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Park A, Lee C, Lee JY. Genomic Evolution and Recombination Dynamics of Human Adenovirus D Species: Insights from Comprehensive Bioinformatic Analysis. J Microbiol 2024; 62:393-407. [PMID: 38451451 DOI: 10.1007/s12275-024-00112-5] [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: 12/10/2023] [Revised: 01/10/2024] [Accepted: 01/14/2024] [Indexed: 03/08/2024]
Abstract
Human adenoviruses (HAdVs) can infect various epithelial mucosal cells, ultimately causing different symptoms in infected organ systems. With more than 110 types classified into seven species (A-G), HAdV-D species possess the highest number of viruses and are the fastest proliferating. The emergence of new adenovirus types and increased diversity are driven by homologous recombination (HR) between viral genes, primarily in structural elements such as the penton base, hexon and fiber proteins, and the E1 and E3 regions. A comprehensive analysis of the HAdV genome provides valuable insights into the evolution of human adenoviruses and identifies genes that display high variation across the entire genome to determine recombination patterns. Hypervariable regions within genetic sequences correlate with functional characteristics, thus allowing for adaptation to new environments and hosts. Proteotyping of newly emerging and already established adenoviruses allows for prediction of the characteristics of novel viruses. HAdV-D species evolved in a direction that increased diversity through gene recombination. Bioinformatics analysis across the genome, particularly in highly variable regions, allows for the verification or re-evaluation of recombination patterns in both newly introduced and pre-existing viruses, ultimately aiding in tracing various biological traits such as virus tropism and pathogenesis. Our research does not only assist in predicting the emergence of new adenoviruses but also offers critical guidance in regard to identifying potential regulatory factors of homologous recombination hotspots.
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Affiliation(s)
- Anyeseu Park
- The Laboratory of Viromics and Evolution, Korea Zoonosis Research Institute, Jeonbuk National University, Iksan, 54531, Republic of Korea
| | - Chanhee Lee
- The Laboratory of Viromics and Evolution, Korea Zoonosis Research Institute, Jeonbuk National University, Iksan, 54531, Republic of Korea
| | - Jeong Yoon Lee
- The Laboratory of Viromics and Evolution, Korea Zoonosis Research Institute, Jeonbuk National University, Iksan, 54531, Republic of Korea.
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2
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Schwarz B, Matejka N, Rudigkeit S, Sammer M, Reindl J. Chromatin Organization after High-LET Irradiation Revealed by Super-Resolution STED Microscopy. Int J Mol Sci 2024; 25:628. [PMID: 38203799 PMCID: PMC10779204 DOI: 10.3390/ijms25010628] [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: 11/28/2023] [Revised: 12/15/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
Ion-radiation-induced DNA double-strand breaks can lead to severe cellular damage ranging from mutations up to direct cell death. The interplay between the chromatin surrounding the damage and the proteins responsible for damage recognition and repair determines the efficiency and outcome of DNA repair. The chromatin is organized in three major functional compartments throughout the interphase: the chromatin territories, the interchromatin compartment, and the perichromatin lying in between. In this study, we perform correlation analysis using super-resolution STED images of chromatin; splicing factor SC35, as an interchromatin marker; and the DNA repair factors 53BP1, Rad51, and γH2AX in carbon-ion-irradiated human HeLa cells. Chromatin and interchromatin overlap only in protruding chromatin branches, which is the same for the correlation between chromatin and 53BP1. In contrast, between interchromatin and 53BP1, a gap of (270 ± 40) nm is visible. Rad51 shows overlap with decondensed euchromatic regions located at the borders of condensed heterochromatin with further correlation with γH2AX. We conclude that the DNA damage is repaired in decondensed DNA loops in the perichromatin, located in the periphery of the DNA-dense chromatin compartments containing the heterochromatin. Proteins like γH2AX and 53BP1 serve as supporters of the chromatin structure.
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3
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Hu J, Ferlez B, Dau J, Crickard JB. Rad53 regulates the lifetime of Rdh54 at homologous recombination intermediates. Nucleic Acids Res 2023; 51:11688-11705. [PMID: 37850655 PMCID: PMC10681728 DOI: 10.1093/nar/gkad848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 09/12/2023] [Accepted: 09/21/2023] [Indexed: 10/19/2023] Open
Abstract
Rdh54 is a conserved DNA translocase that participates in homologous recombination (HR), DNA checkpoint adaptation, and chromosome segregation. Saccharomyces cerevisiae Rdh54 is a known target of the Mec1/Rad53 signaling axis, which globally protects genome integrity during DNA metabolism. While phosphorylation of DNA repair proteins by Mec1/Rad53 is critical for HR progression little is known about how specific post translational modifications alter HR reactions. Phosphorylation of Rdh54 is linked to protection of genomic integrity but the consequences of modification remain poorly understood. Here, we demonstrate that phosphorylation of the Rdh54 C-terminus by the effector kinase Rad53 regulates Rdh54 clustering activity as revealed by single molecule imaging. This stems from phosphorylation dependent and independent interactions between Rdh54 and Rad53. Genetic assays reveal that loss of phosphorylation leads to phenotypic changes resulting in loss-of-heterozygosity (LOH) outcomes. Our data highlight Rad53 as a key regulator of HR intermediates through activation and attenuation of Rdh54 motor function.
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Affiliation(s)
- Jingyi Hu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Bryan Ferlez
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Jennifer Dau
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - J Brooks Crickard
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
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4
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Deveryshetty J, Chadda R, Mattice JR, Karunakaran S, Rau MJ, Basore K, Pokhrel N, Englander N, Fitzpatrick JAJ, Bothner B, Antony E. Yeast Rad52 is a homodecamer and possesses BRCA2-like bipartite Rad51 binding modes. Nat Commun 2023; 14:6215. [PMID: 37798272 PMCID: PMC10556141 DOI: 10.1038/s41467-023-41993-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/25/2023] [Indexed: 10/07/2023] Open
Abstract
Homologous recombination (HR) is an essential double-stranded DNA break repair pathway. In HR, Rad52 facilitates the formation of Rad51 nucleoprotein filaments on RPA-coated ssDNA. Here, we decipher how Rad52 functions using single-particle cryo-electron microscopy and biophysical approaches. We report that Rad52 is a homodecameric ring and each subunit possesses an ordered N-terminal and disordered C-terminal half. An intrinsic structural asymmetry is observed where a few of the C-terminal halves interact with the ordered ring. We describe two conserved charged patches in the C-terminal half that harbor Rad51 and RPA interacting motifs. Interactions between these patches regulate ssDNA binding. Surprisingly, Rad51 interacts with Rad52 at two different bindings sites: one within the positive patch in the disordered C-terminus and the other in the ordered ring. We propose that these features drive Rad51 nucleation onto a single position on the DNA to promote formation of uniform pre-synaptic Rad51 filaments in HR.
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Affiliation(s)
- Jaigeeth Deveryshetty
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Rahul Chadda
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Jenna R Mattice
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA
| | - Simrithaa Karunakaran
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Michael J Rau
- Center for Cellular Imaging, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Katherine Basore
- Center for Cellular Imaging, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Nilisha Pokhrel
- Department of Biological Sciences, Marquette University, Milwaukee, WI, USA
- Aera Therapeutics, Boston, MA, USA
| | - Noah Englander
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - James A J Fitzpatrick
- Center for Cellular Imaging, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA
| | - Edwin Antony
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA.
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5
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Luo SC, Yeh MC, Lien YH, Yeh HY, Siao HL, Tu IP, Chi P, Ho MC. A RAD51-ADP double filament structure unveils the mechanism of filament dynamics in homologous recombination. Nat Commun 2023; 14:4993. [PMID: 37591853 PMCID: PMC10435448 DOI: 10.1038/s41467-023-40672-5] [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: 12/28/2022] [Accepted: 08/04/2023] [Indexed: 08/19/2023] Open
Abstract
ATP-dependent RAD51 recombinases play an essential role in eukaryotic homologous recombination by catalyzing a four-step process: 1) formation of a RAD51 single-filament assembly on ssDNA in the presence of ATP, 2) complementary DNA strand-exchange, 3) ATP hydrolysis transforming the RAD51 filament into an ADP-bound disassembly-competent state, and 4) RAD51 disassembly to provide access for DNA repairing enzymes. Of these steps, filament dynamics between the ATP- and ADP-bound states, and the RAD51 disassembly mechanism, are poorly understood due to the lack of near-atomic-resolution information of the ADP-bound RAD51-DNA filament structure. We report the cryo-EM structure of ADP-bound RAD51-DNA filaments at 3.1 Å resolution, revealing a unique RAD51 double-filament that wraps around ssDNA. Structural analysis, supported by ATP-chase and time-resolved cryo-EM experiments, reveals a collapsing mechanism involving two four-protomer movements along ssDNA for mechanical transition between RAD51 single- and double-filament without RAD51 dissociation. This mechanism enables elastic change of RAD51 filament length during structural transitions between ATP- and ADP-states.
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Affiliation(s)
- Shih-Chi Luo
- Institute of Biological Chemistry, Academia Sinica, 11529, Taipei, Taiwan
| | - Min-Chi Yeh
- Institute of Biological Chemistry, Academia Sinica, 11529, Taipei, Taiwan
- Institute of Biochemical Sciences, National Taiwan University, 10617, Taipei, Taiwan
| | - Yu-Hsiang Lien
- Institute of Statistical Science, Academia Sinica, 11529, Taipei, Taiwan
| | - Hsin-Yi Yeh
- Institute of Biochemical Sciences, National Taiwan University, 10617, Taipei, Taiwan
| | - Huei-Lun Siao
- Institute of Statistical Science, Academia Sinica, 11529, Taipei, Taiwan
| | - I-Ping Tu
- Institute of Statistical Science, Academia Sinica, 11529, Taipei, Taiwan
| | - Peter Chi
- Institute of Biological Chemistry, Academia Sinica, 11529, Taipei, Taiwan
- Institute of Biochemical Sciences, National Taiwan University, 10617, Taipei, Taiwan
| | - Meng-Chiao Ho
- Institute of Biological Chemistry, Academia Sinica, 11529, Taipei, Taiwan.
