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Provasek VE, Kodavati M, Kim B, Mitra J, Hegde ML. TDP43 interacts with MLH1 and MSH6 proteins in a DNA damage-inducible manner. Mol Brain 2024; 17:32. [PMID: 38840222 PMCID: PMC11155029 DOI: 10.1186/s13041-024-01108-3] [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: 05/21/2024] [Accepted: 05/30/2024] [Indexed: 06/07/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that affects the motor neuron. One aspect of the neuropathology involved in ALS includes increased genomic damage and impaired DNA repair capability. The TAR-DNA binding protein 43 (TDP43) has been associated with both sporadic and familial forms of ALS, and is typically observed as cytosolic mislocalization of protein aggregates, termed TDP43 proteinopathy. TDP43 is a ubiquitous RNA/DNA binding protein with functional implications in a wide range of disease processes, including the repair of DNA double-strand breaks (DSBs). While TDP43 is widely known to regulate RNA metabolism, our lab has reported it also functions directly at the protein level to facilitate DNA repair. Here, we show that the TDP43 protein interacts with DNA mismatch repair (MMR) proteins MLH1 and MSH6 in a DNA damage-inducible manner. We utilized differentiated SH-SY5Y neuronal cultures to identify this inducible relationship using complementary approaches of proximity ligation assay (PLA) and co-immunoprecipitation (CoIP) assay. We observed that signals of TDP43 interaction with MLH1 and MSH6 increased significantly following a 2 h treatment of 10 μM methylmethanesulfonate (MMS), a DNA alkylating agent used to induce MMR repair. Likewise, we observed this effect was abolished in cell lines treated with siRNA directed against TDP43. Finally, we demonstrated these protein interactions were significantly increased in lumbar spinal cord samples of ALS-affected patients compared to age-matched controls. These results will inform our future studies to understand the mechanisms and consequences of this TDP43-MMR interaction in the context of ALS-affected neurons.
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Affiliation(s)
- Vincent E Provasek
- Division of DNA Repair Research within the Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, 77030, USA.
- School of Medicine, Texas A&M University, College Station, TX, 77843, USA.
| | - Manohar Kodavati
- Division of DNA Repair Research within the Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Brandon Kim
- Department of Neuroscience, Rice University, Houston, TX, 77006, USA
| | - Joy Mitra
- Division of DNA Repair Research within the Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Muralidhar L Hegde
- Division of DNA Repair Research within the Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX, 77030, USA.
- School of Medicine, Texas A&M University, College Station, TX, 77843, USA.
- Department of Neuroscience, Weill Cornell Medical College, New York, NY, 10065, USA.
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2
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Provasek VE, Kodavati M, Kim B, Mitra J, Hegde ML. TDP43 Interacts with MLH1 and MSH6 Proteins in A DNA Damage-Inducible Manner. RESEARCH SQUARE 2024:rs.3.rs-4439430. [PMID: 38826483 PMCID: PMC11142363 DOI: 10.21203/rs.3.rs-4439430/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that affects the motor neuron. One aspect of the neuropathology involved in ALS includes increased genomic damage and impaired DNA repair capability. The TAR-DNA binding protein 43 (TDP43) has been associated with both sporadic and familial forms of ALS, and is typically observed as cytosolic mislocalization of protein aggregates, termed TDP43 proteinopathy. TDP43 is a ubiquitous RNA/DNA binding protein with functional implications in a wide range of disease processes, including the repair of DNA double strand breaks (DSBs). While TDP43 is widely known to regulate RNA metabolism, our lab has reported it also functions directly at the protein level to facilitate DNA repair. Here, we show that TDP43 protein interacts with DNA mismatch repair (MMR) proteins MLH1 and MSH6 in a DNA damage-inducible manner. We utilized differentiated SH-SY5Y neuronal cultures to identify this inducible relationship using complimentary approaches of proximity ligation assay (PLA) and co-immunoprecipitation (CoIP) assay. We observed that signals of TDP43 interaction with MLH1 and MSH6 increased significantly following a 2 hr treatment of 10μM methylmethanesulfonate (MMS), a DNA alkylating agent used to induce MMR repair. Likewise, we observed this effect was abolished in cell lines treated with siRNA directed against TDP43. Finally, we demonstrated these protein interactions were significantly increased in lumbar spinal cord samples of ALS-affected patients compared to age-matched controls. These results will inform our future studies to understand the mechanisms and consequences of this TDP43-MMR interaction in the context of ALS affected neurons.
