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Al Zouabi L, Stefanutti M, Roumeliotis S, Le Meur G, Boumard B, Riddiford N, Rubanova N, Bohec M, Gervais L, Servant N, Bardin AJ. Molecular underpinnings and environmental drivers of loss of heterozygosity in Drosophila intestinal stem cells. Cell Rep 2023; 42:113485. [PMID: 38032794 DOI: 10.1016/j.celrep.2023.113485] [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: 08/03/2022] [Revised: 09/29/2023] [Accepted: 11/08/2023] [Indexed: 12/02/2023] Open
Abstract
During development and aging, genome mutation leading to loss of heterozygosity (LOH) can uncover recessive phenotypes within tissue compartments. This phenomenon occurs in normal human tissues and is prevalent in pathological genetic conditions and cancers. While studies in yeast have defined DNA repair mechanisms that can promote LOH, the predominant pathways and environmental triggers in somatic tissues of multicellular organisms are not well understood. Here, we investigate mechanisms underlying LOH in intestinal stem cells in Drosophila. Infection with the pathogenic bacteria, Erwinia carotovora carotovora 15, but not Pseudomonas entomophila, increases LOH frequency. Using whole genome sequencing of somatic LOH events, we demonstrate that they arise primarily via mitotic recombination. Molecular features and genetic evidence argue against a break-induced replication mechanism and instead support cross-over via double Holliday junction-based repair. This study provides a mechanistic understanding of mitotic recombination, an important mediator of LOH, and its effects on stem cells in vivo.
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Affiliation(s)
- Lara Al Zouabi
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Marine Stefanutti
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Spyridon Roumeliotis
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Gwenn Le Meur
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Benjamin Boumard
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Nick Riddiford
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Natalia Rubanova
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France; Bioinformatics, Biostatistics, Epidemiology and Computational Systems Unit, Institut Curie, PSL Research University, INSERM U900, 75005 Paris, France
| | - Mylène Bohec
- ICGex Next-Generation Sequencing Platform, Institut Curie, PSL Research University, 75005 Paris, France
| | - Louis Gervais
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Nicolas Servant
- Bioinformatics, Biostatistics, Epidemiology and Computational Systems Unit, Institut Curie, PSL Research University, INSERM U900, 75005 Paris, France
| | - Allison J Bardin
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France.
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2
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Simpson D, Ling J, Jing Y, Adamson B. Mapping the Genetic Interaction Network of PARP inhibitor Response. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.19.553986. [PMID: 37645833 PMCID: PMC10462155 DOI: 10.1101/2023.08.19.553986] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Genetic interactions have long informed our understanding of the coordinated proteins and pathways that respond to DNA damage in mammalian cells, but systematic interrogation of the genetic network underlying that system has yet to be achieved. Towards this goal, we measured 147,153 pairwise interactions among genes implicated in PARP inhibitor (PARPi) response. Evaluating genetic interactions at this scale, with and without exposure to PARPi, revealed hierarchical organization of the pathways and complexes that maintain genome stability during normal growth and defined changes that occur upon accumulation of DNA lesions due to cytotoxic doses of PARPi. We uncovered unexpected relationships among DNA repair genes, including context-specific buffering interactions between the minimally characterized AUNIP and BRCA1-A complex genes. Our work thus establishes a foundation for mapping differential genetic interactions in mammalian cells and provides a comprehensive resource for future studies of DNA repair and PARP inhibitors.
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Affiliation(s)
- Danny Simpson
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Jia Ling
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Yangwode Jing
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Britt Adamson
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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3
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Joudeh LA, DiCintio AJ, Ries MR, Gasperson AS, Griffin KE, Robbins VP, Bonner M, Nolan S, Black E, Waldman AS. Corruption of DNA end-joining in mammalian chromosomes by progerin expression. DNA Repair (Amst) 2023; 126:103491. [PMID: 37018982 PMCID: PMC10133198 DOI: 10.1016/j.dnarep.2023.103491] [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: 12/12/2022] [Revised: 03/23/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023]
Abstract
Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare genetic condition characterized by features of accelerated aging and a life expectancy of about 14 years. HGPS is commonly caused by a point mutation in the LMNA gene which codes for lamin A, an essential component of the nuclear lamina. The HGPS mutation alters splicing of the LMNA transcript, leading to a truncated, farnesylated form of lamin A termed "progerin." Progerin is also produced in small amounts in healthy individuals by alternative splicing of RNA and has been implicated in normal aging. HGPS is associated with an accumulation of genomic DNA double-strand breaks (DSBs), suggesting alteration of DNA repair. DSB repair normally occurs by either homologous recombination (HR), an accurate, templated form of repair, or by nonhomologous end-joining (NHEJ), a non-templated rejoining of DNA ends that can be error-prone; however a good portion of NHEJ events occurs precisely with no alteration to joined sequences. Previously, we reported that over-expression of progerin correlated with increased NHEJ relative to HR. We now report on progerin's impact on the nature of DNA end-joining. We used a model system involving a DNA end-joining reporter substrate integrated into the genome of cultured thymidine kinase-deficient mouse fibroblasts. Some cells were engineered to express progerin. Two closely spaced DSBs were induced in the integrated substrate through expression of endonuclease I-SceI, and DSB repair events were recovered through selection for thymidine kinase function. DNA sequencing revealed that progerin expression correlated with a significant shift away from precise end-joining between the two I-SceI sites and toward imprecise end-joining. Additional experiments revealed that progerin did not reduce HR fidelity. Our work suggests that progerin suppresses interactions between complementary sequences at DNA termini, thereby shifting DSB repair toward low-fidelity DNA end-joining and perhaps contributing to accelerated and normal aging through compromised genome stability.
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Affiliation(s)
- Liza A Joudeh
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Alannah J DiCintio
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Madeline R Ries
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Andrew S Gasperson
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Kennedy E Griffin
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Victoria P Robbins
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Makenzie Bonner
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Sarah Nolan
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Emma Black
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Alan S Waldman
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.
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Altmannova V, Firlej M, Müller F, Janning P, Rauleder R, Rousova D, Schäffler A, Bange T, Weir JR. Biochemical characterisation of Mer3 helicase interactions and the protection of meiotic recombination intermediates. Nucleic Acids Res 2023; 51:4363-4384. [PMID: 36942481 PMCID: PMC10201424 DOI: 10.1093/nar/gkad175] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 02/21/2023] [Accepted: 02/24/2023] [Indexed: 03/23/2023] Open
Abstract
Crossing over between homologs is critical for the stable segregation of chromosomes during the first meiotic division. Saccharomyces cerevisiae Mer3 (HFM1 in mammals) is a SF2 helicase and member of the ZMM group of proteins, that facilitates the formation of the majority of crossovers during meiosis. Here, we describe the structural organisation of Mer3 and using AlphaFold modelling and XL-MS we further characterise the previously described interaction with Mlh1-Mlh2. We find that Mer3 also forms a previously undescribed complex with the recombination regulating factors Top3 and Rmi1 and that this interaction is competitive with Sgs1BLM helicase. Using in vitro reconstituted D-loop assays we show that Mer3 inhibits the anti-recombination activity of Sgs1 helicase, but only in the presence of Dmc1. Thus we provide a mechanism whereby Mer3 interacts with a network of proteins to protect Dmc1 derived D-loops from dissolution.
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Affiliation(s)
- Veronika Altmannova
- Friedrich Miescher Laboratory of the Max Planck Society, Max-Planck-Ring 9, 72076 Tübingen, Germany
| | - Magdalena Firlej
- Friedrich Miescher Laboratory of the Max Planck Society, Max-Planck-Ring 9, 72076 Tübingen, Germany
| | - Franziska Müller
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227, Dortmund, Germany
| | - Petra Janning
- Department of Chemical Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Str. 11, 44227, Dortmund, Germany
| | - Rahel Rauleder
- Friedrich Miescher Laboratory of the Max Planck Society, Max-Planck-Ring 9, 72076 Tübingen, Germany
| | - Dorota Rousova
- Friedrich Miescher Laboratory of the Max Planck Society, Max-Planck-Ring 9, 72076 Tübingen, Germany
| | - Andreas Schäffler
- Friedrich Miescher Laboratory of the Max Planck Society, Max-Planck-Ring 9, 72076 Tübingen, Germany
| | - Tanja Bange
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Germany
| | - John R Weir
- Friedrich Miescher Laboratory of the Max Planck Society, Max-Planck-Ring 9, 72076 Tübingen, Germany
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5
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Ma XY, Zhao JF, Ruan Y, Zhang WM, Zhang LQ, Cai ZD, Xu HQ. ML216-Induced BLM Helicase Inhibition Sensitizes PCa Cells to the DNA-Crosslinking Agent Cisplatin. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27248790. [PMID: 36557923 PMCID: PMC9788632 DOI: 10.3390/molecules27248790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/02/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
Using standard DNA-damaging medicines with DNA repair inhibitors is a promising anticancer tool to achieve better therapeutic responses and reduce therapy-related side effects. Cell viability assay, neutral comet assay, western blotting (WB), and cell cycle and apoptosis analysis were used to determine the synergistic effect and mechanism of ML216, a Bloom syndrome protein (BLM) helicase inhibitor, and cisplatin (CDDP), a DNA-crosslinking agent, in PCa cells. Based on the online database research, our findings revealed that BLM was substantially expressed in PCa, which is associated with a bad prognosis for PCa patients. The combination of ML216 and CDDP improved the antiproliferative properties of three PCa cell lines. As indicated by the increased production of γH2AX and caspase-3 cleavage, ML216 significantly reduced the DNA damage-induced high expression of BLM, making PC3 more susceptible to apoptosis and DNA damage caused by CDDP. Furthermore, the combination of ML216 and CDDP increased p-Chk1 and p-Chk2 expression. The DNA damage may have triggered the ATR-Chk1 and ATM-Chk2 pathways simultaneously. Our results demonstrated that ML216 and CDDP combination therapy exhibited synergistic effects, and combination chemotherapy could be a novel anticancer tactic.
