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Marie L, Symington LS. Mechanism for inverted-repeat recombination induced by a replication fork barrier. Nat Commun 2022; 13:32. [PMID: 35013185 PMCID: PMC8748988 DOI: 10.1038/s41467-021-27443-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 11/22/2021] [Indexed: 01/11/2023] Open
Abstract
Replication stress and abundant repetitive sequences have emerged as primary conditions underlying genomic instability in eukaryotes. To gain insight into the mechanism of recombination between repeated sequences in the context of replication stress, we used a prokaryotic Tus/Ter barrier designed to induce transient replication fork stalling near inverted repeats in the budding yeast genome. Our study reveals that the replication fork block stimulates a unique recombination pathway dependent on Rad51 strand invasion and Rad52-Rad59 strand annealing activities, Mph1/Rad5 fork remodelers, Mre11/Exo1/Dna2 resection machineries, Rad1-Rad10 nuclease and DNA polymerase δ. Furthermore, we show recombination at stalled replication forks is limited by the Srs2 helicase and Mus81-Mms4/Yen1 nucleases. Physical analysis of the replication-associated recombinants revealed that half are associated with an inversion of sequence between the repeats. Based on our extensive genetic characterization, we propose a model for recombination of closely linked repeats that can robustly generate chromosome rearrangements. Replication stress and abundant repetitive sequences have emerged as primary conditions underlying genomic instability in eukaryotes. Here the authors use a prokaryotic Tus/Ter barrier designed to induce transient replication fork stalling near inverted repeats in the budding yeast genome to support a model for recombination of closely linked repeats at stalled replication forks.
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Affiliation(s)
- Léa Marie
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Lorraine S Symington
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA. .,Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY, 10032, USA.
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2
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Clear AD, Manthey GM, Lewis O, Lopez IY, Rico R, Owens S, Negritto MC, Wolf EW, Xu J, Kenjić N, Perry JJP, Adamson AW, Neuhausen SL, Bailis AM. Variants of the human RAD52 gene confer defects in ionizing radiation resistance and homologous recombination repair in budding yeast. ACTA ACUST UNITED AC 2020; 7:270-285. [PMID: 33015141 PMCID: PMC7517009 DOI: 10.15698/mic2020.10.732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
RAD52 is a structurally and functionally conserved component of the DNA double-strand break (DSB) repair apparatus from budding yeast to humans. We recently showed that expressing the human gene, HsRAD52 in rad52 mutant budding yeast cells can suppress both their ionizing radiation (IR) sensitivity and homologous recombination repair (HRR) defects. Intriguingly, we observed that HsRAD52 supports DSB repair by a mechanism of HRR that conserves genome structure and is independent of the canonical HR machinery. In this study we report that naturally occurring variants of HsRAD52, one of which suppresses the pathogenicity of BRCA2 mutations, were unable to suppress the IR sensitivity and HRR defects of rad52 mutant yeast cells, but fully suppressed a defect in DSB repair by single-strand annealing (SSA). This failure to suppress both IR sensitivity and the HRR defect correlated with an inability of HsRAD52 protein to associate with and drive an interaction between genomic sequences during DSB repair by HRR. These results suggest that HsRAD52 supports multiple, distinct DSB repair apparatuses in budding yeast cells and help further define its mechanism of action in HRR. They also imply that disruption of HsRAD52-dependent HRR in BRCA2-defective human cells may contribute to protection against tumorigenesis and provide a target for killing BRCA2-defective cancers.