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Affiliation(s)
- Vincent E. Provasek
- Division of DNA Repair Research within the Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX 77030, USA
- School of Medicine, Texas A&M University, College Station, TX 77843, USA
| | - Manohar Kodavati
- Division of DNA Repair Research within the Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Brandon Kim
- Department of Neuroscience, Rice University, Houston, TX 77006
| | - Joy Mitra
- Division of DNA Repair Research within the Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Muralidhar L. Hegde
- Division of DNA Repair Research within the Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX 77030, USA
- School of Medicine, Texas A&M University, College Station, TX 77843, USA
- Department of Neuroscience, Weill Cornell Medical College, New York, NY 10065, USA
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3
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Pussila M, Laiho A, Törönen P, Björkbacka P, Nykänen S, Pylvänäinen K, Holm L, Mecklin JP, Renkonen-Sinisalo L, Lehtonen T, Lepistö A, Linden J, Mäki-Nevala S, Peltomäki P, Nyström M. Mitotic abnormalities precede microsatellite instability in lynch syndrome-associated colorectal tumourigenesis. EBioMedicine 2024; 103:105111. [PMID: 38583260 PMCID: PMC11002576 DOI: 10.1016/j.ebiom.2024.105111] [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: 09/08/2023] [Revised: 03/21/2024] [Accepted: 03/26/2024] [Indexed: 04/09/2024] Open
Abstract
BACKGROUND Lynch syndrome (LS) is one of the most common hereditary cancer syndromes worldwide. Dominantly inherited mutation in one of four DNA mismatch repair genes combined with somatic events leads to mismatch repair deficiency and microsatellite instability (MSI) in tumours. Due to a high lifetime risk of cancer, regular surveillance plays a key role in cancer prevention; yet the observation of frequent interval cancers points to insufficient cancer prevention by colonoscopy-based methods alone. This study aimed to identify precancerous functional changes in colonic mucosa that could facilitate the monitoring and prevention of cancer development in LS. METHODS The study material comprised colon biopsy specimens (n = 71) collected during colonoscopy examinations from LS carriers (tumour-free, or diagnosed with adenoma, or diagnosed with carcinoma) and a control group, which included sporadic cases without LS or neoplasia. The majority (80%) of LS carriers had an inherited genetic MLH1 mutation. The remaining 20% included MSH2 mutation carriers (13%) and MSH6 mutation carriers (7%). The transcriptomes were first analysed with RNA-sequencing and followed up with Gorilla Ontology analysis and Reactome Knowledgebase and Ingenuity Pathway Analyses to detect functional changes that might be associated with the initiation of the neoplastic process in LS individuals. FINDINGS With pathway and gene ontology analyses combined with measurement of mitotic perimeters from colonic mucosa and tumours, we found an increased tendency to chromosomal instability (CIN), already present in macroscopically normal LS mucosa. Our results suggest that CIN is an earlier aberration than MSI and may be the initial cancer driving aberration, whereas MSI accelerates tumour formation. Furthermore, our results suggest that MLH1 deficiency plays a significant role in the development of CIN. INTERPRETATION The results validate our previous findings from mice and highlight early mitotic abnormalities as an important contributor and precancerous marker of colorectal tumourigenesis in LS. FUNDING This work was supported by grants from the Jane and Aatos Erkko Foundation, the Academy of Finland (330606 and 331284), Cancer Foundation Finland sr, and the Sigrid Jusélius Foundation. Open access is funded by Helsinki University Library.
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Affiliation(s)
- Marjaana Pussila
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.
| | - Aleksi Laiho
- Organismal and Evolutionary Biology Research Program, Faculty of Biosciences, and Institute of Biotechnology, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland
| | - Petri Törönen
- Organismal and Evolutionary Biology Research Program, Faculty of Biosciences, and Institute of Biotechnology, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland
| | - Pauliina Björkbacka
- Department of Veterinary Biosciences, and Finnish Centre for Laboratory Animal Pathology (FCLAP), Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland
| | - Sonja Nykänen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Kirsi Pylvänäinen
- Faculty of Sports and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Liisa Holm
- Organismal and Evolutionary Biology Research Program, Faculty of Biosciences, and Institute of Biotechnology, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland
| | - Jukka-Pekka Mecklin
- Well Being Services County of Central Finland, Department of Science, Jyväskylä, Finland; Faculty of Sports and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Laura Renkonen-Sinisalo
- Department of Surgery, Helsinki University Hospital, Helsinki, Finland; Applied Tumour Genomics, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - Taru Lehtonen
- Department of Surgery, Helsinki University Hospital, Helsinki, Finland
| | - Anna Lepistö
- Department of Surgery, Helsinki University Hospital, Helsinki, Finland; Applied Tumour Genomics, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - Jere Linden
- Department of Veterinary Biosciences, and Finnish Centre for Laboratory Animal Pathology (FCLAP), Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland
| | - Satu Mäki-Nevala
- Department of Medical and Clinical Genetics, University of Helsinki, Finland
| | - Päivi Peltomäki
- Department of Medical and Clinical Genetics, University of Helsinki, Finland; HUSLAB Laboratory of Genetics, HUS Diagnostic Center, Helsinki University Hospital, Helsinki, Finland
| | - Minna Nyström
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
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4
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Vasilopoulos SN, Güner H, Uça Apaydın M, Pavlopoulou A, Georgakilas AG. Dual Targeting of DNA Damage Response Proteins Implicated in Cancer Radioresistance. Genes (Basel) 2023; 14:2227. [PMID: 38137049 PMCID: PMC10742610 DOI: 10.3390/genes14122227] [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: 11/26/2023] [Revised: 12/13/2023] [Accepted: 12/13/2023] [Indexed: 12/24/2023] Open
Abstract
Ionizing radiation can induce different types of DNA lesions, leading to genomic instability and ultimately cell death. Radiation therapy or radiotherapy, a major modality in cancer treatment, harnesses the genotoxic potential of radiation to target and destroy cancer cells. Nevertheless, cancer cells have the capacity to develop resistance to radiation treatment (radioresistance), which poses a major obstacle in the effective management of cancer. It has been shown that administration of platinum-based drugs to cancer patients can increase tumor radiosensitivity, but despite this, it is associated with severe adverse effects. Several lines of evidence support that activation of the DNA damage response and repair machinery in the irradiated cancer cells enhances radioresistance and cellular survival through the efficient repair of DNA lesions. Therefore, targeting of key DNA damage repair factors would render cancer cells vulnerable to the irradiation effects, increase cancer cell killing, and reduce the risk of side effects on healthy tissue. Herein, we have employed a computer-aided drug design approach for generating ab initio a chemical compound with drug-like properties potentially targeting two proteins implicated in multiple DNA repair pathways. The findings of this study could be taken into consideration in clinical decision-making in terms of co-administering radiation with DNA damage repair factor-based drugs.
