1
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Joris S, Giron P, Olsen C, Seneca S, Gheldof A, Staessens S, Shahi RB, De Brakeleer S, Teugels E, De Grève J, Hes FJ. Identification of RAD17 as a candidate cancer predisposition gene in families with histories of pancreatic and breast cancers. BMC Cancer 2024; 24:723. [PMID: 38872153 PMCID: PMC11170902 DOI: 10.1186/s12885-024-12442-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 05/28/2024] [Indexed: 06/15/2024] Open
Abstract
BACKGROUND Among the 10% of pancreatic cancers that occur in a familial context, around a third carry a pathogenic variant in a cancer predisposition gene. Genetic studies of pancreatic cancer predisposition are limited by high mortality rates amongst index patients and other affected family members. The genetic risk for pancreatic cancer is often shared with breast cancer susceptibility genes, most notably BRCA2, PALB2, ATM and BRCA1. Therefore, we hypothesized that additional shared genetic etiologies might be uncovered by studying families presenting with both breast and pancreatic cancer. METHODS Focusing on a multigene panel of 276 DNA Damage Repair (DDR) genes, we performed next-generation sequencing in a cohort of 41 families with at least three breast cancer cases and one pancreatic cancer. When the index patient with pancreatic cancer was deceased, close relatives (first or second-degree) affected with breast cancer were tested (39 families). RESULTS We identified 27 variants of uncertain significance in DDR genes. A splice site variant (c.1605 + 2T > A) in the RAD17 gene stood out, as a likely loss of function variant. RAD17 is a checkpoint protein that recruits the MRN (MRE11-RAD50-NBS1) complex to initiate DNA signaling, leading to DNA double-strand break repair. CONCLUSION Within families with breast and pancreatic cancer, we identified RAD17 as a novel candidate predisposition gene. Further genetic studies are warranted to better understand the potential pathogenic effect of RAD17 variants and in other DDR genes.
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Affiliation(s)
- Sofie Joris
- Clinical Sciences, Research Group Reproduction and Genetics, Centre for Medical Genetics, Universitair Ziekenhuis Brussel (UZ Brussel), Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, Brussels, 1090, Belgium.
- The Oncology Research Center, the Laboratory for Medical & Molecular Oncology (LMMO), Faculty of Medicine, Vrije Universiteit Brussel (VUB), Brussels, Belgium.
| | - Philippe Giron
- Clinical Sciences, Research Group Reproduction and Genetics, Centre for Medical Genetics, Universitair Ziekenhuis Brussel (UZ Brussel), Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, Brussels, 1090, Belgium
| | - Catharina Olsen
- Clinical Sciences, Research Group Reproduction and Genetics, Centre for Medical Genetics, Universitair Ziekenhuis Brussel (UZ Brussel), Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, Brussels, 1090, Belgium
| | - Sara Seneca
- Clinical Sciences, Research Group Reproduction and Genetics, Centre for Medical Genetics, Universitair Ziekenhuis Brussel (UZ Brussel), Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, Brussels, 1090, Belgium
| | - Alexander Gheldof
- Clinical Sciences, Research Group Reproduction and Genetics, Centre for Medical Genetics, Universitair Ziekenhuis Brussel (UZ Brussel), Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, Brussels, 1090, Belgium
| | - Shula Staessens
- The Oncology Research Center, the Laboratory for Medical & Molecular Oncology (LMMO), Faculty of Medicine, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Rajendra Bahadur Shahi
- The Oncology Research Center, the Laboratory for Medical & Molecular Oncology (LMMO), Faculty of Medicine, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Sylvia De Brakeleer
- The Oncology Research Center, the Laboratory for Medical & Molecular Oncology (LMMO), Faculty of Medicine, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Erik Teugels
- The Oncology Research Center, the Laboratory for Medical & Molecular Oncology (LMMO), Faculty of Medicine, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Jacques De Grève
- Clinical Sciences, Research Group Reproduction and Genetics, Centre for Medical Genetics, Universitair Ziekenhuis Brussel (UZ Brussel), Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, Brussels, 1090, Belgium
- The Oncology Research Center, the Laboratory for Medical & Molecular Oncology (LMMO), Faculty of Medicine, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Frederik J Hes
- Clinical Sciences, Research Group Reproduction and Genetics, Centre for Medical Genetics, Universitair Ziekenhuis Brussel (UZ Brussel), Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, Brussels, 1090, Belgium
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2
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Sallmyr A, Bhandari SK, Naila T, Tomkinson AE. Mammalian DNA ligases; roles in maintaining genome integrity. J Mol Biol 2024; 436:168276. [PMID: 37714297 PMCID: PMC10843057 DOI: 10.1016/j.jmb.2023.168276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/17/2023]
Abstract
The joining of breaks in the DNA phosphodiester backbone is essential for genome integrity. Breaks are generated during normal processes such as DNA replication, cytosine demethylation during differentiation, gene rearrangement in the immune system and germ cell development. In addition, they are generated either directly by a DNA damaging agent or indirectly due to damage excision during repair. Breaks are joined by a DNA ligase that catalyzes phosphodiester bond formation at DNA nicks with 3' hydroxyl and 5' phosphate termini. Three human genes encode ATP-dependent DNA ligases. These enzymes have a conserved catalytic core consisting of three subdomains that encircle nicked duplex DNA during ligation. The DNA ligases are targeted to different nuclear DNA transactions by specific protein-protein interactions. Both DNA ligase IIIα and DNA ligase IV form stable complexes with DNA repair proteins, XRCC1 and XRCC4, respectively. There is functional redundancy between DNA ligase I and DNA ligase IIIα in DNA replication, excision repair and single-strand break repair. Although DNA ligase IV is a core component of the major double-strand break repair pathway, non-homologous end joining, the other enzymes participate in minor, alternative double-strand break repair pathways. In contrast to the nucleus, only DNA ligase IIIα is present in mitochondria and is essential for maintaining the mitochondrial genome. Human immunodeficiency syndromes caused by mutations in either LIG1 or LIG4 have been described. Preclinical studies with DNA ligase inhibitors have identified potentially targetable abnormalities in cancer cells and evidence that DNA ligases are potential targets for cancer therapy.
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Affiliation(s)
- Annahita Sallmyr
- University of New Mexico Comprehensive Cancer Center and the Departments of Internal Medicine, and Molecular Genetics & Microbiology, University of New Mexico Health Sciences Center, United States
| | - Seema Khattri Bhandari
- University of New Mexico Comprehensive Cancer Center and the Departments of Internal Medicine, and Molecular Genetics & Microbiology, University of New Mexico Health Sciences Center, United States
| | - Tasmin Naila
- University of New Mexico Comprehensive Cancer Center and the Departments of Internal Medicine, and Molecular Genetics & Microbiology, University of New Mexico Health Sciences Center, United States
| | - Alan E Tomkinson
- University of New Mexico Comprehensive Cancer Center and the Departments of Internal Medicine, and Molecular Genetics & Microbiology, University of New Mexico Health Sciences Center, United States.
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3
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Kiran K, Patil KN. Characterization of Staphylococcus aureus RecX protein: Molecular insights into negative regulation of RecA protein and implications in HR processes. J Biochem 2023; 174:227-237. [PMID: 37115499 DOI: 10.1093/jb/mvad039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 04/11/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
Homologous recombination (HR) is essential for genome stability and for maintaining genetic diversity. In eubacteria, RecA protein plays a key role during DNA repair, transcription, and HR. RecA is regulated at multiple levels, but majorly by RecX protein. Moreover, studies have shown RecX is a potent inhibitor of RecA and thus acts as an antirecombinase. Staphylococcus aureus is a major food-borne pathogen that causes skin, bone joint, and bloodstream infections. To date, RecX's role in S. aureus has remained enigmatic. Here, we show that S. aureus RecX (SaRecX) is expressed during exposure to DNA-damaging agents, and purified RecX protein directly interacts physically with RecA protein. The SaRecX is competent to bind with single-stranded DNA preferentially and double-stranded DNA feebly. Significantly, SaRecX impedes the RecA-driven displacement loop and inhibits formation of the strand exchange. Notably, SaRecX also abrogates adenosine triphosphate hydrolysis and abolishes the LexA coprotease activity. These findings highlight the role of the RecX protein as an antirecombinase during HR and play a pivotal role in regulation of RecA during the DNA transactions.
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Affiliation(s)
- Kajal Kiran
- Department of Microbiology and Fermentation Technology, Council of Scientific and Industrial Research-Central Food Technological Research Institute (CSIR-CFTRI), Mysuru 570 020, Karnataka, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India
| | - K Neelakanteshwar Patil
- Department of Microbiology and Fermentation Technology, Council of Scientific and Industrial Research-Central Food Technological Research Institute (CSIR-CFTRI), Mysuru 570 020, Karnataka, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India
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4
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Holland CL, Weis MF, England CJ, Berry AM, Hall PD, Lewis LK. Deficiency in homologous recombination is associated with changes in cell cycling and morphology in Saccharomyces cerevisiae. Exp Cell Res 2023:113701. [PMID: 37393982 DOI: 10.1016/j.yexcr.2023.113701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/23/2023] [Accepted: 06/25/2023] [Indexed: 07/04/2023]
Abstract
Exposure of eukaryotic cells to ionizing radiation or clastogenic chemicals leads to formation of DNA double-strand breaks (DSBs). These lesions are also generated internally by chemicals and enzymes, in the absence of exogenous agents, though the sources and consequences of such endogenously generated DSBs remain poorly understood. In the current study, we have investigated the impact of reduced recombinational repair of endogenous DSBs on stress responses, cell morphology and other physical properties of S. cerevisiae (budding yeast) cells. Use of phase contrast and DAPI-based fluorescence microscopy combined with FACS analysis confirmed that recombination-deficient rad52 cell cultures exhibit chronically high levels of G2 phase cells. Cell cycle phase transit times during G1, S and M were similar in WT and rad52 cells, but the length of G2 phase was increased by three-fold in the mutants. rad52 cells were larger than WT in all phases of the cycle and displayed other quantifiable changes in physical characteristics. The high G2 cell phenotype was abolished when DNA damage checkpoint genes, but not spindle assembly checkpoint genes, were co-inactivated with RAD52. Several other RAD52 group mutants (rad51, rad54, rad55, rad57 and rad59) also exhibited the high G2 cell phenotype. The results indicate that recombination deficiency leads to accumulation of unrepaired DSBs during normal mitotic growth that activate a major stress response and produce distinct changes in cellular physiology and morphology.
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Affiliation(s)
- Cory L Holland
- Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA
| | - Monica F Weis
- Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA
| | - Corbin J England
- Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA
| | - Armand M Berry
- Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA
| | - Paige D Hall
- Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA
| | - L Kevin Lewis
- Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA.
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5
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Bell JC, Dombrowski CC, Plank JL, Jensen RB, Kowalczykowski SC. BRCA2 chaperones RAD51 to single molecules of RPA-coated ssDNA. Proc Natl Acad Sci U S A 2023; 120:e2221971120. [PMID: 36976771 PMCID: PMC10083600 DOI: 10.1073/pnas.2221971120] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 02/24/2023] [Indexed: 03/29/2023] Open
Abstract
Mutations in the breast cancer susceptibility gene, BRCA2, greatly increase an individual's lifetime risk of developing breast and ovarian cancers. BRCA2 suppresses tumor formation by potentiating DNA repair via homologous recombination. Central to recombination is the assembly of a RAD51 nucleoprotein filament, which forms on single-stranded DNA (ssDNA) generated at or near the site of chromosomal damage. However, replication protein-A (RPA) rapidly binds to and continuously sequesters this ssDNA, imposing a kinetic barrier to RAD51 filament assembly that suppresses unregulated recombination. Recombination mediator proteins-of which BRCA2 is the defining member in humans-alleviate this kinetic barrier to catalyze RAD51 filament formation. We combined microfluidics, microscopy, and micromanipulation to directly measure both the binding of full-length BRCA2 to-and the assembly of RAD51 filaments on-a region of RPA-coated ssDNA within individual DNA molecules designed to mimic a resected DNA lesion common in replication-coupled recombinational repair. We demonstrate that a dimer of RAD51 is minimally required for spontaneous nucleation; however, growth self-terminates below the diffraction limit. BRCA2 accelerates nucleation of RAD51 to a rate that approaches the rapid association of RAD51 to naked ssDNA, thereby overcoming the kinetic block imposed by RPA. Furthermore, BRCA2 eliminates the need for the rate-limiting nucleation of RAD51 by chaperoning a short preassembled RAD51 filament onto the ssDNA complexed with RPA. Therefore, BRCA2 regulates recombination by initiating RAD51 filament formation.