- Institute of Biochemical Sciences, National Taiwan University, 10617, Taipei, Taiwan.
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6
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Liang P, Lister K, Yates L, Argunhan B, Zhang X. Phosphoregulation of DNA repair via the Rad51 auxiliary factor Swi5-Sfr1. J Biol Chem 2023; 299:104929. [PMID: 37330173 PMCID: PMC10366545 DOI: 10.1016/j.jbc.2023.104929] [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: 03/09/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/19/2023] Open
Abstract
Homologous recombination (HR) is a major pathway for the repair of DNA double-strand breaks, the most severe form of DNA damage. The Rad51 protein is central to HR, but multiple auxiliary factors regulate its activity. The heterodimeric Swi5-Sfr1 complex is one such factor. It was previously shown that two sites within the intrinsically disordered domain of Sfr1 are critical for the interaction with Rad51. Here, we show that phosphorylation of five residues within this domain regulates the interaction of Swi5-Sfr1 with Rad51. Biochemical reconstitutions demonstrated that a phosphomimetic mutant version of Swi5-Sfr1 is defective in both the physical and functional interaction with Rad51. This translated to a defect in DNA repair, with the phosphomimetic mutant yeast strain phenocopying a previously established interaction mutant. Interestingly, a strain in which Sfr1 phosphorylation was blocked also displayed sensitivity to DNA damage. Taken together, we propose that controlled phosphorylation of Sfr1 is important for the role of Swi5-Sfr1 in promoting Rad51-dependent DNA repair.
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Affiliation(s)
- Pengtao Liang
- Section of Structural and Synthetic Biology, Faculty of Medicine, Imperial College London, London, UK
| | - Katie Lister
- Section of Structural and Synthetic Biology, Faculty of Medicine, Imperial College London, London, UK
| | - Luke Yates
- Section of Structural and Synthetic Biology, Faculty of Medicine, Imperial College London, London, UK
| | - Bilge Argunhan
- Section of Structural and Synthetic Biology, Faculty of Medicine, Imperial College London, London, UK.
| | - Xiaodong Zhang
- Section of Structural and Synthetic Biology, Faculty of Medicine, Imperial College London, London, UK.
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7
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Deveryshetty J, Chadda R, Mattice J, Karunakaran S, Rau MJ, Basore K, Pokhrel N, Englander N, Fitzpatrick JA, Bothner B, Antony E. Homodecameric Rad52 promotes single-position Rad51 nucleation in homologous recombination. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.05.527205. [PMID: 36778491 PMCID: PMC9915710 DOI: 10.1101/2023.02.05.527205] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Homologous recombination (HR) is a pathway for the accurate repair of double-stranded DNA breaks. These breaks are resected to yield single-stranded DNA (ssDNA) that are coated by Replication Protein A (RPA). Saccharomyces cerevisiae Rad52 is a mediator protein that promotes HR by facilitating formation of Rad51 nucleoprotein filaments on RPA-coated ssDNA. Canonically, Rad52 has been described to function by displacing RPA to promote Rad51 binding. However, in vitro, Rad51 readily forms a filament by displacing RPA in the absence of Rad52. Yet, in vivo, Rad52 is essential for HR. Here, we resolve how Rad52 functions as a mediator using single-particle cryo-electron microscopy and biophysical approaches. We show that Rad52 functions as a homodecamer and catalyzes single-position nucleation of Rad51. The N-terminal half of Rad52 is a well-ordered ring, while the C-terminal half is disordered. An intrinsic asymmetry within Rad52 is observed, where one or a few of the C-terminal halves interact with the ordered N-terminal ring. Within the C-terminal half, we identify two conserved charged patches that harbor the Rad51 and RPA interacting motifs. Interactions between these two charged patches regulate a ssDNA binding. These features drive Rad51 binding to a single position on the Rad52 decameric ring. We propose a Rad52 catalyzed single-position nucleation model for the formation of pre-synaptic Rad51 filaments in HR.
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Affiliation(s)
- Jaigeeth Deveryshetty
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
| | - Rahul Chadda
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
| | - Jenna Mattice
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT
| | - Simrithaa Karunakaran
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
| | - Michael J. Rau
- Center for Cellular Imaging, Washington University in St. Louis School of Medicine, St. Louis, MO
| | - Katherine Basore
- Center for Cellular Imaging, Washington University in St. Louis School of Medicine, St. Louis, MO
| | - Nilisha Pokhrel
- Department of Biological Sciences, Marquette University, Milwaukee, WI (Present address: Aera Therapeutics, Boston, MA, USA)
| | - Noah Englander
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
| | - James A.J. Fitzpatrick
- Center for Cellular Imaging, Washington University in St. Louis School of Medicine, St. Louis, MO
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT
| | - Edwin Antony
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
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8
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Miné-Hattab J, Liu S, Taddei A. Repair Foci as Liquid Phase Separation: Evidence and Limitations. Genes (Basel) 2022; 13:1846. [PMID: 36292731 PMCID: PMC9602295 DOI: 10.3390/genes13101846] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 09/29/2022] [Accepted: 09/29/2022] [Indexed: 07/26/2023] Open
Abstract
In response to DNA double strand breaks (DSB), repair proteins accumulate at damaged sites, forming membrane-less condensates or "foci". The formation of these foci and their disassembly within the proper time window are essential for genome integrity. However, how these membrane-less sub-compartments are formed, maintained and disassembled remains unclear. Recently, several studies across different model organisms proposed that DNA repair foci form via liquid phase separation. In this review, we discuss the current research investigating the physical nature of repair foci. First, we present the different models of condensates proposed in the literature, highlighting the criteria to differentiate them. Second, we discuss evidence of liquid phase separation at DNA repair sites and the limitations of this model to fully describe structures formed in response to DNA damage. Finally, we discuss the origin and possible function of liquid phase separation for DNA repair processes.
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9
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Geng K, Merino LG, Wedemann L, Martens A, Sobota M, Sanchez YP, Søndergaard JN, White RJ, Kutter C. Target-enriched nanopore sequencing and de novo assembly reveals co-occurrences of complex on-target genomic rearrangements induced by CRISPR-Cas9 in human cells. Genome Res 2022; 32:1876-1891. [PMID: 36180232 PMCID: PMC9712622 DOI: 10.1101/gr.276901.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 09/19/2022] [Indexed: 11/24/2022]
Abstract
The CRISPR-Cas9 system is widely used to permanently delete genomic regions via dual guide RNAs. Genomic rearrangements induced by CRISPR-Cas9 can occur, but continuous technical developments make it possible to characterize complex on-target effects. We combined an innovative droplet-based target enrichment approach with long-read sequencing and coupled it to a customized de novo sequence assembly. This approach enabled us to dissect the sequence content at kilobase scale within an on-target genomic locus. We here describe extensive genomic disruptions by Cas9, involving the allelic co-occurrence of a genomic duplication and inversion of the target region, as well as integrations of exogenous DNA and clustered interchromosomal DNA fragment rearrangements. Furthermore, we found that these genomic alterations led to functional aberrant DNA fragments and can alter cell proliferation. Our findings broaden the consequential spectrum of the Cas9 deletion system, reinforce the necessity of meticulous genomic validations, and introduce a data-driven workflow enabling detailed dissection of the on-target sequence content with superior resolution.
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Affiliation(s)
- Keyi Geng
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Lara G Merino
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Linda Wedemann
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Aniek Martens
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Małgorzata Sobota
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Yerma P Sanchez
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Jonas Nørskov Søndergaard
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
| | - Robert J White
- Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Claudia Kutter
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institute, Science for Life Laboratory, 171 65, Stockholm, Sweden
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10
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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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11
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Hayward SB, Ciccia A. Towards a CRISPeR understanding of homologous recombination with high-throughput functional genomics. Curr Opin Genet Dev 2021; 71:171-181. [PMID: 34583241 PMCID: PMC8671205 DOI: 10.1016/j.gde.2021.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 12/26/2022]
Abstract
CRISPR-dependent genome editing enables the study of genes and mutations on a large scale. Here we review CRISPR-based functional genomics technologies that generate gene knockouts and single nucleotide variants (SNVs) and discuss how their use has provided new important insights into the function of homologous recombination (HR) genes. In particular, we highlight discoveries from CRISPR screens that have contributed to define the response to PARP inhibition in cells deficient for the HR genes BRCA1 and BRCA2, uncover genes whose loss causes synthetic lethality in combination with BRCA1/2 deficiency, and characterize the function of BRCA1/2 SNVs of uncertain clinical significance. Further use of these approaches, combined with next-generation CRISPR-based technologies, will aid to dissect the genetic network of the HR pathway, define the impact of HR mutations on cancer etiology and treatment, and develop novel targeted therapies for HR-deficient tumors.
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Affiliation(s)
- Samuel B Hayward
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, United States
| | - Alberto Ciccia
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, United States.
