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Abstract
DNA damage by chemicals, radiation, or oxidative stress leads to a mutational spectrum, which is complex because it is determined in part by lesion structure, the DNA sequence context of the lesion, lesion repair kinetics, and the type of cells in which the lesion is replicated. Accumulation of mutations may give rise to genetic diseases such as cancer and therefore understanding the process underlying mutagenesis is of immense importance to preserve human health. Chemical or physical agents that cause cancer often leave their mutational fingerprints, which can be used to back-calculate the molecular events that led to disease. To make a clear link between DNA lesion structure and the mutations a given lesion induces, the field of single-lesion mutagenesis was developed. In the last three decades this area of research has seen much growth in several directions, which we attempt to describe in this Perspective.
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Affiliation(s)
- Ashis K Basu
- Department of Chemistry, The University of Connecticut Storrs, Storrs, Connecticut 06269, United States
| | - John M Essigmann
- Departments of Chemistry, Biological Engineering and Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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2
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Rare POLN mutations confer risk for familial nasopharyngeal carcinoma through weakened Epstein-Barr virus lytic replication. EBioMedicine 2022; 84:104267. [PMID: 36116213 PMCID: PMC9486052 DOI: 10.1016/j.ebiom.2022.104267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 08/29/2022] [Accepted: 08/29/2022] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Nasopharyngeal carcinoma (NPC) exhibits significant familial aggregation; however, its susceptibility genes are largely unknown. Thus, this study aimed to identify germline mutations that might contribute to the risk of familial NPC, and explore their biological functions. METHODS Whole-exome sequencing was performed in 13 NPC pedigrees with multiple cases. Mutations co-segregated with disease status were further validated in a cohort composed of 563 probands from independent families, 2,953 sporadic cases, and 3,175 healthy controls. Experimental studies were used to explore the functions of susceptibility genes and their disease-related mutations. FINDINGS The three rare missense mutations in POLN (DNA polymerase nu) gene, P577L, R303Q, and F545C, were associated with familial NPC risk (5/576 [0·87%] in cases vs. 2/3374 [0·059%] in healthy controls with an adjusted OR of 44·84 [95% CI:3·91-514·34, p = 2·25 × 10-3]). POLN was involved in Epstein-Barr virus (EBV) lytic replication in NPC cells in vitro. POLN promoted viral DNA replication, immediate-early and late lytic gene expression, and progeny viral particle production, ultimately affecting the proliferation of host cells. The three mutations were located in two pivotal functional domains and were predicted to alter the protein stability of POLN in silico. Further assays demonstrated that POLN carrying any of the three mutations displayed reduced protein stability and decreased expression levels, thereby impairing its ability to promote complete EBV lytic replication and facilitate cell survival. INTERPRETATION We identified a susceptibility gene POLN for familial NPC and elucidated its function. FUNDING This study was funded by the National Key Research and Development Program of China (2021YFC2500400); the National Key Research and Development Program of China (2020YFC1316902); the Basic and Applied Basic Research Foundation of Guangdong Province, China (2021B1515420007); the National Natural Science Foundation of China (81973131); the National Natural Science Foundation of China (82003520); the National Natural Science Foundation of China (81903395).
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Lucchese G, Jahantigh HR, De Benedictis L, Lovreglio P, Stufano A. An Epitope Platform for Safe and Effective HTLV-1-Immunization: Potential Applications for mRNA and Peptide-Based Vaccines. Viruses 2021; 13:1461. [PMID: 34452327 PMCID: PMC8402675 DOI: 10.3390/v13081461] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 07/12/2021] [Accepted: 07/21/2021] [Indexed: 11/18/2022] Open
Abstract
Human T-cell lymphotropic virus type 1 (HTLV-1) infection affects millions of individuals worldwide and can lead to severe leukemia, myelopathy/tropical spastic paraparesis, and numerous other disorders. Pursuing a safe and effective immunotherapeutic approach, we compared the viral polyprotein and the human proteome with a sliding window approach in order to identify oligopeptide sequences unique to the virus. The immunological relevance of the viral unique oligopeptides was assessed by searching them in the immune epitope database (IEDB). We found that HTLV-1 has 15 peptide stretches each consisting of uniquely viral non-human pentapeptides which are ideal candidate for a safe and effective anti-HTLV-1 vaccine. Indeed, experimentally validated HTLV-1 epitopes, as retrieved from the IEDB, contain peptide sequences also present in a vast number of human proteins, thus potentially instituting the basis for cross-reactions. We found a potential for cross-reactivity between the virus and the human proteome and described an epitope platform to be used in order to avoid it, thus obtaining effective, specific, and safe immunization. Potential advantages for mRNA and peptide-based vaccine formulations are discussed.