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Affiliation(s)
- Jason C. Bell
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA95616
- Department of Molecular and Cellular Biology, University of California, Davis, CA95616
| | - Christopher C. Dombrowski
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA95616
- Department of Molecular and Cellular Biology, University of California, Davis, CA95616
| | - Jody L. Plank
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA95616
- Department of Molecular and Cellular Biology, University of California, Davis, CA95616
| | - Ryan B. Jensen
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA95616
- Department of Molecular and Cellular Biology, University of California, Davis, CA95616
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT06520
| | - Stephen C. Kowalczykowski
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA95616
- Department of Molecular and Cellular Biology, University of California, Davis, CA95616
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6
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Maloisel L, Ma E, Phipps J, Deshayes A, Mattarocci S, Marcand S, Dubrana K, Coïc E. Rad51 filaments assembled in the absence of the complex formed by the Rad51 paralogs Rad55 and Rad57 are outcompeted by translesion DNA polymerases on UV-induced ssDNA gaps. PLoS Genet 2023; 19:e1010639. [PMID: 36749784 PMCID: PMC9937489 DOI: 10.1371/journal.pgen.1010639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 02/17/2023] [Accepted: 01/26/2023] [Indexed: 02/08/2023] Open
Abstract
The bypass of DNA lesions that block replicative polymerases during DNA replication relies on DNA damage tolerance pathways. The error-prone translesion synthesis (TLS) pathway depends on specialized DNA polymerases that incorporate nucleotides in front of base lesions, potentially inducing mutagenesis. Two error-free pathways can bypass the lesions: the template switching pathway, which uses the sister chromatid as a template, and the homologous recombination pathway (HR), which also can use the homologous chromosome as template. The balance between error-prone and error-free pathways controls the mutagenesis level. Therefore, it is crucial to precisely characterize factors that influence the pathway choice to better understand genetic stability at replication forks. In yeast, the complex formed by the Rad51 paralogs Rad55 and Rad57 promotes HR and template-switching at stalled replication forks. At DNA double-strand breaks (DSBs), this complex promotes Rad51 filament formation and stability, notably by counteracting the Srs2 anti-recombinase. To explore the role of the Rad55-Rad57 complex in error-free pathways, we monitored the genetic interactions between Rad55-Rad57, the translesion polymerases Polζ or Polη, and Srs2 following UV radiation that induces mostly single-strand DNA gaps. We found that the Rad55-Rad57 complex was involved in three ways. First, it protects Rad51 filaments from Srs2, as it does at DSBs. Second, it promotes Rad51 filament stability independently of Srs2. Finally, we observed that UV-induced HR is almost abolished in Rad55-Rad57 deficient cells, and is partially restored upon Polζ or Polη depletion. Hence, we propose that the Rad55-Rad57 complex is essential to promote Rad51 filament stability on single-strand DNA gaps, notably to counteract the error-prone TLS polymerases and mutagenesis.
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Affiliation(s)
- Laurent Maloisel
- Université de Paris and Université Paris-Saclay, INSERM, CEA, Institut de Biologie François Jacob, UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, France
- * E-mail: (LM); (EC)
| | - Emilie Ma
- Université de Paris and Université Paris-Saclay, INSERM, CEA, Institut de Biologie François Jacob, UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, France
| | - Jamie Phipps
- Université de Paris and Université Paris-Saclay, INSERM, CEA, Institut de Biologie François Jacob, UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, France
| | - Alice Deshayes
- Université de Paris and Université Paris-Saclay, INSERM, CEA, Institut de Biologie François Jacob, UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, France
| | - Stefano Mattarocci
- Université de Paris and Université Paris-Saclay, INSERM, CEA, Institut de Biologie François Jacob, UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, France
| | - Stéphane Marcand
- Université de Paris and Université Paris-Saclay, INSERM, CEA, Institut de Biologie François Jacob, UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, France
| | - Karine Dubrana
- Université de Paris and Université Paris-Saclay, INSERM, CEA, Institut de Biologie François Jacob, UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, France
| | - Eric Coïc
- Université de Paris and Université Paris-Saclay, INSERM, CEA, Institut de Biologie François Jacob, UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, France
- * E-mail: (LM); (EC)
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7
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Soniat MM, Nguyen G, Kuo HC, Finkelstein IJ. The MRN complex and topoisomerase IIIa-RMI1/2 synchronize DNA resection motor proteins. J Biol Chem 2023; 299:102802. [PMID: 36529288 PMCID: PMC9971906 DOI: 10.1016/j.jbc.2022.102802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 12/08/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022] Open
Abstract
DNA resection-the nucleolytic processing of broken DNA ends-is the first step of homologous recombination. Resection is catalyzed by the resectosome, a multienzyme complex that includes bloom syndrome helicase (BLM), DNA2 or exonuclease 1 nucleases, and additional DNA-binding proteins. Although the molecular players have been known for over a decade, how the individual proteins work together to regulate DNA resection remains unknown. Using single-molecule imaging, we characterized the roles of the MRE11-RAD50-NBS1 complex (MRN) and topoisomerase IIIa (TOP3A)-RMI1/2 during long-range DNA resection. BLM partners with TOP3A-RMI1/2 to form the BTRR (BLM-TOP3A-RMI1/2) complex (or BLM dissolvasome). We determined that TOP3A-RMI1/2 aids BLM in initiating DNA unwinding, and along with MRN, stimulates DNA2-mediated resection. Furthermore, we found that MRN promotes the association between BTRR and DNA and synchronizes BLM and DNA2 translocation to prevent BLM from pausing during resection. Together, this work provides direct observation of how MRN and DNA2 harness the BTRR complex to resect DNA efficiently and how TOP3A-RMI1/2 regulates the helicase activity of BLM to promote efficient DNA repair.
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Affiliation(s)
- Michael M Soniat
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA.
| | - Giaochau Nguyen
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Hung-Che Kuo
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA.
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8
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Li L, Zou BJ, Zhao JZ, Liang JB, She ZY, Zhou WY, Lin SX, Tian L, Luo WJ, He FZ. A novel DNA damage repair-related signature for predicting prognositc and treatment response in non-small lung cancer. Front Oncol 2022; 12:961274. [PMID: 36408135 PMCID: PMC9673481 DOI: 10.3389/fonc.2022.961274] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 10/14/2022] [Indexed: 10/06/2023] Open
Abstract
DNA damage repair (DDR) is essential for maintaining genome integrity and modulating cancer risk, progression, and therapeutic response. DDR defects are common among non-small lung cancer (NSCLC), resulting in new challenge and promise for NSCLC treatment. Thus, a thorough understanding of the molecular characteristics of DDR in NSCLC is helpful for NSCLC treatment and management. Here, we systematically analyzed the relationship between DDR alterations and NSCLC prognosis, and successfully established and validated a six-DDR gene prognostic model via LASSO Cox regression analysis based on the expression of prognostic related DDR genes, CDC25C, NEIL3, H2AFX, NBN, XRCC5, RAD1. According to this model, NSCLC patients were classified into high-risk subtype and low-risk subtype, each of which has significant differences between the two subtypes in clinical features, molecular features, immune cell components, gene mutations, DDR pathway activation status and clinical outcomes. The high-risk patients was characterized with worse prognosis, lower proportion and number of DDR mutations, unique immune profile and responsive to immunetherapy. And the low-risk patients tend to have superior survival, while being less responsive to immunotherapy and more sensitive to treatment with DNA-damaging chemotherapy drugs. Overall, this molecular classification based on DDR expression profile enables hierarchical management of patients and personalized clinical treatment, and provides potential therapeutic targets for NSCLC.
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Affiliation(s)
- Ling Li
- Department of Pharmacy, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong, China
| | - Bao-jia Zou
- Department of Hepatobiliary Surgery, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, China
| | - Juan-zhi Zhao
- Department of Pharmacy, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong, China
| | - Jia-bi Liang
- Department of Pharmacy, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong, China
| | - Zi-yue She
- Department of Pharmacy, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong, China
| | - Wen-ying Zhou
- Department of Central Laboratory, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong, China
| | - Si-xiao Lin
- Department of Central Laboratory, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong, China
| | - Lin Tian
- Department of Pharmacy, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong, China
| | - Wen-ji Luo
- Department of Pharmacy, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, Guangdong, China
| | - Fa-zhong He
- Department of Quality Control, Zhuhai People’s Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, Guangdong, China
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9
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Mahmoud R, Dhakal S. Single-Molecule Analysis of DNA Branch Migration under Biomimetic Environments. J Phys Chem B 2022; 126:7252-7261. [DOI: 10.1021/acs.jpcb.2c03153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Roaa Mahmoud
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, Virginia 23284, United States
| | - Soma Dhakal
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, Virginia 23284, United States
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10
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Choi J, Kong M, Gallagher DN, Li K, Bronk G, Cao Y, Greene EC, Haber JE. Repair of mismatched templates during Rad51-dependent Break-Induced Replication. PLoS Genet 2022; 18:e1010056. [PMID: 36054210 PMCID: PMC9477423 DOI: 10.1371/journal.pgen.1010056] [Citation(s) in RCA: 3] [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: 01/30/2022] [Revised: 09/15/2022] [Accepted: 08/10/2022] [Indexed: 12/02/2022] Open
Abstract
Using budding yeast, we have studied Rad51-dependent break-induced replication (BIR), where the invading 3’ end of a site-specific double-strand break (DSB) and a donor template share 108 bp of homology that can be easily altered. BIR still occurs about 10% as often when every 6th base is mismatched as with a perfectly matched donor. Here we explore the tolerance of mismatches in more detail, by examining donor templates that each carry 10 mismatches, each with different spatial arrangements. Although 2 of the 6 arrangements we tested were nearly as efficient as the evenly-spaced reference, 4 were significantly less efficient. A donor with all 10 mismatches clustered at the 3’ invading end of the DSB was not impaired compared to arrangements where mismatches were clustered at the 5’ end. Our data suggest that the efficiency of strand invasion is principally dictated by thermodynamic considerations, i.e., by the total number of base pairs that can be formed; but mismatch position-specific effects are also important. We also addressed an apparent difference between in vitro and in vivo strand exchange assays, where in vitro studies had suggested that at a single contiguous stretch of 8 consecutive bases was needed to be paired for stable strand pairing, while in vivo assays using 108-bp substrates found significant recombination even when every 6th base was mismatched. Now, using substrates of either 90 or 108 nt–the latter being the size of the in vivo templates–we find that in vitro D-loop results are very similar to the in vivo results. However, there are still notable differences between in vivo and in vitro assays that are especially evident with unevenly-distributed mismatches. Mismatches in the donor template are incorporated into the BIR product in a strongly polar fashion up to ~40 nucleotides from the 3’ end. Mismatch incorporation depends on the 3’→ 5’ proofreading exonuclease activity of DNA polymerase δ, with little contribution from Msh2/Mlh1 mismatch repair proteins, or from Rad1-Rad10 flap nuclease or the Mph1 helicase. Surprisingly, the probability of a mismatch 27 nt from the 3’ end being replaced by donor sequence was the same whether the preceding 26 nucleotides were mismatched every 6th base or fully homologous. These data suggest that DNA polymerase δ “chews back” the 3’ end of the invading strand without any mismatch-dependent cues from the strand invasion structure. However, there appears to be an alternative way to incorporate a mismatch at the first base at the 3’ end of the donor. DNA double-strand breaks (DSBs) are the most lethal forms of DNA damage and inaccurate repair of these breaks presents a serious threat to genomic integrity and cell viability. Break-induced replication (BIR) is a homologous recombination pathway that results in a nonreciprocal translocation of chromosome ends. We used budding yeast Saccharomyces cerevisiae to investigate Rad51-mediated BIR, where the invading 3’ end of the DSB and a donor template share 108 bp of homology. We examined the tolerance of differently distributed mismatches on a homologous donor template. A donor with all 10 mismatches clustered every 6th base at the 3’ invading end of the DSB was not impaired compared to arrangements where mismatches were clustered at the 5’ end. We also compared the efficiency of in vivo BIR with in vitro D-loop formation and find that for substrates of the same length, the tolerance for mismatches is comparable. However, there are still notable differences between in vivo and in vitro assays that are especially evident in substrates with unevenly-distributed mismatches. Mismatches are incorporated into the BIR product in a strongly polar fashion as far as about 40 nucleotides from the 3’ end, dependent on the 5’ to 3’ proofreading activity of DNA polymerase δ. Pol δ can “chew back” the 3’ end of the invading strand even when the sequences removed have no mismatches for the first 26 nucleotides. However, a mismatch at the first base can be removed from the 3’ end by another, unidentified mechanism.