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12
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Chen WT, Tseng HY, Jiang CL, Lee CY, Chi P, Chen LY, Lo KY, Wang IC, Lin FJ. Elp1 facilitates RAD51-mediated homologous recombination repair via translational regulation. J Biomed Sci 2021; 28:81. [PMID: 34819065 PMCID: PMC8613991 DOI: 10.1186/s12929-021-00773-z] [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: 04/27/2021] [Accepted: 11/02/2021] [Indexed: 11/25/2022] Open
Abstract
Background RAD51-dependent homologous recombination (HR) is one of the most important pathways for repairing DNA double-strand breaks (DSBs), and its regulation is crucial to maintain genome integrity. Elp1 gene encodes IKAP/ELP1, a core subunit of the Elongator complex, which has been implicated in translational regulation. However, how ELP1 contributes to genome maintenance is unclear. Methods To investigate the function of Elp1, Elp1-deficient mouse embryonic fibroblasts (MEFs) were generated. Metaphase chromosome spreading, immunofluorescence, and comet assays were used to access chromosome abnormalities and DSB formation. Functional roles of Elp1 in MEFs were evaluated by cell viability, colony forming capacity, and apoptosis assays. HR-dependent DNA repair was assessed by reporter assay, immunofluorescence, and western blot. Polysome profiling was used to evaluate translational efficiency. Differentially expressed proteins and signaling pathways were identified using a label-free liquid chromatography–tandem mass spectrometry (LC–MS/MS) proteomics approach. Results Here, we report that Elp1 depletion enhanced genomic instability, manifested as chromosome breakage and genotoxic stress-induced genomic DNA fragmentation upon ionizing radiation (IR) exposure. Elp1-deficient cells were hypersensitive to DNA damage and exhibited impaired cell proliferation and defective HR repair. Moreover, Elp1 depletion reduced the formation of IR-induced RAD51 foci and decreased RAD51 protein levels. Polysome profiling analysis revealed that ELP1 regulated RAD51 expression by promoting its translation in response to DNA damage. Notably, the requirement for ELP1 in DSB repair could be partially rescued in Elp1-deficient cells by reintroducing RAD51, suggesting that Elp1-mediated HR-directed repair of DSBs is RAD51-dependent. Finally, using proteome analyses, we identified several proteins involved in cancer pathways and DNA damage responses as being differentially expressed upon Elp1 depletion. Conclusions Our study uncovered a molecular mechanism underlying Elp1-mediated regulation of HR activity and provides a novel link between translational regulation and genome stability. Supplementary Information The online version contains supplementary material available at 10.1186/s12929-021-00773-z.
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Affiliation(s)
- Wei-Ting Chen
- Department of Biochemical Science and Technology, National Taiwan University, No.1, Sec.4, Roosevelt Rd., Taipei, 10617, Taiwan
| | - Huan-Yi Tseng
- Department of Biochemical Science and Technology, National Taiwan University, No.1, Sec.4, Roosevelt Rd., Taipei, 10617, Taiwan
| | - Chung-Lin Jiang
- Department of Biochemical Science and Technology, National Taiwan University, No.1, Sec.4, Roosevelt Rd., Taipei, 10617, Taiwan
| | - Chih-Ying Lee
- Institute of Biochemical Sciences, National Taiwan University, Taipei, 10617, Taiwan
| | - Peter Chi
- Institute of Biochemical Sciences, National Taiwan University, Taipei, 10617, Taiwan.,Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Liuh-Yow Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Kai-Yin Lo
- Department of Agricultural Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - I-Ching Wang
- Institute of Biotechnology, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Fu-Jung Lin
- Department of Biochemical Science and Technology, National Taiwan University, No.1, Sec.4, Roosevelt Rd., Taipei, 10617, Taiwan. .,Research Center for Development Biology and Regenerative Medicine, National Taiwan University, Taipei, 10617, Taiwan.
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13
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Dame RT. Special Issue: Role of Bacterial Chromatin in Environmental Sensing, Adaptation and Evolution. Microorganisms 2021; 9:microorganisms9112406. [PMID: 34835530 PMCID: PMC8619304 DOI: 10.3390/microorganisms9112406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 11/19/2021] [Indexed: 11/16/2022] Open
Abstract
A typical bacterial cell is micron-sized and contains a genome several million base pairs in length [...].
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Affiliation(s)
- Remus T. Dame
- Department of Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands;
- Centre for Microbial Cell Biology, Leiden University, 2333 CC Leiden, The Netherlands
- Centre for Interdisciplinary Genome Research, Leiden University, 2333 CC Leiden, The Netherlands
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14
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Insights into homology search from cryo-EM structures of RecA-DNA recombination intermediates. Curr Opin Genet Dev 2021; 71:188-194. [PMID: 34592688 DOI: 10.1016/j.gde.2021.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/01/2021] [Accepted: 09/10/2021] [Indexed: 11/20/2022]
Abstract
The fundamental reaction in homologous recombination is the exchange of strands between two homologous DNA molecules. This reaction is carried out by the RecA family of ATPases that polymerize on ssDNA to form a presynaptic filament. This filament then binds to dsDNA to form a synaptic filament, a key intermediate that mediates the search for homology and subsequent strand exchange to produce a new heteroduplex. A recent cryo-EM analysis of synaptic filaments has now shed light on this process. The dsDNA strands are separated on binding to the filament. One strand is sequestrated while the other is freed to sample pairing with the ssDNA. Homology, through heteroduplex formation, promotes dsDNA opening. Lack of homology suppresses it, keeping local synapses short so that multiple synapses can form and increasing the probability of encountering homology.
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15
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Crickard JB. Discrete roles for Rad54 and Rdh54 during homologous recombination. Curr Opin Genet Dev 2021; 71:48-54. [PMID: 34293661 DOI: 10.1016/j.gde.2021.06.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/25/2021] [Accepted: 06/29/2021] [Indexed: 11/17/2022]
Abstract
Rad54 and Rdh54 are Snf2 DNA motor proteins that function during maintenance of genomic integrity. Though highly related, Rad54 and Rdh54 have different biochemical and genetic functions during maintenance of genomic integrity. Rad54 functions primarily during the homology search and strand invasion steps of homologous recombination, while Rdh54 appears to play a minor role in these processes. More recently it has been shown that Rdh54 functions as a pathway branch point at HR intermediates, and as has a role in cell cycle recovery. Here we will explore recent advances that have improved our understanding of the role these two DNA motor proteins play during DNA repair.
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Affiliation(s)
- John Brooks Crickard
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
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16
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Tsubouchi H, Argunhan B, Iwasaki H. Biochemical properties of fission yeast homologous recombination enzymes. Curr Opin Genet Dev 2021; 71:19-26. [PMID: 34246071 DOI: 10.1016/j.gde.2021.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/06/2021] [Accepted: 06/14/2021] [Indexed: 12/20/2022]
Abstract
Homologous recombination (HR) is a universal phenomenon conserved from viruses to humans. The mechanisms of HR are essentially the same in humans and simple unicellular eukaryotes like yeast. Two highly diverged yeast species, Saccharomyces cerevisiae and Schizosaccharomyces pombe, have proven exceptionally useful in understanding the fundamental mechanisms of eukaryotic HR by serving as a source for unique biological insights and also complementing each other. Here, we will review the features of S. pombe HR mechanisms in comparison to S. cerevisiae and other model organisms. Particular emphasis will be put on the biochemical characterization of HR mechanisms uncovered using S. pombe proteins.
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Affiliation(s)
- Hideo Tsubouchi
- Institute of Innovative Research, Tokyo Institute of Technology, Kanagawa, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Kanagawa, Japan.
| | - Bilge Argunhan
- Institute of Innovative Research, Tokyo Institute of Technology, Kanagawa, Japan
| | - Hiroshi Iwasaki
- Institute of Innovative Research, Tokyo Institute of Technology, Kanagawa, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Kanagawa, Japan.
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17
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Ouyang J, Yadav T, Zhang JM, Yang H, Rheinbay E, Guo H, Haber DA, Lan L, Zou L. RNA transcripts stimulate homologous recombination by forming DR-loops. Nature 2021; 594:283-288. [PMID: 33981036 PMCID: PMC8855348 DOI: 10.1038/s41586-021-03538-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 04/12/2021] [Indexed: 02/06/2023]
Abstract
Homologous recombination (HR) repairs DNA double-strand breaks (DSBs) in the S and G2 phases of the cell cycle1-3. Several HR proteins are preferentially recruited to DSBs at transcriptionally active loci4-10, but how transcription promotes HR is poorly understood. Here we develop an assay to assess the effect of local transcription on HR. Using this assay, we find that transcription stimulates HR to a substantial extent. Tethering RNA transcripts to the vicinity of DSBs recapitulates the effects of local transcription, which suggests that transcription enhances HR through RNA transcripts. Tethered RNA transcripts stimulate HR in a sequence- and orientation-dependent manner, indicating that they function by forming DNA-RNA hybrids. In contrast to most HR proteins, RAD51-associated protein 1 (RAD51AP1) only promotes HR when local transcription is active. RAD51AP1 drives the formation of R-loops in vitro and is required for tethered RNAs to stimulate HR in cells. Notably, RAD51AP1 is necessary for the DSB-induced formation of DNA-RNA hybrids in donor DNA, linking R-loops to D-loops. In vitro, RAD51AP1-generated R-loops enhance the RAD51-mediated formation of D-loops locally and give rise to intermediates that we term 'DR-loops', which contain both DNA-DNA and DNA-RNA hybrids and favour RAD51 function. Thus, at DSBs in transcribed regions, RAD51AP1 promotes the invasion of RNA transcripts into donor DNA, and stimulates HR through the formation of DR-loops.
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Affiliation(s)
- Jian Ouyang
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA.
| | - Tribhuwan Yadav
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA
| | - Jia-Min Zhang
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA
| | - Haibo Yang
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Esther Rheinbay
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA
| | - Hongshan Guo
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA
- Howard Hughes Medical Institute, Massachusetts General Hospital, Charlestown, MA, USA
| | - Daniel A Haber
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA
- Howard Hughes Medical Institute, Massachusetts General Hospital, Charlestown, MA, USA
| | - Li Lan
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Lee Zou
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA.