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MESH Headings
- Amino Acid Sequence
- Databases, Genetic
- Epitope Mapping
- Epitopes/chemistry
- Epitopes/genetics
- Epitopes/immunology
- HTLV-I Infections/immunology
- HTLV-I Infections/prevention & control
- HTLV-I Infections/virology
- Human T-lymphotropic virus 1/chemistry
- Human T-lymphotropic virus 1/genetics
- Human T-lymphotropic virus 1/immunology
- Humans
- Immunization
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/immunology
- Vaccines, Subunit/chemistry
- Vaccines, Subunit/genetics
- Vaccines, Subunit/immunology
- Vaccines, Synthetic/chemistry
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Viral Vaccines/chemistry
- Viral Vaccines/genetics
- Viral Vaccines/immunology
- mRNA Vaccines/chemistry
- mRNA Vaccines/genetics
- mRNA Vaccines/immunology
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Affiliation(s)
- Guglielmo Lucchese
- Department of Neurology, Medical University of Greifswald, 17475 Greifswald, Germany
| | - Hamid Reza Jahantigh
- Interdisciplinary Department of Medicine-Section of Occupational Medicine, University of Bari, 70124 Bari, Italy; (H.R.J.); (L.D.B.); (P.L.); (A.S.)
- Animal Health and Zoonosis Doctoral Program, Department of Veterinary Medicine, University of Bari, 70010 Bari, Italy
| | - Leonarda De Benedictis
- Interdisciplinary Department of Medicine-Section of Occupational Medicine, University of Bari, 70124 Bari, Italy; (H.R.J.); (L.D.B.); (P.L.); (A.S.)
| | - Piero Lovreglio
- Interdisciplinary Department of Medicine-Section of Occupational Medicine, University of Bari, 70124 Bari, Italy; (H.R.J.); (L.D.B.); (P.L.); (A.S.)
| | - Angela Stufano
- Interdisciplinary Department of Medicine-Section of Occupational Medicine, University of Bari, 70124 Bari, Italy; (H.R.J.); (L.D.B.); (P.L.); (A.S.)
- Animal Health and Zoonosis Doctoral Program, Department of Veterinary Medicine, University of Bari, 70010 Bari, Italy
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Marima R, Hull R, Penny C, Dlamini Z. Mitotic syndicates Aurora Kinase B (AURKB) and mitotic arrest deficient 2 like 2 (MAD2L2) in cohorts of DNA damage response (DDR) and tumorigenesis. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2021; 787:108376. [PMID: 34083040 DOI: 10.1016/j.mrrev.2021.108376] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/05/2021] [Accepted: 04/20/2021] [Indexed: 12/31/2022]
Abstract
Aurora Kinase B (AURKB) and Mitotic Arrest Deficient 2 Like 2 (MAD2L2) are emerging anticancer therapeutic targets. AURKB and MAD2L2 are the least well studied members of their protein families, compared to AURKA and MAD2L1. Both AURKB and MAD2L2 play a critical role in mitosis, cell cycle checkpoint, DNA damage response (DDR) and normal physiological processes. However, the oncogenic roles of AURKB and MAD2L2 in tumorigenesis and genomic instability have also been reported. DDR acts as an arbitrator for cell fate by either repairing the damage or directing the cell to self-destruction. While there is strong evidence of interphase DDR, evidence of mitotic DDR is just emerging and remains largely unelucidated. To date, inhibitors of the DDR components show effective anti-cancer roles. Contrarily, long-term resistance towards drugs that target only one DDR target is becoming a challenge. Targeting interactions between protein-protein or protein-DNA holds prominent therapeutic potential. Both AURKB and MAD2L2 play critical roles in the success of mitosis and their emerging roles in mitotic DDR cannot be ignored. Small molecule inhibitors for AURKB are in clinical trials. A few lead compounds towards MAD2L2 inhibition have been discovered. Targeting mitotic DDR components and their interaction is emerging as a potent next generation anti-cancer therapeutic target. This can be done by developing small molecule inhibitors for AURKB and MAD2L2, thereby targeting DDR components as anti-cancer therapeutic targets and/or targeting mitotic DDR. This review focuses on AURKB and MAD2L2 prospective synergy to deregulate the p53 DDR pathway and promote favourable conditions for uncontrolled cell proliferation.