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Affiliation(s)
- Jihyun Choi
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts, United States of America
| | - Muwen Kong
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, New York, United States of America
| | - Danielle N. Gallagher
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts, United States of America
| | - Kevin Li
- Department of Physics, Brandeis University, Waltham, Massachusetts, United States of America
| | - Gabriel Bronk
- Department of Physics, Brandeis University, Waltham, Massachusetts, United States of America
| | - Yiting Cao
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts, United States of America
| | - Eric C. Greene
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, New York, United States of America
| | - James E. Haber
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts, United States of America
- * E-mail:
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11
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Wang BB, Xu JZ, Zhang F, Liu S, Liu J, Zhang WG. Review of DNA repair enzymes in bacteria: With a major focus on AddAB and RecBCD. DNA Repair (Amst) 2022; 118:103389. [PMID: 36030574 DOI: 10.1016/j.dnarep.2022.103389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/18/2022] [Accepted: 08/20/2022] [Indexed: 11/03/2022]
Abstract
DNA recombination repair systems are essential for organisms to maintain genomic stability. In recent years, we have improved our understanding of the mechanisms of RecBCD/AddAB family-mediated DNA double-strand break repair. In E. coli, it is RecBCD that plays a central role, and in Firmicute Bacillus subtilis it is the AddAB complex that functions. However, there are open questions about the mechanism of DNA repair in bacteria. For example, how bacteria containing crossover hotspot instigator (Chi) sites regulate the activity of proteins. In addition, we still do not know the exact process by which the RecB nuclease or AddA nuclease structural domains load RecA onto DNA. We also know little about the mechanism of DNA repair in the industrially important production bacterium Corynebacterium glutamicum (C. glutamicum). Therefore, exploring DNA repair mechanisms in bacteria may not only deepen our understanding of the DNA repair process in this species but also guide us in the targeted treatment of diseases associated with recombination defects, such as cancer. In this paper, we firstly review the classical proteins RecBCD and AddAB involved in DNA recombination repair, secondly focus on the novel helical nuclease AdnAB found in the genus Mycobacterium.
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Affiliation(s)
- Bing-Bing Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, WuXi 214122, People's Republic of China
| | - Jian-Zhong Xu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, WuXi 214122, People's Republic of China.
| | - Feng Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, WuXi 214122, People's Republic of China
| | - Shuai Liu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, WuXi 214122, People's Republic of China
| | - Jie Liu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, WuXi 214122, People's Republic of China
| | - Wei-Guo Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, WuXi 214122, People's Republic of China.
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12
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Shams F, Bayat H, Mohammadian O, Mahboudi S, Vahidnezhad H, Soosanabadi M, Rahimpour A. Advance trends in targeting homology-directed repair for accurate gene editing: An inclusive review of small molecules and modified CRISPR-Cas9 systems. BIOIMPACTS 2022; 12:371-391. [PMID: 35975201 PMCID: PMC9376165 DOI: 10.34172/bi.2022.23871] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 11/21/2021] [Accepted: 11/21/2021] [Indexed: 11/25/2022]
Abstract
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Introduction: Clustered regularly interspaced short palindromic repeat and its associated protein (CRISPR-Cas)-based technologies generate targeted modifications in host genome by inducing site-specific double-strand breaks (DSBs) that can serve as a substrate for homology-directed repair (HDR) in both in vitro and in vivo models. HDR pathway could enhance incorporation of exogenous DNA templates into the CRISPR-Cas9-mediated DSB site. Owing to low rate of HDR pathway, the efficiency of accurate genome editing is diminished. Enhancing the efficiency of HDR can provide fast, easy, and accurate technologies based on CRISPR-Cas9 technologies.
Methods: The current study presents an overview of attempts conducted on the precise genome editing strategies based on small molecules and modified CRISPR-Cas9 systems.
Results: In order to increase HDR rate in targeted cells, several logical strategies have been introduced such as generating CRISPR effector chimeric proteins, anti-CRISPR proteins, modified Cas9 with donor template, and using validated synthetic or natural small molecules for either inhibiting non-homologous end joining (NHEJ), stimulating HDR, or synchronizing cell cycle. Recently, high-throughput screening methods have been applied for identification of small molecules which along with the CRISPR system can regulate precise genome editing through HDR.
Conclusion: The stimulation of HDR components or inhibiting NHEJ can increase the accuracy of CRISPR-Cas-mediated engineering systems. Generating chimeric programmable endonucleases provide this opportunity to direct DNA template close proximity of CRISPR-Cas-mediated DSB. Small molecules and their derivatives can also proficiently block or activate certain DNA repair pathways and bring up novel perspectives for increasing HDR efficiency, especially in human cells. Further, high throughput screening of small molecule libraries could result in more discoveries of promising chemicals that improve HDR efficiency and CRISPR-Cas9 systems.
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Affiliation(s)
- Forough Shams
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hadi Bayat
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Omid Mohammadian
- Medical Nano-Technology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Somayeh Mahboudi
- Department of Food Science and Technology, School of Agriculture, Shiraz University, Shiraz, Iran
| | - Hassan Vahidnezhad
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
- Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Mohsen Soosanabadi
- Department of Medical Genetics, Semnan University of Medical Sciences, Semnan, Iran
| | - Azam Rahimpour
- Medical Nano-Technology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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13
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Fleurier S, Dapa T, Tenaillon O, Condon C, Matic I. rRNA operon multiplicity as a bacterial genome stability insurance policy. Nucleic Acids Res 2022; 50:12601-12620. [PMID: 35552441 PMCID: PMC9825170 DOI: 10.1093/nar/gkac332] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 04/12/2022] [Accepted: 04/21/2022] [Indexed: 01/29/2023] Open
Abstract
Quick growth restart after upon encountering favourable environmental conditions is a major fitness contributor in natural environment. It is widely assumed that the time required to restart growth after nutritional upshift is determined by how long it takes for cells to synthesize enough ribosomes to produce the proteins required to reinitiate growth. Here we show that a reduction in the capacity to synthesize ribosomes by reducing number of ribosomal RNA (rRNA) operons (rrn) causes a longer transition from stationary phase to growth of Escherichia coli primarily due to high mortality rates. Cell death results from DNA replication blockage and massive DNA breakage at the sites of the remaining rrn operons that become overloaded with RNA polymerases (RNAPs). Mortality rates and growth restart duration can be reduced by preventing R-loop formation and improving DNA repair capacity. The same molecular mechanisms determine the duration of the recovery phase after ribosome-damaging stresses, such as antibiotics, exposure to bile salts or high temperature. Our study therefore suggests that a major function of rrn operon multiplicity is to ensure that individual rrn operons are not saturated by RNAPs, which can result in catastrophic chromosome replication failure and cell death during adaptation to environmental fluctuations.
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Affiliation(s)
- Sebastien Fleurier
- Department of Infection, Immunity and Inflammation, Institut Cochin, Inserm U1016, CNRS UMR8104, Université de Paris, 75014 Paris, France
| | - Tanja Dapa
- Department of Infection, Immunity and Inflammation, Institut Cochin, Inserm U1016, CNRS UMR8104, Université de Paris, 75014 Paris, France
| | | | - Ciarán Condon
- Institut de Biologie Physico-Chimique, CNRS UMR8261, Université de Paris, 75005 Paris, France
| | - Ivan Matic
- To whom correspondence should be addressed.
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14
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Ali A, Xiao W, Babar ME, Bi Y. Double-Stranded Break Repair in Mammalian Cells and Precise Genome Editing. Genes (Basel) 2022; 13:genes13050737. [PMID: 35627122 PMCID: PMC9142082 DOI: 10.3390/genes13050737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 12/16/2022] Open
Abstract
In mammalian cells, double-strand breaks (DSBs) are repaired predominantly by error-prone non-homologous end joining (NHEJ), but less prevalently by error-free template-dependent homologous recombination (HR). DSB repair pathway selection is the bedrock for genome editing. NHEJ results in random mutations when repairing DSB, while HR induces high-fidelity sequence-specific variations, but with an undesirable low efficiency. In this review, we first discuss the latest insights into the action mode of NHEJ and HR in a panoramic view. We then propose the future direction of genome editing by virtue of these advancements. We suggest that by switching NHEJ to HR, full fidelity genome editing and robust gene knock-in could be enabled. We also envision that RNA molecules could be repurposed by RNA-templated DSB repair to mediate precise genetic editing.
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Affiliation(s)
- Akhtar Ali
- Key Laboratory of Animal Embryo and Molecular Breeding of Hubei Province, Institute of Animal Science and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430064, China; (A.A.); (W.X.)
- Department of Biotechnology, Virtual University of Pakistan, Lahore 54000, Pakistan
| | - Wei Xiao
- Key Laboratory of Animal Embryo and Molecular Breeding of Hubei Province, Institute of Animal Science and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430064, China; (A.A.); (W.X.)
| | - Masroor Ellahi Babar
- The University of Agriculture Dera Ismail Khan, Dera Ismail Khan 29220, Pakistan;
| | - Yanzhen Bi
- Key Laboratory of Animal Embryo and Molecular Breeding of Hubei Province, Institute of Animal Science and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430064, China; (A.A.); (W.X.)
- Correspondence: ; Tel.: +86-151-0714-8708
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15
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Liu H, Weng J. A Pan-Cancer Bioinformatic Analysis of RAD51 Regarding the Values for Diagnosis, Prognosis, and Therapeutic Prediction. Front Oncol 2022; 12:858756. [PMID: 35359409 PMCID: PMC8960930 DOI: 10.3389/fonc.2022.858756] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 02/17/2022] [Indexed: 12/21/2022] Open
Abstract
Background RAD51, a critical protein for DNA repairment, has been found to associate with multiple cancer types, but, so far, a systematic pan-cancer analysis of RAD51 has not been done yet. Methods Data were obtained from multiple open databases and genetic alteration, gene expression, survival association, functional enrichment, stemness, mutation association, immunity association, and drug therapy association of RAD51were analyzed. A prognostic model of RAD51 for overall glioma was constructed as an example application of RAD51 as a biomarker. Results RAD51 was overexpressed in 28 types of cancers and was associated with worse overall survival in 11 cancer types. RAD51 correlated genes were enriched in cell cycle terms. RAD51 was associated with cancer stemness, tumor mutational burden, and multiple immunomodulators in different cancer types. RAD51 expression was different across immune subtypes in 11 cancer types. RAD51 was closely associated with cancer immune microenvironments in some cancer types. Proliferating T cells was the cell type that expressed highest RAD51 across most of the cancer samples analyzed. RAD51 expression had an AUC of over 0.5 in 12 of the 23 ICB subcohorts. The Tumor Immune Dysfunction and Exclusion of 9 cancer types were different between RAD51 high and low groups. RAD51 expression showed negative correlations with the sensitivity of most drugs. A prognostic nomogram was constructed with a high confidence. Conclusion RAD51 is a clinical valuable biomarker for multiple cancer types, regarding its potential power for diagnosis, prognosis, and therapeutic prediction.
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Affiliation(s)
| | - Jieling Weng
- Department of Pathology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
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16
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Modulation of RecFORQ- and RecA-Mediated Homologous Recombination in Escherichia coli by Isoforms of Translation Initiation Factor IF2. J Bacteriol 2022; 204:e0056921. [PMID: 35343793 DOI: 10.1128/jb.00569-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Homologous recombination (HR) is critically important for chromosomal replication, as well as DNA damage repair in all life forms. In Escherichia coli, the process of HR comprises (i) two parallel presynaptic pathways that are mediated, respectively, by proteins RecB/C/D and RecF/O/R/Q; (ii) a synaptic step mediated by RecA that leads to generation of Holliday junctions (HJs); and (iii) postsynaptic steps mediated sequentially by HJ-acting proteins RuvA/B/C followed by proteins PriA/B/C of replication restart. Combined loss of RuvA/B/C and a DNA helicase UvrD is synthetically lethal, which is attributed to toxicity caused by accumulated HJs since viability in these double mutant strains is restored by removal of the presynaptic or synaptic proteins RecF/O/R/Q or RecA, respectively. Here we show that, as in ΔuvrD strains, ruv mutations confer synthetic lethality in cells deficient for transcription termination factor Rho, and that loss of RecFORQ presynaptic pathway proteins or of RecA suppresses this lethality. Furthermore, loss of IF2-1 (which is one of three isoforms [IF2-1, IF2-2, and IF2-3] of the essential translation initiation factor IF2 that are synthesized from three in-frame initiation codons in infB) also suppressed uvrD-ruv and rho-ruv lethalities, whereas deficiency of IF2-2 and IF2-3 exacerbated the synthetic defects. Our results suggest that Rho deficiency is associated with an increased frequency of HR that is mediated by the RecFORQ pathway along with RecA. They also lend support to earlier reports that IF2 isoforms participate in DNA transactions, and we propose that they do so by modulation of HR functions. IMPORTANCE The process of homologous recombination (HR) is important for maintenance of genome integrity in all cells. In Escherichia coli, the RecA protein is a critical participant in HR, which acts at a step common to and downstream of two HR pathways mediated by the RecBCD and RecFOR proteins, respectively. In this study, an isoform (IF2-1) of the translation initiation factor IF2 has been identified as a novel facilitator of RecA's function in vivo during HR.