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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18
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Jimeno S, Balestra FR, Huertas P. The Emerging Role of RNA Modifications in DNA Double-Strand Break Repair. Front Mol Biosci 2021; 8:664872. [PMID: 33996910 PMCID: PMC8116738 DOI: 10.3389/fmolb.2021.664872] [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: 02/06/2021] [Accepted: 04/08/2021] [Indexed: 11/14/2022] Open
Abstract
The correct repair of DNA double-strand breaks is essential for maintaining the stability of the genome, thus ensuring the survival and fitness of any living organism. Indeed, the repair of these lesions is a complicated affair, in which several pathways compete for the DNA ends in a complex balance. Thus, the fine-tuning of the DNA double-strand break repair pathway choice relies on the different regulatory layers that respond to environmental cues. Among those different tiers of regulation, RNA modifications have just emerged as a promising field.
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Affiliation(s)
- Sonia Jimeno
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Fernando R. Balestra
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Pablo Huertas
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
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19
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de Polo A, Labbé DP. Diet-Dependent Metabolic Regulation of DNA Double-Strand Break Repair in Cancer: More Choices on the Menu. Cancer Prev Res (Phila) 2021; 14:403-414. [PMID: 33509805 DOI: 10.1158/1940-6207.capr-20-0470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/27/2020] [Accepted: 01/21/2021] [Indexed: 11/16/2022]
Abstract
Despite several epidemiologic and preclinical studies supporting the role of diet in cancer progression, the complexity of the diet-cancer link makes it challenging to deconvolute the underlying mechanisms, which remain scantly elucidated. This review focuses on genomic instability as one of the cancer hallmarks affected by diet-dependent metabolic alterations. We discuss how altered dietary intake of metabolites of the one-carbon metabolism, including methionine, folate, and vitamins B and C, can impact the methylation processes and thereby tumorigenesis. We present the concept that the protumorigenic effect of certain diets, such as the Western diet, is in part due to a diet-induced erosion of the DNA repair capacity caused by altered epigenetic and epitranscriptomic landscapes, while the protective effect of other dietary patterns, such as the Mediterranean diet, can be partly explained by their ability to sustain a proficient DNA repair. In particular, considering that diet-dependent alterations of the one-carbon metabolism can impact the rate of methylation processes, changes in dietary patterns can affect the activity of writers and erasers of histone and RNA methyl marks and consequently impair their role in ensuring a proficient DNA damage repair.
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Affiliation(s)
- Anna de Polo
- Division of Urology, Department of Surgery, McGill University and Cancer Research Program, Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - David P Labbé
- Division of Urology, Department of Surgery, McGill University and Cancer Research Program, Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.
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20
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Afshar N, Argunhan B, Palihati M, Taniguchi G, Tsubouchi H, Iwasaki H. A novel motif of Rad51 serves as an interaction hub for recombination auxiliary factors. eLife 2021; 10:64131. [PMID: 33493431 PMCID: PMC7837696 DOI: 10.7554/elife.64131] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 12/26/2020] [Indexed: 12/14/2022] Open
Abstract
Homologous recombination (HR) is essential for maintaining genome stability. Although Rad51 is the key protein that drives HR, multiple auxiliary factors interact with Rad51 to potentiate its activity. Here, we present an interdisciplinary characterization of the interactions between Rad51 and these factors. Through structural analysis, we identified an evolutionarily conserved acidic patch of Rad51. The neutralization of this patch completely abolished recombinational DNA repair due to defects in the recruitment of Rad51 to DNA damage sites. This acidic patch was found to be important for the interaction with Rad55-Rad57 and essential for the interaction with Rad52. Furthermore, biochemical reconstitutions demonstrated that neutralization of this acidic patch also impaired the interaction with Rad54, indicating that a single motif is important for the interaction with multiple auxiliary factors. We propose that this patch is a fundamental motif that facilitates interactions with auxiliary factors and is therefore essential for recombinational DNA repair.
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Affiliation(s)
- Negar Afshar
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Bilge Argunhan
- Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Maierdan Palihati
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Goki Taniguchi
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Hideo Tsubouchi
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Hiroshi Iwasaki
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
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21
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Luo SC, Yeh HY, Lan WH, Wu YM, Yang CH, Chang HY, Su GC, Lee CY, Wu WJ, Li HW, Ho MC, Chi P, Tsai MD. Identification of fidelity-governing factors in human recombinases DMC1 and RAD51 from cryo-EM structures. Nat Commun 2021; 12:115. [PMID: 33446654 PMCID: PMC7809202 DOI: 10.1038/s41467-020-20258-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 11/23/2020] [Indexed: 11/24/2022] Open
Abstract
Both high-fidelity and mismatch-tolerant recombination, catalyzed by RAD51 and DMC1 recombinases, respectively, are indispensable for genomic integrity. Here, we use cryo-EM, MD simulation and functional analysis to elucidate the structural basis for the mismatch tolerance of DMC1. Structural analysis of DMC1 presynaptic and postsynaptic complexes suggested that the lineage-specific Loop 1 Gln244 (Met243 in RAD51) may help stabilize DNA backbone, whereas Loop 2 Pro274 and Gly275 (Val273/Asp274 in RAD51) may provide an open “triplet gate” for mismatch tolerance. In support, DMC1-Q244M displayed marked increase in DNA dynamics, leading to unobservable DNA map. MD simulation showed highly dispersive mismatched DNA ensemble in RAD51 but well-converged DNA in DMC1 and RAD51-V273P/D274G. Replacing Loop 1 or Loop 2 residues in DMC1 with RAD51 counterparts enhanced DMC1 fidelity, while reciprocal mutations in RAD51 attenuated its fidelity. Our results show that three Loop 1/Loop 2 residues jointly enact contrasting fidelities of DNA recombinases. RAD51 and DMC1 recombinases catalyse high-fidelity and mismatch tolerant recombination, processes that are indispensable for the maintenance of genomic integrity. Here, the authors via cryo-EM, molecular dynamics simulation and functional analysis elucidate the structural difference between RAD51 and DMC1 with regard to mismatch tolerance.
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Affiliation(s)
- Shih-Chi Luo
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hsin-Yi Yeh
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Wei-Hsuan Lan
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Yi-Min Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Cheng-Han Yang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hao-Yen Chang
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Guan-Chin Su
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Chia-Yi Lee
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Wen-Jin Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hung-Wen Li
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Meng-Chiao Ho
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan. .,Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.
| | - Peter Chi
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan. .,Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.
| | - Ming-Daw Tsai
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan. .,Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.
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22
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Yang H, Zhou C, Dhar A, Pavletich NP. Mechanism of strand exchange from RecA-DNA synaptic and D-loop structures. Nature 2020; 586:801-806. [PMID: 33057191 PMCID: PMC8366275 DOI: 10.1038/s41586-020-2820-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 09/10/2020] [Indexed: 02/08/2023]
Abstract
The strand exchange reaction is central to homologous recombination. It is catalyzed by the RecA family of ATPases that form a helical filament with single-stranded DNA (ssDNA) and ATP. This filament binds to a donor double-stranded DNA (dsDNA) to form synaptic filaments that search for homology, and then catalyze the exchange of the complementary strand to form a new heteroduplex, or a D-loop if homology is limited1,2. Here we report the Cryo-EM analysis of synaptic mini filaments with both non-complementary and partially-complementary dsDNA, and structures of RecA–D-loop complexes containing a 10 or 12 base pair heteroduplex at 2.8 and 2.9 Å, respectively. The RecA C-terminal domain (CTD) binds to dsDNA and directs it to the L2 loop, which inserts into and opens the duplex. The opening propagates through RecA sequestering the homologous strand at a secondary DNA-binding site, freeing the complementary strand to sample pairing with the ssDNA. Duplex opening has a significant probability of stopping at each RecA step, with the as yet unopened dsDNA portion binding to another CTD. Homology suppresses this process through heteroduplex pairing cooperating with secondary site-ssDNA binding to extend dsDNA opening. This mechanism locally limits the length of ssDNA sampled for pairing if homology is not encountered, and it may provide for the formation of multiple synapses separated substantially on the donor dsDNA, increasing the probability of encountering homology.
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Affiliation(s)
- Haijuan Yang
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Chun Zhou
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.,Zhejiang University School of Medicine, Zhejiang, China
| | - Ankita Dhar
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Nikola P Pavletich
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA. .,Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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23
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Dwyer DS. Genomic Chaos Begets Psychiatric Disorder. Complex Psychiatry 2020; 6:20-29. [PMID: 34883501 PMCID: PMC7673594 DOI: 10.1159/000507988] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 04/06/2020] [Indexed: 12/21/2022] Open
Abstract
The processes that created the primordial genome are inextricably linked to current day vulnerability to developing a psychiatric disorder as summarized in this review article. Chaos and dynamic forces including duplication, transposition, and recombination generated the protogenome. To survive early stages of genome evolution, self-organization emerged to curb chaos. Eventually, the human genome evolved through a delicate balance of chaos/instability and organization/stability. However, recombination coldspots, silencing of transposable elements, and other measures to limit chaos also led to retention of variants that increase risk for disease. Moreover, ongoing dynamics in the genome creates various new mutations that determine liability for psychiatric disorders. Homologous recombination, long-range gene regulation, and gene interactions were all guided by spooky action-at-a-distance, which increased variability in the system. A probabilistic system of life was required to deal with a changing environment. This ensured the generation of outliers in the population, which enhanced the probability that some members would survive unfavorable environmental impacts. Some of the outliers produced through this process in man are ill suited to cope with the complex demands of modern life. Genomic chaos and mental distress from the psychological challenges of modern living will inevitably converge to produce psychiatric disorders in man.