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Affiliation(s)
- Xiao-Yan Ma
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, College of Life Sciences, Guizhou University, Guiyang 550025, China
- Guizhou Institute of Technology, College of Food and Pharmaceutical Engineering, Guiyang 550003, China
- College of Animal Science, Guizhou University, Guiyang 550025, China
| | - Jia-Fu Zhao
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, College of Life Sciences, Guizhou University, Guiyang 550025, China
- College of Animal Science, Guizhou University, Guiyang 550025, China
| | - Yong Ruan
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, College of Life Sciences, Guizhou University, Guiyang 550025, China
- College of Animal Science, Guizhou University, Guiyang 550025, China
| | - Wang-Ming Zhang
- Department of Immunology, Basic Medical College, Guizhou Medical University, Guiyang 550014, China
| | - Lun-Qing Zhang
- Guizhou Institute of Technology, College of Food and Pharmaceutical Engineering, Guiyang 550003, China
| | - Zheng-Dong Cai
- Guizhou Institute of Technology, College of Food and Pharmaceutical Engineering, Guiyang 550003, China
| | - Hou-Qiang Xu
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, College of Life Sciences, Guizhou University, Guiyang 550025, China
- College of Animal Science, Guizhou University, Guiyang 550025, China
- Correspondence: ; Tel.: +86-13765056884
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Liddiard K, Aston-Evans AN, Cleal K, Hendrickson E, Baird D. POLQ suppresses genome instability and alterations in DNA repeat tract lengths. NAR Cancer 2022; 4:zcac020. [PMID: 35774233 PMCID: PMC9241439 DOI: 10.1093/narcan/zcac020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/19/2022] [Accepted: 06/10/2022] [Indexed: 11/26/2022] Open
Abstract
DNA polymerase theta (POLQ) is a principal component of the alternative non-homologous end-joining (ANHEJ) DNA repair pathway that ligates DNA double-strand breaks. Utilizing independent models of POLQ insufficiency during telomere-driven crisis, we found that POLQ - /- cells are resistant to crisis-induced growth deceleration despite sustaining inter-chromosomal telomere fusion frequencies equivalent to wild-type (WT) cells. We recorded longer telomeres in POLQ - / - than WT cells pre- and post-crisis, notwithstanding elevated total telomere erosion and fusion rates. POLQ - /- cells emerging from crisis exhibited reduced incidence of clonal gross chromosomal abnormalities in accordance with increased genetic heterogeneity. High-throughput sequencing of telomere fusion amplicons from POLQ-deficient cells revealed significantly raised frequencies of inter-chromosomal fusions with correspondingly depreciated intra-chromosomal recombinations. Long-range interactions culminating in telomere fusions with centromere alpha-satellite repeats, as well as expansions in HSAT2 and HSAT3 satellite and contractions in ribosomal DNA repeats, were detected in POLQ - / - cells. In conjunction with the expanded telomere lengths of POLQ - /- cells, these results indicate a hitherto unrealized capacity of POLQ for regulation of repeat arrays within the genome. Our findings uncover novel considerations for the efficacy of POLQ inhibitors in clinical cancer interventions, where potential genome destabilizing consequences could drive clonal evolution and resistant disease.
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Affiliation(s)
- Kate Liddiard
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Alys N Aston-Evans
- Dementia Research Institute, School of Medicine, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK
| | - Kez Cleal
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Eric A Hendrickson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Duncan M Baird
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
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7
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Merlini A, Centomo ML, Ferrero G, Chiabotto G, Miglio U, Berrino E, Giordano G, Brusco S, Pisacane A, Maldi E, Sarotto I, Capozzi F, Lano C, Isella C, Crisafulli G, Aglietta M, Dei Tos AP, Sbaraglia M, Sangiolo D, D’Ambrosio L, Bardelli A, Pignochino Y, Grignani G. DNA damage response and repair genes in advanced bone and soft tissue sarcomas: An 8-gene signature as a candidate predictive biomarker of response to trabectedin and olaparib combination. Front Oncol 2022; 12:844250. [PMID: 36110934 PMCID: PMC9469659 DOI: 10.3389/fonc.2022.844250] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 07/26/2022] [Indexed: 11/21/2022] Open
Abstract
Background Advanced and unresectable bone and soft tissue sarcomas (BSTS) still represent an unmet medical need. We demonstrated that the alkylating agent trabectedin and the PARP1-inhibitor olaparib display antitumor activity in BSTS preclinical models. Moreover, in a phase Ib clinical trial (NCT02398058), feasibility, tolerability and encouraging results have been observed and the treatment combination is currently under study in a phase II trial (NCT03838744). Methods Differential expression of genes involved in DNA Damage Response and Repair was evaluated by Nanostring® technology, extracting RNA from pre-treatment tumor samples of 16 responder (≥6-month progression free survival) and 16 non-responder patients. Data validation was performed by quantitative real-time PCR, RNA in situ hybridization, and immunohistochemistry. The correlation between the identified candidate genes and both progression-free survival and overall survival was investigated in the publicly available dataset “Sarcoma (TCGA, The Cancer Genome Atlas)”. Results Differential RNA expression analysis revealed an 8-gene signature (CDKN2A, PIK3R1, SLFN11, ATM, APEX2, BLM, XRCC2, MAD2L2) defining patients with better outcome upon trabectedin+olaparib treatment. In responder vs. non-responder patients, a significant differential expression of these genes was further confirmed by RNA in situ hybridization and by qRT-PCR and immunohistochemistry in selected experiments. Correlation between survival outcomes and genetic alterations in the identified genes was shown in the TCGA sarcoma dataset. Conclusions This work identified an 8-gene expression signature to improve prediction of response to trabectedin+olaparib combination in BSTS. The predictive role of these potential biomarkers warrants further investigation.
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Affiliation(s)
- Alessandra Merlini
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Oncology, University of Torino, Turin, Italy
| | - Maria Laura Centomo
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Oncology, University of Torino, Turin, Italy
| | - Giulio Ferrero
- Department of Clinical and Biological Sciences, University of Torino, Turin, Italy
- Department of Computer Science, University of Torino, Turin, Italy
| | - Giulia Chiabotto
- Department of Medical Sciences, University of Torino, Turin, Italy
| | | | - Enrico Berrino
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Medical Sciences, University of Torino, Turin, Italy
| | - Giorgia Giordano
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Oncology, University of Torino, Turin, Italy
| | - Silvia Brusco
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Oncology, University of Torino, Turin, Italy
| | | | - Elena Maldi
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
| | | | | | - Cristina Lano
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Oncology, University of Torino, Turin, Italy
| | - Claudio Isella
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Oncology, University of Torino, Turin, Italy
| | - Giovanni Crisafulli
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Oncology, University of Torino, Turin, Italy
| | - Massimo Aglietta
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Oncology, University of Torino, Turin, Italy
| | - Angelo Paolo Dei Tos
- Department of Pathology, Azienda Ospedale-Università Padova, Padua, Italy
- Department of Medicine (DIMED), University of Padua School of Medicine, Padua, Italy
| | - Marta Sbaraglia
- Department of Pathology, Azienda Ospedale-Università Padova, Padua, Italy
| | - Dario Sangiolo
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Oncology, University of Torino, Turin, Italy
| | - Lorenzo D’Ambrosio
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Oncology, University of Torino, Turin, Italy
- Medical Oncology, AOU San Luigi Gonzaga, Orbassano (TO), Italy
| | - Alberto Bardelli
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Oncology, University of Torino, Turin, Italy
| | - Ymera Pignochino
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- Department of Clinical and Biological Sciences, University of Torino, Turin, Italy
- *Correspondence: Ymera Pignochino, ; Giovanni Grignani,
| | - Giovanni Grignani
- Candiolo Cancer Institute, FPO-IRCCS, Turin, Italy
- *Correspondence: Ymera Pignochino, ; Giovanni Grignani,
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8
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Wang J, Thomas HR, Chen Y, Percival SM, Waldrep SC, Ramaker RC, Thompson RG, Cooper SJ, Chong Z, Parant JM. Reduced sister chromatid cohesion acts as a tumor penetrance modifier. PLoS Genet 2022; 18:e1010341. [PMID: 35994499 PMCID: PMC9436123 DOI: 10.1371/journal.pgen.1010341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 09/01/2022] [Accepted: 07/14/2022] [Indexed: 11/23/2022] Open
Abstract
Sister chromatid cohesion (SCC) is an important process in chromosome segregation. ESCO2 is essential for establishment of SCC and is often deleted/altered in human cancers. We demonstrate that esco2 haploinsufficiency results in reduced SCC and accelerates the timing of tumor onset in both zebrafish and mouse p53 heterozygous null models, but not in p53 homozygous mutant or wild-type animals. These data indicate that esco2 haploinsufficiency accelerates tumor onset in a loss of heterozygosity (LOH) sensitive background. Analysis of The Cancer Genome Atlas (TCGA) confirmed ESCO2 deficient tumors have elevated number of LOH events throughout the genome. Further, we demonstrated heterozygous loss of sgo1, important in maintaining SCC, also results in reduced SCC and accelerated tumor formation in a p53 heterozygous background. Surprisingly, while we did observe elevated levels of chromosome missegregation and micronuclei formation in esco2 heterozygous mutant animals, this chromosomal instability did not contribute to the accelerated tumor onset in a p53 heterozygous background. Interestingly, SCC also plays a role in homologous recombination, and we did observe elevated levels of mitotic recombination derived p53 LOH in tumors from esco2 haploinsufficient animals; as well as elevated levels of mitotic recombination throughout the genome of human ESCO2 deficient tumors. Together these data suggest that reduced SCC contributes to accelerated tumor penetrance through elevated mitotic recombination. Tumorigenesis often involves the inactivation of tumor suppressor genes. This often encompasses an inactivation mutation in one allele and loss of the other wild-type allele, referred to as loss of heterozygosity (LOH). The rate at which the cells lose the wild-type allele can influence the timing of tumor onset, and therefore an indicator of a patient’s risk of cancer. Factors that influence this process could be used as a predictive indicator of cancer risk, however these factors are still unclear. We demonstrate that partial impairment of sister chromatid cohesion (SCC), a fundamental component of the chromosome segregation in mitosis and homologous recombination repair, enhanced tumorigenesis. Our data suggest this is through elevated levels of mitotic recombination derived p53 LOH. This study emphasizes the importance of understanding how impaired SCC, mitotic recombination rates, and LOH rates influence cancer risk.
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Affiliation(s)
- Jun Wang
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, United States of America
| | - Holly R. Thomas
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, United States of America
| | - Yu Chen
- Department of Genetics, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, United States of America
- Informatics Institute, University of Alabama at Birmingham Heersink School of Medicine, Alabama, United States of America
| | - Stefanie M. Percival
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, United States of America
| | - Stephanie C. Waldrep
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, United States of America
| | - Ryne C. Ramaker
- Hudson Alpha Institute for Biotechnology, Huntsville, Alabama, United States of America
| | - Robert G. Thompson
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, United States of America
| | - Sara J. Cooper
- Hudson Alpha Institute for Biotechnology, Huntsville, Alabama, United States of America
| | - Zechen Chong
- Department of Genetics, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, United States of America
- Informatics Institute, University of Alabama at Birmingham Heersink School of Medicine, Alabama, United States of America
| | - John M. Parant
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, United States of America
- * E-mail:
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9
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Wieland J, Buchan S, Sen Gupta S, Mantzouratou A. Genomic instability and the link to infertility: A focus on microsatellites and genomic instability syndromes. Eur J Obstet Gynecol Reprod Biol 2022; 274:229-237. [PMID: 35671666 DOI: 10.1016/j.ejogrb.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/25/2022] [Accepted: 06/01/2022] [Indexed: 12/01/2022]
Abstract
Infertility is associated to multiple types of different genomic instabilities and is a genetic feature of genomic instability syndromes. While the mismatch repair machinery contributes to the maintenance of genome integrity, surprisingly its potential role in infertility is overlooked. Defects in mismatch repair mechanisms contribute to microsatellite instability and genomic instability syndromes, due to the inability to repair newly replicated DNA. This article reviews the literature to date to elucidate the contribution of microsatellite instability to genomic instability syndromes and infertility. The key findings presented reveal microsatellite instability is poorly researched in genomic instability syndromes and infertility.
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Affiliation(s)
- Jack Wieland
- Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Poole BH12 5BB, UK.
| | - Sarah Buchan
- Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Poole BH12 5BB, UK.
| | - Sioban Sen Gupta
- Institute for Women's Health, 86-96 Chenies Mews, University College London, London WC1E 6HX, UK.
| | - Anna Mantzouratou
- Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Poole BH12 5BB, UK.