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Affiliation(s)
- Spyridon N. Vasilopoulos
- DNA Damage Laboratory, Physics Department, School of Applied Mathematical and Physical Sciences, National Technical University of Athens (NTUA), Zografou Campus, 15780 Athens, Greece;
- Department of Science and Mathematics, Deree-The American College of Greece, 6 Gravias Street, 15342 Athens, Greece
| | - Hüseyin Güner
- Izmir Biomedicine and Genome Center (IBG), 35340 Izmir, Turkey; (H.G.); (M.U.A.)
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, 35340 Izmir, Turkey
- Department of Molecular Biology and Genetics, Faculty of Life and Natural Science, Abdullah Gül University, 38080 Kayseri, Turkey
| | - Merve Uça Apaydın
- Izmir Biomedicine and Genome Center (IBG), 35340 Izmir, Turkey; (H.G.); (M.U.A.)
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, 35340 Izmir, Turkey
| | - Athanasia Pavlopoulou
- Izmir Biomedicine and Genome Center (IBG), 35340 Izmir, Turkey; (H.G.); (M.U.A.)
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, 35340 Izmir, Turkey
| | - Alexandros G. Georgakilas
- DNA Damage Laboratory, Physics Department, School of Applied Mathematical and Physical Sciences, National Technical University of Athens (NTUA), Zografou Campus, 15780 Athens, Greece;
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5
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Hao Q, Zhan C, Lian C, Luo S, Cao W, Wang B, Xie X, Ye X, Gui T, Voena C, Pighi C, Wang Y, Tian Y, Wang X, Dai P, Cai Y, Liu X, Ouyang S, Sun S, Hu Q, Liu J, Ye Y, Zhao J, Lu A, Wang JY, Huang C, Su B, Meng FL, Chiarle R, Pan-Hammarström Q, Yeap LS. DNA repair mechanisms that promote insertion-deletion events during immunoglobulin gene diversification. Sci Immunol 2023; 8:eade1167. [PMID: 36961908 PMCID: PMC10351598 DOI: 10.1126/sciimmunol.ade1167] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 03/01/2023] [Indexed: 03/26/2023]
Abstract
Insertions and deletions (indels) are low-frequency deleterious genomic DNA alterations. Despite their rarity, indels are common, and insertions leading to long complementarity-determining region 3 (CDR3) are vital for antigen-binding functions in broadly neutralizing and polyreactive antibodies targeting viruses. Because of challenges in detecting indels, the mechanism that generates indels during immunoglobulin diversification processes remains poorly understood. We carried out ultra-deep profiling of indels and systematically dissected the underlying mechanisms using passenger-immunoglobulin mouse models. We found that activation-induced cytidine deaminase-dependent ±1-base pair (bp) indels are the most prevalent indel events, biasing deleterious outcomes, whereas longer in-frame indels, especially insertions that can extend the CDR3 length, are rare outcomes. The ±1-bp indels are channeled by base excision repair, but longer indels require additional DNA-processing factors. Ectopic expression of a DNA exonuclease or perturbation of the balance of DNA polymerases can increase the frequency of longer indels, thus paving the way for models that can generate antibodies with long CDR3. Our study reveals the mechanisms that generate beneficial and deleterious indels during the process of antibody somatic hypermutation and has implications in understanding the detrimental genomic alterations in various conditions, including tumorigenesis.