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Affiliation(s)
- Donard S. Dwyer
- Departments of Psychiatry and Behavioral Medicine and Pharmacology, Toxicology and Neuroscience, LSU Health Shreveport, Shreveport, Louisiana, USA
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24
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Mismatch sensing by nucleofilament deciphers mechanism of RecA-mediated homologous recombination. Proc Natl Acad Sci U S A 2020; 117:20549-20554. [PMID: 32788357 DOI: 10.1073/pnas.1920265117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recombinases polymerize along single-stranded DNA (ssDNA) at the end of a broken DNA to form a helical nucleofilament with a periodicity of ∼18 bases. The filament catalyzes the search and checking for homologous sequences and promotes strand exchange with a donor duplex during homologous recombination (HR), the mechanism of which has remained mysterious since its discovery. Here, by inserting mismatched segments into donor duplexes and using single-molecule techniques to catch transient intermediates in HR, we found that, even though 3 base pairs (bp) is still the basic unit, both the homology checking and the strand exchange may proceed in multiple steps at a time, resulting in ∼9-bp large steps on average. More interestingly, the strand exchange is blocked remotely by the mismatched segment, terminating at positions ∼9 bp before the match-mismatch joint. The homology checking and the strand exchange are thus separated in space, with the strand exchange lagging behind. Our data suggest that the strand exchange progresses like a traveling wave in which the donor DNA is incorporated successively into the ssDNA-RecA filament to check homology in ∼9-bp steps in the frontier, followed by a hypothetical transitional segment and then the post-strand-exchanged duplex.
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25
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Crickard JB, Moevus CJ, Kwon Y, Sung P, Greene EC. Rad54 Drives ATP Hydrolysis-Dependent DNA Sequence Alignment during Homologous Recombination. Cell 2020; 181:1380-1394.e18. [PMID: 32502392 DOI: 10.1016/j.cell.2020.04.056] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/07/2020] [Accepted: 04/29/2020] [Indexed: 12/30/2022]
Abstract
Homologous recombination (HR) helps maintain genome integrity, and HR defects give rise to disease, especially cancer. During HR, damaged DNA must be aligned with an undamaged template through a process referred to as the homology search. Despite decades of study, key aspects of this search remain undefined. Here, we use single-molecule imaging to demonstrate that Rad54, a conserved Snf2-like protein found in all eukaryotes, switches the search from the diffusion-based pathways characteristic of the basal HR machinery to an active process in which DNA sequences are aligned via an ATP-dependent molecular motor-driven mechanism. We further demonstrate that Rad54 disrupts the donor template strands, enabling the search to take place within a migrating DNA bubble-like structure that is bound by replication protein A (RPA). Our results reveal that Rad54, working together with RPA, fundamentally alters how DNA sequences are aligned during HR.
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Affiliation(s)
- J Brooks Crickard
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Corentin J Moevus
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Youngho Kwon
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Patrick Sung
- 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.
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26
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Sheng DH, Wang YX, Qiu M, Zhao JY, Yue XJ, Li YZ. Functional Division Between the RecA1 and RecA2 Proteins in Myxococcus xanthus. Front Microbiol 2020; 11:140. [PMID: 32117159 PMCID: PMC7029660 DOI: 10.3389/fmicb.2020.00140] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 01/21/2020] [Indexed: 12/18/2022] Open
Abstract
Myxococcus xanthus DK1622 has two RecA genes, recA1 (MXAN_1441) and recA2 (MXAN_1388), with unknown functional differentiation. Herein, we showed that both recA genes were induced by ultraviolet (UV) irradiation but that the induction of recA1 was more delayed than that of recA2. Deletion of recA1 did not affect the growth but significantly decreased the UV-radiation survival, homologous recombination (HR) ability, and induction of LexA-dependent SOS genes. In contrast, the deletion of recA2 markedly prolonged the lag phase of bacterial growth and increased the sensitivity to DNA damage caused by hydrogen peroxide but did not change the UV-radiation resistance or SOS gene inducibility. Protein activity analysis demonstrated that RecA1, but not RecA2, catalyzed DNA strand exchange (DSE) and LexA autocleavage in vitro. Transcriptomic analysis indicated that RecA2 has evolved mainly to regulate gene expression for cellular transportation and antioxidation. This is the first report of functional divergence of duplicated bacterial recA genes. The results highlight the evolutionary strategy of M. xanthus cells for DNA HR and genome sophistication.
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Affiliation(s)
- Duo-Hong Sheng
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China
| | - Yi-Xue Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China
| | - Miao Qiu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China
| | - Jin-Yi Zhao
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China
| | - Xin-Jing Yue
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China
| | - Yue-Zhong Li
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China
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27
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Samarasinghe S, Reid R, Al-Bayati M. The anti-virulence effect of cranberry active compound proanthocyanins (PACs) on expression of genes in the third-generation cephalosporin-resistant Escherichia coli CTX-M-15 associated with urinary tract infection. Antimicrob Resist Infect Control 2019; 8:181. [PMID: 31832181 PMCID: PMC6865039 DOI: 10.1186/s13756-019-0637-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 10/28/2019] [Indexed: 11/24/2022] Open
Abstract
Background Urinary tract infections (UTIs) are one of the most common infections found in humans, with uropathogenic Escherichia coli (UPEC) being the most common cause. Prevention of UTI is a major global concern due to its recurrent nature, medical cost, and most importantly, the increased antimicrobial resistance among UPEC. The resistance in UPEC is mainly due to the Extended-Spectrum β-lactamases (ESBL), particularly the E. coli CTXM-15 type which is known for its rapid dissemination worldwide. Treatment options for E. coli CTXM-15 have become limited over recent years because of their multi-drug resistance, hence anti-virulent strategies based on herbal remedies, have considered as a viable option. The cranberry product, Cysticlean® capsules, contain 240 mg of proanthocyanins (PACs), which have been shown to significantly inhibit E. coli adherence, both in vitro and ex vivo, to uroepithelial cells. Method In this study, the cephalosporin-resistant E. coli isolate NCTC 1553 (E. coli CTXM-15) was analysed by qRT-PCR (quantitative Reverse Transcriptase -Polymerase Chain Reaction) for the expression of virulence factors after treatment with Cysticlean®. qRT-PCR was carried out to detect virulence determinants encoding for toxins SAT, and USP, the iron acquisition system ChuA, the protectins SoxS, KPSM, TraT and RecA, the antibiotic resistance gene CTX-M (encode β-lactamases), and the transporters IdfB and HcaT. Results Cysticlean® significantly reduced the expression of all ten selected genes encoding for virulence factors and β-lactamases. Conclusion Cranberry product Cysticlean® could represent a practicable alternative option for the prevention of recurrent UTI caused by multi-drug resistant E. coli CTXM-15, as the product acts on multiple bacterial targets.
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Affiliation(s)
- Shivanthi Samarasinghe
- Molecular Microbiology, Leicester School of Allied Health Sciences, Faculty of Health & Life Sciences, The Gateway, De Montfort University, Leicester, LE1 9BH UK
| | - Ruth Reid
- Molecular Microbiology, Leicester School of Allied Health Sciences, Faculty of Health & Life Sciences, The Gateway, De Montfort University, Leicester, LE1 9BH UK
| | - Majid Al-Bayati
- Molecular Microbiology, Leicester School of Allied Health Sciences, Faculty of Health & Life Sciences, The Gateway, De Montfort University, Leicester, LE1 9BH UK
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28
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Wien F, Martinez D, Le Brun E, Jones NC, Vrønning Hoffmann S, Waeytens J, Berbon M, Habenstein B, Arluison V. The Bacterial Amyloid-Like Hfq Promotes In Vitro DNA Alignment. Microorganisms 2019; 7:microorganisms7120639. [PMID: 31816864 PMCID: PMC6956100 DOI: 10.3390/microorganisms7120639] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 11/25/2019] [Accepted: 11/28/2019] [Indexed: 12/14/2022] Open
Abstract
The Hfq protein is reported to be involved in environmental adaptation and virulence of several bacteria. In Gram-negative bacteria, Hfq mediates the interaction between regulatory noncoding RNAs and their target mRNAs. Besides these RNA-related functions, Hfq is also associated with DNA and is a part of the bacterial chromatin. Its precise role in DNA structuration is, however, unclear and whether Hfq plays a direct role in DNA-related processes such as replication or recombination is controversial. In previous works, we showed that Escherichia coli Hfq, or more precisely its amyloid-like C-terminal region (CTR), induces DNA compaction into a condensed form. In this paper, we evidence a new property for Hfq; precisely we show that its CTR influences double helix structure and base tilting, resulting in a strong local alignment of nucleoprotein Hfq:DNA fibers. The significance of this alignment is discussed in terms of chromatin structuration and possible functional consequences on evolutionary processes and adaptation to environment.
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Affiliation(s)
- Frank Wien
- Synchrotron SOLEIL, 91192 Gif-sur-Yvette, France
- Correspondence: (F.W.); (V.A.); Tel.: +33-(0)1-69-35-96-65 (F.W.); +33-(0)1-69-08-32-82 (V.A.)
| | - Denis Martinez
- Institute of Chemistry and Biology of Membranes and Nano-objects, CBMN UMR5248 CNRS Université de Bordeaux INP, 33607 Pessac, France; (D.M.); (M.B.); (B.H.)
| | - Etienne Le Brun
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France;
| | - Nykola C. Jones
- ISA, Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark; (N.C.J.); (S.V.H.)
| | - Søren Vrønning Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark; (N.C.J.); (S.V.H.)
| | - Jehan Waeytens
- Structure et Fonction des Membranes Biologiques, Université libre de Bruxelles, B1050 Bruxelles, Belgique;
- Laboratoire de Chimie Physique d’Orsay, CNRS UMR8000, Université Paris-Sud, Université Paris-Saclay 91400 Orsay, France
| | - Melanie Berbon
- Institute of Chemistry and Biology of Membranes and Nano-objects, CBMN UMR5248 CNRS Université de Bordeaux INP, 33607 Pessac, France; (D.M.); (M.B.); (B.H.)
| | - Birgit Habenstein
- Institute of Chemistry and Biology of Membranes and Nano-objects, CBMN UMR5248 CNRS Université de Bordeaux INP, 33607 Pessac, France; (D.M.); (M.B.); (B.H.)