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10
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Cruzan MB, Streisfeld MA, Schwoch JA. Fitness effects of somatic mutations accumulating during vegetative growth. Evol Ecol 2022. [DOI: 10.1007/s10682-022-10188-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AbstractThe unique life form of plants promotes the accumulation of somatic mutations that can be passed to offspring in the next generation, because the same meristem cells responsible for vegetative growth also generate gametes for sexual reproduction. However, little is known about the consequences of somatic mutation accumulation for offspring fitness. We evaluate the fitness effects of somatic mutations in Mimulus guttatus by comparing progeny from self-pollinations made within the same flower (autogamy) to progeny from self-pollinations made between stems on the same plant (geitonogamy). The effects of somatic mutations are evident from this comparison, as autogamy leads to homozygosity of a proportion of somatic mutations, but progeny from geitonogamy remain heterozygous for mutations unique to each stem. In two different experiments, we find consistent fitness effects of somatic mutations from individual stems. Surprisingly, several progeny groups from autogamous crosses displayed increases in fitness compared to progeny from geitonogamy crosses, likely indicating that beneficial somatic mutations occurred in some stems. These results support the hypothesis that somatic mutations accumulate during vegetative growth, but they are filtered by different forms of selection that occur throughout development, resulting in the culling of expressed deleterious mutations and the retention of beneficial mutations.
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11
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Dahiya R, Hu Q, Ly P. Mechanistic origins of diverse genome rearrangements in cancer. Semin Cell Dev Biol 2022; 123:100-109. [PMID: 33824062 PMCID: PMC8487437 DOI: 10.1016/j.semcdb.2021.03.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/08/2021] [Indexed: 12/14/2022]
Abstract
Cancer genomes frequently harbor structural chromosomal rearrangements that disrupt the linear DNA sequence order and copy number. To date, diverse classes of structural variants have been identified across multiple cancer types. These aberrations span a wide spectrum of complexity, ranging from simple translocations to intricate patterns of rearrangements involving multiple chromosomes. Although most somatic rearrangements are acquired gradually throughout tumorigenesis, recent interrogation of cancer genomes have uncovered novel categories of complex rearrangements that arises rapidly through a one-off catastrophic event, including chromothripsis and chromoplexy. Here we review the cellular and molecular mechanisms contributing to the formation of diverse structural rearrangement classes during cancer development. Genotoxic stress from a myriad of extrinsic and intrinsic sources can trigger DNA double-strand breaks that are subjected to DNA repair with potentially mutagenic outcomes. We also highlight how aberrant nuclear structures generated through mitotic cell division errors, such as rupture-prone micronuclei and chromosome bridges, can instigate massive DNA damage and the formation of complex rearrangements in cancer genomes.
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Affiliation(s)
- Rashmi Dahiya
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Qing Hu
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Peter Ly
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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12
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Balbo Pogliano C, Ceppi I, Giovannini S, Petroulaki V, Palmer N, Uliana F, Gatti M, Kasaciunaite K, Freire R, Seidel R, Altmeyer M, Cejka P, Matos J. The CDK1-TOPBP1-PLK1 axis regulates the Bloom's syndrome helicase BLM to suppress crossover recombination in somatic cells. SCIENCE ADVANCES 2022; 8:eabk0221. [PMID: 35119917 PMCID: PMC8816346 DOI: 10.1126/sciadv.abk0221] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 12/14/2021] [Indexed: 06/14/2023]
Abstract
Bloom's syndrome is caused by inactivation of the BLM helicase, which functions with TOP3A and RMI1-2 (BTR complex) to dissolve recombination intermediates and avoid somatic crossing-over. We show here that crossover avoidance by BTR further requires the activity of cyclin-dependent kinase-1 (CDK1), Polo-like kinase-1 (PLK1), and the DDR mediator protein TOPBP1, which act in the same pathway. Mechanistically, CDK1 phosphorylates BLM and TOPBP1 and promotes the interaction of both proteins with PLK1. This is amplified by the ability of TOPBP1 to facilitate phosphorylation of BLM at sites that stimulate both BLM-PLK1 and BLM-TOPBP1 binding, creating a positive feedback loop that drives rapid BLM phosphorylation at the G2-M transition. In vitro, BLM phosphorylation by CDK/PLK1/TOPBP1 stimulates the dissolution of topologically linked DNA intermediates by BLM-TOP3A. Thus, we propose that the CDK1-TOPBP1-PLK1 axis enhances BTR-mediated dissolution of recombination intermediates late in the cell cycle to suppress crossover recombination and curtail genomic instability.
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Affiliation(s)
| | - Ilaria Ceppi
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, Università della Svizzera italiana (USI), 6500 Bellinzona, Switzerland
| | - Sara Giovannini
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
| | - Vasiliki Petroulaki
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter, Vienna, Austria
| | - Nathan Palmer
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter, Vienna, Austria
| | - Federico Uliana
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
| | - Marco Gatti
- Department of Molecular Mechanisms of Disease, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Kristina Kasaciunaite
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, 04103 Leipzig, Germany
| | - Raimundo Freire
- Unidad de Investigación, Hospital Universitario de Canarias–FIISC, Ofra s/n, 38320 La Laguna, Tenerife, Spain
- Instituto de Tecnologías Biomédicas, Universidad de La Laguna, Tenerife, Spain
- Universidad Fernando Pessoa Canarias, 35450 Las Palmas de Gran Canaria, Spain
| | - Ralf Seidel
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, 04103 Leipzig, Germany
| | - Matthias Altmeyer
- Department of Molecular Mechanisms of Disease, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Petr Cejka
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, Università della Svizzera italiana (USI), 6500 Bellinzona, Switzerland
| | - Joao Matos
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter, Vienna, Austria
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13
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Ramsden DA, Carvajal-Garcia J, Gupta GP. Mechanism, cellular functions and cancer roles of polymerase-theta-mediated DNA end joining. Nat Rev Mol Cell Biol 2022; 23:125-140. [PMID: 34522048 DOI: 10.1038/s41580-021-00405-2] [Citation(s) in RCA: 87] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2021] [Indexed: 02/08/2023]
Abstract
Cellular pathways that repair chromosomal double-strand breaks (DSBs) have pivotal roles in cell growth, development and cancer. These DSB repair pathways have been the target of intensive investigation, but one pathway - alternative end joining (a-EJ) - has long resisted elucidation. In this Review, we highlight recent progress in our understanding of a-EJ, especially the assignment of DNA polymerase theta (Polθ) as the predominant mediator of a-EJ in most eukaryotes, and discuss a potential molecular mechanism by which Polθ-mediated end joining (TMEJ) occurs. We address possible cellular functions of TMEJ in resolving DSBs that are refractory to repair by non-homologous end joining (NHEJ), DSBs generated following replication fork collapse and DSBs present owing to stalling of repair by homologous recombination. We also discuss how these context-dependent cellular roles explain how TMEJ can both protect against and cause genome instability, and the emerging potential of Polθ as a therapeutic target in cancer.
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Affiliation(s)
- Dale A Ramsden
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Juan Carvajal-Garcia
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Gaorav P Gupta
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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14
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Hua LL, Casas C, Mikawa T. Mitotic Antipairing of Homologous Chromosomes. Results Probl Cell Differ 2022; 70:191-220. [PMID: 36348108 PMCID: PMC9731508 DOI: 10.1007/978-3-031-06573-6_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chromosome organization is highly dynamic and plays an essential role during cell function. It was recently found that pairs of the homologous chromosomes are continuously separated at mitosis and display a haploid (1n) chromosome set, or "antipairing," organization in human cells. Here, we provide an introduction to the current knowledge of homologous antipairing in humans and its implications in human disease.
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Affiliation(s)
- Lisa L. Hua
- Department of Biology, Sonoma State University, San Francisco
| | - Christian Casas
- Department of Biology, Sonoma State University, San Francisco
| | - Takashi Mikawa
- Department of Anatomy, Cardiovascular Research Institute, University of California, San Francisco,Corresponding author:
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15
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Yannuzzi I, Butler MA, Fernandez J, LaRocque JR. The Role of Drosophila CtIP in Homology-Directed Repair of DNA Double-Strand Breaks. Genes (Basel) 2021; 12:genes12091430. [PMID: 34573412 PMCID: PMC8468788 DOI: 10.3390/genes12091430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/05/2021] [Accepted: 09/14/2021] [Indexed: 11/16/2022] Open
Abstract
DNA double-strand breaks (DSBs) are a particularly genotoxic type of DNA damage that can result in chromosomal aberrations. Thus, proper repair of DSBs is essential to maintaining genome integrity. DSBs can be repaired by non-homologous end joining (NHEJ), where ends are processed before joining through ligation. Alternatively, DSBs can be repaired through homology-directed repair, either by homologous recombination (HR) or single-strand annealing (SSA). Both types of homology-directed repair are initiated by DNA end resection. In cultured human cells, the protein CtIP has been shown to play a role in DNA end resection through its interactions with CDK, BRCA1, DNA2, and the MRN complex. To elucidate the role of CtIP in a multicellular context, CRISPR/Cas9 genome editing was used to create a DmCtIPΔ allele in Drosophila melanogaster. Using the DSB repair reporter assay direct repeat of white (DR-white), a two-fold decrease in HR in DmCtIPΔ/Δ mutants was observed when compared to heterozygous controls. However, analysis of HR gene conversion tracts (GCTs) suggests DmCtIP plays a minimal role in determining GCT length. To assess the function of DmCtIP on both short (~550 bp) and long (~3.6 kb) end resection, modified homology-directed SSA repair assays were implemented, resulting in a two-fold decrease in SSA repair in both short and extensive end resection requirements in the DmCtIPΔ/Δ mutants compared to heterozygote controls. Through these analyses, we affirmed the importance of end resection on DSB repair pathway choice in multicellular systems, described the function of DmCtIP in short and extensive DNA end resection, and determined the impact of end resection on GCT length during HR.
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Affiliation(s)
- Ian Yannuzzi
- Biology Department, Georgetown College, Georgetown University, Washington, DC 20057, USA;
| | - Margaret A. Butler
- Georgetown University Medical Center, Department of Human Science, Georgetown University, Washington, DC 20057, USA; (M.A.B.); (J.F.)
| | - Joel Fernandez
- Georgetown University Medical Center, Department of Human Science, Georgetown University, Washington, DC 20057, USA; (M.A.B.); (J.F.)
| | - Jeannine R. LaRocque
- Georgetown University Medical Center, Department of Human Science, Georgetown University, Washington, DC 20057, USA; (M.A.B.); (J.F.)
- Correspondence:
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16
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Elbakry A, Löbrich M. Homologous Recombination Subpathways: A Tangle to Resolve. Front Genet 2021; 12:723847. [PMID: 34408777 PMCID: PMC8365153 DOI: 10.3389/fgene.2021.723847] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/12/2021] [Indexed: 11/26/2022] Open
Abstract
Homologous recombination (HR) is an essential pathway for DNA double-strand break (DSB) repair, which can proceed through various subpathways that have distinct elements and genetic outcomes. In this mini-review, we highlight the main features known about HR subpathways operating at DSBs in human cells and the factors regulating subpathway choice. We examine new developments that provide alternative models of subpathway usage in different cell types revise the nature of HR intermediates involved and reassess the frequency of repair outcomes. We discuss the impact of expanding our understanding of HR subpathways and how it can be clinically exploited.