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Affiliation(s)
- Qian Hao
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Chuanzong Zhan
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Chaoyang Lian
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Simin Luo
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Wenyi Cao
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Binbin Wang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Xia Xie
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Xiaofei Ye
- Department of Biosciences and Nutrition, Karolinska Institutet; SE141-83, Huddinge, Stockholm, Sweden
- Present address: Kindstar Global Precision Medicine Institute, Wuhan, China and Kindstar Biotech, Wuhan, China
| | - Tuantuan Gui
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Claudia Voena
- Department of Molecular Biotechnology and Health Sciences, University of Torino; 10126 Torino, Italy
| | - Chiara Pighi
- Department of Molecular Biotechnology and Health Sciences, University of Torino; 10126 Torino, Italy
- Department of Pathology, Boston Children’s Hospital, and Harvard Medical School; Boston, MA 02115, USA
| | - Yanyan Wang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Ying Tian
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Xin Wang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Pengfei Dai
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Yanni Cai
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Xiaojing Liu
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Shengqun Ouyang
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Shiqi Sun
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Qianwen Hu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Jun Liu
- Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Youqiong Ye
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Jingkun Zhao
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Aiguo Lu
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Ji-Yang Wang
- Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
- Department of Microbiology and Immunology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Chuanxin Huang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Bing Su
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Departments of Endocrinology and Gastroenterology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Jiao Tong University School of Medicine-Yale Institute for Immune Metabolism, Shanghai Jiao Tong University School of Medicine, Shanghai 200025
| | - Fei-Long Meng
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Roberto Chiarle
- Department of Molecular Biotechnology and Health Sciences, University of Torino; 10126 Torino, Italy
- Department of Pathology, Boston Children’s Hospital, and Harvard Medical School; Boston, MA 02115, USA
| | - Qiang Pan-Hammarström
- Department of Biosciences and Nutrition, Karolinska Institutet; SE141-83, Huddinge, Stockholm, Sweden
| | - Leng-Siew Yeap
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
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6
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Wang S, Lee K, Gray S, Zhang Y, Tang C, Morrish RB, Tosti E, van Oers J, Amin MR, Cohen PE, MacCarthy T, Roa S, Scharff MD, Edelmann W, Chahwan R. Role of EXO1 nuclease activity in genome maintenance, the immune response and tumor suppression in Exo1D173A mice. Nucleic Acids Res 2022; 50:8093-8106. [PMID: 35849338 PMCID: PMC9371890 DOI: 10.1093/nar/gkac616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 05/30/2022] [Accepted: 06/30/2022] [Indexed: 11/14/2022] Open
Abstract
DNA damage response pathways rely extensively on nuclease activity to process DNA intermediates. Exonuclease 1 (EXO1) is a pleiotropic evolutionary conserved DNA exonuclease involved in various DNA repair pathways, replication, antibody diversification, and meiosis. But, whether EXO1 facilitates these DNA metabolic processes through its enzymatic or scaffolding functions remains unclear. Here, we dissect the contribution of EXO1 enzymatic versus scaffolding activity by comparing Exo1DA/DA mice expressing a proven nuclease-dead mutant form of EXO1 to entirely EXO1-deficient Exo1−/− and EXO1 wild type Exo1+/+ mice. We show that Exo1DA/DA and Exo1–/– mice are compromised in canonical DNA repair processing, suggesting that the EXO1 enzymatic role is important for error-free DNA mismatch and double-strand break repair pathways. However, in non-canonical repair pathways, EXO1 appears to have a more nuanced function. Next-generation sequencing of heavy chain V region in B cells showed the mutation spectra of Exo1DA/DA mice to be intermediate between Exo1+/+ and Exo1–/– mice, suggesting that both catalytic and scaffolding roles of EXO1 are important for somatic hypermutation. Similarly, while overall class switch recombination in Exo1DA/DA and Exo1–/– mice was comparably defective, switch junction analysis suggests that EXO1 might fulfill an additional scaffolding function downstream of class switching. In contrast to Exo1−/− mice that are infertile, meiosis progressed normally in Exo1DA/DA and Exo1+/+ cohorts, indicating that a structural but not the nuclease function of EXO1 is critical for meiosis. However, both Exo1DA/DA and Exo1–/– mice displayed similar mortality and cancer predisposition profiles. Taken together, these data demonstrate that EXO1 has both scaffolding and enzymatic functions in distinct DNA repair processes and suggest a more composite and intricate role for EXO1 in DNA metabolic processes and disease.
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Affiliation(s)
- Shanzhi Wang
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, NY 10461, USA.,Current position: Department of Chemistry, University of Arkansas at Little Rock, Little Rock, AR 72204, USA
| | - Kyeryoung Lee
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, NY 10461, USA
| | - Stephen Gray
- Department of Biomedical Sciences, Cornell University, NY 14853, USA.,Current position: School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK
| | - Yongwei Zhang
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, NY 10461, USA
| | - Catherine Tang
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, USA
| | - Rikke B Morrish
- Current position: School of Physics and Astronomy, University of Exeter, Exeter EX4 4QD, UK
| | - Elena Tosti
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, NY 10461, USA
| | - Johanna van Oers
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, NY 10461, USA
| | - Mohammad Ruhul Amin
- Department of Computer and Information Science, Fordham University, Bronx, NY, USA
| | - Paula E Cohen
- Department of Biomedical Sciences, Cornell University, NY 14853, USA
| | - Thomas MacCarthy
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, USA
| | - Sergio Roa
- Department of Biochemistry and Genetics, University of Navarra, 31008Pamplona, Spain.,Centro de Investigacion Biomedica en Red de Cancer (CIBERONC), Instituto de Salud Carlos III, Madrid, Spain.,Navarra Institute for Health Research (IdiSNA), Pamplona, Spain
| | - Matthew D Scharff
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, NY 10461, USA
| | - Winfried Edelmann
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, NY 10461, USA
| | - Richard Chahwan
- Institute of Experimental Immunology, University of Zurich, Zurich 8057, Switzerland
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7
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Goyache F, Pérez-Pardal L, Fernández I, Traoré A, Menéndez-Arias NA, Álvarez I. Ancient autozygous segments subject to positive selection suggest adaptive immune responses in West African cattle. Gene 2021; 803:145899. [PMID: 34400278 DOI: 10.1016/j.gene.2021.145899] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/05/2021] [Accepted: 08/10/2021] [Indexed: 11/19/2022]
Abstract
Small-sized and trypanotolerant West African taurine (Bos taurus) cattle are a unique case of human-mediated process of adaptation to a challenging environment. Extensive gene flow with Sahelian zebu (B. indicus), bigger and with some resistance to tick attack, occurred for centuries and allowed the apparition of stable crossbred populations (sanga) having intermediate characteristics. Up to 237 individuals belonging to 10 different taurine, zebu and sanga cattle populations sampled in Benin, Burkina Faso and Niger were typed using the BovineHD BeadChip of Illumina to identify signatures of selection, assessed using three different Extended-Haplotype-Homozygosity-based statistics, overlapping with ancient, originated 1024 or 2048 generations ago, Homozygosity-By-Descent segments in the cattle genome. Candidate genomic regions were defined ensuring their importance within cattle type and using zebu as reference. Functional annotation analysis identified four statistically significant Annotation Clusters in taurine cattle (from ACt1 to ACt4), one (ACs1) in sanga, and another (ACz1) in zebu cattle, fitting well with expectations. ACt1 included genes primarily associated with innate immunity; ACt2 involved bitter taste receptor genes of importance to adaptation to changing environments; ACt3 included 68 genes coding ATP-binding proteins, some of them located on trypanotolerance-related QTL regions, that can partially underlie immune response and the additive mechanism of trypanotolerance; ACt4 was associated with growth and small size (NPPC gene); ACs1 included genes involved in immune response; and ACz1 is related with ectoparasite resistance. Our results provide a new set of genomic areas and candidate genes giving new insights on the genomic impact of adaptation in West African cattle.