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17
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Essential Role for an Isoform of Escherichia coli Translation Initiation Factor IF2 in Repair of Two-Ended DNA Double-Strand Breaks. J Bacteriol 2022; 204:e0057121. [PMID: 35343794 DOI: 10.1128/jb.00571-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In Escherichia coli, three isoforms of the essential translation initiation factor IF2 (IF2-1, IF2-2, and IF2-3) are generated from separate in-frame initiation codons in infB. The isoforms have earlier been suggested to additionally participate in DNA damage repair and replication restart. It is also known that the proteins RecA and RecBCD are needed for repair of DNA double-strand breaks (DSBs) in E. coli. Here, we show that strains lacking IF2-1 are profoundly sensitive to two-ended DSBs in DNA generated by radiomimetic agents phleomycin or bleomycin, or by endonuclease I-SceI. However, these strains remained tolerant to other DSB-generating genotoxic agents or perturbations to which recA and recBC mutants remained sensitive, such as to mitomycin C, type-2 DNA topoisomerase inhibitors, or DSB caused by palindrome cleavage behind a replication fork. Data from genome-wide copy number analyses following I-SceI cleavage at a single chromosomal locus suggested that, in a strain lacking IF2-1, the magnitude of recombination-dependent replication through replication restart mechanisms is largely preserved but the extent of DNA resection around the DSB site is reduced. We propose that in the absence of IF2-1 it is the synapsis of a RecA nucleoprotein filament to its homologous target that is weakened, which in turn leads to a specific failure in assembly of Ter-to-oriC directed replisomes needed for consummation of two-ended DSB repair. IMPORTANCE Double-strand breaks (DSBs) in DNA are major threats to genome integrity. In Escherichia coli, DSBs are repaired by RecA- and RecBCD-mediated homologous recombination (HR). This study demonstrates a critical role for an isoform (IF2-1) of the translation initiation factor IF2 in the repair of two-ended DSBs in E. coli (that can be generated by ionizing radiation, certain DNA-damaging chemicals, or endonuclease action). It is proposed that IF2-1 acts to facilitate the function of RecA in the synapsis between a pair of DNA molecules during HR.
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18
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Aicart-Ramos C, Hormeno S, Wilkinson OJ, Dillingham MS, Moreno-Herrero F. Long DNA constructs to study helicases and nucleic acid translocases using optical tweezers. Methods Enzymol 2022; 673:311-358. [DOI: 10.1016/bs.mie.2022.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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19
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Xie S, Wang Y, Huang J, Li G. A novel m6A-related prognostic signature for predicting the overall survival of hepatocellular carcinoma patients. IET Syst Biol 2021; 16:1-17. [PMID: 34647424 PMCID: PMC8849219 DOI: 10.1049/syb2.12036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/25/2021] [Accepted: 10/03/2021] [Indexed: 12/13/2022] Open
Abstract
Liver hepatocellular carcinoma (LIHC) comprises most cases of liver cancer with a poor prognosis. N6‐methyladenosine (m6A) plays important biological functions in cancers. Thus, the present research was aimed to determine biomarkers of m6A regulators that could effectively predict the prognosis of LIHC patients. Based on the data collected from the Cancer Genome Atlas (TCGA) database, the correlation between the mRNA expression levels and copy number variation (CNV) patterns were determined. Higher mRNA expression resulted from the increasing number of 9 genes. Using the univariate Cox regression analysis, 11 m6A regulators that had close correlations with the LIHC prognosis were identified. In addition, under the support of the multivariate Cox regression models and the least absolute shrinkage and selection operator, a 4‐gene (YTHDF2, IGF2BP3, KIAA1429, and ALKBH5) signature of m6A regulators was constructed. This signature was expected to present a prognostic value in LIHC (log‐rank test p value < 0.0001). The GSE76427 (n = 94) and ICGC‐LIRI‐JP (n = 212) datasets were used to validate the prognostic signature, suggesting strong power to predict patients' prognosis for LIHC. To sum up, genetic alterations in m6A regulatory genes were identified as reliable and effective biomarkers for predicting the prognosis of LIHC patients.
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Affiliation(s)
- Shiyang Xie
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
| | - Yaxuan Wang
- Department of Anesthesiology, The First Hospital of China Medical University, Shenyang, China
| | - Jin Huang
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
| | - Guang Li
- Department of Radiation Oncology, The First Hospital of China Medical University, Shenyang, China
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20
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Prakash R, Freyer L, Saiz N, Gavrilov S, Wang RQ, Romanienko PJ, Lacy E, Hadjantonakis AK, Jasin M. XRCC3 loss leads to midgestational embryonic lethality in mice. DNA Repair (Amst) 2021; 108:103227. [PMID: 34601382 DOI: 10.1016/j.dnarep.2021.103227] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 09/09/2021] [Accepted: 09/11/2021] [Indexed: 10/20/2022]
Abstract
RAD51 paralogs are key components of the homologous recombination (HR) machinery. Mouse mutants have been reported for four of the canonical RAD51 paralogs, and each of these mutants exhibits embryonic lethality, although at different gestational stages. However, the phenotype of mice deficient in the fifth RAD51 paralog, XRCC3, has not been reported. Here we report that Xrcc3 knockout mice exhibit midgestational lethality, with mild phenotypes beginning at about E8.25 but severe developmental abnormalities evident by E9.0-9.5. The most obvious phenotypes are small size and a failure of the embryo to turn to a fetal position. A knockin mutation at a key ATPase residue in the Walker A box results in embryonic lethality at a similar stage. Death of knockout mice can be delayed a few days for some embryos by homozygous or heterozygous Trp53 mutation, in keeping with an important role for XRCC3 in promoting genome integrity. Given that XRCC3 is a unique member of one of two RAD51 paralog complexes with RAD51C, these results demonstrate that both RAD51 paralog complexes are required for mouse development.
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Affiliation(s)
- Rohit Prakash
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, 430 East 67 Street, New York, NY 10065, United States; Regeneron Pharmaceuticals, Tarrytown, New York, NY, United States
| | - Laina Freyer
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, 430 East 67 Street, New York, NY 10065, United States; Institut Pasteur, Paris, France
| | - Néstor Saiz
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, 430 East 67 Street, New York, NY 10065, United States; Rockefeller University Press, New York, NY, United States
| | - Svetlana Gavrilov
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, 430 East 67 Street, New York, NY 10065, United States; Bristol-Myers Squibb, New York, NY, United States
| | - Raymond Q Wang
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, 430 East 67 Street, New York, NY 10065, United States
| | - Peter J Romanienko
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, 430 East 67 Street, New York, NY 10065, United States; Rutgers-Cancer Institute of New Jersey, New Brunswick, NJ, United States
| | - Elizabeth Lacy
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, 430 East 67 Street, New York, NY 10065, United States
| | - Anna-Katerina Hadjantonakis
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, 430 East 67 Street, New York, NY 10065, United States
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, 430 East 67 Street, New York, NY 10065, United States.
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21
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The Role of the Rad55-Rad57 Complex in DNA Repair. Genes (Basel) 2021; 12:genes12091390. [PMID: 34573372 PMCID: PMC8472222 DOI: 10.3390/genes12091390] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 08/30/2021] [Accepted: 09/03/2021] [Indexed: 11/29/2022] Open
Abstract
Homologous recombination (HR) is a mechanism conserved from bacteria to humans essential for the accurate repair of DNA double-stranded breaks, and maintenance of genome integrity. In eukaryotes, the key DNA transactions in HR are catalyzed by the Rad51 recombinase, assisted by a host of regulatory factors including mediators such as Rad52 and Rad51 paralogs. Rad51 paralogs play a crucial role in regulating proper levels of HR, and mutations in the human counterparts have been associated with diseases such as cancer and Fanconi Anemia. In this review, we focus on the Saccharomyces cerevisiae Rad51 paralog complex Rad55–Rad57, which has served as a model for understanding the conserved role of Rad51 paralogs in higher eukaryotes. Here, we discuss the results from early genetic studies, biochemical assays, and new single-molecule observations that have together contributed to our current understanding of the molecular role of Rad55–Rad57 in HR.
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22
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Probing DNA-protein interactions using single-molecule diffusivity contrast. BIOPHYSICAL REPORTS 2021; 1:100009. [PMID: 36425309 PMCID: PMC9680706 DOI: 10.1016/j.bpr.2021.100009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 07/20/2021] [Indexed: 11/28/2022]
Abstract
Single-molecule fluorescence investigations of protein-nucleic acid interactions require robust means to identify the binding state of individual substrate molecules in real time. Here, we show that diffusivity contrast, widely used in fluorescence correlation spectroscopy at the ensemble level and in single-particle tracking on individual (but slowly diffusing) species, can be used as a general readout to determine the binding state of single DNA molecules with unlabeled proteins in solution. We first describe the technical basis of drift-free single-molecule diffusivity measurements in an anti-Brownian electrokinetic trap. We then cross-validate our method with protein-induced fluorescence enhancement, a popular technique to detect protein binding on nucleic acid substrates with single-molecule sensitivity. We extend an existing hydrodynamic modeling framework to link measured diffusivity to particular DNA-protein structures and obtain good agreement between the measured and predicted diffusivity values. Finally, we show that combining diffusivity contrast with protein-induced fluorescence enhancement allows simultaneous mapping of binding stoichiometry and location on individual DNA-protein complexes, potentially enhancing single-molecule views of relevant biophysical processes.
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23
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Lin P, Gao RZ, Wen R, He Y, Yang H. DNA Damage Repair Profiles Alteration Characterize a Hepatocellular Carcinoma Subtype With Unique Molecular and Clinicopathologic Features. Front Immunol 2021; 12:715460. [PMID: 34456923 PMCID: PMC8387599 DOI: 10.3389/fimmu.2021.715460] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/27/2021] [Indexed: 01/11/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is one of the most common malignancies and displays high heterogeneity of molecular phenotypes. We investigated DNA damage repair (DDR) alterations in HCC by integrating multi-omics data. HCC patients were classified into two heterogeneous subtypes with distinct clinical and molecular features: the DDR-activated subtype and the DDR-suppressed subtype. The DDR-activated subgroup is characterized by inferior prognosis and clinicopathological features that result in aggressive clinical behavior. Tumors of the DDR-suppressed class, which have distinct clinical and molecular characteristics, tend to have superior survival. A DDR subtype signature was ultimately generated to enable HCC DDR classification, and the results were confirmed by using multi-layer date cohorts. Furthermore, immune profiles and immunotherapy responses are also different between the two DDR subtypes. Altogether, this study illustrates the DDR heterogeneity of HCCs and is helpful to the understanding of personalized clinicopathological and molecular mechanisms responsible for unique tumor DDR profiles.
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Affiliation(s)
- Peng Lin
- Department of Medical Ultrasound, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Rui-Zhi Gao
- Department of Medical Ultrasound, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Rong Wen
- Department of Medical Ultrasound, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Yun He
- Department of Medical Ultrasound, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Hong Yang
- Department of Medical Ultrasound, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
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24
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Shkundina IS, Gall AA, Dick A, Cocklin S, Mazin AV. New RAD51 Inhibitors to Target Homologous Recombination in Human Cells. Genes (Basel) 2021; 12:genes12060920. [PMID: 34208492 PMCID: PMC8235719 DOI: 10.3390/genes12060920] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/10/2021] [Accepted: 06/11/2021] [Indexed: 12/31/2022] Open
Abstract
Targeting DNA repair proteins with small-molecule inhibitors became a proven anti-cancer strategy. Previously, we identified an inhibitor of a major protein of homologous recombination (HR) RAD51, named B02. B02 inhibited HR in human cells and sensitized them to chemotherapeutic drugs in vitro and in vivo. Here, using a medicinal chemistry approach, we aimed to improve the potency of B02. We identified the B02 analog, B02-isomer, which inhibits HR in human cells with significantly higher efficiency. We also show that B02-iso sensitizes triple-negative breast cancer MDA-MB-231 cells to the PARP inhibitor (PARPi) olaparib.