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Affiliation(s)
- Alissa D Clear
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, Duarte, CA, USA.,Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope, Duarte, CA, USA.,bioStrategies Group, Chicago, IL, USA
| | - Glenn M Manthey
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, Duarte, CA, USA.,Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope, Duarte, CA, USA
| | - Olivia Lewis
- City of Hope - Duarte High School NIH Science Education Partnership Award Program, Duarte, CA, USA.,Barbara Bush Houston Literacy Foundation, Houston, TX, USA
| | - Isabelle Y Lopez
- City of Hope - Duarte High School NIH Science Education Partnership Award Program, Duarte, CA, USA.,California State Polytechnic University at Pomona, Pomona, CA, USA
| | - Rossana Rico
- City of Hope - Duarte High School NIH Science Education Partnership Award Program, Duarte, CA, USA.,Henry Samueli School of Engineering and Applied Sciences, University of California at Los Angeles, Los Angeles, CA, USA
| | - Shannon Owens
- Eugene and Ruth Roberts Summer Student Academy, Beckman Research Institute of City of Hope, Duarte, CA, USA.,Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, CA, USA
| | | | - Elise W Wolf
- Molecular Biology Program, Pomona College, Claremont, CA, USA.,Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA, USA
| | - Jason Xu
- Molecular Biology Program, Pomona College, Claremont, CA, USA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nikola Kenjić
- Department of Biochemistry, University of California at Riverside, Riverside, CA, USA
| | - J Jefferson P Perry
- Department of Biochemistry, University of California at Riverside, Riverside, CA, USA
| | - Aaron W Adamson
- Department of Population Sciences, Beckman Research Institute of City of Hope, Duarte, CA, USA
| | - Susan L Neuhausen
- Department of Population Sciences, Beckman Research Institute of City of Hope, Duarte, CA, USA
| | - Adam M Bailis
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, Duarte, CA, USA.,Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope, Duarte, CA, USA.,College of Health Professions, Thomas Jefferson University, Philadelphia, PA, USA
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3
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Partner Choice in Spontaneous Mitotic Recombination in Wild Type and Homologous Recombination Mutants of Candida albicans. G3-GENES GENOMES GENETICS 2019; 9:3631-3644. [PMID: 31690596 PMCID: PMC6829120 DOI: 10.1534/g3.119.400516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Candida albicans, the most common fungal pathogen, is a diploid with a genome that is rich in repeats and has high levels of heterozygosity. To study the role of different recombination pathways on direct-repeat recombination, we replaced either allele of the RAD52 gene (Chr6) with the URA-blaster cassette (hisG-URA3-hisG), measured rates of URA3 loss as resistance to 5-fluoroorotic acid (5FOAR) and used CHEF Southern hybridization and SNP-RFLP analysis to identify recombination mechanisms and their frequency in wildtype and recombination mutants. FOAR rates varied little across different strain backgrounds. In contrast, the type and frequency of mechanisms underlying direct repeat recombination varied greatly. For example, wildtype, rad59 and lig4 strains all displayed a bias for URA3 loss via pop-out/deletion vs. inter-homolog recombination and this bias was reduced in rad51 mutants. In addition, in rad51-derived 5FOAR strains direct repeat recombination was associated with ectopic translocation (5%), chromosome loss/truncation (14%) and inter-homolog recombination (6%). In the absence of RAD52, URA3 loss was mostly due to chromosome loss and truncation (80–90%), and the bias of retained allele frequency points to the presence of a recessive lethal allele on Chr6B. However, a few single-strand annealing (SSA)-like events were identified and these were independent of either Rad59 or Lig4. Finally, the specific sizes of Chr6 truncations suggest that the inserted URA-blaster could represent a fragile site.
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4
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Silva S, Altmannova V, Eckert-Boulet N, Kolesar P, Gallina I, Hang L, Chung I, Arneric M, Zhao X, Buron LD, Mortensen UH, Krejci L, Lisby M. SUMOylation of Rad52-Rad59 synergistically change the outcome of mitotic recombination. DNA Repair (Amst) 2016; 42:11-25. [PMID: 27130983 DOI: 10.1016/j.dnarep.2016.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 04/02/2016] [Accepted: 04/05/2016] [Indexed: 11/18/2022]
Abstract
Homologous recombination (HR) is essential for maintenance of genome stability through double-strand break (DSB) repair, but at the same time HR can lead to loss of heterozygosity and uncontrolled recombination can be genotoxic. The post-translational modification by SUMO (small ubiquitin-like modifier) has been shown to modulate recombination, but the exact mechanism of this regulation remains unclear. Here we show that SUMOylation stabilizes the interaction between the recombination mediator Rad52 and its paralogue Rad59 in Saccharomyces cerevisiae. Although Rad59 SUMOylation is not required for survival after genotoxic stress, it affects the outcome of recombination to promote conservative DNA repair. In some genetic assays, Rad52 and Rad59 SUMOylation act synergistically. Collectively, our data indicate that the described SUMO modifications affect the balance between conservative and non-conservative mechanisms of HR.