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Affiliation(s)
- Félix Goyache
- SERIDA-Deva, Camino de Rioseco 1225, E-33394-Gijón, Spain.
| | | | - Iván Fernández
- SERIDA-Deva, Camino de Rioseco 1225, E-33394-Gijón, Spain
| | - Amadou Traoré
- Institut de l'Environnement et des Recherches Agricoles (INERA), Ouagadougou 04 BP 8645, Burkina Faso
| | | | - Isabel Álvarez
- SERIDA-Deva, Camino de Rioseco 1225, E-33394-Gijón, Spain
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8
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Babushkina NP, Postrigan AE, Kucher AN. Involvement of Variants in the Genes Encoding BRCA1-Associated Genome Surveillance Complex (BASC) in the Development of Human Common Diseases. Mol Biol 2021. [DOI: 10.1134/s0026893321020047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Mlh1 deficiency increases the risk of hematopoietic malignancy after simulated space radiation exposure. Leukemia 2018; 33:1135-1147. [PMID: 30275527 PMCID: PMC6443507 DOI: 10.1038/s41375-018-0269-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/20/2018] [Accepted: 08/29/2018] [Indexed: 12/13/2022]
Abstract
Cancer-causing genome instability is a major concern during space travel due to exposure of astronauts to potent sources of high-linear energy transfer (LET) ionizing radiation. Hematopoietic stem cells (HSCs) are particularly susceptible to genotoxic stress, and accumulation of damage can lead to HSC dysfunction and oncogenesis. Our group recently demonstrated that aging human HSCs accumulate microsatellite instability coincident with loss of MLH1, a DNA Mismatch Repair (MMR) protein, which could reasonably predispose to radiation-induced HSC malignancies. Therefore, in an effort to reduce risk uncertainty for cancer development during deep space travel, we employed an Mlh1+/− mouse model to study the effects high-LET 56Fe ion space-like radiation. Irradiated Mlh1+/− mice showed a significantly higher incidence of lymphomagenesis with 56Fe ions compared to γ-rays and unirradiated mice, and malignancy correlated with increased MSI in the tumors. In addition, whole exome sequencing analysis revealed high SNVs and INDELs in lymphomas being driven by loss of Mlh1 and frequently mutated genes had a strong correlation with human leukemias. Therefore, the data suggest that age-related MMR deficiencies could lead to HSC malignancies after space radiation, and that countermeasure strategies will be required to adequately protect the astronaut population on the journey to Mars.
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10
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Jia P, Chai W. The MLH1 ATPase domain is needed for suppressing aberrant formation of interstitial telomeric sequences. DNA Repair (Amst) 2018; 65:20-25. [PMID: 29544212 DOI: 10.1016/j.dnarep.2018.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/02/2018] [Accepted: 03/05/2018] [Indexed: 02/05/2023]
Abstract
Genome instability gives rise to cancer. MLH1, commonly known for its important role in mismatch repair (MMR), DNA damage signaling and double-strand break (DSB) repair, safeguards genome stability. Recently we have reported a novel role of MLH1 in preventing aberrant formation of interstitial telomeric sequences (ITSs) at intra-chromosomal regions. Deficiency in MLH1, in particular its N-terminus, leads to an increase of ITSs. Here, we identify that the ATPase activity in the MLH1 N-terminal domain is important for suppressing the formation of ITSs. The ATPase activity is also needed for recruiting MLH1 to DSBs. Moreover, defective ATPase activity of MLH1 causes an increase in micronuclei formation. Our results highlight the crucial role of MLH1's ATPase domain in preventing the aberrant formation of telomeric sequences at the intra-chromosomal regions and preserving genome stability.
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Affiliation(s)
- Pingping Jia
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, United States
| | - Weihang Chai
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, United States.