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Affiliation(s)
- Amira Elbakry
- Radiation Biology and DNA Repair, Technical University of Darmstadt, Darmstadt, Germany
| | - Markus Löbrich
- Radiation Biology and DNA Repair, Technical University of Darmstadt, Darmstadt, Germany
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17
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Al-Zain AM, Symington LS. The dark side of homology-directed repair. DNA Repair (Amst) 2021; 106:103181. [PMID: 34311272 DOI: 10.1016/j.dnarep.2021.103181] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/16/2021] [Accepted: 07/16/2021] [Indexed: 10/20/2022]
Abstract
DNA double strand breaks (DSB) are cytotoxic lesions that can lead to genome rearrangements and genomic instability, which are hallmarks of cancer. The two main DSB repair pathways are non-homologous end joining and homologous recombination (HR). While HR is generally highly accurate, it has the potential for rearrangements that occur directly or through intermediates generated during the repair process. Whole genome sequencing of cancers has revealed numerous types of structural rearrangement signatures that are often indicative of repair mediated by sequence homology. However, it can be challenging to delineate repair mechanisms from sequence analysis of rearrangement end products from cancer genomes, or even model systems, because the same rearrangements can be generated by different pathways. Here, we review homology-directed repair pathways and their consequences. Exploring those pathways can lead to a greater understanding of rearrangements that occur in cancer cells.
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Affiliation(s)
- Amr M Al-Zain
- Program in Biological Sciences, Columbia University, New York, NY, 10027, United States; Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, United States
| | - Lorraine S Symington
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, United States; Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY, 10032, United States.
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18
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Prakash R, Sandoval T, Morati F, Zagelbaum JA, Lim PX, White T, Taylor B, Wang R, Desclos ECB, Sullivan MR, Rein HL, Bernstein KA, Krawczyk PM, Gautier J, Modesti M, Vanoli F, Jasin M. Distinct pathways of homologous recombination controlled by the SWS1-SWSAP1-SPIDR complex. Nat Commun 2021; 12:4255. [PMID: 34253720 PMCID: PMC8275761 DOI: 10.1038/s41467-021-24205-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 06/04/2021] [Indexed: 02/06/2023] Open
Abstract
Homology-directed repair (HDR), a critical DNA repair pathway in mammalian cells, is complex, leading to multiple outcomes with different impacts on genomic integrity. However, the factors that control these different outcomes are often not well understood. Here we show that SWS1-SWSAP1-SPIDR controls distinct types of HDR. Despite their requirement for stable assembly of RAD51 recombinase at DNA damage sites, these proteins are not essential for intra-chromosomal HDR, providing insight into why patients and mice with mutations are viable. However, SWS1-SWSAP1-SPIDR is critical for inter-homolog HDR, the first mitotic factor identified specifically for this function. Furthermore, SWS1-SWSAP1-SPIDR drives the high level of sister-chromatid exchange, promotes long-range loss of heterozygosity often involved with cancer initiation, and impels the poor growth of BLM helicase-deficient cells. The relevance of these genetic interactions is evident as SWSAP1 loss prolongs Blm-mutant embryo survival, suggesting a possible druggable target for the treatment of Bloom syndrome.
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Affiliation(s)
- Rohit Prakash
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
| | - Thomas Sandoval
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Florian Morati
- Cancer Research Center of Marseille, CNRS, Inserm, Institut Paoli-Calmettes, Aix-Marseille Université, Marseille, France
| | - Jennifer A Zagelbaum
- Department of Genetics and Development and Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Pei-Xin Lim
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Travis White
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Brett Taylor
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Raymond Wang
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Emilie C B Desclos
- Department of Medical Biology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Meghan R Sullivan
- Department of Microbiology and Molecular Genetics, UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Hayley L Rein
- Department of Microbiology and Molecular Genetics, UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Kara A Bernstein
- Department of Microbiology and Molecular Genetics, UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Przemek M Krawczyk
- Department of Medical Biology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Jean Gautier
- Department of Genetics and Development and Institute for Cancer Genetics, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Mauro Modesti
- Cancer Research Center of Marseille, CNRS, Inserm, Institut Paoli-Calmettes, Aix-Marseille Université, Marseille, France
| | - Fabio Vanoli
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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19
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Wilde JJ, Aida T, Del Rosario RCH, Kaiser T, Qi P, Wienisch M, Zhang Q, Colvin S, Feng G. Efficient embryonic homozygous gene conversion via RAD51-enhanced interhomolog repair. Cell 2021; 184:3267-3280.e18. [PMID: 34043941 PMCID: PMC8240950 DOI: 10.1016/j.cell.2021.04.035] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 03/03/2021] [Accepted: 04/19/2021] [Indexed: 12/20/2022]
Abstract
Searching for factors to improve knockin efficiency for therapeutic applications, biotechnology, and generation of non-human primate models of disease, we found that the strand exchange protein RAD51 can significantly increase Cas9-mediated homozygous knockin in mouse embryos through an interhomolog repair (IHR) mechanism. IHR is a hallmark of meiosis but only occurs at low frequencies in somatic cells, and its occurrence in zygotes is controversial. Using multiple approaches, we provide evidence for an endogenous IHR mechanism in the early embryo that can be enhanced by RAD51. This process can be harnessed to generate homozygotes from wild-type zygotes using exogenous donors and to convert heterozygous alleles into homozygous alleles without exogenous templates. Furthermore, we identify additional IHR-promoting factors and describe features of IHR events. Together, our findings show conclusive evidence for IHR in mouse embryos and describe an efficient method for enhanced gene conversion.
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Affiliation(s)
- Jonathan J Wilde
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
| | - Tomomi Aida
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Ricardo C H Del Rosario
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Tobias Kaiser
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Peimin Qi
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Martin Wienisch
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Qiangge Zhang
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Steven Colvin
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Guoping Feng
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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20
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Mendez-Dorantes C, Tsai LJ, Jahanshir E, Lopezcolorado FW, Stark JM. BLM has Contrary Effects on Repeat-Mediated Deletions, based on the Distance of DNA DSBs to a Repeat and Repeat Divergence. Cell Rep 2021; 30:1342-1357.e4. [PMID: 32023454 PMCID: PMC7085117 DOI: 10.1016/j.celrep.2020.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/08/2019] [Accepted: 12/31/2019] [Indexed: 12/30/2022] Open
Abstract
Repeat-mediated deletions (RMDs) often involve repetitive elements (e.g., short interspersed elements) with sequence divergence that is separated by several kilobase pairs (kbps). We have examined RMDs induced by DNA double-strand breaks (DSBs) under varying conditions of repeat sequence divergence (identical versus 1% and 3% divergent) and DSB/repeat distance (16 bp–28.4 kbp). We find that the BLM helicase promotes RMDs with long DSB/repeat distances (e.g., 28.4 kbp), which is consistent with a role in extensive DSB end resection, because the resection nucleases EXO1 and DNA2 affect RMDs similarly to BLM. In contrast, BLM suppresses RMDs with sequence divergence and intermediate (e.g., 3.3 kbp) DSB/repeat distances, which supports a role in heteroduplex rejection. The role of BLM in heteroduplex rejection is not epistatic with MSH2 and is independent of the annealing factor RAD52. Accordingly, the role of BLM on RMDs is substantially affected by DSB/repeat distance and repeat sequence divergence. Mendez-Dorantes et al. identify the BLM helicase as a key regulator of repeat-mediated deletions (RMDs). BLM, EXO1, and DNA2 mediate RMDs with remarkably long DNA break/repeat distances. BLM suppresses RMDs with sequence divergence that is optimal with a long non-homologous tail and is independent of MSH2 and RAD52.
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Affiliation(s)
- Carlos Mendez-Dorantes
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | - L Jillianne Tsai
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | - Eva Jahanshir
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | | | - Jeremy M Stark
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.
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21
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Single-Strand Annealing in Cancer. Int J Mol Sci 2021; 22:ijms22042167. [PMID: 33671579 PMCID: PMC7926775 DOI: 10.3390/ijms22042167] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 12/23/2022] Open
Abstract
DNA double-strand breaks (DSBs) are among the most serious forms of DNA damage. In humans, DSBs are repaired mainly by non-homologous end joining (NHEJ) and homologous recombination repair (HRR). Single-strand annealing (SSA), another DSB repair system, uses homologous repeats flanking a DSB to join DNA ends and is error-prone, as it removes DNA fragments between repeats along with one repeat. Many DNA deletions observed in cancer cells display homology at breakpoint junctions, suggesting the involvement of SSA. When multiple DSBs occur in different chromosomes, SSA may result in chromosomal translocations, essential in the pathogenesis of many cancers. Inhibition of RAD52 (RAD52 Homolog, DNA Repair Protein), the master regulator of SSA, results in decreased proliferation of BRCA1/2 (BRCA1/2 DNA Repair Associated)-deficient cells, occurring in many hereditary breast and ovarian cancer cases. Therefore, RAD52 may be targeted in synthetic lethality in cancer. SSA may modulate the response to platinum-based anticancer drugs and radiation. SSA may increase the efficacy of the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas9 (CRISPR associated 9) genome editing and reduce its off-target effect. Several basic problems associated with SSA, including its evolutionary role, interplay with HRR and NHEJ and should be addressed to better understand its role in cancer pathogenesis and therapy.
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22
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Shorrocks AMK, Jones SE, Tsukada K, Morrow CA, Belblidia Z, Shen J, Vendrell I, Fischer R, Kessler BM, Blackford AN. The Bloom syndrome complex senses RPA-coated single-stranded DNA to restart stalled replication forks. Nat Commun 2021; 12:585. [PMID: 33500419 PMCID: PMC7838300 DOI: 10.1038/s41467-020-20818-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 12/22/2020] [Indexed: 01/30/2023] Open
Abstract
The Bloom syndrome helicase BLM interacts with topoisomerase IIIα (TOP3A), RMI1 and RMI2 to form the BTR complex, which dissolves double Holliday junctions to produce non-crossover homologous recombination (HR) products. BLM also promotes DNA-end resection, restart of stalled replication forks, and processing of ultra-fine DNA bridges in mitosis. How these activities of the BTR complex are regulated in cells is still unclear. Here, we identify multiple conserved motifs within the BTR complex that interact cooperatively with the single-stranded DNA (ssDNA)-binding protein RPA. Furthermore, we demonstrate that RPA-binding is required for stable BLM recruitment to sites of DNA replication stress and for fork restart, but not for its roles in HR or mitosis. Our findings suggest a model in which the BTR complex contains the intrinsic ability to sense levels of RPA-ssDNA at replication forks, which controls BLM recruitment and activation in response to replication stress.
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Affiliation(s)
- Ann-Marie K Shorrocks
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Samuel E Jones
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Kaima Tsukada
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
- Department of Transdisciplinary Science and Engineering, School of Environment and Society, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Carl A Morrow
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Zoulikha Belblidia
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Johanna Shen
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, 06520, USA
| | - Iolanda Vendrell
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
- Target Discovery Institute, Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | - Roman Fischer
- Target Discovery Institute, Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | - Benedikt M Kessler
- Target Discovery Institute, Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK
| | - Andrew N Blackford
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK.