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Affiliation(s)
- Rahaba Marima
- SA-MRC/UP Precision Prevention and Novel Drug Targets for HIV-Associated Cancers Extramural Unit, Pan African Cancer Research Institute, Faculty of Health Sciences, University of Pretoria, Hatfield, 0028, South Africa.
| | - Rodney Hull
- SA-MRC/UP Precision Prevention and Novel Drug Targets for HIV-Associated Cancers Extramural Unit, Pan African Cancer Research Institute, Faculty of Health Sciences, University of Pretoria, Hatfield, 0028, South Africa
| | - Clement Penny
- Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Parktown, 2193, South Africa
| | - Zodwa Dlamini
- SA-MRC/UP Precision Prevention and Novel Drug Targets for HIV-Associated Cancers Extramural Unit, Pan African Cancer Research Institute, Faculty of Health Sciences, University of Pretoria, Hatfield, 0028, South Africa
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Leal AZ, Schwebs M, Briggs E, Weisert N, Reis H, Lemgruber L, Luko K, Wilkes J, Butter F, McCulloch R, Janzen CJ. Genome maintenance functions of a putative Trypanosoma brucei translesion DNA polymerase include telomere association and a role in antigenic variation. Nucleic Acids Res 2020; 48:9660-9680. [PMID: 32890403 PMCID: PMC7515707 DOI: 10.1093/nar/gkaa686] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 08/03/2020] [Accepted: 09/03/2020] [Indexed: 12/17/2022] Open
Abstract
Maintenance of genome integrity is critical to guarantee transfer of an intact genome from parent to offspring during cell division. DNA polymerases (Pols) provide roles in both replication of the genome and the repair of a wide range of lesions. Amongst replicative DNA Pols, translesion DNA Pols play a particular role: replication to bypass DNA damage. All cells express a range of translesion Pols, but little work has examined their function in parasites, including whether the enzymes might contribute to host-parasite interactions. Here, we describe a dual function of one putative translesion Pol in African trypanosomes, which we now name TbPolIE. Previously, we demonstrated that TbPolIE is associated with telomeric sequences and here we show that RNAi-mediated depletion of TbPolIE transcripts results in slowed growth, altered DNA content, changes in cell morphology, and increased sensitivity to DNA damaging agents. We also show that TbPolIE displays pronounced localization at the nuclear periphery, and that its depletion leads to chromosome segregation defects and increased levels of endogenous DNA damage. Finally, we demonstrate that TbPolIE depletion leads to deregulation of telomeric variant surface glycoprotein genes, linking the function of this putative translesion DNA polymerase to host immune evasion by antigenic variation.