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Affiliation(s)
- Sonia Silva
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Veronika Altmannova
- Department of Biology, Masaryk University, Kamenice 5/A7, 62500 Brno, Czech Republic
| | - Nadine Eckert-Boulet
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Peter Kolesar
- Department of Biology, Masaryk University, Kamenice 5/A7, 62500 Brno, Czech Republic
| | - Irene Gallina
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Lisa Hang
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Inn Chung
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Milica Arneric
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Xiaolan Zhao
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Line Due Buron
- Department of Systems Biology, Technical University of Denmark, Building 223, 2800 Kgs. Lyngby, Denmark
| | - Uffe H Mortensen
- Department of Systems Biology, Technical University of Denmark, Building 223, 2800 Kgs. Lyngby, Denmark
| | - Lumir Krejci
- Department of Biology, Masaryk University, Kamenice 5/A7, 62500 Brno, Czech Republic; National Centre for Biomolecular Research, Masaryk University, Kamenice 5/A4, Brno 625 00, Czech Republic; International Clinical Research Center, Center for Biomolecular and Cellular Engineering, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Michael Lisby
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
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Morrical SW. DNA-pairing and annealing processes in homologous recombination and homology-directed repair. Cold Spring Harb Perspect Biol 2015; 7:a016444. [PMID: 25646379 DOI: 10.1101/cshperspect.a016444] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The formation of heteroduplex DNA is a central step in the exchange of DNA sequences via homologous recombination, and in the accurate repair of broken chromosomes via homology-directed repair pathways. In cells, heteroduplex DNA largely arises through the activities of recombination proteins that promote DNA-pairing and annealing reactions. Classes of proteins involved in pairing and annealing include RecA-family DNA-pairing proteins, single-stranded DNA (ssDNA)-binding proteins, recombination mediator proteins, annealing proteins, and nucleases. This review explores the properties of these pairing and annealing proteins, and highlights their roles in complex recombination processes including the double Holliday junction (DhJ) formation, synthesis-dependent strand annealing, and single-strand annealing pathways--DNA transactions that are critical both for genome stability in individual organisms and for the evolution of species.
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Affiliation(s)
- Scott W Morrical
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, Vermont 05405
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6
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Liddell LC, Manthey GM, Owens SN, Fu BXH, Bailis AM. Alleles of the homologous recombination gene, RAD59, identify multiple responses to disrupted DNA replication in Saccharomyces cerevisiae. BMC Microbiol 2013; 13:229. [PMID: 24125552 PMCID: PMC3852934 DOI: 10.1186/1471-2180-13-229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 10/04/2013] [Indexed: 11/26/2022] Open
Abstract
Background In Saccharomyces cerevisiae, Rad59 is required for multiple homologous recombination mechanisms and viability in DNA replication-defective rad27 mutant cells. Recently, four rad59 missense alleles were found to have distinct effects on homologous recombination that are consistent with separation-of-function mutations. The rad59-K166A allele alters an amino acid in a conserved α-helical domain, and, like the rad59 null allele diminishes association of Rad52 with double-strand breaks. The rad59-K174A and rad59-F180A alleles alter amino acids in the same domain and have genetically similar effects on homologous recombination. The rad59-Y92A allele alters a conserved amino acid in a separate domain, has genetically distinct effects on homologous recombination, and does not diminish association of Rad52 with double-strand breaks. Results In this study, rad59 mutant strains were crossed with a rad27 null mutant to examine the effects of the rad59 alleles on the link between viability, growth and the stimulation of homologous recombination in replication-defective cells. Like the rad59 null allele, rad59-K166A was synthetically lethal in combination with rad27. The rad59-K174A and rad59-F180A alleles were not synthetically lethal in combination with rad27, had effects on growth that coincided with decreased ectopic gene conversion, but did not affect mutation, unequal sister-chromatid recombination, or loss of heterozygosity. The rad59-Y92A allele was not synthetically lethal when combined with rad27, stimulated ectopic gene conversion and heteroallelic recombination independently from rad27, and was mutually epistatic with srs2. Unlike rad27, the stimulatory effect of rad59-Y92A on homologous recombination was not accompanied by effects on growth rate, cell cycle distribution, mutation, unequal sister-chromatid recombination, or loss of heterozygosity. Conclusions The synthetic lethality conferred by rad59 null and rad59-K166A alleles correlates with their inhibitory effect on association of Rad52 with double-strand breaks, suggesting that this may be essential for rescuing replication lesions in rad27 mutant cells. The rad59-K174A and rad59-F180A alleles may fractionally reduce this same function, which proportionally reduced repair of replication lesions by homologous recombination and growth rate. In contrast, rad59-Y92A stimulates homologous recombination, perhaps by affecting association of replication lesions with the Rad51 recombinase. This suggests that Rad59 influences the rescue of replication lesions by multiple recombination factors.
