essential for TNBC cells to survive and proliferate in vitro and in vivo. Compromising RECQL5 function in TNBC cells results in persistence of DNA damage, G2 arrest, and ultimately, cessation of proliferation. Our results suggest RECQL5 may be a potential therapeutic target for TNBC.

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“…2C). Given its upstream role in DNA end resection and HDR (Chen et al, 2018a), reduced recruitment of BRCA1 may contribute to modest HDR defects seen in FUS -/cells (Mastrocola et al, 2013). Despite the changes in 53BP1 and BRCA1 recruitment to IR-induced foci, FUS -/cells did not exhibit significant hypersensitivity to mechanistically distinct genotoxins, including hydroxyurea (HU, replication stress), mitomycin C (MMC, DNA crosslinker), camptothecin (CPT, Top1 inhibitor), and calicheamicin γ1 (CLM, radiomimetic) (Sup.…”

Section: Resultsmentioning

confidence: 99%

Fused in sarcoma regulates DNA replication timing and progression

Jia

Scalf

Tonzi

et al. 2020

Preprint

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Fused in sarcoma (FUS) encodes a low complexity RNA-binding protein with diverse roles in transcriptional activation and RNA processing.While oncogenic fusions of FUS and transcription factor DNA-binding domains are associated with soft tissue sarcomas, dominant mutations in FUS cause amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). FUS has also been implicated in DNA double-strand break repair (DSBR) and genome maintenance. However, the underlying mechanisms are unknown. Here we employed quantitative proteomics, trancriptomics, and DNA copy number analysis (Sort-Seq), in conjunction with FUS -/cells to ascertain roles of FUS in genome protection. FUS-deficient cells exhibited alterations in the recruitment and retention of DSBR factors BRCA1 and 53BP1 but were not overtly sensitive to genotoxins. FUS-deficient cells exhibited reduced proliferative potential that correlated with reduced replication fork speed, diminished loading of prereplication complexes, and attenuated expression of S-phase associated genes. FUS interacted with replisome components, including lagging strand synthesis factors, but did not translocate with active replication forks. Finally, we show that FUS contributes to genome-wide control of DNA replication timing. Alterations in DNA replication initiation and timing may contribute to genome instability and functional defects in mitotically active cells harboring disease-associated FUS fusions FUS regulates pre-replication complex (pre-RC) loading and associates with DNA replication factors. Given their reduced DNA replication rate, we investigated whether FUS -/cells exhibited defects in the chromatin loading of replication licensing factors, including the origin recognition complex (ORC), CDC6, and CDT,and the MCM replicative helicase (Fragkos et al., 2015)). Mitotically arrested FUS +/+ , FUS -/-, and FUS -/-:FUS cells were released into early G 1 phase and soluble and chromatin fractions analyzed by immunoblotting. FUS-deficient cells showed normal cell progression from G 2 /M to G 1 phase and unchanged ORC loading onto chrmatin in G 1 (Fig. 5A and B). By contrast, recruitment of CDC6 and CDT1 was significantly decreased in FUS -/cells and rescued by FUS reexpression (Fig. 5B). As expected, CDC6 and CDT1-dependent loading of MCM complex was also reduced in FUS -/cells (Sup. Fig. 6). Collectively, these results revealed that FUS facilitates ORC-dependent recruitment of pre-RC factors CDC6 and CDT1 to replication origins.

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Homology-Directed Repair and the Role of BRCA1, BRCA2, and Related Proteins in Genome Integrity and Cancer

Cited by 257 publications

References 206 publications

ATM and PRDM9 Regulate SPO11-bound Recombination Intermediates During Meiosis

ATM and PRDM9 Regulate SPO11-bound Recombination Intermediates During Meiosis

RECQL5 plays an essential role in maintaining genome stability and viability of triple‐negative breast cancer cells

Fused in sarcoma regulates DNA replication timing and progression

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