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Affiliation(s)
- Irina S. Shkundina
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA; (I.S.S.); (A.D.); (S.C.)
| | | | - Alexej Dick
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA; (I.S.S.); (A.D.); (S.C.)
| | - Simon Cocklin
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA; (I.S.S.); (A.D.); (S.C.)
| | - Alexander V. Mazin
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA; (I.S.S.); (A.D.); (S.C.)
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA
- Correspondence:
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25
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Chen L, Gao H, Zhou B, Wang Y. Comprehensive optimization of a reporter assay toolbox for three distinct CRISPR-Cas systems. FEBS Open Bio 2021; 11:1965-1980. [PMID: 33999508 PMCID: PMC8255852 DOI: 10.1002/2211-5463.13198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/30/2021] [Accepted: 05/14/2021] [Indexed: 12/18/2022] Open
Abstract
The clustered, regularly interspaced, short palindromic repeats‐associated DNA nuclease (CRISPR‐Cas) protein system allows programmable gene editing through inducing double‐strand breaks. Reporter assays for DNA cleavage and DNA repair events play an important role in advancing the CRISPR technology and improving our understanding of the underlying molecular mechanisms. Here, we developed a series of reporter assays to probe mechanisms of action of various editing processes, including nonhomologous DNA end joining, homology‐directed repair and single‐strand annealing. With special target design, the reporter assays as an optimized toolbox can be used to take advantage of three distinct CRISPR‐Cas systems (Streptococcus pyogenes Cas9, Staphylococcus aureus Cas9 and Francisella novicida U112 Cpf1) and two different reporters (GFP and Gaussia luciferase). We further validated the Gaussia reporter assays using a series of small molecules, including NU7441, RI‐1 and Mirin, and showcased the use of a GFP reporter assay as an effective tool for enrichment of cells with edited genome.
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Affiliation(s)
- Li Chen
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Haoyuan Gao
- College of Life Sciences and Oceanography, Shenzhen University, China.,Department of Biology, Oberlin College, OH, USA
| | - Bing Zhou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
| | - Yu Wang
- College of Life Sciences and Oceanography, Shenzhen University, China
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26
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Rajpurohit YS, Sharma DK, Misra HS. PprA Protein Inhibits DNA Strand Exchange and ATP Hydrolysis of Deinococcus RecA and Regulates the Recombination in Gamma-Irradiated Cells. Front Cell Dev Biol 2021; 9:636178. [PMID: 33959605 PMCID: PMC8093518 DOI: 10.3389/fcell.2021.636178] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/23/2021] [Indexed: 11/14/2022] Open
Abstract
DrRecA and PprA proteins function are crucial for the extraordinary resistance to γ-radiation and DNA strand break repair in Deinococcus radiodurans. DrRecA mediated homologous recombination help in DNA strand break repair and cell survival, while the PprA protein confers radio-resistance via its roles in DNA repair, genome maintenance, and cell division. Genetically recA and pprA genes interact and constitute an epistatic group however, the mechanism underlying their functional interaction is not clear. Here, we showed the physical and functional interaction of DrRecA and PprA protein both in solution and inside the cells. The absence of the pprA gene increases the recombination frequency in gamma-irradiated D. radiodurans cells and genomic instability in cells growing under normal conditions. PprA negatively regulates the DrRecA functions by inhibiting DrRecA mediated DNA strand exchange and ATPase function in vitro. Furthermore, it is shown that the inhibitory effect of PprA on DrRecA catalyzed DNA strand exchange was not due to sequestration of homologous dsDNA and was dependent on PprA oligomerization and DNA binding property. Together, results suggest that PprA is a new member of recombination mediator proteins (RMPs), and able to regulate the DrRecA function in γ-irradiated cells by protecting the D. radiodurans genome from hyper-recombination and associated negative effects.
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Affiliation(s)
- Yogendra Singh Rajpurohit
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute (DAE- Deemed University), Mumbai, India
| | - Dhirendra Kumar Sharma
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute (DAE- Deemed University), Mumbai, India
| | - Hari S Misra
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute (DAE- Deemed University), Mumbai, India
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27
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Yuan Z, Zhang D, Yu F, Ma Y, Liu Y, Li X, Wang H. Precise sequencing of single protected-DNA fragment molecules for profiling of protein distribution and assembly on DNA. Chem Sci 2021; 12:2039-2049. [PMID: 34163966 PMCID: PMC8179319 DOI: 10.1039/d0sc01742f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 12/31/2020] [Indexed: 11/21/2022] Open
Abstract
Multiple DNA-interacting protein molecules are often dynamically distributed and/or assembled along a DNA molecule to adapt to their intricate functions temporally. However, analytical technology for measuring such binding behaviours is still missing. Here, we demonstrate the unique capacity of a supernuclease for a highly efficient cutting of the unprotected-DNA segments and with complete preservation of the protein-occluded DNA segments at near single-nucleotide resolution. By exploring this high-resolution cutting, an unprecedented assay that allows a precise sequencing of single protected-DNA fragment molecules (SPDFMS) was developed. As relevant applications, relevant information was gained on the respective distribution/assembly patterns and coordinated displacement of single-stranded DNA-binding protein and recombinase RecA, two model proteins, on DNA. Benefiting from this assay, we also for the first time provide direct measurement of the length of single RecA nucleofilaments, showing the predominant stoichiometry of 5-7 RecA monomers per RecA nucleofilament under physiologically relevant conditions. This innovative assay appears as a promising analytical tool for studying diverse protein-DNA interactions implicated in DNA replication, transcription, recombination, repair, and gene editing.
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Affiliation(s)
- Zheng Yuan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences Beijing 100085 P. R. China +86 10 62849600 +86 10 62849600
- University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Dapeng Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences Beijing 100085 P. R. China +86 10 62849600 +86 10 62849600
- Institute of Environment and Health, Hangzhou, Institute for Advanced Study, UCAS Hangzhou 310000 P. R. China
| | - Fangzhi Yu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences Beijing 100085 P. R. China +86 10 62849600 +86 10 62849600
- University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Yangde Ma
- University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Yan Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences Beijing 100085 P. R. China +86 10 62849600 +86 10 62849600
- University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Xiangjun Li
- University of Chinese Academy of Sciences Beijing 100049 P. R. China
| | - Hailin Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences Beijing 100085 P. R. China +86 10 62849600 +86 10 62849600
- University of Chinese Academy of Sciences Beijing 100049 P. R. China
- Institute of Environment and Health, Jianghan University Wuhan Hubei 430056 P. R. China
- Institute of Environment and Health, Hangzhou, Institute for Advanced Study, UCAS Hangzhou 310000 P. R. China
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28
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The molecular basis and disease relevance of non-homologous DNA end joining. Nat Rev Mol Cell Biol 2020; 21:765-781. [PMID: 33077885 DOI: 10.1038/s41580-020-00297-8] [Citation(s) in RCA: 201] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2020] [Indexed: 12/26/2022]
Abstract
Non-homologous DNA end joining (NHEJ) is the predominant repair mechanism of any type of DNA double-strand break (DSB) during most of the cell cycle and is essential for the development of antigen receptors. Defects in NHEJ result in sensitivity to ionizing radiation and loss of lymphocytes. The most critical step of NHEJ is synapsis, or the juxtaposition of the two DNA ends of a DSB, because all subsequent steps rely on it. Recent findings show that, like the end processing step, synapsis can be achieved through several mechanisms. In this Review, we first discuss repair pathway choice between NHEJ and other DSB repair pathways. We then integrate recent insights into the mechanisms of NHEJ synapsis with updates on other steps of NHEJ, such as DNA end processing and ligation. Finally, we discuss NHEJ-related human diseases, including inherited disorders and neoplasia, which arise from rare failures at different NHEJ steps.
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29
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Teng FY, Jiang ZZ, Huang LY, Guo M, Chen F, Hou XM, Xi XG, Xu Y. A Toolbox for Site-Specific Labeling of RecQ Helicase With a Single Fluorophore Used in the Single-Molecule Assay. Front Mol Biosci 2020; 7:586450. [PMID: 33102530 PMCID: PMC7545742 DOI: 10.3389/fmolb.2020.586450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 08/25/2020] [Indexed: 01/16/2023] Open
Abstract
Fluorescently labeled proteins can improve the detection sensitivity and have been widely used in a variety of biological measurements. In single-molecule assays, site-specific labeling of proteins enables the visualization of molecular interactions, conformational changes in proteins, and enzymatic activity. In this study, based on a flexible linker in the Escherichia coli RecQ helicase, we established a scheme involving a combination of fluorophore labeling and sortase A ligation to allow site-specific labeling of the HRDC domain of RecQ with a single Cy5 fluorophore, without inletting extra fluorescent domain or peptide fragment. Using single-molecule fluorescence resonance energy transfer, we visualized that Cy5-labeled HRDC could directly interact with RecA domains and could bind to both the 3′ and 5′ ends of the overhang DNA dynamically in vitro for the first time. The present work not only reveals the functional mechanism of the HRDC domain, but also provides a feasible method for site-specific labeling of a domain with a single fluorophore used in single-molecule assays.
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Affiliation(s)
- Fang-Yuan Teng
- Experimental Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, China.,Department of Endocrinology and Metabolism, and Cardiovascular and Metabolic Diseases Key Laboratory of Luzhou, and Sichuan Clinical Research Center for Nephropathy, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Academician (Expert) Workstation of Sichuan Province, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Zong-Zhe Jiang
- Experimental Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Department of Endocrinology and Metabolism, and Cardiovascular and Metabolic Diseases Key Laboratory of Luzhou, and Sichuan Clinical Research Center for Nephropathy, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Ling-Yun Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, China
| | - Man Guo
- Department of Endocrinology and Metabolism, and Cardiovascular and Metabolic Diseases Key Laboratory of Luzhou, and Sichuan Clinical Research Center for Nephropathy, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Feng Chen
- Experimental Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Xi-Miao Hou
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, China
| | - Xu-Guang Xi
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, China.,LBPA, Ecole normale supérieure Paris-Saclay, Centre national de la recherche scientifique (CNRS), Université Paris Saclay, Cachan, France
| | - Yong Xu
- Experimental Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou, China.,Department of Endocrinology and Metabolism, and Cardiovascular and Metabolic Diseases Key Laboratory of Luzhou, and Sichuan Clinical Research Center for Nephropathy, The Affiliated Hospital of Southwest Medical University, Luzhou, China
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30
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Real-time tracking reveals catalytic roles for the two DNA binding sites of Rad51. Nat Commun 2020; 11:2950. [PMID: 32528002 PMCID: PMC7289862 DOI: 10.1038/s41467-020-16750-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 05/19/2020] [Indexed: 02/03/2023] Open
Abstract
During homologous recombination, Rad51 forms a nucleoprotein filament on single-stranded DNA to promote DNA strand exchange. This filament binds to double-stranded DNA (dsDNA), searches for homology, and promotes transfer of the complementary strand, producing a new heteroduplex. Strand exchange proceeds via two distinct three-strand intermediates, C1 and C2. C1 contains the intact donor dsDNA whereas C2 contains newly formed heteroduplex DNA. Here, we show that the conserved DNA binding motifs, loop 1 (L1) and loop 2 (L2) in site I of Rad51, play distinct roles in this process. L1 is involved in formation of the C1 complex whereas L2 mediates the C1–C2 transition, producing the heteroduplex. Another DNA binding motif, site II, serves as the DNA entry position for initial Rad51 filament formation, as well as for donor dsDNA incorporation. Our study provides a comprehensive molecular model for the catalytic process of strand exchange mediated by eukaryotic RecA-family recombinases. Rad51 drives DNA strand exchange, the central reaction in recombinational DNA repair. Two sites of Rad51 are responsible for DNA binding, but the function of these sites has proven elusive. Here, the authors employ real-time assays to reveal catalytic roles for the two DNA binding sites of Rad51.