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK.
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Abstract
Homologous recombination is a critical mechanism for the repair of DNA double-strand breaks (DSBs). It occurs predominantly between identical sister chromatids and at lower frequency can also occur between homologs. Interhomolog homologous recombination (IH-HR) has the potential lead to substantial loss of genetic information, i.e., loss of heterozygosity (LOH), when it is accompanied by crossing over. In this chapter, we describe a system to study IH-HR induced by a defined DSB in mouse embryonic stem cells derived from F1 hybrid mice. This system is based on the placement of mutant selectable marker genes, one of which contains an I-SceI endonuclease cleavage site, on the two homologs such that repair of the I-SceI-generated DSB from the homolog leads to drug resistance. Loss of heterozygosity arising during IH-HR is analyzed using a PCR-based approach. Finally, we present a strategy to analyze the role of BLM helicase in this system.
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24
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Komari CJ, Guttman AO, Carr SR, Trachtenberg TL, Orloff EA, Haas AV, Patrick AR, Chowdhary S, Waldman BC, Waldman AS. Alteration of genetic recombination and double-strand break repair in human cells by progerin expression. DNA Repair (Amst) 2020; 96:102975. [PMID: 33010688 DOI: 10.1016/j.dnarep.2020.102975] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/21/2020] [Accepted: 09/04/2020] [Indexed: 01/04/2023]
Abstract
Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare autosomal, dominant genetic condition characterized by many features of accelerated aging. On average, children with HGPS live to about fourteen years of age. The syndrome is commonly caused by a point mutation in the LMNA gene which normally codes for lamin A and its splice variant lamin C, components of the nuclear lamina. The LMNA mutation alters splicing, leading to production of a truncated, farnesylated form of lamin A referred to as "progerin." Progerin is also expressed at very low levels in healthy individuals and appears to play a role in normal aging. HGPS is associated with an accumulation of genomic DNA double-strand breaks (DSBs), suggesting corruption of DNA repair. In this work, we investigated the influence of progerin expression on DSB repair in the human genome at the nucleotide level. We used a model system that involves a reporter DNA substrate inserted in the genome of cultured human cells. A DSB could be induced within the substrate through exogenous expression of endonuclease I-SceI, and DSB repair events occurring via either homologous recombination (HR) or nonhomologous end-joining (NHEJ) were recoverable. Additionally, spontaneous HR events were recoverable in the absence of artificial DSB induction. We compared DSB repair and spontaneous HR in cells overexpressing progerin versus cells expressing no progerin. We report that overexpression of progerin correlated with an increase in DSB repair via NHEJ relative to HR, as well as an increased fraction of HR events occurring via gene conversion. Progerin also engendered an apparent increase in spontaneous HR events, with a highly significant shift toward gene conversion events, and an increase in DNA amplification events. Such influences of progerin on DNA transactions may impact genome stability and contribute to aging.
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Affiliation(s)
- Celina J Komari
- Department of Public Health, University of South Carolina, Columbia, SC 29208, USA
| | - Anne O Guttman
- Department of Exercise Science, University of South Carolina, Columbia, SC 29208, USA
| | - Shelby R Carr
- Department of Exercise Science, University of South Carolina, Columbia, SC 29208, USA
| | - Taylor L Trachtenberg
- Department of Exercise Science, University of South Carolina, Columbia, SC 29208, USA
| | - Elise A Orloff
- Department of Exercise Science, University of South Carolina, Columbia, SC 29208, USA
| | - Ashley V Haas
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Andrew R Patrick
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Sona Chowdhary
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Barbara C Waldman
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Alan S Waldman
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.
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25
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Davis L, Khoo KJ, Zhang Y, Maizels N. POLQ suppresses interhomolog recombination and loss of heterozygosity at targeted DNA breaks. Proc Natl Acad Sci U S A 2020; 117:22900-22909. [PMID: 32873648 PMCID: PMC7502765 DOI: 10.1073/pnas.2008073117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Interhomolog recombination (IHR) occurs spontaneously in somatic human cells at frequencies that are low but sufficient to ameliorate some genetic diseases caused by heterozygous mutations or autosomal dominant mutations. Here we demonstrate that DNA nicks or double-strand breaks (DSBs) targeted by CRISPR-Cas9 to both homologs can stimulate IHR and associated copy-neutral loss of heterozygosity (cnLOH) in human cells. The frequency of IHR is 10-fold lower at nicks than at DSBs, but cnLOH is evident in a greater fraction of recombinants. IHR at DSBs occurs predominantly via reciprocal end joining. At DSBs, depletion of POLQ caused a dramatic increase in IHR and in the fraction of recombinants exhibiting cnLOH, suggesting that POLQ promotes end joining in cis, which limits breaks available for recombination in trans These results define conditions that may produce cnLOH as a mutagenic signature in cancer and may, conversely, promote therapeutic correction of both compound heterozygous and dominant negative mutations associated with genetic disease.
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Affiliation(s)
- Luther Davis
- Department of Immunology, University of Washington School of Medicine, Seattle, WA 98195
| | - Kevin J Khoo
- Department of Immunology, University of Washington School of Medicine, Seattle, WA 98195
- Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195
| | - Yinbo Zhang
- Department of Immunology, University of Washington School of Medicine, Seattle, WA 98195
| | - Nancy Maizels
- Department of Immunology, University of Washington School of Medicine, Seattle, WA 98195;
- Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195
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26
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C-Terminal HA Tags Compromise Function and Exacerbate Phenotypes of Saccharomyces cerevisiae Bloom's Helicase Homolog Sgs1 SUMOylation-Associated Mutants. G3-GENES GENOMES GENETICS 2020; 10:2811-2818. [PMID: 32540865 PMCID: PMC7407464 DOI: 10.1534/g3.120.401324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The Sgs1 helicase and Top3-Rmi1 decatenase form a complex that affects homologous recombination outcomes during the mitotic cell cycle and during meiosis. Previous studies have reported that Sgs1-Top3-Rmi1 function is regulated by SUMOylation that is catalyzed by the Smc5-Smc6-Mms21 complex. These studies used strains in which SGS1 was C-terminally tagged with three or six copies of a human influenza hemagglutinin-derived epitope tag (3HA and 6HA). They identified SGS1 mutants that affect its SUMOylation, which we will refer to as SGS1 SUMO-site mutants. In previous work, these mutants showed phenotypes consistent with substantial loss of Sgs1-Top3-Rmi1 function during the mitotic cell cycle. We find that the reported phenotypes are largely due to the presence of the HA epitope tags. Untagged SGS1 SUMO-site mutants show either wild-type or weak hypomorphic phenotypes, depending on the assay. These phenotypes are exacerbated by both 6HA and 3HA epitope tags in two different S. cerevisiae strain backgrounds. Importantly, a C-terminal 6HA tag confers strong hypomorphic or null phenotypes on an otherwise wild-type Sgs1 protein. Taken together, these results suggest that the HA epitope tags used in previous studies seriously compromise Sgs1 function. Furthermore, they raise the possibilities either that sufficient SUMOylation of the Sgs1-Top3-Rmi1 complex might still occur in the SUMO-site mutants isolated, or that Smc5-Smc6-Mms21-mediated SUMOylation plays a minor role in the regulation of Sgs1-Top3-Rmi1 during recombination.
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27
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Palmer N, Kaldis P. Less-well known functions of cyclin/CDK complexes. Semin Cell Dev Biol 2020; 107:54-62. [PMID: 32386818 DOI: 10.1016/j.semcdb.2020.04.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 12/31/2022]
Abstract
Cyclin-dependent kinases (CDKs) are activated by cyclins, which play important roles in dictating the actions of CDK/cyclin complexes. Cyclin binding influences the substrate specificity of these complexes in addition to their susceptibility to inhibition or degradation. CDK/cyclin complexes are best known to promote cell cycle progression in the mitotic cell cycle but are also crucial for important cellular processes not strictly associated with cellular division. This chapter primarily explores the understudied topic of CDK/cyclin complex functionality during the DNA damage response. We detail how CDK/cyclin complexes perform dual roles both as targets of DNA damage checkpoint signaling as well as effectors of DNA repair. Additionally, we discuss the potential CDK-independent roles of cyclins in these processes and the impact of such roles in human diseases such as cancer. Our goal is to place the spotlight on these important functions of cyclins either acting as independent entities or within CDK/cyclin complexes which have attracted less attention in the past. We consider that this will be important for a more complete understanding of the intricate functions of cell cycle proteins in the DNA damage response.
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Affiliation(s)
- Nathan Palmer
- Institute of Molecular and Cell Biology (IMCB), A⁎STAR (Agency for Science, Technology and Research), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore; National University of Singapore (NUS), Department of Biochemistry, Singapore, 117597, Republic of Singapore
| | - Philipp Kaldis
- Institute of Molecular and Cell Biology (IMCB), A⁎STAR (Agency for Science, Technology and Research), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore; National University of Singapore (NUS), Department of Biochemistry, Singapore, 117597, Republic of Singapore; Department of Clinical Sciences, Lund University, Clinical Research Centre (CRC), Box 50332, SE-202 13, Malmö, Sweden.
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28
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Huselid E, Bunting SF. The Regulation of Homologous Recombination by Helicases. Genes (Basel) 2020; 11:genes11050498. [PMID: 32369918 PMCID: PMC7290689 DOI: 10.3390/genes11050498] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/29/2020] [Accepted: 04/29/2020] [Indexed: 11/16/2022] Open
Abstract
Homologous recombination is essential for DNA repair, replication and the exchange of genetic material between parental chromosomes during meiosis. The stages of recombination involve complex reorganization of DNA structures, and the successful completion of these steps is dependent on the activities of multiple helicase enzymes. Helicases of many different families coordinate the processing of broken DNA ends, and the subsequent formation and disassembly of the recombination intermediates that are necessary for template-based DNA repair. Loss of recombination-associated helicase activities can therefore lead to genomic instability, cell death and increased risk of tumor formation. The efficiency of recombination is also influenced by the ‘anti-recombinase’ effect of certain helicases, which can direct DNA breaks toward repair by other pathways. Other helicases regulate the crossover versus non-crossover outcomes of repair. The use of recombination is increased when replication forks and the transcription machinery collide, or encounter lesions in the DNA template. Successful completion of recombination in these situations is also regulated by helicases, allowing normal cell growth, and the maintenance of genomic integrity.
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29
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Griffin WC, Trakselis MA. The MCM8/9 complex: A recent recruit to the roster of helicases involved in genome maintenance. DNA Repair (Amst) 2019; 76:1-10. [PMID: 30743181 DOI: 10.1016/j.dnarep.2019.02.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/03/2019] [Indexed: 12/11/2022]
Abstract
There are several DNA helicases involved in seemingly overlapping aspects of homologous and homoeologous recombination. Mutations of many of these helicases are directly implicated in genetic diseases including cancer, rapid aging, and infertility. MCM8/9 are recent additions to the catalog of helicases involved in recombination, and so far, the evidence is sparse, making assignment of function difficult. Mutations in MCM8/9 correlate principally with primary ovarian failure/insufficiency (POF/POI) and infertility indicating a meiotic defect. However, they also act when replication forks collapse/break shuttling products into mitotic recombination and several mutations are found in various somatic cancers. This review puts MCM8/9 in context with other replication and recombination helicases to narrow down its genomic maintenance role. We discuss the known structure/function relationship, the mutational spectrum, and dissect the available cellular and organismal data to better define its role in recombination.