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, CEA, CNRS UMR12, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France;
- Université de Paris, UFR Sciences du vivant, 35 rue Hélène Brion, 75205 Paris cedex, France
- Correspondence: (F.W.); (V.A.); Tel.: +33-(0)1-69-35-96-65 (F.W.); +33-(0)1-69-08-32-82 (V.A.)
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29
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Abstract
The expanding field of precision gene editing is empowering researchers to directly modify DNA. Gene editing is made possible using synonymous technologies: a DNA-binding platform to molecularly locate user-selected genomic sequences and an associated biochemical activity that serves as a functional editor. The advent of accessible DNA-targeting molecular systems, such as zinc-finger nucleases, transcription activator-like effectors (TALEs) and CRISPR-Cas9 gene editing systems, has unlocked the ability to target nearly any DNA sequence with nucleotide-level precision. Progress has also been made in harnessing endogenous DNA repair machineries, such as non-homologous end joining, homology-directed repair and microhomology-mediated end joining, to functionally manipulate genetic sequences. As understanding of how DNA damage results in deletions, insertions and modifications increases, the genome becomes more predictably mutable. DNA-binding platforms such as TALEs and CRISPR can also be used to make locus-specific epigenetic changes and to transcriptionally enhance or suppress genes. Although many challenges remain, the application of precision gene editing technology in the field of nephrology has enabled the generation of new animal models of disease as well as advances in the development of novel therapeutic approaches such as gene therapy and xenotransplantation.
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30
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Špírek M, Mlcoušková J, Belán O, Gyimesi M, Harami GM, Molnár E, Novacek J, Kovács M, Krejci L. Human RAD51 rapidly forms intrinsically dynamic nucleoprotein filaments modulated by nucleotide binding state. Nucleic Acids Res 2019; 46:3967-3980. [PMID: 29481689 PMCID: PMC5934667 DOI: 10.1093/nar/gky111] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 02/08/2018] [Indexed: 12/31/2022] Open
Abstract
Formation of RAD51 filaments on single-stranded DNA is an essential event during homologous recombination, which is required for homology search, strand exchange and protection of replication forks. Formation of nucleoprotein filaments (NF) is required for development and genomic stability, and its failure is associated with developmental abnormalities and tumorigenesis. Here we describe the structure of the human RAD51 NFs and of its Walker box mutants using electron microscopy. Wild-type RAD51 filaments adopt an ‘open’ conformation when compared to a ‘closed’ structure formed by mutants, reflecting alterations in helical pitch. The kinetics of formation/disassembly of RAD51 filaments show rapid and high ssDNA coverage via low cooperativity binding of RAD51 units along the DNA. Subsequently, a series of isomerization or dissociation events mediated by nucleotide binding state creates intrinsically dynamic RAD51 NFs. Our findings highlight important a mechanistic divergence among recombinases from different organisms, in line with the diversity of biological mechanisms of HR initiation and quality control. These data reveal unexpected intrinsic dynamic properties of the RAD51 filament during assembly/disassembly, which may be important for the proper control of homologous recombination.
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Affiliation(s)
- Mário Špírek
- Department of Biology, Masaryk University, Brno 62500, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno 65691, Czech Republic
| | - Jarmila Mlcoušková
- Department of Biology, Masaryk University, Brno 62500, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno 65691, Czech Republic
| | - Ondrej Belán
- Department of Biology, Masaryk University, Brno 62500, Czech Republic
| | - Máté Gyimesi
- Department of Biochemistry, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Gábor M Harami
- Department of Biochemistry, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Eszter Molnár
- Department of Biochemistry, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Jiri Novacek
- CEITEC, Masaryk University, Brno, Czech Republic
| | - Mihály Kovács
- Department of Biochemistry, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Lumir Krejci
- Department of Biology, Masaryk University, Brno 62500, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno 65691, Czech Republic.,National Centre for Biomolecular Research, Masaryk University, Brno 62500, Czech Republic
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31
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Jimeno S, Prados-Carvajal R, Huertas P. The role of RNA and RNA-related proteins in the regulation of DNA double strand break repair pathway choice. DNA Repair (Amst) 2019; 81:102662. [PMID: 31303544 DOI: 10.1016/j.dnarep.2019.102662] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
DNA end resection is a critical step in the repair of DNA double strand breaks. It controls the way the lesion is going to be repaired, thus its regulation has a great importance in maintaining genomic stability. In this review, we focus in recent discoveries in the field that point to a modulation of resection by RNA molecules and RNA-related proteins. Moreover, we aim to reconcile contradictory reports on the positive or negative effect of DNA:RNA hybrids in the resection process.
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Affiliation(s)
- Sonia Jimeno
- Departamento de Genética, Universidad de Sevilla, Sevilla, 41080, Spain; Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, 41092, Spain
| | - Rosario Prados-Carvajal
- Departamento de Genética, Universidad de Sevilla, Sevilla, 41080, Spain; Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, 41092, Spain
| | - Pablo Huertas
- Departamento de Genética, Universidad de Sevilla, Sevilla, 41080, Spain; Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, 41092, Spain.
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32
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Tashjian TF, Danilowicz C, Molza AE, Nguyen BH, Prévost C, Prentiss M, Godoy VG. Residues in the fingers domain of the translesion DNA polymerase DinB enable its unique participation in error-prone double-strand break repair. J Biol Chem 2019; 294:7588-7600. [PMID: 30872406 DOI: 10.1074/jbc.ra118.006233] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 02/28/2019] [Indexed: 11/06/2022] Open
Abstract
The evolutionarily conserved Escherichia coli translesion DNA polymerase IV (DinB) is one of three enzymes that can bypass potentially deadly DNA lesions on the template strand during DNA replication. Remarkably, however, DinB is the only known translesion DNA polymerase active in RecA-mediated strand exchange during error-prone double-strand break repair. In this process, a single-stranded DNA (ssDNA)-RecA nucleoprotein filament invades homologous dsDNA, pairing the ssDNA with the complementary strand in the dsDNA. When exchange reaches the 3' end of the ssDNA, a DNA polymerase can add nucleotides onto the end, using one strand of dsDNA as a template and displacing the other. It is unknown what makes DinB uniquely capable of participating in this reaction. To explore this topic, we performed molecular modeling of DinB's interactions with the RecA filament during strand exchange, identifying key contacts made with residues in the DinB fingers domain. These residues are highly conserved in DinB, but not in other translesion DNA polymerases. Using a novel FRET-based assay, we found that DinB variants with mutations in these conserved residues are less effective at stabilizing RecA-mediated strand exchange than native DinB. Furthermore, these variants are specifically deficient in strand displacement in the absence of RecA filament. We propose that the amino acid patch of highly conserved residues in DinB-like proteins provides a mechanistic explanation for DinB's function in strand exchange and improves our understanding of recombination by providing evidence that RecA plays a role in facilitating DinB's activity during strand exchange.
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Affiliation(s)
- Tommy F Tashjian
- From the Department of Biology, Northeastern University, Boston, Massachusetts 02115
| | - Claudia Danilowicz
- the Department of Physics, Harvard University, Cambridge, Massachusetts 02138, and
| | - Anne-Elizabeth Molza
- the Laboratoire de Biochimie Théorique, CNRS UPR9080 and Université Paris Diderot, IBPC, 75005 Paris, France
| | - Brian H Nguyen
- From the Department of Biology, Northeastern University, Boston, Massachusetts 02115
| | - Chantal Prévost
- the Laboratoire de Biochimie Théorique, CNRS UPR9080 and Université Paris Diderot, IBPC, 75005 Paris, France
| | - Mara Prentiss
- the Department of Physics, Harvard University, Cambridge, Massachusetts 02138, and
| | - Veronica G Godoy
- From the Department of Biology, Northeastern University, Boston, Massachusetts 02115,
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33
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Crickard JB, Kwon Y, Sung P, Greene EC. Dynamic interactions of the homologous pairing 2 (Hop2)-meiotic nuclear divisions 1 (Mnd1) protein complex with meiotic presynaptic filaments in budding yeast. J Biol Chem 2019; 294:490-501. [PMID: 30420424 PMCID: PMC6333877 DOI: 10.1074/jbc.ra118.006146] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/02/2018] [Indexed: 12/19/2022] Open
Abstract
Homologous recombination (HR) is a universally conserved DNA repair pathway that can result in the exchange of genetic material. In eukaryotes, HR has evolved into an essential step in meiosis. During meiosis many eukaryotes utilize a two-recombinase pathway. This system consists of Rad51 and the meiosis-specific recombinase Dmc1. Both recombinases have distinct activities during meiotic HR, despite being highly similar in sequence and having closely related biochemical activities, raising the question of how these two proteins can perform separate functions. A likely explanation for their differential regulation involves the meiosis-specific recombination proteins Hop2 and Mnd1, which are part of a highly conserved eukaryotic protein complex that participates in HR, albeit through poorly understood mechanisms. To better understand how Hop2-Mnd1 functions during HR, here we used DNA curtains in conjunction with single-molecule imaging to measure and quantify the binding of the Hop2-Mnd1 complex from Saccharomyces cerevisiae to recombination intermediates comprising Rad51- and Dmc1-ssDNA in real time. We found that yeast Hop2-Mnd1 bound rapidly to Dmc1-ssDNA filaments with high affinity and remained bound for ∼1.3 min before dissociating. We also observed that this binding interaction was highly specific for Dmc1 and found no evidence for an association of Hop2-Mnd1 with Rad51-ssDNA or RPA-ssDNA. Our findings provide new quantitative insights into the binding dynamics of Hop2-Mnd1 with the meiotic presynaptic complex. On the basis of these findings, we propose a model in which recombinase specificities for meiotic accessory proteins enhance separation of the recombinases' functions during meiotic HR.