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11
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Jia P, Chastain M, Zou Y, Her C, Chai W. Human MLH1 suppresses the insertion of telomeric sequences at intra-chromosomal sites in telomerase-expressing cells. Nucleic Acids Res 2017; 45:1219-1232. [PMID: 28180301 PMCID: PMC5388398 DOI: 10.1093/nar/gkw1170] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 10/26/2016] [Accepted: 11/09/2016] [Indexed: 11/29/2022] Open
Abstract
Aberrant formation of interstitial telomeric sequences (ITSs) promotes genome instabilities. However, it is unclear how aberrant ITS formation is suppressed in human cells. Here, we report that MLH1, a key protein involved in mismatch repair (MMR), suppresses telomeric sequence insertion (TSI) at intra-chromosomal regions. The frequency of TSI can be elevated by double-strand break (DSB) inducer and abolished by ATM/ATR inhibition. Suppression of TSI requires MLH1 recruitment to DSBs, indicating that MLH1's role in DSB response/repair is important for suppressing TSI. Moreover, TSI requires telomerase activity but is independent of the functional status of p53 and Rb. Lastly, we show that TSI is associated with chromosome instabilities including chromosome loss, micronuclei formation and chromosome breakage that are further elevated by replication stress. Our studies uncover a novel link between MLH1, telomerase, telomere and genome stability.
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Affiliation(s)
- Pingping Jia
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Megan Chastain
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Ying Zou
- Cytogenetics Laboratory, Department of Pathology, the University of Maryland School of Medicine, Baltimore, MD, USA
| | - Chengtao Her
- School of Molecular Biosciences, Washington State University, Pullman, WA, USA
| | - Weihang Chai
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
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12
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Girelli Zubani G, Zivojnovic M, De Smet A, Albagli-Curiel O, Huetz F, Weill JC, Reynaud CA, Storck S. Pms2 and uracil-DNA glycosylases act jointly in the mismatch repair pathway to generate Ig gene mutations at A-T base pairs. J Exp Med 2017; 214:1169-1180. [PMID: 28283534 PMCID: PMC5379981 DOI: 10.1084/jem.20161576] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 12/19/2016] [Accepted: 01/26/2017] [Indexed: 11/06/2022] Open
Abstract
Girelli Zubani et al. show that the Pms2 component of the mismatch repair complex and multiple uracil glycosylases contribute, each with a distinct strand bias, to enlarge the Ig gene mutation spectrum from G-C to A-T bases. During somatic hypermutation (SHM) of immunoglobulin genes, uracils introduced by activation-induced cytidine deaminase are processed by uracil-DNA glycosylase (UNG) and mismatch repair (MMR) pathways to generate mutations at G-C and A-T base pairs, respectively. Paradoxically, the MMR-nicking complex Pms2/Mlh1 is apparently dispensable for A-T mutagenesis. Thus, how detection of U:G mismatches is translated into the single-strand nick required for error-prone synthesis is an open question. One model proposed that UNG could cooperate with MMR by excising a second uracil in the vicinity of the U:G mismatch, but it failed to explain the low impact of UNG inactivation on A-T mutagenesis. In this study, we show that uracils generated in the G1 phase in B cells can generate equal proportions of A-T and G-C mutations, which suggests that UNG and MMR can operate within the same time frame during SHM. Furthermore, we show that Ung−/−Pms2−/− mice display a 50% reduction in mutations at A-T base pairs and that most remaining mutations at A-T bases depend on two additional uracil glycosylases, thymine-DNA glycosylase and SMUG1. These results demonstrate that Pms2/Mlh1 and multiple uracil glycosylases act jointly, each one with a distinct strand bias, to enlarge the immunoglobulin gene mutation spectrum from G-C to A-T bases.
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Affiliation(s)
- Giulia Girelli Zubani
- Institut Necker-Enfants Malades, Institut National de la Santé et de la Recherche Médicale U1151, Centre National de la Recherche Scientifique UMR 8253, Faculté de Médecine-Site Broussais, Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Marija Zivojnovic
- Institut Necker-Enfants Malades, Institut National de la Santé et de la Recherche Médicale U1151, Centre National de la Recherche Scientifique UMR 8253, Faculté de Médecine-Site Broussais, Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Annie De Smet
- Institut Necker-Enfants Malades, Institut National de la Santé et de la Recherche Médicale U1151, Centre National de la Recherche Scientifique UMR 8253, Faculté de Médecine-Site Broussais, Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Olivier Albagli-Curiel
- Institut Cochin, Institut National de la Santé et de la Recherche Médicale U1016, Centre National de la Recherche Scientifique UMR8104, Faculté de Médecine-Site Cochin, Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France
| | - François Huetz
- Institut Necker-Enfants Malades, Institut National de la Santé et de la Recherche Médicale U1151, Centre National de la Recherche Scientifique UMR 8253, Faculté de Médecine-Site Broussais, Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France.,Département d'Immunologie, Institut Pasteur, 75015 Paris, France
| | - Jean-Claude Weill
- Institut Necker-Enfants Malades, Institut National de la Santé et de la Recherche Médicale U1151, Centre National de la Recherche Scientifique UMR 8253, Faculté de Médecine-Site Broussais, Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Claude-Agnès Reynaud
- Institut Necker-Enfants Malades, Institut National de la Santé et de la Recherche Médicale U1151, Centre National de la Recherche Scientifique UMR 8253, Faculté de Médecine-Site Broussais, Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Sébastien Storck
- Institut Necker-Enfants Malades, Institut National de la Santé et de la Recherche Médicale U1151, Centre National de la Recherche Scientifique UMR 8253, Faculté de Médecine-Site Broussais, Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
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Methot S, Di Noia J. Molecular Mechanisms of Somatic Hypermutation and Class Switch Recombination. Adv Immunol 2017; 133:37-87. [DOI: 10.1016/bs.ai.2016.11.002] [Citation(s) in RCA: 165] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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14
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Zanotti KJ, Gearhart PJ. Antibody diversification caused by disrupted mismatch repair and promiscuous DNA polymerases. DNA Repair (Amst) 2016; 38:110-116. [PMID: 26719140 PMCID: PMC4740194 DOI: 10.1016/j.dnarep.2015.11.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/30/2015] [Indexed: 10/25/2022]
Abstract
The enzyme activation-induced deaminase (AID) targets the immunoglobulin loci in activated B cells and creates DNA mutations in the antigen-binding variable region and DNA breaks in the switch region through processes known, respectively, as somatic hypermutation and class switch recombination. AID deaminates cytosine to uracil in DNA to create a U:G mismatch. During somatic hypermutation, the MutSα complex binds to the mismatch, and the error-prone DNA polymerase η generates mutations at A and T bases. During class switch recombination, both MutSα and MutLα complexes bind to the mismatch, resulting in double-strand break formation and end-joining. This review is centered on the mechanisms of how the MMR pathway is commandeered by B cells to generate antibody diversity.