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Affiliation(s)
- Wezley C Griffin
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas, 76798, USA
| | - Michael A Trakselis
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas, 76798, USA.
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30
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Homologous recombination occurs frequently at innate GT microsatellites in normal somatic and germ cells in vivo. BMC Genomics 2018; 19:359. [PMID: 29751739 PMCID: PMC5948810 DOI: 10.1186/s12864-018-4758-y] [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: 02/09/2017] [Accepted: 05/03/2018] [Indexed: 12/30/2022] Open
Abstract
Background In somatic cells, homologous recombination (HR) is a rare event caused by eventual DNA double-strand breaks (DSBs). In contrast, germ cells show high frequency of HR caused by programmed DSBs. Microsatellites are prone to DSBs during genome replication and, thereby, capable of promoting HR. It remains unclear whether HR occurs frequently at microsatellites both in normal somatic cells and germ cells in a similar manner. Results By examining the linkage pattern of multiple paternal and maternal markers flanking innate GT microsatellites, we measured HR at the GT microsatellites in various somatic cells and germ cells in a goldfish intraspecific heterozygote. During embryogenesis, the HR products accumulate gradually with the increase of the number of cell divisions. The frequency of HR at the GT microsatellites in advanced embryos, adult tissues and germ cells is surprisingly high. The type of exchanges between the homologous chromosomes is similar in normal advanced embryos and germ cells. Furthermore, a long GT microsatellite is more active than a short one in promoting HR in both somatic and germ cells. Conclusions HR occurs frequently at innate GT microsatellites in normal somatic cells and germ cells in a similar manner. Electronic supplementary material The online version of this article (10.1186/s12864-018-4758-y) contains supplementary material, which is available to authorized users.
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31
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van Wietmarschen N, Merzouk S, Halsema N, Spierings DCJ, Guryev V, Lansdorp PM. BLM helicase suppresses recombination at G-quadruplex motifs in transcribed genes. Nat Commun 2018; 9:271. [PMID: 29348659 PMCID: PMC5773480 DOI: 10.1038/s41467-017-02760-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 12/21/2017] [Indexed: 11/16/2022] Open
Abstract
Bloom syndrome is a cancer predisposition disorder caused by mutations in the BLM helicase gene. Cells from persons with Bloom syndrome exhibit striking genomic instability characterized by excessive sister chromatid exchange events (SCEs). We applied single-cell DNA template strand sequencing (Strand-seq) to map the genomic locations of SCEs. Our results show that in the absence of BLM, SCEs in human and murine cells do not occur randomly throughout the genome but are strikingly enriched at coding regions, specifically at sites of guanine quadruplex (G4) motifs in transcribed genes. We propose that BLM protects against genome instability by suppressing recombination at sites of G4 structures, particularly in transcribed regions of the genome. Bloom syndrome is characterized by high levels of sister chromatid exchanges (SCEs). Here, the authors use single-cell DNA template strand-sequencing to map SCEs in patient cells, and propose that the BLM helicase protects the genome against unwanted recombination at sites of G-quadruplex structures.
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Affiliation(s)
- Niek van Wietmarschen
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Sarra Merzouk
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Nancy Halsema
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Diana C J Spierings
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Victor Guryev
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Peter M Lansdorp
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands. .,Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, V5Z 1L3, Canada. .,Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
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32
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Brunet E, Jasin M. Induction of Chromosomal Translocations with CRISPR-Cas9 and Other Nucleases: Understanding the Repair Mechanisms That Give Rise to Translocations. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1044:15-25. [PMID: 29956288 DOI: 10.1007/978-981-13-0593-1_2] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Chromosomal translocations are associated with several tumor types, including hematopoietic malignancies, sarcomas, and solid tumors of epithelial origin, due to their activation of a proto-oncogene or generation of a novel fusion protein with oncogenic potential. In many cases, the availability of suitable human models has been lacking because of the difficulty in recapitulating precise expression of the fusion protein or other reasons. Further, understanding how translocations form mechanistically has been a goal, as it may suggest ways to prevent their occurrence. Chromosomal translocations arise when DNA ends from double-strand breaks (DSBs) on two heterologous chromosomes are improperly joined. This review provides a summary of DSB repair mechanisms and their contribution to translocation formation, the various programmable nuclease platforms that have been used to generate translocations, and the successes that have been achieved in this area.
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Affiliation(s)
- Erika Brunet
- Genome Dynamics in the Immune System Laboratory, Institut Imagine, INSERM UMR 1163, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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33
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Bloom's syndrome: Why not premature aging?: A comparison of the BLM and WRN helicases. Ageing Res Rev 2017; 33:36-51. [PMID: 27238185 DOI: 10.1016/j.arr.2016.05.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 05/17/2016] [Accepted: 05/19/2016] [Indexed: 01/19/2023]
Abstract
Genomic instability is a hallmark of cancer and aging. Premature aging (progeroid) syndromes are often caused by mutations in genes whose function is to ensure genomic integrity. The RecQ family of DNA helicases is highly conserved and plays crucial roles as genome caretakers. In humans, mutations in three RecQ genes - BLM, WRN, and RECQL4 - give rise to Bloom's syndrome (BS), Werner syndrome (WS), and Rothmund-Thomson syndrome (RTS), respectively. WS is a prototypic premature aging disorder; however, the clinical features present in BS and RTS do not indicate accelerated aging. The BLM helicase has pivotal functions at the crossroads of DNA replication, recombination, and repair. BS cells exhibit a characteristic form of genomic instability that includes excessive homologous recombination. The excessive homologous recombination drives the development in BS of the many types of cancers that affect persons in the normal population. Replication delay and slower cell turnover rates have been proposed to explain many features of BS, such as short stature. More recently, aberrant transcriptional regulation of growth and survival genes has been proposed as a hypothesis to explain features of BS.
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34
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Hudson DF, Amor DJ, Boys A, Butler K, Williams L, Zhang T, Kalitsis P. Loss of RMI2 Increases Genome Instability and Causes a Bloom-Like Syndrome. PLoS Genet 2016; 12:e1006483. [PMID: 27977684 PMCID: PMC5157948 DOI: 10.1371/journal.pgen.1006483] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 11/15/2016] [Indexed: 12/03/2022] Open
Abstract
Bloom syndrome is a recessive human genetic disorder with features of genome instability, growth deficiency and predisposition to cancer. The only known causative gene is the BLM helicase that is a member of a protein complex along with topoisomerase III alpha, RMI1 and 2, which maintains replication fork stability and dissolves double Holliday junctions to prevent genome instability. Here we report the identification of a second gene, RMI2, that is deleted in affected siblings with Bloom-like features. Cells from homozygous individuals exhibit elevated rates of sister chromatid exchange, anaphase DNA bridges and micronuclei. Similar genome and chromosome instability phenotypes are observed in independently derived RMI2 knockout cells. In both patient and knockout cell lines reduced localisation of BLM to ultra fine DNA bridges and FANCD2 at foci linking bridges are observed. Overall, loss of RMI2 produces a partially active BLM complex with mild features of Bloom syndrome. Cells contain specific protein complexes that are needed to correct errors during the replication and segregation of DNA. Impairment in the activity of these proteins can be detrimental to the viability of the cell and organism development. Bloom syndrome is an example of a genome instability disorder where cells cannot efficiently untangle DNA after replication. The only gene that is known to cause Bloom syndrome is the BLM helicase. In this article, we describe two affected individuals with Bloom-like features with a homozygous deletion of the RMI2 gene. The RMI2 protein has previously been shown to form a complex with BLM, topoisomerase III alpha and RMI1. Deletion of RMI2 in patient and unrelated cell lines show hyper-recombination and chromosome entanglements during cell division. Furthermore, we show that the BLM and FANCD2 proteins are diminished in the binding of DNA bridges that need to be dissolved during the late stages of cell division. Therefore, loss of RMI2 produces a milder Bloom phenotype and impairs the full activity of the BLM complex.
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Affiliation(s)
- Damien F. Hudson
- Murdoch Childrens Research Institute, Royal Children’s Hospital, Melbourne, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
- * E-mail: (PK); (DFH)
| | - David J. Amor
- Murdoch Childrens Research Institute, Royal Children’s Hospital, Melbourne, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Amber Boys
- Cytogenetics Laboratory, Victorian Clinical Genetics Services, Murdoch Childrens Research Institute, Royal Children’s Hospital, Melbourne, Parkville, Victoria, Australia
| | - Kathy Butler
- Cytogenetics Laboratory, Victorian Clinical Genetics Services, Murdoch Childrens Research Institute, Royal Children’s Hospital, Melbourne, Parkville, Victoria, Australia
| | - Lorna Williams
- Cytogenetics Laboratory, Victorian Clinical Genetics Services, Murdoch Childrens Research Institute, Royal Children’s Hospital, Melbourne, Parkville, Victoria, Australia
| | - Tao Zhang
- Murdoch Childrens Research Institute, Royal Children’s Hospital, Melbourne, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Paul Kalitsis
- Murdoch Childrens Research Institute, Royal Children’s Hospital, Melbourne, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
- * E-mail: (PK); (DFH)
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35
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Mutator Phenotype and DNA Double-Strand Break Repair in BLM Helicase-Deficient Human Cells. Mol Cell Biol 2016; 36:2877-2889. [PMID: 27601585 PMCID: PMC5108877 DOI: 10.1128/mcb.00443-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 08/25/2016] [Indexed: 12/16/2022] Open
Abstract
Bloom syndrome (BS), an autosomal recessive disorder of the BLM gene, predisposes sufferers to various cancers. To investigate the mutator phenotype and genetic consequences of DNA double-strand breaks (DSBs) in BS cells, we developed BLM helicase-deficient human cells by disrupting the BLM gene. Cells with a loss of heterozygosity (LOH) due to homologous recombination (HR) or nonhomologous end joining (NHEJ) can be restored with or without site-directed DSB induction. BLM cells exhibited a high frequency of spontaneous interallelic HR with crossover, but noncrossover events with long-tract gene conversions also occurred. Despite the highly interallelic HR events, BLM cells predominantly produced hemizygous LOH by spontaneous deletion. These phenotypes manifested during repair of DSBs. Both NHEJ and HR appropriately repaired DSBs in BLM cells, resulting in hemizygous and homozygous LOHs, respectively. However, the magnitude of the LOH was exacerbated in BLM cells, as evidenced by large deletions and long-tract gene conversions with crossover. BLM helicase suppresses the elongation of branch migration and crossover of double Holliday junctions (HJs) during HR repair, and a deficiency in this enzyme causes collapse, abnormal elongation, and/or preferable resolution to crossover of double HJs, resulting in a large-scale LOH. This mechanism underlies the predisposition for cancer in BS.