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Affiliation(s)
- J Brooks Crickard
- From the Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032
| | - Youngho Kwon
- the Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, and
- the Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, Texas 78229
| | - Patrick Sung
- the Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, and
- the Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, Texas 78229
| | - Eric C Greene
- From the Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032,
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34
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Abstract
Polyamines, often elevated in cancer cells, have been shown to promote cell growth and proliferation. Whether polyamines regulate other cell functions remains unclear. Here, we explore whether and how polyamines affect genome integrity. When DNA double-strand break (DSB) is induced in hair follicles by ionizing radiation, reduction of cellular polyamines augments dystrophic changes with delayed regeneration. Mechanistically, polyamines facilitate homologous recombination-mediated DSB repair without affecting repair via non-homologous DNA end-joining and single-strand DNA annealing. Biochemical reconstitution and functional analyses demonstrate that polyamines enhance the DNA strand exchange activity of RAD51 recombinase. The effect of polyamines on RAD51 stems from their ability to enhance the capture of homologous duplex DNA and synaptic complex formation by the RAD51-ssDNA nucleoprotein filament. Our work demonstrates a novel function of polyamines in the maintenance of genome integrity via homology-directed DNA repair. The maintenance polyamines homeostasis is important for cell growth, and several cancers harbor elevated levels of polyamines that may contribute to sustained proliferative potential. Here the authors demonstrate that polyamines participate in DNA double-strand break repair through the stimulation of RAD51-mediated homologous DNA pairing and strand exchange.
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35
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Jimeno S, Mejías-Navarro F, Prados-Carvajal R, Huertas P. Controlling the balance between chromosome break repair pathways. DNA Repair (Amst) 2019; 115:95-134. [DOI: 10.1016/bs.apcsb.2018.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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36
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Abstract
Meiosis is the basis for sexual reproduction and is marked by the sequential reduction of chromosome number during successive cell cycles, resulting in four haploid gametes. A central component of the meiotic program is the formation and repair of programmed double strand breaks. Recombination-driven repair of these meiotic breaks differs from recombination during mitosis in that meiotic breaks are preferentially repaired using the homologous chromosomes in a process known as homolog bias. Homolog bias allows for physical interactions between homologous chromosomes that are required for proper chromosome segregation, and the formation of crossover products ensuring genetic diversity in progeny. An important aspect of meiosis in the differential regulation of the two eukaryotic RecA homologs, Rad51 and Dmc1. In this review we will discuss the relationship between biological programs designed to regulate recombinase function.
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Affiliation(s)
- J Brooks Crickard
- a Department of Biochemistry & Molecular Biophysics , Columbia University , New York , NY , USA
| | - Eric C Greene
- a Department of Biochemistry & Molecular Biophysics , Columbia University , New York , NY , USA
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37
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Saragliadis A, Trunk T, Leo JC. Producing Gene Deletions in Escherichia coli by P1 Transduction with Excisable Antibiotic Resistance Cassettes. J Vis Exp 2018. [PMID: 30222159 DOI: 10.3791/58267] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A first approach to study the function of an unknown gene in bacteria is to create a knock-out of this gene. Here, we describe a robust and fast protocol for transferring gene deletion mutations from one Escherichia coli strain to another by using generalized transduction with the bacteriophage P1. This method requires that the mutation be selectable (e.g., based on gene disruptions using antibiotic cassette insertions). Such antibiotic cassettes can be mobilized from a donor strain and introduced into a recipient strain of interest to quickly and easily generate a gene deletion mutant. The antibiotic cassette can be designed to include flippase recognition sites that allow the excision of the cassette by a site-specific recombinase to produce a clean knock-out with only a ~100-base-pair-long scar sequence in the genome. We demonstrate the protocol by knocking out the tamA gene encoding an assembly factor involved in autotransporter biogenesis and test the effect of this knock-out on the biogenesis and function of two trimeric autotransporter adhesins. Though gene deletion by P1 transduction has its limitations, the ease and speed of its implementation make it an attractive alternative to other methods of gene deletion.
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Affiliation(s)
| | - Thomas Trunk
- Evolution and Genetics, Department of Biosciences, University of Oslo
| | - Jack C Leo
- Evolution and Genetics, Department of Biosciences, University of Oslo;
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38
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Brinkman EK, Chen T, de Haas M, Holland HA, Akhtar W, van Steensel B. Kinetics and Fidelity of the Repair of Cas9-Induced Double-Strand DNA Breaks. Mol Cell 2018; 70:801-813.e6. [PMID: 29804829 PMCID: PMC5993873 DOI: 10.1016/j.molcel.2018.04.016] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 01/29/2018] [Accepted: 04/18/2018] [Indexed: 12/26/2022]
Abstract
The RNA-guided DNA endonuclease Cas9 is a powerful tool for genome editing. Little is known about the kinetics and fidelity of the double-strand break (DSB) repair process that follows a Cas9 cutting event in living cells. Here, we developed a strategy to measure the kinetics of DSB repair for single loci in human cells. Quantitative modeling of repaired DNA in time series after Cas9 activation reveals variable and often slow repair rates, with half-life times up to ∼10 hr. Furthermore, repair of the DSBs tends to be error prone. Both classical and microhomology-mediated end joining pathways contribute to the erroneous repair. Estimation of their individual rate constants indicates that the balance between these two pathways changes over time and can be altered by additional ionizing radiation. Our approach provides quantitative insights into DSB repair kinetics and fidelity in single loci and indicates that Cas9-induced DSBs are repaired in an unusual manner.
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Affiliation(s)
- Eva K Brinkman
- Oncode Institute; Division of Gene Regulation, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands
| | - Tao Chen
- Division of Gene Regulation, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands
| | - Marcel de Haas
- Oncode Institute; Division of Gene Regulation, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands
| | - Hanna A Holland
- Division of Gene Regulation, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands
| | - Waseem Akhtar
- Division of Molecular Genetics, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands
| | - Bas van Steensel
- Oncode Institute; Division of Gene Regulation, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands.
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39
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Braslavsky I, Stavans J. Application of Algebraic Topology to Homologous Recombination of DNA. iScience 2018; 4:64-67. [PMID: 30240753 PMCID: PMC6146625 DOI: 10.1016/j.isci.2018.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/30/2018] [Accepted: 05/11/2018] [Indexed: 11/23/2022] Open
Abstract
Brouwer's fixed point theorem, a fundamental theorem in algebraic topology proved more than a hundred years ago, states that given any continuous map from a closed, simply connected set into itself, there is a point that is mapped unto itself. Here we point out the connection between a one-dimensional application of Brouwer's fixed point theorem and a mechanism proposed to explain how extension of single-stranded DNA substrates by recombinases of the RecA superfamily facilitates significantly the search for homologous sequences on long chromosomes. RecA family recombinases stretch their DNA substrates by 1.5 Stretching facilitates the search for homologous genomic targets during recombination This facilitating mechanism derives from a foundational theorem of Algebraic Topology
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Affiliation(s)
- Ido Braslavsky
- The Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel.
| | - Joel Stavans
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 7610001, Israel.
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40
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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: 406] [Impact Index Per Article: 67.7] [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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41
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Abstract
Genetic recombination occurs in all organisms and is vital for genome stability. Indeed, in humans, aberrant recombination can lead to diseases such as cancer. Our understanding of homologous recombination is built upon more than a century of scientific inquiry, but achieving a more complete picture using ensemble biochemical and genetic approaches is hampered by population heterogeneity and transient recombination intermediates. Recent advances in single-molecule and super-resolution microscopy methods help to overcome these limitations and have led to new and refined insights into recombination mechanisms, including a detailed understanding of DNA helicase function and synaptonemal complex structure. The ability to view cellular processes at single-molecule resolution promises to transform our understanding of recombination and related processes.
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42
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Korona D, Koestler SA, Russell S. Engineering the Drosophila Genome for Developmental Biology. J Dev Biol 2017; 5:jdb5040016. [PMID: 29615571 PMCID: PMC5831791 DOI: 10.3390/jdb5040016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 02/07/2023] Open
Abstract
The recent development of transposon and CRISPR-Cas9-based tools for manipulating the fly genome in vivo promises tremendous progress in our ability to study developmental processes. Tools for introducing tags into genes at their endogenous genomic loci facilitate imaging or biochemistry approaches at the cellular or subcellular levels. Similarly, the ability to make specific alterations to the genome sequence allows much more precise genetic control to address questions of gene function.
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Affiliation(s)
- Dagmara Korona
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
| | - Stefan A Koestler
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
| | - Steven Russell
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
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43
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Ito K, Murayama Y, Takahashi M, Iwasaki H. Two three-strand intermediates are processed during Rad51-driven DNA strand exchange. Nat Struct Mol Biol 2017; 25:29-36. [PMID: 29323270 DOI: 10.1038/s41594-017-0002-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/31/2017] [Indexed: 11/09/2022]
Abstract
During homologous recombination, Rad51 forms a nucleoprotein filament with single-stranded DNA (ssDNA) that undergoes strand exchange with homologous double-stranded DNA (dsDNA). Here, we use real-time analysis to show that strand exchange by fission yeast Rad51 proceeds via two distinct three-strand intermediates, C1 and C2. Both intermediates contain Rad51, but whereas the donor duplex remains intact in C1, the ssDNA strand is intertwined with the complementary strand of the donor duplex in C2. Swi5-Sfr1, an evolutionarily conserved recombination activator, facilitates the C1-C2 transition and subsequent ssDNA release from C2 to complete strand exchange in an ATP-hydrolysis-dependent manner. In contrast, Ca2+, which activates the Rad51 filament by curbing ATP hydrolysis, facilitates the C1-C2 transition but does not promote strand exchange. These results reveal that Swi5-Sfr1 and Ca2+ have different activation modes in the late synaptic phase, despite their common function in stabilizing the presynaptic filament.
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Affiliation(s)
- Kentaro Ito
- School and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan
| | - Yasuto Murayama
- School and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan.,National Institute of Genetics, Shizuoka, Japan
| | - Masayuki Takahashi
- School and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan
| | - Hiroshi Iwasaki
- School and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan. .,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan.