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Affiliation(s)
- Kimberly J Zanotti
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Patricia J Gearhart
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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15
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ZOU YUHUI, WANG QIONG, WANG WEIMIN. MutL homolog 1 contributes to temozolomide-induced autophagy via ataxia-telangiectasia mutated in glioma. Mol Med Rep 2015; 11:4591-6. [DOI: 10.3892/mmr.2015.3293] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 12/02/2014] [Indexed: 11/06/2022] Open
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16
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Bak ST, Sakellariou D, Pena-Diaz J. The dual nature of mismatch repair as antimutator and mutator: for better or for worse. Front Genet 2014; 5:287. [PMID: 25191341 PMCID: PMC4139959 DOI: 10.3389/fgene.2014.00287] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 08/04/2014] [Indexed: 01/19/2023] Open
Abstract
DNA is constantly under attack by a number of both exogenous and endogenous agents that challenge its integrity. Among the mechanisms that have evolved to counteract this deleterious action, mismatch repair (MMR) has specialized in removing DNA biosynthetic errors that occur when replicating the genome. Malfunction or inactivation of this system results in an increase in spontaneous mutability and a strong predisposition to tumor development. Besides this key corrective role, MMR proteins are involved in other pathways of DNA metabolism such as mitotic and meiotic recombination and processing of oxidative damage. Surprisingly, MMR is also required for certain mutagenic processes. The mutagenic MMR has beneficial consequences contributing to the generation of a vast repertoire of antibodies through class switch recombination and somatic hypermutation processes. However, this non-canonical mutagenic MMR also has detrimental effects; it promotes repeat expansions associated with neuromuscular and neurodegenerative diseases and may contribute to cancer/disease-related aberrant mutations and translocations. The reaction responsible for replication error correction has been the most thoroughly studied and it is the subject to numerous reviews. This review describes briefly the biochemistry of MMR and focuses primarily on the non-canonical MMR activities described in mammals as well as emerging research implicating interplay of MMR and chromatin.
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Affiliation(s)
- Sara Thornby Bak
- Department of Neuroscience and Pharmacology and Center for Healthy Aging, University of Copenhagen Copenhagen, Denmark
| | - Despoina Sakellariou
- Department of Neuroscience and Pharmacology and Center for Healthy Aging, University of Copenhagen Copenhagen, Denmark
| | - Javier Pena-Diaz
- Department of Neuroscience and Pharmacology and Center for Healthy Aging, University of Copenhagen Copenhagen, Denmark
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17
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Horiuchi K, Imai K, Mitsui-Sekinaka K, Yeh TW, Ochs HD, Durandy A, Nonoyama S. Analysis of somatic hypermutations in the IgM switch region in human B cells. J Allergy Clin Immunol 2014; 134:411-9. [DOI: 10.1016/j.jaci.2014.02.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 02/06/2014] [Accepted: 02/06/2014] [Indexed: 11/16/2022]
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18
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Ezzatizadeh V, Sandi C, Sandi M, Anjomani-Virmouni S, Al-Mahdawi S, Pook MA. MutLα heterodimers modify the molecular phenotype of Friedreich ataxia. PLoS One 2014; 9:e100523. [PMID: 24971578 PMCID: PMC4074104 DOI: 10.1371/journal.pone.0100523] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/28/2014] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Friedreich ataxia (FRDA), the most common autosomal recessive ataxia disorder, is caused by a dynamic GAA repeat expansion mutation within intron 1 of FXN gene, resulting in down-regulation of frataxin expression. Studies of cell and mouse models have revealed a role for the mismatch repair (MMR) MutS-heterodimer complexes and the PMS2 component of the MutLα complex in the dynamics of intergenerational and somatic GAA repeat expansions: MSH2, MSH3 and MSH6 promote GAA repeat expansions, while PMS2 inhibits GAA repeat expansions. METHODOLOGY/PRINCIPAL FINDINGS To determine the potential role of the other component of the MutLα complex, MLH1, in GAA repeat instability in FRDA, we have analyzed intergenerational and somatic GAA repeat expansions from FXN transgenic mice that have been crossed with Mlh1 deficient mice. We find that loss of Mlh1 activity reduces both intergenerational and somatic GAA repeat expansions. However, we also find that loss of either Mlh1 or Pms2 reduces FXN transcription, suggesting different mechanisms of action for Mlh1 and Pms2 on GAA repeat expansion dynamics and regulation of FXN transcription. CONCLUSIONS/SIGNIFICANCE Both MutLα components, PMS2 and MLH1, have now been shown to modify the molecular phenotype of FRDA. We propose that upregulation of MLH1 or PMS2 could be potential FRDA therapeutic approaches to increase FXN transcription.