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Affiliation(s)
- Lauren C Liddell
- Department of Molecular and Cellular Biology, Beckman Research Institute of the City of Hope, 91010 Duarte, CA, USA.
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Pardo B, Aguilera A. Complex chromosomal rearrangements mediated by break-induced replication involve structure-selective endonucleases. PLoS Genet 2012; 8:e1002979. [PMID: 23071463 PMCID: PMC3459980 DOI: 10.1371/journal.pgen.1002979] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 08/08/2012] [Indexed: 11/18/2022] Open
Abstract
DNA double-strand break (DSB) repair occurring in repeated DNA sequences often leads to the generation of chromosomal rearrangements. Homologous recombination normally ensures a faithful repair of DSBs through a mechanism that transfers the genetic information of an intact donor template to the broken molecule. When only one DSB end shares homology to the donor template, conventional gene conversion fails to occur and repair can be channeled to a recombination-dependent replication pathway termed break-induced replication (BIR), which is prone to produce chromosome non-reciprocal translocations (NRTs), a classical feature of numerous human cancers. Using a newly designed substrate for the analysis of DSB-induced chromosomal translocations, we show that Mus81 and Yen1 structure-selective endonucleases (SSEs) promote BIR, thus causing NRTs. We propose that Mus81 and Yen1 are recruited at the strand invasion intermediate to allow the establishment of a replication fork, which is required to complete BIR. Replication template switching during BIR, a feature of this pathway, engenders complex chromosomal rearrangements when using repeated DNA sequences dispersed over the genome. We demonstrate here that Mus81 and Yen1, together with Slx4, also promote template switching during BIR. Altogether, our study provides evidence for a role of SSEs at multiple steps during BIR, thus participating in the destabilization of the genome by generating complex chromosomal rearrangements.
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Affiliation(s)
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla, Sevilla, Spain
- * E-mail:
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8
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Pannunzio NR, Manthey GM, Liddell LC, Fu BXH, Roberts CM, Bailis AM. Rad59 regulates association of Rad52 with DNA double-strand breaks. Microbiologyopen 2012; 1:285-97. [PMID: 23170228 PMCID: PMC3496973 DOI: 10.1002/mbo3.31] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 06/06/2012] [Accepted: 07/02/2012] [Indexed: 11/25/2022] Open
Abstract
Homologous recombination among repetitive sequences is an important mode of DNA repair in eukaryotes following acute radiation exposure. We have developed an assay in Saccharomyces cerevisiae that models how multiple DNA double-strand breaks form chromosomal translocations by a nonconservative homologous recombination mechanism, single-strand annealing, and identified the Rad52 paralog, Rad59, as an important factor. We show through genetic and molecular analyses that Rad59 possesses distinct Rad52-dependent and -independent functions, and that Rad59 plays a critical role in the localization of Rad52 to double-strand breaks. Our analysis further suggests that Rad52 and Rad59 act in multiple, sequential processes that determine genome structure following acute exposure to DNA damaging agents.