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31
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Prasad D, Muniyappa K. The extended N-terminus of Mycobacterium smegmatis RecX potentiates its ability to antagonize RecA functions. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140468. [PMID: 32526474 DOI: 10.1016/j.bbapap.2020.140468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/21/2020] [Accepted: 06/05/2020] [Indexed: 01/13/2023]
Abstract
The members of the RecX family of proteins have a unique capacity to regulate the catalytic activities of RecA/Rad51 proteins in both prokaryotic and eukaryotic organisms. However, our understanding of the functional roles of RecX in pathogenic and non-pathogenic mycobacteria has been limited by insufficient knowledge of the molecular mechanisms of its activity and regulation. Moreover, the significance of a unique 14 amino acid N-terminal extension in Mycobacterium smegmatis RecX (MsRecX) to its function remains unknown. Here, we advance our understanding of the antagonistic roles of mycobacterial RecX proteins and the functional significance of the extended N-terminus of MsRecX. The full-length MsRecX acts as an antagonist of RecA, negatively regulating RecA promoted functions, including DNA strand exchange, LexA cleavage and ATP hydrolysis, but not binding of ATP. The N-terminally truncated MsRecX variants retain the RecA inhibitory activity, albeit with lower efficiencies compared to the full-length protein. Perhaps most importantly, direct visualization of RecA nucleoprotein filaments, which had been incubated with RecX proteins, showed that they promote disassembly of nucleoprotein filaments primarily within the filaments. In addition, interaction of RecX proteins with the RecA nucleoprotein filaments results in the formation of stiff and irregularly shaped nucleoprotein filaments. Thus, these findings add an additional mechanism by which RecX disassembles RecA nucleoprotein filaments. Overall, this study provides strong evidence for the notion that the N-terminal 14 amino acid region of MsRecX plays an important role in the negative regulation of RecA functions and new insights into the molecular mechanism underlying RecX function.
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Affiliation(s)
- Deepika Prasad
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India
| | - Kalappa Muniyappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India.
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32
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Atwell SX, Migliozzi D, Dupont A, Viovy JL, Cappello G. Structural transitions and mechanochemical coupling in the nucleoprotein filament explain homology selectivity and Rad51 protein cooperativity in cellular DNA repair. Phys Rev E 2020; 101:032407. [PMID: 32289957 DOI: 10.1103/physreve.101.032407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/17/2020] [Indexed: 11/07/2022]
Abstract
The nucleoprotein filament (NPF) is the fundamental element of homologous recombination (HR), a major mechanism for the repair of double-strand DNA breaks in the cell. The NPF is made of the damaged DNA strand surrounded by recombinase proteins, and its sensitivity to base-pairing mismatches is a crucial feature that guarantees the fidelity of the repair. The concurrent recombinases are also essential for several steps of HR. In this work, we used torque-sensitive magnetic tweezers to probe and apply mechanical constraints to single nucleoprotein filaments (NPFs). We demonstrated that the NPF undergoes structural transitions from a stretched to a compact state, and we measured the corresponding mechanochemical signatures. Using an active two-state model, we proposed a free-energy landscape for the NPF transition. Using this quantitative model, we explained both how the sensitivity of the NPF to the homology length is regulated by its structural transition and how the cooperativity of Rad51 favors selectivity to relatively long homologous sequences.
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Affiliation(s)
- Scott X Atwell
- Institut Curie, PSL Research University, Centre National de la Recherche Scientifique, Sorbonne Universités, UPMC Univ Paris 06, Unité Mixte de Recherche 168, 75005 Paris, France
| | - Daniel Migliozzi
- Institut Curie, PSL Research University, Centre National de la Recherche Scientifique, Sorbonne Universités, UPMC Univ Paris 06, Unité Mixte de Recherche 168, 75005 Paris, France.,Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Aurélie Dupont
- Institut Curie, PSL Research University, Centre National de la Recherche Scientifique, Sorbonne Universités, UPMC Univ Paris 06, Unité Mixte de Recherche 168, 75005 Paris, France.,Université Grenoble Alpes, Laboratoire Interdisciplinaire de Physique, CNRS, F-38000 Grenoble, France
| | - Jean-Louis Viovy
- Institut Curie, PSL Research University, Centre National de la Recherche Scientifique, Sorbonne Universités, UPMC Univ Paris 06, Unité Mixte de Recherche 168, Institut Pierre Gilles de Gennes, MMBM Group, 75005 Paris, France
| | - Giovanni Cappello
- Institut Curie, PSL Research University, Centre National de la Recherche Scientifique, Sorbonne Universités, UPMC Univ Paris 06, Unité Mixte de Recherche 168, 75005 Paris, France.,Université Grenoble Alpes, Laboratoire Interdisciplinaire de Physique, CNRS, F-38000 Grenoble, France
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33
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Regulation of Cell Division in Bacteria by Monitoring Genome Integrity and DNA Replication Status. J Bacteriol 2020; 202:JB.00408-19. [PMID: 31548275 DOI: 10.1128/jb.00408-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
All organisms regulate cell cycle progression by coordinating cell division with DNA replication status. In eukaryotes, DNA damage or problems with replication fork progression induce the DNA damage response (DDR), causing cyclin-dependent kinases to remain active, preventing further cell cycle progression until replication and repair are complete. In bacteria, cell division is coordinated with chromosome segregation, preventing cell division ring formation over the nucleoid in a process termed nucleoid occlusion. In addition to nucleoid occlusion, bacteria induce the SOS response after replication forks encounter DNA damage or impediments that slow or block their progression. During SOS induction, Escherichia coli expresses a cytoplasmic protein, SulA, that inhibits cell division by directly binding FtsZ. After the SOS response is turned off, SulA is degraded by Lon protease, allowing for cell division to resume. Recently, it has become clear that SulA is restricted to bacteria closely related to E. coli and that most bacteria enforce the DNA damage checkpoint by expressing a small integral membrane protein. Resumption of cell division is then mediated by membrane-bound proteases that cleave the cell division inhibitor. Further, many bacterial cells have mechanisms to inhibit cell division that are regulated independently from the canonical LexA-mediated SOS response. In this review, we discuss several pathways used by bacteria to prevent cell division from occurring when genome instability is detected or before the chromosome has been fully replicated and segregated.
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34
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Homologous Recombination under the Single-Molecule Fluorescence Microscope. Int J Mol Sci 2019; 20:ijms20236102. [PMID: 31816946 PMCID: PMC6929127 DOI: 10.3390/ijms20236102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/26/2019] [Accepted: 11/30/2019] [Indexed: 11/16/2022] Open
Abstract
Homologous recombination (HR) is a complex biological process and is central to meiosis and for repair of DNA double-strand breaks. Although the HR process has been the subject of intensive study for more than three decades, the complex protein–protein and protein–DNA interactions during HR present a significant challenge for determining the molecular mechanism(s) of the process. This knowledge gap is largely because of the dynamic interactions between HR proteins and DNA which is difficult to capture by routine biochemical or structural biology methods. In recent years, single-molecule fluorescence microscopy has been a popular method in the field of HR to visualize these complex and dynamic interactions at high spatiotemporal resolution, revealing mechanistic insights of the process. In this review, we describe recent efforts that employ single-molecule fluorescence microscopy to investigate protein–protein and protein–DNA interactions operating on three key DNA-substrates: single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), and four-way DNA called Holliday junction (HJ). We also outline the technological advances and several key insights revealed by these studies in terms of protein assembly on these DNA substrates and highlight the foreseeable promise of single-molecule fluorescence microscopy in advancing our understanding of homologous recombination.
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35
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Chromosome Preference During Homologous Recombination Repair of DNA Double-Strand Breaks in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2019; 9:3773-3780. [PMID: 31519746 PMCID: PMC6829126 DOI: 10.1534/g3.119.400607] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
DNA double-strand breaks (DSBs) are especially toxic DNA lesions that, if left unrepaired, can lead to wide-ranging genomic instability. Of the pathways available to repair DSBs, the most accurate is homologous recombination (HR), where a homologous sequence is used as a donor template to restore genetic information at the break site. While much of the biochemical aspects of HR repair have been characterized, how the repair machinery locates and discriminates between potential homologous donor templates throughout the genome remains elusive. We use Drosophila melanogaster to investigate whether there is a preference between intrachromosomal and interhomolog donor sequences in mitotically dividing cells. Our results demonstrate that, although interhomolog HR is possible and frequent if another donor template is not available, intrachromosomal donor templates are highly preferred. This is true even if the interhomolog donor template is less diverged than the intrachromosomal donor template. Thus, despite the stringent requirements for homology, the chromosomal location of the donor template plays a more significant role in donor template choice.
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36
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Yan Z, Xue C, Kumar S, Crickard JB, Yu Y, Wang W, Pham N, Li Y, Niu H, Sung P, Greene EC, Ira G. Rad52 Restrains Resection at DNA Double-Strand Break Ends in Yeast. Mol Cell 2019; 76:699-711.e6. [PMID: 31542296 DOI: 10.1016/j.molcel.2019.08.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/26/2019] [Accepted: 08/20/2019] [Indexed: 12/29/2022]
Abstract
Rad52 is a key factor for homologous recombination (HR) in yeast. Rad52 helps assemble Rad51-ssDNA nucleoprotein filaments that catalyze DNA strand exchange, and it mediates single-strand DNA annealing. We find that Rad52 has an even earlier function in HR in restricting DNA double-stranded break ends resection that generates 3' single-stranded DNA (ssDNA) tails. In fission yeast, Exo1 is the primary resection nuclease, with the helicase Rqh1 playing a minor role. We demonstrate that the choice of two extensive resection pathways is regulated by Rad52. In rad52 cells, the resection rate increases from ∼3-5 kb/h up to ∼10-20 kb/h in an Rqh1-dependent manner, while Exo1 becomes dispensable. Budding yeast Rad52 similarly inhibits Sgs1-dependent resection. Single-molecule analysis with purified budding yeast proteins shows that Rad52 competes with Sgs1 for DNA end binding and inhibits Sgs1 translocation along DNA. These results identify a role for Rad52 in limiting ssDNA generated by end resection.
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Affiliation(s)
- Zhenxin Yan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Chaoyou Xue
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Sandeep Kumar
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - J Brooks Crickard
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Yang Yu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Weibin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Nhung Pham
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yuxi Li
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Hengyao Niu
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Patrick Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229 USA.
| | - Eric C Greene
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA.
| | - Grzegorz Ira
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
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37
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Buljubašić M, Hlevnjak A, Repar J, Đermić D, Filić V, Weber I, Zahradka K, Zahradka D. RecBCD- RecFOR-independent pathway of homologous recombination in Escherichia coli. DNA Repair (Amst) 2019; 83:102670. [PMID: 31378505 DOI: 10.1016/j.dnarep.2019.102670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/05/2019] [Accepted: 07/05/2019] [Indexed: 10/26/2022]
Abstract
The RecA protein is a key bacterial recombination enzyme that catalyzes pairing and strand exchange between homologous DNA duplexes. In Escherichia coli, RecA protein assembly on DNA is mediated either by the RecBCD or RecFOR protein complexes. Correspondingly, two recombination pathways, RecBCD and RecF (or RecFOR), are distinguished in E. coli. Inactivation of both pathways in recB(CD) recF(OR) mutants results in severe recombination deficiency. Here we describe a novel, RecBCD- RecFOR-independent (RecBFI) recombination pathway that is active in ΔrecBCD sbcB15 sbcC(D) ΔrecF(OR) mutants of E. coli. In transductional crosses, these mutants show only four-fold decrease of recombination frequency relative to the wild-type strain. At the same time they recombine 40- to 90-fold better than their sbcB+ sbcC+ and ΔsbcB sbcC counterparts. The RecBFI pathway strongly depends on recA, recJ and recQ gene functions, and moderately depends on recG and lexA functions. Inactivation of dinI, helD, recX, recN, radA, ruvABC and uvrD genes has a slight effect on RecBFI recombination. After exposure to UV and gamma irradiation, the ΔrecBCD sbcB15 sbcC ΔrecF mutants show moderately increased DNA repair proficiency relative to their sbcB+ sbcC+ and ΔsbcB sbcC counterparts. However, introduction of recA730 allele (encoding RecA protein with enhanced DNA binding properties) completely restores repair proficiency to ΔrecBCD sbcB15 sbcC ΔrecF mutants, but not to their sbcB+ sbcC+ and ΔsbcB sbcC derivatives. Fluorescence microscopy with UV-irradiated recA-gfp fusion mutants suggests that the kinetics of RecA filament formation might be slowed down in the RecBFI pathway. Inactivation of 3'-5' exonucleases ExoVII, ExoIX and ExoX cannot activate the RecBFI pathway in ΔrecBCD ΔsbcB sbcC ΔrecF mutants. Taken together, our results show that the product of the sbcB15 allele is crucial for RecBFI pathway. Besides protecting 3' overhangs, SbcB15 protein might play an additional, more active role in formation of the RecA filament.
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Affiliation(s)
- Maja Buljubašić
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Ana Hlevnjak
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Jelena Repar
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Damir Đermić
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Vedrana Filić
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Igor Weber
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Ksenija Zahradka
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Davor Zahradka
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia.