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Bhargava R, Onyango DO, Stark JM. Regulation of Single-Strand Annealing and its Role in Genome Maintenance. Trends Genet 2016; 32:566-575. [PMID: 27450436 DOI: 10.1016/j.tig.2016.06.007] [Citation(s) in RCA: 311] [Impact Index Per Article: 38.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 06/28/2016] [Accepted: 06/29/2016] [Indexed: 01/19/2023]
Abstract
Single-strand annealing (SSA) is a DNA double-strand break (DSB) repair pathway that uses homologous repeats to bridge DSB ends. SSA involving repeats that flank a single DSB causes a deletion rearrangement between the repeats, and hence is relatively mutagenic. Nevertheless, this pathway is conserved, in that SSA events have been found in several organisms. In this review, we describe the mechanism of SSA and its regulation, including the cellular conditions that may favor SSA versus other DSB repair events. We will also evaluate the potential contribution of SSA to cancer-associated genome rearrangements, and to DSB-induced gene targeting.
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Affiliation(s)
- Ragini Bhargava
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, CA, USA; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA, USA
| | - David O Onyango
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, CA, USA
| | - Jeremy M Stark
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, CA, USA; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA, USA.
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Ito S, Murphy CG, Doubrovina E, Jasin M, Moynahan ME. PARP Inhibitors in Clinical Use Induce Genomic Instability in Normal Human Cells. PLoS One 2016; 11:e0159341. [PMID: 27428646 PMCID: PMC4948780 DOI: 10.1371/journal.pone.0159341] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 06/30/2016] [Indexed: 11/18/2022] Open
Abstract
Poly(ADP-ribose) polymerases (PARPs) are the first proteins involved in cellular DNA repair pathways to be targeted by specific inhibitors for clinical benefit. Tumors harboring genetic defects in homologous recombination (HR), a DNA double-strand break (DSB) repair pathway, are hypersensitive to PARP inhibitors (PARPi). Early phase clinical trials with PARPi have been promising in patients with advanced BRCA1 or BRCA2-associated breast, ovary and prostate cancer and have led to limited approval for treatment of BRCA-deficient ovary cancer. Unlike HR-defective cells, HR-proficient cells manifest very low cytotoxicity when exposed to PARPi, although they mount a DNA damage response. However, the genotoxic effects on normal human cells when agents including PARPi disturb proficient cellular repair processes have not been substantially investigated. We quantified cytogenetic alterations of human cells, including primary lymphoid cells and non-tumorigenic and tumorigenic epithelial cell lines, exposed to PARPi at clinically relevant doses by both sister chromatid exchange (SCE) assays and chromosome spreading. As expected, both olaparib and veliparib effectively inhibited poly-ADP-ribosylation (PAR), and caused marked hypersensitivity in HR-deficient cells. Significant dose-dependent increases in SCEs were observed in normal and non-tumorigenic cells with minimal residual PAR activity. Clinically relevant doses of the FDA-approved olaparib led to a marked increase of SCEs (5-10-fold) and chromatid aberrations (2-6-fold). Furthermore, olaparib potentiated SCE induction by cisplatin in normal human cells. Our data have important implications for therapies with regard to sustained genotoxicity to normal cells. Genomic instability arising from PARPi warrants consideration, especially if these agents will be used in people with early stage cancers, in prevention strategies or for non-oncologic indications.
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Affiliation(s)
- Shuhei Ito
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
- Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan
| | - Conleth G. Murphy
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
| | - Ekaterina Doubrovina
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
| | - Mary Ellen Moynahan
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
- * E-mail:
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Mechanistic insight into cadmium-induced inactivation of the Bloom protein. Sci Rep 2016; 6:26225. [PMID: 27194376 PMCID: PMC4872126 DOI: 10.1038/srep26225] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 04/25/2016] [Indexed: 11/08/2022] Open
Abstract
Cadmium is a toxic metal that inactivates DNA-repair proteins via multiple mechanisms, including zinc substitution. In this study, we investigated the effect of Cd(2+) on the Bloom protein (BLM), a DNA-repair helicase carrying a zinc-binding domain (ZBD) and playing a critical role to ensure genomic stability. One characteristics of BLM-deficient cells is the elevated rate of sister chromatid exchanges, a phenomenon that is also induced by Cd(2+). Here, we show that Cd(2+) strongly inhibits both ATPase and helicase activities of BLM. Cd(2+) primarily prevents BLM-DNA interaction via its binding to sulfhydryl groups of solvent-exposed cysteine residues and, concomitantly, promotes the formation of large BLM multimers/aggregates. In contrast to previously described Cd(2+) effects on other zinc-containing DNA-repair proteins, the ZBD appears to play a minor role in the Cd(2+)-mediated inhibition. While the Cd(2+)-dependent formation of inactive multimers and the defect of DNA-binding were fully reversible upon addition of EDTA, the inhibition of the DNA unwinding activity was not counteracted by EDTA, indicating another mechanism of inhibition by Cd(2+) relative to the targeting of a catalytic residue. Altogether, our results provide new clues for understanding the mechanism behind the ZBD-independent inactivation of BLM by Cd(2+) leading to accumulation of DNA double-strand breaks.
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Wang Y, Li S, Smith K, Waldman BC, Waldman AS. Intrachromosomal recombination between highly diverged DNA sequences is enabled in human cells deficient in Bloom helicase. DNA Repair (Amst) 2016; 41:73-84. [PMID: 27100209 DOI: 10.1016/j.dnarep.2016.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/21/2016] [Indexed: 11/30/2022]
Abstract
Mutation of Bloom helicase (BLM) causes Bloom syndrome (BS), a rare human genetic disorder associated with genome instability, elevation of sister chromatid exchanges, and predisposition to cancer. Deficiency in BLM homologs in Drosophila and yeast brings about significantly increased rates of recombination between imperfectly matched sequences ("homeologous recombination," or HeR). To assess whether BLM deficiency provokes an increase in HeR in human cells, we transfected an HeR substrate into a BLM-null cell line derived from a BS patient. The substrate contained a thymidine kinase (tk)-neo fusion gene disrupted by the recognition site for endonuclease I-SceI, as well as a functional tk gene to serve as a potential recombination partner for the tk-neo gene. The two tk sequences on the substrate displayed 19% divergence. A double-strand break was introduced by expression of I-SceI and repair events were recovered by selection for G418-resistant clones. Among 181 events recovered, 30 were accomplished via HeR with the balance accomplished by nonhomologous end-joining. The frequency of HeR events in the BS cells was elevated significantly compared to that seen in normal human fibroblasts or in BS cells complemented for BLM expression. We conclude that BLM deficiency enables HeR in human cells.
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Affiliation(s)
- Yibin Wang
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Shen Li
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Krissy Smith
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | | | - Alan S Waldman
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.
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Poot M, Haaf T. Mechanisms of Origin, Phenotypic Effects and Diagnostic Implications of Complex Chromosome Rearrangements. Mol Syndromol 2015; 6:110-34. [PMID: 26732513 DOI: 10.1159/000438812] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/23/2015] [Indexed: 01/08/2023] Open
Abstract
Complex chromosome rearrangements (CCRs) are currently defined as structural genome variations that involve more than 2 chromosome breaks and result in exchanges of chromosomal segments. They are thought to be extremely rare, but their detection rate is rising because of improvements in molecular cytogenetic technology. Their population frequency is also underestimated, since many CCRs may not elicit a phenotypic effect. CCRs may be the result of fork stalling and template switching, microhomology-mediated break-induced repair, breakage-fusion-bridge cycles, or chromothripsis. Patients with chromosomal instability syndromes show elevated rates of CCRs due to impaired DNA double-strand break responses during meiosis. Therefore, the putative functions of the proteins encoded by ATM, BLM, WRN, ATR, MRE11, NBS1, and RAD51 in preventing CCRs are discussed. CCRs may exert a pathogenic effect by either (1) gene dosage-dependent mechanisms, e.g. haploinsufficiency, (2) mechanisms based on disruption of the genomic architecture, such that genes, parts of genes or regulatory elements are truncated, fused or relocated and thus their interactions disturbed - these mechanisms will predominantly affect gene expression - or (3) mixed mutation mechanisms in which a CCR on one chromosome is combined with a different type of mutation on the other chromosome. Such inferred mechanisms of pathogenicity need corroboration by mRNA sequencing. Also, future studies with in vitro models, such as inducible pluripotent stem cells from patients with CCRs, and transgenic model organisms should substantiate current inferences regarding putative pathogenic effects of CCRs. The ramifications of the growing body of information on CCRs for clinical and experimental genetics and future treatment modalities are briefly illustrated with 2 cases, one of which suggests KDM4C (JMJD2C) as a novel candidate gene for mental retardation.
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Affiliation(s)
- Martin Poot
- Department of Human Genetics, University of Würzburg, Würzburg, Germany
| | - Thomas Haaf
- Department of Human Genetics, University of Würzburg, Würzburg, Germany
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Absence of heterozygosity due to template switching during replicative rearrangements. Am J Hum Genet 2015; 96:555-64. [PMID: 25799105 DOI: 10.1016/j.ajhg.2015.01.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 01/30/2015] [Indexed: 10/23/2022] Open
Abstract
We investigated complex genomic rearrangements (CGRs) consisting of triplication copy-number variants (CNVs) that were accompanied by extended regions of copy-number-neutral absence of heterozygosity (AOH) in subjects with multiple congenital abnormalities. Molecular analyses provided observational evidence that in humans, post-zygotically generated CGRs can lead to regional uniparental disomy (UPD) due to template switches between homologs versus sister chromatids by using microhomology to prime DNA replication-a prediction of the replicative repair model, MMBIR. Our findings suggest that replication-based mechanisms might underlie the formation of diverse types of genomic alterations (CGRs and AOH) implicated in constitutional disorders.
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de Sant’Anna JR, Franco CCDS, Mathias PCDF, de Castro-Prado MAA. Assessment of in vivo and in vitro genotoxicity of glibenclamide in eukaryotic cells. PLoS One 2015; 10:e0120675. [PMID: 25803314 PMCID: PMC4372363 DOI: 10.1371/journal.pone.0120675] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 01/25/2015] [Indexed: 12/18/2022] Open
Abstract
Glibenclamide is an oral hypoglycemic drug commonly prescribed for the treatment of type 2 diabetes mellitus, whose anti-tumor activity has been recently described in several human cancer cells. The mutagenic potential of such an antidiabetic drug and its recombinogenic activity in eukaryotic cells were evaluated, the latter for the first time. The mutagenic potential of glibenclamide in therapeutically plasma (0.6 μM) and higher concentrations (10 μM, 100 μM, 240 μM and 480 μM) was assessed by the in vitro mammalian cell micronucleus test in human lymphocytes. Since the loss of heterozygosity arising from allelic recombination is an important biologically significant consequence of oxidative damage, the glibenclamide recombinogenic activity at 1 μM, 10 μM and 100 μM concentrations was evaluated by the in vivo homozygotization assay. Glibenclamide failed to alter the frequency of micronuclei between 0.6 μM and 480 μM concentrations and the cytokinesis block proliferation index between 0.6 μM and 240 μM concentrations. On the other hand, glibenclamide changed the cell-proliferation kinetics when used at 480 μM. In the homozygotization assay, the homozygotization indices for the analyzed markers were lower than 2.0 and demonstrated the lack of recombinogenic activity of glibenclamide. Data in the current study demonstrate that glibenclamide, in current experimental conditions, is devoid of significant genotoxic effects. This fact encourages further investigations on the use of this antidiabetic agent as a chemotherapeutic drug.