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44
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Yamada S, Kim S, Tischfield SE, Jasin M, Lange J, Keeney S. Genomic and chromatin features shaping meiotic double-strand break formation and repair in mice. Cell Cycle 2017; 16:1870-1884. [PMID: 28820351 PMCID: PMC5638367 DOI: 10.1080/15384101.2017.1361065] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 06/27/2017] [Accepted: 07/25/2017] [Indexed: 11/12/2022] Open
Abstract
The SPO11-generated DNA double-strand breaks (DSBs) that initiate meiotic recombination occur non-randomly across genomes, but mechanisms shaping their distribution and repair remain incompletely understood. Here, we expand on recent studies of nucleotide-resolution DSB maps in mouse spermatocytes. We find that trimethylation of histone H3 lysine 36 around DSB hotspots is highly correlated, both spatially and quantitatively, with trimethylation of H3 lysine 4, consistent with coordinated formation and action of both PRDM9-dependent histone modifications. In contrast, the DSB-responsive kinase ATM contributes independently of PRDM9 to controlling hotspot activity, and combined action of ATM and PRDM9 can explain nearly two-thirds of the variation in DSB frequency between hotspots. DSBs were modestly underrepresented in most repetitive sequences such as segmental duplications and transposons. Nonetheless, numerous DSBs form within repetitive sequences in each meiosis and some classes of repeats are preferentially targeted. Implications of these findings are discussed for evolution of PRDM9 and its role in hybrid strain sterility in mice. Finally, we document the relationship between mouse strain-specific DNA sequence variants within PRDM9 recognition motifs and attendant differences in recombination outcomes. Our results provide further insights into the complex web of factors that influence meiotic recombination patterns.
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Affiliation(s)
- Shintaro Yamada
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Seoyoung Kim
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Sam E. Tischfield
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Tri-Institutional Training Program in Computational Biology and Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Julian Lange
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Scott Keeney
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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45
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Jones DL, Leroy P, Unoson C, Fange D, Ćurić V, Lawson MJ, Elf J. Kinetics of dCas9 target search in Escherichia coli. Science 2017; 357:1420-1424. [PMID: 28963258 DOI: 10.1126/science.aah7084] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 06/09/2017] [Accepted: 08/24/2017] [Indexed: 12/12/2022]
Abstract
How fast can a cell locate a specific chromosomal DNA sequence specified by a single-stranded oligonucleotide? To address this question, we investigate the intracellular search processes of the Cas9 protein, which can be programmed by a guide RNA to bind essentially any DNA sequence. This targeting flexibility requires Cas9 to unwind the DNA double helix to test for correct base pairing to the guide RNA. Here we study the search mechanisms of the catalytically inactive Cas9 (dCas9) in living Escherichia coli by combining single-molecule fluorescence microscopy and bulk restriction-protection assays. We find that it takes a single fluorescently labeled dCas9 6 hours to find the correct target sequence, which implies that each potential target is bound for less than 30 milliseconds. Once bound, dCas9 remains associated until replication. To achieve fast targeting, both Cas9 and its guide RNA have to be present at high concentrations.
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Affiliation(s)
- Daniel Lawson Jones
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Prune Leroy
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Cecilia Unoson
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - David Fange
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Vladimir Ćurić
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Michael J Lawson
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Johan Elf
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
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46
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Cebrian-Serrano A, Davies B. CRISPR-Cas orthologues and variants: optimizing the repertoire, specificity and delivery of genome engineering tools. Mamm Genome 2017; 28:247-261. [PMID: 28634692 PMCID: PMC5569134 DOI: 10.1007/s00335-017-9697-4] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 05/26/2017] [Indexed: 12/17/2022]
Abstract
Robust and cost-effective genome editing in a diverse array of cells and model organisms is now possible thanks to the discovery of the RNA-guided endonucleases of the CRISPR-Cas system. The commonly used Cas9 of Streptococcus pyogenes shows high levels of activity but, depending on the application, has been associated with some shortcomings. Firstly, the enzyme has been shown to cause mutagenesis at genomic sequences resembling the target sequence. Secondly, the stringent requirement for a specific motif adjacent to the selected target site can limit the target range of this enzyme. Lastly, the physical size of Cas9 challenges the efficient delivery of genomic engineering tools based on this enzyme as viral particles for potential therapeutic applications. Related and parallel strategies have been employed to address these issues. Taking advantage of the wealth of structural information that is becoming available for CRISPR-Cas effector proteins, Cas9 has been redesigned by mutagenizing key residues contributing to activity and target recognition. The protein has also been shortened and redesigned into component subunits in an attempt to facilitate its efficient delivery. Furthermore, the CRISPR-Cas toolbox has been expanded by exploring the properties of Cas9 orthologues and other related effector proteins from diverse bacterial species, some of which exhibit different target site specificities and reduced molecular size. It is hoped that the improvements in accuracy, target range and efficiency of delivery will facilitate the therapeutic application of these site-specific nucleases.
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Affiliation(s)
| | - Benjamin Davies
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK.
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47
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Anand R, Beach A, Li K, Haber J. Rad51-mediated double-strand break repair and mismatch correction of divergent substrates. Nature 2017; 544:377-380. [PMID: 28405019 PMCID: PMC5544500 DOI: 10.1038/nature22046] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 03/06/2017] [Indexed: 01/14/2023]
Abstract
The Rad51 (also known as RecA) family of recombinases executes the critical step in homologous recombination: the search for homologous DNA to serve as a template during the repair of DNA double-strand breaks (DSBs). Although budding yeast Rad51 has been extensively characterized in vitro, the stringency of its search and sensitivity to mismatched sequences in vivo remain poorly defined. Here, in Saccharomyces cerevisiae, we analysed Rad51-dependent break-induced replication in which the invading DSB end and its donor template share a 108-base-pair homology region and the donor carries different densities of single-base-pair mismatches. With every eighth base pair mismatched, repair was about 14% of that of completely homologous sequences. With every sixth base pair mismatched, repair was still more than 5%. Thus, completing break-induced replication in vivo overcomes the apparent requirement for at least 6-8 consecutive paired bases that has been inferred from in vitro studies. When recombination occurs without a protruding nonhomologous 3' tail, the mismatch repair protein Msh2 does not discourage homeologous recombination. However, when the DSB end contains a 3' protruding nonhomologous tail, Msh2 promotes the rejection of mismatched substrates. Mismatch correction of strand invasion heteroduplex DNA is strongly polar, favouring correction close to the DSB end. Nearly all mismatch correction depends on the proofreading activity of DNA polymerase-δ, although the repair proteins Msh2, Mlh1 and Exo1 influence the extent of correction.
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Affiliation(s)
| | - Annette Beach
- Rosenstiel Basic Medical Sciences Research Center and Department of Biology, Brandeis University, Waltham, Massachusetts 02254-9110
| | - Kevin Li
- Rosenstiel Basic Medical Sciences Research Center and Department of Biology, Brandeis University, Waltham, Massachusetts 02254-9110
| | - James Haber
- Rosenstiel Basic Medical Sciences Research Center and Department of Biology, Brandeis University, Waltham, Massachusetts 02254-9110
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48
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Cheng Y, Yang B, Xi Y, Chen X. RAD51B as a potential biomarker for early detection and poor prognostic evaluation contributes to tumorigenesis of gastric cancer. Tumour Biol 2016; 37:14969-14978. [PMID: 27651161 DOI: 10.1007/s13277-016-5340-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/06/2016] [Indexed: 01/30/2023] Open
Abstract
Gastric cancer (GC) is a common and deadly disease worldwide. Outcomes of patients are poor largely due to chemoresistance or recurrence. Thus, identifying novel biomarkers to predict response to therapy and/or prognosis are urgently needed. RAD51B, a key player in DNA repair/recombination, has the potential to be a candidate oncogene and biomarker for cancer diagnosis and prognosis. However, its relationship with GC remains unclear. To evaluate clinicopathological and prognostic significance of RAD51B in GC, we examined messenger RNA (mRNA) and protein expression via quantitative real-time polymerase chain reaction (qRT-PCR) from 69 and tissue microarray from 144 GC patients, respectively. Our results showed that RAD51B mRNA expression was significantly up-regulated in tumors compared to that of matched noncancerous tissues (P < 0.001). In parallel, RAD51B protein showed a mainly nucleus-staining pattern, and the positive rate in tumors and stomach atypical hyperplasia was significantly higher than that in matched noncancerous tissues (P = 0.015). Moreover, high level of RAD51B protein was correlated with advanced stage (P = 0.009), aggressive differentiation (P = 0.022), and lymph node metastasis (P = 0.001). Further, Kaplan-Meier analysis indicated that patients with high level of RAD51B expression exhibited worse overall survival compared to patients with low level (P = 0.040). A multivariate Cox regression analysis suggested that RAD51B may be an independent prognostic factor for GC patients in Chinese population (P = 0.004). Additionally, functional studies indicated that over-expression of RAD51B promoted cell proliferation, aneuploidy, and drug resistance, while RAD51B knockdown led to G1 arrest and sensitized cells to 5-fluorouracil (5-FU). In conclusion, RAD51B may act as an oncogene during GC progression, and its hyper-expression may be a potential biomarker for early detection and poor prognosis of GC.
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Affiliation(s)
- Yikun Cheng
- Beijing New Oriental Foreign Language School at Yangzhou, Yangzhou, Jiangsu, 225006, China
| | - Bin Yang
- Department of Tumor Surgery, Shanxi Cancer Hospital, Taiyuan, Shanxi, 030001, People's Republic of China
| | - Yanfeng Xi
- Department of Pathology, Shanxi Cancer Hospital, Taiyuan, Shanxi, 030001, People's Republic of China.
| | - Xing Chen
- Department of Endoscopy, Shanxi Cancer Hospital, Taiyuan, Shanxi, 030001, China.
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