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Affiliation(s)
- Nicholas R Pannunzio
- Department of Molecular and Cellular Biology, Beckman Research Institute of the City of Hope Duarte, California, 91010, USA ; The Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope Duarte, California, 91010, USA
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Liddell L, Manthey G, Pannunzio N, Bailis A. Quantitation and analysis of the formation of HO-endonuclease stimulated chromosomal translocations by single-strand annealing in Saccharomyces cerevisiae. J Vis Exp 2011:3150. [PMID: 21968396 PMCID: PMC3230211 DOI: 10.3791/3150] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Genetic variation is frequently mediated by genomic rearrangements that arise through interaction between dispersed repetitive elements present in every eukaryotic genome. This process is an important mechanism for generating diversity between and within organisms1-3. The human genome consists of approximately 40% repetitive sequence of retrotransposon origin, including a variety of LINEs and SINEs4. Exchange events between these repetitive elements can lead to genome rearrangements, including translocations, that can disrupt gene dosage and expression that can result in autoimmune and cardiovascular diseases5, as well as cancer in humans6-9. Exchange between repetitive elements occurs in a variety of ways. Exchange between sequences that share perfect (or near-perfect) homology occurs by a process called homologous recombination (HR). By contrast, non-homologous end joining (NHEJ) uses little-or-no sequence homology for exchange10,11. The primary purpose of HR, in mitotic cells, is to repair double-strand breaks (DSBs) generated endogenously by aberrant DNA replication and oxidative lesions, or by exposure to ionizing radiation (IR), and other exogenous DNA damaging agents. In the assay described here, DSBs are simultaneously created bordering recombination substrates at two different chromosomal loci in diploid cells by a galactose-inducible HO-endonuclease (Figure 1). The repair of the broken chromosomes generates chromosomal translocations by single strand annealing (SSA), a process where homologous sequences adjacent to the chromosome ends are covalently joined subsequent to annealing. One of the substrates, his3-Δ3', contains a 3' truncated HIS3 allele and is located on one copy of chromosome XV at the native HIS3 locus. The second substrate, his3-Δ5', is located at the LEU2 locus on one copy of chromosome III, and contains a 5' truncated HIS3 allele. Both substrates are flanked by a HO endonuclease recognition site that can be targeted for incision by HO-endonuclease. HO endonuclease recognition sites native to the MAT locus, on both copies of chromosome III, have been deleted in all strains. This prevents interaction between the recombination substrates and other broken chromosome ends from interfering in the assay. The KAN-MX-marked galactose-inducible HO endonuclease expression cassette is inserted at the TRP1 locus on chromosome IV. The substrates share 311 bp or 60 bp of the HIS3 coding sequence that can be used by the HR machinery for repair by SSA. Cells that use these substrates to repair broken chromosomes by HR form an intact HIS3 allele and a tXV::III chromosomal translocation that can be selected for by the ability to grow on medium lacking histidine (Figure 2A). Translocation frequency by HR is calculated by dividing the number of histidine prototrophic colonies that arise on selective medium by the total number of viable cells that arise after plating appropriate dilutions onto non-selective medium (Figure 2B). A variety of DNA repair mutants have been used to study the genetic control of translocation formation by SSA using this system12-14.
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Affiliation(s)
- Lauren Liddell
- Irell & Manella Graduate School of Biological Sciences, Department of Molecular and Cellular Biology, City of Hope Comprehensive Cancer Center and Beckman Research Institute,University of Southern California, USA
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Manthey GM, Bailis AM. Rad51 inhibits translocation formation by non-conservative homologous recombination in Saccharomyces cerevisiae. PLoS One 2010; 5:e11889. [PMID: 20686691 PMCID: PMC2912366 DOI: 10.1371/journal.pone.0011889] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 07/07/2010] [Indexed: 11/24/2022] Open
Abstract
Chromosomal translocations are a primary biological response to ionizing radiation (IR) exposure, and are likely to result from the inappropriate repair of the DNA double-strand breaks (DSBs) that are created. An abundance of repetitive sequences in eukaryotic genomes provides ample opportunity for such breaks to be repaired by homologous recombination (HR) between non-allelic repeats. Interestingly, in the budding yeast, Saccharomyces cerevisiae the central strand exchange protein, Rad51 that is required for DSB repair by gene conversion between unlinked repeats that conserves genomic structure also suppresses translocation formation by several HR mechanisms. In particular, Rad51 suppresses translocation formation by single-strand annealing (SSA), perhaps the most efficient mechanism for translocation formation by HR in both yeast and mammalian cells. Further, the enhanced translocation formation that emerges in the absence of Rad51 displays a distinct pattern of genetic control, suggesting that this occurs by a separate mechanism. Since hypomorphic mutations in RAD51 in mammalian cells also reduce DSB repair by conservative gene conversion and stimulate non-conservative repair by SSA, this mechanism may also operate in humans and, perhaps contribute to the genome instability that propels the development of cancer.
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Affiliation(s)
- Glenn M. Manthey
- Department of Molecular and Cellular Biology, Beckman Research Institute, City of Hope National Medical Center, Duarte, California, United States of America
| | - Adam M. Bailis
- Department of Molecular and Cellular Biology, Beckman Research Institute, City of Hope National Medical Center, Duarte, California, United States of America
- * E-mail:
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11
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Current awareness on yeast. Yeast 2010. [DOI: 10.1002/yea.1719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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