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38
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Prasad D, Arora D, Nandicoori VK, Muniyappa K. Elucidating the functional role of Mycobacterium smegmatis recX in stress response. Sci Rep 2019; 9:10912. [PMID: 31358794 PMCID: PMC6662834 DOI: 10.1038/s41598-019-47312-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 07/15/2019] [Indexed: 12/20/2022] Open
Abstract
The RecX protein has attracted considerable interest because the recX mutants exhibit multiple phenotypes associated with RecA functions. To further our understanding of the functional relationship between recA and recX, the effect of different stress treatments on their expression profiles, cell yield and viability were investigated. A significant correlation was found between the expression of Mycobacterium smegmatis recA and recX genes at different stages of growth, and in response to different stress treatments albeit recX exhibiting lower transcript and protein abundance at the mid-log and stationary phases of the bacterial growth cycle. To ascertain their roles in vivo, a targeted deletion of the recX and recArecX was performed in M. smegmatis. The growth kinetics of these mutant strains and their sensitivity patterns to different stress treatments were assessed relative to the wild-type strain. The deletion of recA affected normal cell growth and survival, while recX deletion showed no significant effect. Interestingly, deletion of both recX and recA genes results in a phenotype that is intermediate between the phenotypes of the ΔrecA mutant and the wild-type strain. Collectively, these results reveal a previously unrecognized role for M. smegmatis recX and support the notion that it may regulate a subset of the yet unknown genes involved in normal cell growth and DNA-damage repair.
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Affiliation(s)
- Deepika Prasad
- Department of Biochemistry, Indian Institute of Science, Bengaluru, 560012, India
| | - Divya Arora
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | | | - K Muniyappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru, 560012, India.
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39
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Ho HN, Zalami D, Köhler J, van Oijen AM, Ghodke H. Identification of Multiple Kinetic Populations of DNA-Binding Proteins in Live Cells. Biophys J 2019; 117:950-961. [PMID: 31383358 DOI: 10.1016/j.bpj.2019.07.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 06/28/2019] [Accepted: 07/08/2019] [Indexed: 01/20/2023] Open
Abstract
Understanding how multiprotein complexes function in cells requires detailed quantitative understanding of their association and dissociation kinetics. Analysis of the heterogeneity of binding lifetimes enables the interrogation of the various intermediate states formed during the reaction. Single-molecule fluorescence imaging permits the measurement of reaction kinetics inside living organisms with minimal perturbation. However, poor photophysical properties of fluorescent probes limit the dynamic range and accuracy of measurements of off rates in live cells. Time-lapse single-molecule fluorescence imaging can partially overcome the limits of photobleaching; however, limitations of this technique remain uncharacterized. Here, we present a structured analysis of which timescales are most accessible using the time-lapse imaging approach and explore uncertainties in determining kinetic subpopulations. We demonstrate the effect of shot noise on the precision of the measurements as well as the resolution and dynamic range limits that are inherent to the method. Our work provides a convenient implementation to determine theoretical errors from measurements and to support interpretation of experimental data.
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Affiliation(s)
- Han N Ho
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia; Illawarra Health and Medical Research Institute, Wollongong, Australia
| | - Daniel Zalami
- Spectroscopy of Soft Matter, University of Bayreuth, Bayreuth, Germany
| | - Jürgen Köhler
- Spectroscopy of Soft Matter, University of Bayreuth, Bayreuth, Germany; Bavarian Polymer Institute, Bayreuth, Germany; Bayreuth Institute of Macromolecular Research, University of Bayreuth, Bayreuth, Germany
| | - Antoine M van Oijen
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia; Illawarra Health and Medical Research Institute, Wollongong, Australia.
| | - Harshad Ghodke
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia; Illawarra Health and Medical Research Institute, Wollongong, Australia.
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40
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Haas KT, Lee M, Esposito A, Venkitaraman AR. Single-molecule localization microscopy reveals molecular transactions during RAD51 filament assembly at cellular DNA damage sites. Nucleic Acids Res 2019; 46:2398-2416. [PMID: 29309696 PMCID: PMC5861458 DOI: 10.1093/nar/gkx1303] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 12/19/2017] [Indexed: 11/14/2022] Open
Abstract
RAD51 recombinase assembles on single-stranded (ss)DNA substrates exposed by DNA end-resection to initiate homologous recombination (HR), a process fundamental to genome integrity. RAD51 assembly has been characterized using purified proteins, but its ultrastructural topography in the cell nucleus is unexplored. Here, we combine cell genetics with single-molecule localization microscopy and a palette of bespoke analytical tools, to visualize molecular transactions during RAD51 assembly in the cellular milieu at resolutions approaching 30-40 nm. In several human cell types, RAD51 focalizes in clusters that progressively extend into long filaments, which abut-but do not overlap-with globular bundles of replication protein A (RPA). Extended filaments alter topographically over time, suggestive of succeeding steps in HR. In cells depleted of the tumor suppressor protein BRCA2, or overexpressing its RAD51-binding BRC repeats, RAD51 fails to assemble at damage sites, although RPA accumulates unhindered. By contrast, in cells lacking a BRCA2 carboxyl (C)-terminal region targeted by cancer-causing mutations, damage-induced RAD51 assemblies initiate but do not extend into filaments. We suggest a model wherein RAD51 assembly proceeds concurrently with end-resection at adjacent sites, via an initiation step dependent on the BRC repeats, followed by filament extension through the C-terminal region of BRCA2.
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Affiliation(s)
- Kalina T Haas
- The Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK
| | - MiYoung Lee
- The Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK
| | - Alessandro Esposito
- The Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK
| | - Ashok R Venkitaraman
- The Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK
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41
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Wasserman MR, Liu S. A Tour de Force on the Double Helix: Exploiting DNA Mechanics To Study DNA-Based Molecular Machines. Biochemistry 2019; 58:4667-4676. [PMID: 31251042 DOI: 10.1021/acs.biochem.9b00346] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
DNA is both a fundamental building block of life and a fascinating natural polymer. The advent of single-molecule manipulation tools made it possible to exert controlled force on individual DNA molecules and measure their mechanical response. Such investigations elucidated the elastic properties of DNA and revealed its distinctive structural configurations across force regimes. In the meantime, a detailed understanding of DNA mechanics laid the groundwork for single-molecule studies of DNA-binding proteins and DNA-processing enzymes that bend, stretch, and twist DNA. These studies shed new light on the metabolism and transactions of nucleic acids, which constitute a major part of the cell's operating system. Furthermore, the marriage of single-molecule fluorescence visualization and force manipulation has enabled researchers to directly correlate the applied tension to changes in the DNA structure and the behavior of DNA-templated complexes. Overall, experimental exploitation of DNA mechanics has been and will continue to be a unique and powerful strategy for understanding how molecular machineries recognize and modify the physical state of DNA to accomplish their biological functions.
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Affiliation(s)
- Michael R Wasserman
- Laboratory of Nanoscale Biophysics and Biochemistry , The Rockefeller University , New York , New York 10065 , United States
| | - Shixin Liu
- Laboratory of Nanoscale Biophysics and Biochemistry , The Rockefeller University , New York , New York 10065 , United States
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42
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Jiang YJ, Zhong JH, Zhou ZH, Qiu MQ, Zhou XG, Liu YC, Huo RR, Liang XM, Chen Z, Lin QL, Yu XY, Yu HP. Association between polymorphisms in MicroRNA target sites of RAD51D genes and risk of hepatocellular carcinoma. Cancer Med 2019; 8:2545-2552. [PMID: 30883040 PMCID: PMC6536933 DOI: 10.1002/cam4.2068] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 02/10/2019] [Accepted: 02/12/2019] [Indexed: 01/27/2023] Open
Abstract
RAD51D (RAD51L3) is a member of the RAD51 gene family which plays important roles in maintaining genomic stability and preventing DNA damage. This study is aimed to investigate the associations between RAD51D polymorphisms and the hereditary susceptibility of hepatocellular carcinoma (HCC). In this study we conducted a hospital–based case‐control study including 805 cases (HCC patients) and 846 controls (nontumor patients) in Guangxi, China. A total of two Single–nucleotide polymorphisms (SNPs) rs12947947 and rs28363292 of RAD51D were selected and genotyped. Although we did not find two SNPs individually that had any significant main effect on risk of HCC, We found that the combined genotypes with 1‐2 risk genotypes were associated with significantly increased overall risk of HCC (OR = 1.462, 95% CI = 1.050‐2.036). According to the results of further stratification analysis, GT/GG genotype of rs28363292 increased HCC risk in zhuang people (OR = 3.913, 95% CI = 1.873‐8.175) and nonhepatitis B virus (HBV) infection population (OR = 1.774, 95% CI = 1.060‐2.969), the combined 1‐2 risk genotypes increased the risk of HCC in zhuang people (OR = 2.817, 95% CI = 1.532‐5.182) and non‐HBV infected population (OR = 1.567, 95% CI = 1.042‐2.358). Our results suggest that rs12947947 and rs28363292 polymorphisms may jointly contribute to the risk of HCC. Further large studies and functional studies are required to validate our findings.
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Affiliation(s)
- Yan-Ji Jiang
- Affiliated Tumor Hospital of Guangxi Medical University, Guangxi, China.,School of Public Health, Guangxi Medical University, Guangxi, China
| | - Jian-Hong Zhong
- Affiliated Tumor Hospital of Guangxi Medical University, Guangxi, China
| | - Zi-Han Zhou
- Affiliated Tumor Hospital of Guangxi Medical University, Guangxi, China.,School of Public Health, Guangxi Medical University, Guangxi, China
| | - Mo-Qin Qiu
- Affiliated Tumor Hospital of Guangxi Medical University, Guangxi, China.,School of Public Health, Guangxi Medical University, Guangxi, China
| | - Xian-Guo Zhou
- Affiliated Tumor Hospital of Guangxi Medical University, Guangxi, China
| | - Ying-Chun Liu
- Affiliated Tumor Hospital of Guangxi Medical University, Guangxi, China
| | - Rong-Rui Huo
- Affiliated Tumor Hospital of Guangxi Medical University, Guangxi, China
| | - Xiu-Mei Liang
- Affiliated Tumor Hospital of Guangxi Medical University, Guangxi, China
| | - Zhu Chen
- Affiliated Hospital of Guilin Medical University, Guangxi, China
| | - Qiu-Ling Lin
- Affiliated Tumor Hospital of Guangxi Medical University, Guangxi, China.,School of Public Health, Guangxi Medical University, Guangxi, China
| | - Xiang-Yuan Yu
- School of Public Health, Guilin Medical University, Guangxi, China
| | - Hong-Ping Yu
- Affiliated Tumor Hospital of Guangxi Medical University, Guangxi, China.,School of Public Health, Guangxi Medical University, Guangxi, China
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43
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Recombinases and Related Proteins in the Context of Homologous Recombination Analyzed by Molecular Microscopy. Methods Mol Biol 2019; 1805:251-270. [PMID: 29971722 DOI: 10.1007/978-1-4939-8556-2_13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
Transmission electron microscopy (TEM) and atomic force microscopy (AFM) are powerful tools to study the behavior of various actors in homologous recombination including molecular motors such as recombinases and helicases/translocases. Here we present specific approaches developed in terms of sample preparation and imaging methods to contribute to the understanding of homologous recombination process and its regulation focusing on the interplay between recombinases and other related proteins such as mediators or antirecombinase actors.Homologous recombination (HR) is a high-fidelity DNA repair pathway since it uses a homologous DNA as template. Recombinases such as RecA in bacteria, RadA in archaea, and Rad51 in eukaryotes are key proteins in the HR pathway: HR is initiated with formation of an ssDNA overhang on which recombinases polymerize and form a dynamic active nucleoprotein filament able to search for homology and to exchange DNA strand in an ATP-dependent manner. We provide practical methods to analyze presynaptic filament formation on ssDNA, its composition and regulation in presence of mediator partners, antirecombinase activity of translocase, and chromatin remodeling events.
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44
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DNA damage and genome instability by G-quadruplex ligands are mediated by R loops in human cancer cells. Proc Natl Acad Sci U S A 2018; 116:816-825. [PMID: 30591567 DOI: 10.1073/pnas.1810409116] [Citation(s) in RCA: 189] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
G quadruplexes (G4s) and R loops are noncanonical DNA structures that can regulate basic nuclear processes and trigger DNA damage, genome instability, and cell killing. By different technical approaches, we here establish that specific G4 ligands stabilize G4s and simultaneously increase R-loop levels within minutes in human cancer cells. Genome-wide mapping of R loops showed that the studied G4 ligands likely cause the spreading of R loops to adjacent regions containing G4 structures, preferentially at 3'-end regions of expressed genes, which are partially ligand-specific. Overexpression of an exogenous human RNaseH1 rescued DNA damage induced by G4 ligands in BRCA2-proficient and BRCA2-silenced cancer cells. Moreover, even if the studied G4 ligands increased noncanonical DNA structures at similar levels in nuclear chromatin, their cellular effects were different in relation to cell-killing activity and stimulation of micronuclei, a hallmark of genome instability. Our findings therefore establish that G4 ligands can induce DNA damage by an R loop-dependent mechanism that can eventually lead to different cellular consequences depending on the chemical nature of the ligands.