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Affiliation(s)
- Vahid Ezzatizadeh
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
| | - Chiranjeevi Sandi
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
| | - Madhavi Sandi
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
| | - Sara Anjomani-Virmouni
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
| | - Sahar Al-Mahdawi
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
| | - Mark A. Pook
- Division of Biosciences, School of Health Sciences and Social Care, Brunel University London, Uxbridge, United Kingdom
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19
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Litvinov SV. Main repair pathways of double-strand breaks in the genomic DNA and interactions between them. CYTOL GENET+ 2014. [DOI: 10.3103/s0095452714030062] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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20
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Chen Z, Wang JH. Generation and repair of AID-initiated DNA lesions in B lymphocytes. Front Med 2014; 8:201-16. [PMID: 24748462 PMCID: PMC4039616 DOI: 10.1007/s11684-014-0324-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 12/30/2013] [Indexed: 01/12/2023]
Abstract
Activation-induced deaminase (AID) initiates the secondary antibody diversification process in B lymphocytes. In mammalian B cells, this process includes somatic hypermutation (SHM) and class switch recombination (CSR), both of which require AID. AID induces U:G mismatch lesions in DNA that are subsequently converted into point mutations or DNA double stranded breaks during SHM/CSR. In a physiological context, AID targets immunoglobulin (Ig) loci to mediate SHM/CSR. However, recent studies reveal genome-wide access of AID to numerous non-Ig loci. Thus, AID poses a threat to the genome of B cells if AID-initiated DNA lesions cannot be properly repaired. In this review, we focus on the molecular mechanisms that regulate the specificity of AID targeting and the repair pathways responsible for processing AID-initiated DNA lesions.
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Affiliation(s)
- Zhangguo Chen
- Integrated Department of Immunology, University of Colorado Anschutz Medical Campus and National Jewish Health, Denver, CO 80206
| | - Jing H. Wang
- Integrated Department of Immunology, University of Colorado Anschutz Medical Campus and National Jewish Health, Denver, CO 80206
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Abstract
B-cell maturation and germinal center (GC) formation are dependent on the interplay between BCL6 and other transcriptional regulators. FOXP1 is a transcription factor that regulates early B-cell development, but whether it plays a role in mature B cells is unknown. Analysis of human tonsillar B-cell subpopulations revealed that FOXP1 shows the opposite expression pattern to BCL6, suggesting that FOXP1 regulates the transition from resting follicular B cell to activated GC B cell. Chromatin immunoprecipitation-on-chip and gene expression assays on B cells indicated that FOXP1 acts as a transcriptional activator and repressor of genes involved in the GC reaction, half of which are also BCL6 targets. To study FOXP1 function in vivo, we developed transgenic mice expressing human FOXP1 in lymphoid cells. These mice exhibited irregular formation of splenic GCs, showing a modest increase in naïve and marginal-zone B cells and a significant decrease in GC B cells. Furthermore, aberrant expression of FOXP1 impaired transcription of noncoding γ1 germline transcripts and inhibited efficient class switching to the immunoglobulin G1 isotype. These studies show that FOXP1 is physiologically downregulated in GC B cells and that aberrant expression of FOXP1 impairs mechanisms triggered by B-cell activation, potentially contributing to B-cell lymphomagenesis.
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22
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AIDing antibody diversity by error-prone mismatch repair. Semin Immunol 2012; 24:293-300. [PMID: 22703640 DOI: 10.1016/j.smim.2012.05.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 05/18/2012] [Indexed: 11/20/2022]
Abstract
The creation of a highly diverse antibody repertoire requires the synergistic activity of a DNA mutator, known as activation-induced deaminase (AID), coupled with an error-prone repair process that recognizes the DNA mismatch catalyzed by AID. Instead of facilitating the canonical error-free response, which generally occurs throughout the genome, DNA mismatch repair (MMR) participates in an error-prone repair mode that promotes A:T mutagenesis and double-strand breaks at the immunoglobulin (Ig) genes. As such, MMR is capable of compounding the mutation frequency of AID activity as well as broadening the spectrum of base mutations; thereby increasing the efficiency of antibody maturation. We here review the current understanding of this MMR-mediated process and describe how the MMR signaling cascade downstream of AID diverges in a locus dependent manner and even within the Ig locus itself to differentially promote somatic hypermutation (SHM) and class switch recombination (CSR) in B cells.
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