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Affiliation(s)
- Andrea Zurita Leal
- The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Marie Schwebs
- Department of Cell & Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Emma Briggs
- The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Nadine Weisert
- Department of Cell & Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Helena Reis
- Department of Cell & Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Leandro Lemgruber
- The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Katarina Luko
- Quantitative Proteomics, Institute of Molecular Biology (IMB), Mainz, Germany
| | - Jonathan Wilkes
- The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Falk Butter
- Quantitative Proteomics, Institute of Molecular Biology (IMB), Mainz, Germany
| | - Richard McCulloch
- The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Christian J Janzen
- Department of Cell & Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
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Silvestri R, Landi S. DNA polymerases in the risk and prognosis of colorectal and pancreatic cancers. Mutagenesis 2020; 34:363-374. [PMID: 31647559 DOI: 10.1093/mutage/gez031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 09/17/2019] [Indexed: 12/30/2022] Open
Abstract
Human cancers arise from the alteration of genes involved in important pathways that mainly affect cell growth and proliferation. DNA replication and DNA damages recognition and repair are among these pathways and DNA polymerases that take part in these processes are frequently involved in cancer onset and progression. For example, damaging alterations within the proofreading domain of replicative polymerases, often reported in patients affected by colorectal cancer (CRC), are considered risk factors and drivers of carcinogenesis as they can lead to the accumulation of several mutations throughout the genome. Thus, replicative polymerases can be involved in cancer when losses of their physiological functions occur. On the contrary, reparative polymerases are often involved in cancer precisely because of their physiological role. In fact, their ability to repair and bypass DNA damages, which confers genome stability, can also counteract the effect of most anticancer drugs. In addition, the altered expression can characterise some type of cancers, which exacerbates this aspect. For example, all of the DNA polymerases involved a damage bypass mechanism, known as translesion synthesis, with the only exception of polymerase theta, are downregulated in CRC. Conversely, in pancreatic ductal adenocarcinoma (PDAC), most of these polymerase result upregulated. This suggests that different types of cancer can rely on different reparative polymerases to acquire drug resistance. Here we will examine all of the aspects that link DNA polymerases with CRC and PDAC.
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Affiliation(s)
| | - Stefano Landi
- Department of Biology, University of Pisa, Pisa, Italy
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7
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Acharya N, Khandagale P, Thakur S, Sahu JK, Utkalaja BG. Quaternary structural diversity in eukaryotic DNA polymerases: monomeric to multimeric form. Curr Genet 2020; 66:635-655. [PMID: 32236653 DOI: 10.1007/s00294-020-01071-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 03/13/2020] [Accepted: 03/24/2020] [Indexed: 12/14/2022]
Abstract
Sixteen eukaryotic DNA polymerases have been identified and studied so far. Based on the sequence similarity of the catalytic subunits of DNA polymerases, these have been classified into four A, B, X and Y families except PrimPol, which belongs to the AEP family. The quaternary structure of these polymerases also varies depending upon whether they are composed of one or more subunits. Therefore, in this review, we used a quaternary structure-based classification approach to group DNA polymerases as either monomeric or multimeric and highlighted functional significance of their accessory subunits. Additionally, we have briefly summarized various DNA polymerase discoveries from a historical perspective, emphasized unique catalytic mechanism of each DNA polymerase and highlighted recent advances in understanding their cellular functions.
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Affiliation(s)
- Narottam Acharya
- Laboratory of Genomic Instability and Diseases, Department of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, 751023, India.
| | - Prashant Khandagale
- Laboratory of Genomic Instability and Diseases, Department of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, 751023, India
| | - Shweta Thakur
- Laboratory of Genomic Instability and Diseases, Department of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, 751023, India
| | - Jugal Kishor Sahu
- Laboratory of Genomic Instability and Diseases, Department of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, 751023, India
| | - Bhabasha Gyanadeep Utkalaja
- Laboratory of Genomic Instability and Diseases, Department of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, 751023, India
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8
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Grgurevic S, Montilla-Perez P, Bradbury A, Gilhodes J, Queille S, Pelofy S, Bancaud A, Filleron T, Ysebaert L, Récher C, Laurent G, Fournié JJ, Cazaux C, Quillet-Mary A, Hoffmann JS. DNA polymerase ν gene expression influences fludarabine resistance in chronic lymphocytic leukemia independently of p53 status. Haematologica 2018; 103:1038-1046. [PMID: 29567785 PMCID: PMC6058778 DOI: 10.3324/haematol.2017.174243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 03/16/2018] [Indexed: 01/09/2023] Open
Abstract
Alteration in the DNA replication, repair or recombination processes is a highly relevant mechanism of genomic instability. Despite genomic aberrations manifested in hematologic malignancies, such a defect as a source of biomarkers has been underexplored. Here, we investigated the prognostic value of expression of 82 genes involved in DNA replication-repair-recombination in a series of 99 patients with chronic lymphocytic leukemia without detectable 17p deletion or TP53 mutation. We found that expression of the POLN gene, encoding the specialized DNA polymerase ν (Pol ν) correlates with time to relapse after first-line therapy with fludarabine. Moreover, we found that POLN was the only gene up-regulated in primary patients’ lymphocytes when exposed in vitro to proliferative and pro-survival stimuli. By using two cell lines that were sequentially established from the same patient during the course of the disease and Pol ν knockout mouse embryonic fibroblasts, we reveal that high relative POLN expression is important for DNA synthesis and cell survival upon fludarabine treatment. These findings suggest that Pol ν could influence therapeutic resistance in chronic lymphocytic leukemia. (Patients’ samples were obtained from the CLL 2007 FMP clinical trial registered at: clinicaltrials.gov identifer: 00564512).