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45
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van der Zon NL, Kanaar R, Wyman C. Variation in RAD51 details a hub of functions: opportunities to advance cancer diagnosis and therapy. F1000Res 2018; 7. [PMID: 30271574 PMCID: PMC6137408 DOI: 10.12688/f1000research.15650.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/29/2018] [Indexed: 11/30/2022] Open
Abstract
Loss of genome stability is one of the hallmarks of the enabling characteristics of cancer development. Homologous recombination is a DNA repair process that often breaks down as a prelude to developing cancer. Conversely, homologous recombination can be the Achilles’ heel in common anti-cancer therapies, which are effective by inducing irreparable DNA damage. Here, we review recent structural and functional studies of RAD51, the protein that catalyzes the defining step of homologous recombination: homology recognition and DNA strand exchange. Specific mutations can be linked to structural changes and known essential functions. Additional RAD51 interactions and functions may be revealed. The identification of viable mutations in this essential protein may help define the range of activity and interactions needed. All of this information provides opportunities to fine-tune existing therapies based on homologous recombination status, guide diagnosis, and hopefully develop new clinical tools.
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Affiliation(s)
- Nick Ll van der Zon
- Department of Molecular Genetics, Erasmus MC, Rotterdam, PO Box 2040, 3000 CA, The Netherlands
| | - Roland Kanaar
- Department of Molecular Genetics, Erasmus MC, Rotterdam, PO Box 2040, 3000 CA, The Netherlands.,Oncode Institute, Erasmus MC, Rotterdam, PO Box 2040, 3000 CA, The Netherlands
| | - Claire Wyman
- Department of Molecular Genetics, Erasmus MC, Rotterdam, PO Box 2040, 3000 CA, The Netherlands.,Department of Radiation Oncology, Erasmus MC, Rotterdam, PO Box 2040, 3000 CA, The Netherlands
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46
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van der Zon NLL, Kanaar R, Wyman C. Variation in RAD51 details a hub of functions: opportunities to advance cancer diagnosis and therapy. F1000Res 2018; 7:F1000 Faculty Rev-1453. [PMID: 30271574 PMCID: PMC6137408 DOI: 10.12688/f1000research.15650.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/29/2018] [Indexed: 11/06/2023] Open
Abstract
Loss of genome stability is one of the hallmarks of the enabling characteristics of cancer development. Homologous recombination is a DNA repair process that often breaks down as a prelude to developing cancer. Conversely, homologous recombination can be the Achilles' heel in common anti-cancer therapies, which are effective by inducing irreparable DNA damage. Here, we review recent structural and functional studies of RAD51, the protein that catalyzes the defining step of homologous recombination: homology recognition and DNA strand exchange. Specific mutations can be linked to structural changes and known essential functions. Additional RAD51 interactions and functions may be revealed. The identification of viable mutations in this essential protein may help define the range of activity and interactions needed. All of this information provides opportunities to fine-tune existing therapies based on homologous recombination status, guide diagnosis, and hopefully develop new clinical tools.
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Affiliation(s)
- Nick LL van der Zon
- Department of Molecular Genetics, Erasmus MC, Rotterdam, PO Box 2040, 3000 CA, The Netherlands
| | - Roland Kanaar
- Department of Molecular Genetics, Erasmus MC, Rotterdam, PO Box 2040, 3000 CA, The Netherlands
- Oncode Institute, Erasmus MC, Rotterdam, PO Box 2040, 3000 CA, The Netherlands
| | - Claire Wyman
- Department of Molecular Genetics, Erasmus MC, Rotterdam, PO Box 2040, 3000 CA, The Netherlands
- Department of Radiation Oncology, Erasmus MC, Rotterdam, PO Box 2040, 3000 CA, The Netherlands
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47
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Abstract
Most everyday processes in life involve a necessity for an entity to locate its target. On a cellular level, many proteins have to find their target to perform their function. From gene-expression regulation to DNA repair to host defense, numerous nucleic acid-interacting proteins use distinct target search mechanisms. Several proteins achieve that with the help of short RNA strands known as guides. This review focuses on single-molecule advances studying the target search and recognition mechanism of Argonaute and CRISPR (clustered regularly interspaced short palindromic repeats) systems. We discuss different steps involved in search and recognition, from the initial complex prearrangement into the target-search competent state to the final proofreading steps. We focus on target search mechanisms that range from weak interactions, to one- and three-dimensional diffusion, to conformational proofreading. We compare the mechanisms of Argonaute and CRISPR with a well-studied target search system, RecA.
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Affiliation(s)
- Viktorija Globyte
- Kavli Institute of Nanoscience and Department of Bionanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands; , ,
| | - Sung Hyun Kim
- Kavli Institute of Nanoscience and Department of Bionanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands; , ,
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Chirlmin Joo
- Kavli Institute of Nanoscience and Department of Bionanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands; , ,
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48
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Piazza A, Heyer WD. Multi-Invasion-Induced Rearrangements as a Pathway for Physiological and Pathological Recombination. Bioessays 2018; 40:e1700249. [PMID: 29578583 PMCID: PMC6072258 DOI: 10.1002/bies.201700249] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/08/2018] [Indexed: 01/24/2023]
Abstract
Cells mitigate the detrimental consequences of DNA damage on genome stability by attempting high fidelity repair. Homologous recombination templates DNA double-strand break (DSB) repair on an identical or near identical donor sequence in a process that can in principle access the entire genome. Other physiological processes, such as homolog recognition and pairing during meiosis, also harness the HR machinery using programmed DSBs to physically link homologs and generate crossovers. A consequence of the homology search process by a long nucleoprotein filament is the formation of multi-invasions (MI), a joint molecule in which the damaged ssDNA has invaded more than one donor molecule. Processing of MI joint molecules can compromise the integrity of both donor sites and lead to their rearrangement. Here, two mechanisms for the generation of rearrangements as a pathological consequence of MI processing are detailed and the potential relevance for non-allelic homologous recombination discussed. Finally, it is proposed that MI-induced crossover formation may be a feature of physiological recombination.
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Affiliation(s)
- Aurèle Piazza
- Department of Microbiology and Molecular Genetics, One Shields Avenue, University of California, Davis, CA, 95616, USA
- Spatial Regulation of Genomes, Department of Genomes and Genetics, Institut Pasteur, 25-28 Rue du Docteur Roux, 75015 Paris, France
| | - Wolf-Dietrich Heyer
- Department of Microbiology and Molecular Genetics, One Shields Avenue, University of California, Davis, CA, 95616, USA
- Department of Molecular and Cellular Biology, One Shields Avenue, University of California, Davis, CA, 95616, USA
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49
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Knijnenburg TA, Wang L, Zimmermann MT, Chambwe N, Gao GF, Cherniack AD, Fan H, Shen H, Way GP, Greene CS, Liu Y, Akbani R, Feng B, Donehower LA, Miller C, Shen Y, Karimi M, Chen H, Kim P, Jia P, Shinbrot E, Zhang S, Liu J, Hu H, Bailey MH, Yau C, Wolf D, Zhao Z, Weinstein JN, Li L, Ding L, Mills GB, Laird PW, Wheeler DA, Shmulevich I, Monnat RJ, Xiao Y, Wang C. Genomic and Molecular Landscape of DNA Damage Repair Deficiency across The Cancer Genome Atlas. Cell Rep 2018; 23:239-254.e6. [PMID: 29617664 PMCID: PMC5961503 DOI: 10.1016/j.celrep.2018.03.076] [Citation(s) in RCA: 675] [Impact Index Per Article: 112.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 03/07/2018] [Accepted: 03/19/2018] [Indexed: 12/20/2022] Open
Abstract
DNA damage repair (DDR) pathways modulate cancer risk, progression, and therapeutic response. We systematically analyzed somatic alterations to provide a comprehensive view of DDR deficiency across 33 cancer types. Mutations with accompanying loss of heterozygosity were observed in over 1/3 of DDR genes, including TP53 and BRCA1/2. Other prevalent alterations included epigenetic silencing of the direct repair genes EXO5, MGMT, and ALKBH3 in ∼20% of samples. Homologous recombination deficiency (HRD) was present at varying frequency in many cancer types, most notably ovarian cancer. However, in contrast to ovarian cancer, HRD was associated with worse outcomes in several other cancers. Protein structure-based analyses allowed us to predict functional consequences of rare, recurrent DDR mutations. A new machine-learning-based classifier developed from gene expression data allowed us to identify alterations that phenocopy deleterious TP53 mutations. These frequent DDR gene alterations in many human cancers have functional consequences that may determine cancer progression and guide therapy.
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Affiliation(s)
| | - Linghua Wang
- Department of Genomic Medicine, Division of Cancer Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Michael T Zimmermann
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226-0509, USA; Department of Health Sciences Research, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | | | - Galen F Gao
- The Eli and Edythe L. Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02142, USA
| | - Andrew D Cherniack
- The Eli and Edythe L. Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02142, USA
| | - Huihui Fan
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Hui Shen
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Gregory P Way
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19103, USA
| | - Casey S Greene
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19103, USA
| | - Yuexin Liu
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Rehan Akbani
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Bin Feng
- TESARO Inc., Waltham, MA 02451, USA
| | - Lawrence A Donehower
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Chase Miller
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yang Shen
- Department of Electrical and Computer Engineering, 3128 TAMU, Texas A&M University, College Station, TX 77843, USA
| | - Mostafa Karimi
- Department of Electrical and Computer Engineering, 3128 TAMU, Texas A&M University, College Station, TX 77843, USA
| | - Haoran Chen
- Department of Electrical and Computer Engineering, 3128 TAMU, Texas A&M University, College Station, TX 77843, USA
| | - Pora Kim
- Center for Precision Health, School of Biomedical Informatics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Peilin Jia
- Center for Precision Health, School of Biomedical Informatics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Eve Shinbrot
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Shaojun Zhang
- Department of Genomic Medicine, Division of Cancer Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Jianfang Liu
- Chan Soon-Shiong Institute of Molecular Medicine at Windber, Windber, PA 15963, USA
| | - Hai Hu
- Chan Soon-Shiong Institute of Molecular Medicine at Windber, Windber, PA 15963, USA
| | - Matthew H Bailey
- Division of Oncology, Department of Medicine, Washington University, St. Louis, MO 63110, USA; McDonnell Genome Institute, Washington University, St. Louis, MO 63110, USA
| | - Christina Yau
- University of California, San Francisco, San Francisco, CA 94115, USA; Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Denise Wolf
- University of California, San Francisco, San Francisco, CA 94115, USA
| | - Zhongming Zhao
- Center for Precision Health, School of Biomedical Informatics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - John N Weinstein
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Lei Li
- Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer, Houston, TX 77030, USA
| | - Li Ding
- Division of Oncology, Department of Medicine, Washington University, St. Louis, MO 63110, USA; McDonnell Genome Institute, Washington University, St. Louis, MO 63110, USA; Department of Genetics, Washington University, St. Louis, MO 63110, USA; Siteman Cancer Center, Washington University, St. Louis, MO 63110, USA
| | - Gordon B Mills
- Department of Systems Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Peter W Laird
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - David A Wheeler
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Raymond J Monnat
- Departments of Pathology & Genome Sciences, University of Washington, Seattle, WA 98195-7705, USA.
| | | | - Chen Wang
- Department of Health Sciences Research, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA; Department of Obstetrics and Gynecology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
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50
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Wright WD, Shah SS, Heyer WD. Homologous recombination and the repair of DNA double-strand breaks. J Biol Chem 2018; 293:10524-10535. [PMID: 29599286 DOI: 10.1074/jbc.tm118.000372] [Citation(s) in RCA: 410] [Impact Index Per Article: 68.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Homologous recombination enables the cell to access and copy intact DNA sequence information in trans, particularly to repair DNA damage affecting both strands of the double helix. Here, we discuss the DNA transactions and enzymatic activities required for this elegantly orchestrated process in the context of the repair of DNA double-strand breaks in somatic cells. This includes homology search, DNA strand invasion, repair DNA synthesis, and restoration of intact chromosomes. Aspects of DNA topology affecting individual steps are highlighted. Overall, recombination is a dynamic pathway with multiple metastable and reversible intermediates designed to achieve DNA repair with high fidelity.
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Affiliation(s)
| | | | - Wolf-Dietrich Heyer
- From the Departments of Microbiology and Molecular Genetics and .,Molecular and Cellular Biology, University of California, Davis, Davis, California 95616-8665
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