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Affiliation(s)
- Juliane Rocha de Sant’Anna
- Departamento de Biotecnologia, Genética e Biologia Celular, Laboratório de Genética de Microorganismos e Mutagênese, Universidade Estadual de Maringá, Maringá, Paraná, Brazil
| | - Claudinéia Conationi da Silva Franco
- Departamento de Biotecnologia, Genética e Biologia Celular, Laboratório de Biologia Celular e Secreção, Universidade Estadual de Maringá, Maringá, Paraná, Brazil
| | - Paulo Cezar de Freitas Mathias
- Departamento de Biotecnologia, Genética e Biologia Celular, Laboratório de Biologia Celular e Secreção, Universidade Estadual de Maringá, Maringá, Paraná, Brazil
| | - Marialba Avezum Alves de Castro-Prado
- Departamento de Biotecnologia, Genética e Biologia Celular, Laboratório de Genética de Microorganismos e Mutagênese, Universidade Estadual de Maringá, Maringá, Paraná, Brazil
- * E-mail:
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Fasching CL, Cejka P, Kowalczykowski SC, Heyer WD. Top3-Rmi1 dissolve Rad51-mediated D loops by a topoisomerase-based mechanism. Mol Cell 2015; 57:595-606. [PMID: 25699708 PMCID: PMC4338411 DOI: 10.1016/j.molcel.2015.01.022] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/03/2014] [Accepted: 01/02/2015] [Indexed: 11/19/2022]
Abstract
The displacement loop (D loop) is a DNA strand invasion product formed during homologous recombination. Disruption of nascent D loops prevents recombination, and during synthesis-dependent strand annealing (SDSA), disruption of D loops extended by DNA polymerase ensures a non-crossover outcome. The proteins implicated in D loop disruption are DNA motor proteins/helicases that act by moving DNA junctions. Here we report that D loops can also be disrupted by DNA topoisomerase 3 (Top3), and this disruption depends on Top3's catalytic activity. Yeast Top3 specifically disrupts D loops mediated by yeast Rad51/Rad54; protein-free D loops or D loop mediated by bacterial RecA protein or human RAD51/RAD54 resist dissolution. Also, the human Topoisomerase IIIa-RMI1-RMI2 complex is capable of dissolving D loops. Consistent with genetic data, we suggest that the extreme growth defect and hyper-recombination phenotype of Top3-deficient yeast cells is partially a result of unprocessed D loops.
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Affiliation(s)
- Clare L Fasching
- Department of Microbiology & Molecular Genetics, University of California, Davis, Davis, CA 95616-8665, USA
| | - Petr Cejka
- Department of Microbiology & Molecular Genetics, University of California, Davis, Davis, CA 95616-8665, USA
| | - Stephen C Kowalczykowski
- Department of Microbiology & Molecular Genetics, University of California, Davis, Davis, CA 95616-8665, USA; Department of Molecular & Cellular Biology, University of California, Davis, Davis, CA 95616-8665, USA
| | - Wolf-Dietrich Heyer
- Department of Microbiology & Molecular Genetics, University of California, Davis, Davis, CA 95616-8665, USA; Department of Molecular & Cellular Biology, University of California, Davis, Davis, CA 95616-8665, USA.
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45
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Lecona E, Fernández-Capetillo O. Replication stress and cancer: it takes two to tango. Exp Cell Res 2014; 329:26-34. [PMID: 25257608 DOI: 10.1016/j.yexcr.2014.09.019] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Revised: 09/05/2014] [Accepted: 09/15/2014] [Indexed: 12/24/2022]
Abstract
Problems arising during DNA replication require the activation of the ATR-CHK1 pathway to ensure the stabilization and repair of the forks, and to prevent the entry into mitosis with unreplicated genomes. Whereas the pathway is essential at the cellular level, limiting its activity is particularly detrimental for some cancer cells. Here we review the links between replication stress (RS) and cancer, which provide a rationale for the use of ATR and Chk1 inhibitors in chemotherapy. First, we describe how the activation of oncogene-induced RS promotes genome rearrangements and chromosome instability, both of which could potentially fuel carcinogenesis. Next, we review the various pathways that contribute to the suppression of RS, and how mutations in these components lead to increased cancer incidence and/or accelerated ageing. Finally, we summarize the evidence showing that tumors with high levels of RS are dependent on a proficient RS-response, and therefore vulnerable to ATR or Chk1 inhibitors.
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Affiliation(s)
- Emilio Lecona
- Genomic Instability Group, Spanish National Cancer Research Centre (CNIO), C/ Melchor Fernández Almagro 3, 28029 Madrid, Spain
| | - Oscar Fernández-Capetillo
- Genomic Instability Group, Spanish National Cancer Research Centre (CNIO), C/ Melchor Fernández Almagro 3, 28029 Madrid, Spain.
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Abstract
Double Holliday junctions (dHJS) are important intermediates of homologous recombination. The separate junctions can each be cleaved by DNA structure-selective endonucleases known as Holliday junction resolvases. Alternatively, double Holliday junctions can be processed by a reaction known as "double Holliday junction dissolution." This reaction requires the cooperative action of a so-called "dissolvasome" comprising a Holliday junction branch migration enzyme (Sgs1/BLM RecQ helicase) and a type IA topoisomerase (Top3/TopoIIIα) in complex with its OB (oligonucleotide/oligosaccharide binding) fold containing accessory factor (Rmi1). This review details our current knowledge of the dissolution process and the players involved in catalyzing this mechanistically complex means of completing homologous recombination reactions.
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Affiliation(s)
- Anna H Bizard
- Nordea Center for Healthy Aging, Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Ian D Hickson
- Nordea Center for Healthy Aging, Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, 2200 Copenhagen N, Denmark
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Bocquet N, Bizard AH, Abdulrahman W, Larsen NB, Faty M, Cavadini S, Bunker RD, Kowalczykowski SC, Cejka P, Hickson ID, Thomä NH. Structural and mechanistic insight into Holliday-junction dissolution by topoisomerase IIIα and RMI1. Nat Struct Mol Biol 2014; 21:261-8. [PMID: 24509834 PMCID: PMC4292918 DOI: 10.1038/nsmb.2775] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 01/17/2014] [Indexed: 12/19/2022]
Abstract
Repair of DNA double-strand breaks via homologous recombination can produce double Holliday junctions (dHJs) that require enzymatic separation. Topoisomerase IIIα (TopIIIα) together with RMI1 disentangles the final hemicatenane intermediate obtained once dHJs have converged. How binding of RMI1 to TopIIIα influences it to behave as a hemicatenane dissolvase, rather than as an enzyme that relaxes DNA topology, is unknown. Here, we present the crystal structure of human TopIIIα complexed to the first oligonucleotide-binding domain (OB fold) of RMI1. TopIII assumes a toroidal type 1A topoisomerase fold. RMI1 attaches to the edge of the gate in TopIIIα through which DNA passes. RMI1 projects a 23-residue loop into the TopIIIα gate, thereby influencing the dynamics of its opening and closing. Our results provide a mechanistic rationale for how RMI1 stabilizes TopIIIα-gate opening to enable dissolution and illustrate how binding partners modulate topoisomerase function.
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Affiliation(s)
- Nicolas Bocquet
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Anna H Bizard
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Wassim Abdulrahman
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Nicolai B Larsen
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Mahamadou Faty
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Simone Cavadini
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Richard D Bunker
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Stephen C Kowalczykowski
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, California, USA
| | - Petr Cejka
- 1] Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, California, USA. [2]
| | - Ian D Hickson
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Nicolas H Thomä
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
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Chen SH, Plank JL, Willcox S, Griffith JD, Hsieh TS. Top3α is required during the convergent migration step of double Holliday junction dissolution. PLoS One 2014; 9:e83582. [PMID: 24392087 PMCID: PMC3879244 DOI: 10.1371/journal.pone.0083582] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 11/06/2013] [Indexed: 11/19/2022] Open
Abstract
Although Blm and Top3α are known to form a minimal dissolvasome that can uniquely undo a double Holliday junction structure, the details of the mechanism remain unknown. It was originally suggested that Blm acts first to create a hemicatenane structure from branch migration of the junctions, followed by Top3α performing strand passage to decatenate the interlocking single strands. Recent evidence suggests that Top3α may also be important for assisting in the migration of the junctions. Using a mismatch-dHJ substrate (MM-DHJS) and eukaryotic Top1 (in place of Top3α), we show that the presence of a topoisomerase is required for Blm to substantially migrate a topologically constrained Holliday junction. When investigated by electron microscopy, these migrated structures did not resemble a hemicatenane. However, when Blm is together with Top3α, the dissolution reaction is processive with no pausing at a partially migrated structure. Potential mechanisms are discussed.
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Affiliation(s)
- Stefanie Hartman Chen
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Jody L. Plank
- Department of Microbiology, University of California Davis, Davis, California, United States of America
| | - Smaranda Willcox
- Lineberger Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Jack D. Griffith
- Lineberger Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Tao-shih Hsieh
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, United States of America
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
- * E-mail:
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49
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Abstract
In this review, we discuss the repair of DNA double-strand breaks (DSBs) using a homologous DNA sequence (i.e., homologous recombination [HR]), focusing mainly on yeast and mammals. We provide a historical context for the current view of HR and describe how DSBs are processed during HR as well as interactions with other DSB repair pathways. We discuss the enzymology of the process, followed by studies on DSB repair in living cells. Whenever possible, we cite both original articles and reviews to aid the reader for further studies.
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Affiliation(s)
- Maria Jasin
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center New York, New York 10065
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50
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Castor D, Nair N, Déclais AC, Lachaud C, Toth R, Macartney TJ, Lilley DMJ, Arthur JSC, Rouse J. Cooperative control of holliday junction resolution and DNA repair by the SLX1 and MUS81-EME1 nucleases. Mol Cell 2013; 52:221-33. [PMID: 24076219 PMCID: PMC3808987 DOI: 10.1016/j.molcel.2013.08.036] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 07/19/2013] [Accepted: 08/14/2013] [Indexed: 12/20/2022]
Abstract
Holliday junctions (HJs) are X-shaped DNA structures that arise during homologous recombination, which must be removed to enable chromosome segregation. The SLX1 and MUS81-EME1 nucleases can both process HJs in vitro, and they bind in close proximity on the SLX4 scaffold, hinting at possible cooperation. However, the cellular roles of mammalian SLX1 are not yet known. Here, we use mouse genetics and structure function analysis to investigate SLX1 function. Disrupting the murine Slx1 and Slx4 genes revealed that they are essential for HJ resolution in mitotic cells. Moreover, SLX1 and MUS81-EME1 act together to resolve HJs in a manner that requires tethering to SLX4. We also show that SLX1, like MUS81-EME1, is required for repair of DNA interstrand crosslinks, but this role appears to be independent of HJ cleavage, at least in mouse cells. These findings shed light on HJ resolution in mammals and on maintenance of genome stability. Resolution of Holliday junctions in mouse cells requires the SLX1 nuclease SLX1 acts cooperatively with MUS81-EME1 in HJ resolution and ICL repair Mutations in SLX4 that prevent it binding to SLX1 and MUS81-EME1 abolish HJ resolution DNA substrates of SLX1 and MUS81-EME1 in ICL repair appear to be different from HJs
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Affiliation(s)
- Dennis Castor
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
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