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Affiliation(s)
- Srdana Grgurevic
- CRCT, Université de Toulouse, Inserm, CNRS, UPS, France; Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, France
| | - Patricia Montilla-Perez
- CRCT, Université de Toulouse, Inserm, CNRS, UPS, France; Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, France
| | | | - Julia Gilhodes
- Clinical Trials Office - Biostatistics Unit, Institute Claudius Regaud, Institute Universitaire du Cancer Toulouse-Oncopole (IUCT-O), Toulouse, France
| | - Sophie Queille
- CRCT, Université de Toulouse, Inserm, CNRS, UPS, France; Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, France
| | | | | | - Thomas Filleron
- Clinical Trials Office - Biostatistics Unit, Institute Claudius Regaud, Institute Universitaire du Cancer Toulouse-Oncopole (IUCT-O), Toulouse, France
| | - Loïc Ysebaert
- Department of Hematology, Institut Universitaire du Cancer Toulouse-Oncopole, Toulouse, France
| | - Christian Récher
- Department of Hematology, Institut Universitaire du Cancer Toulouse-Oncopole, Toulouse, France
| | - Guy Laurent
- Department of Hematology, Institut Universitaire du Cancer Toulouse-Oncopole, Toulouse, France
| | - Jean-Jacques Fournié
- CRCT, Université de Toulouse, Inserm, CNRS, UPS, France; Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, France
| | - Christophe Cazaux
- CRCT, Université de Toulouse, Inserm, CNRS, UPS, France; Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, France
| | - Anne Quillet-Mary
- CRCT, Université de Toulouse, Inserm, CNRS, UPS, France; Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, France
| | - Jean-Sébastien Hoffmann
- CRCT, Université de Toulouse, Inserm, CNRS, UPS, France; Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, France
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Quinet A, Lerner LK, Martins DJ, Menck CFM. Filling gaps in translesion DNA synthesis in human cells. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2018; 836:127-142. [PMID: 30442338 DOI: 10.1016/j.mrgentox.2018.02.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 02/21/2018] [Indexed: 01/06/2023]
Abstract
During DNA replication, forks may encounter unrepaired lesions that hamper DNA synthesis. Cells have universal strategies to promote damage bypass allowing cells to survive. DNA damage tolerance can be performed upon template switch or by specialized DNA polymerases, known as translesion (TLS) polymerases. Human cells count on more than eleven TLS polymerases and this work reviews the functions of some of these enzymes: Rev1, Pol η, Pol ι, Pol κ, Pol θ and Pol ζ. The mechanisms of damage bypass vary according to the lesion, as well as to the TLS polymerases available, and may occur directly at the fork during replication. Alternatively, the lesion may be skipped, leaving a single-stranded DNA gap that will be replicated later. Details of the participation of these enzymes are revised for the replication of damaged template. TLS polymerases also have functions in other cellular processes. These include involvement in somatic hypermutation in immunoglobulin genes, direct participation in recombination and repair processes, and contributing to replicating noncanonical DNA structures. The importance of DNA damage replication to cell survival is supported by recent discoveries that certain genes encoding TLS polymerases are induced in response to DNA damaging agents, protecting cells from a subsequent challenge to DNA replication. We retrace the findings on these genotoxic (adaptive) responses of human cells and show the common aspects with the SOS responses in bacteria. Paradoxically, although TLS of DNA damage is normally an error prone mechanism, in general it protects from carcinogenesis, as evidenced by increased tumorigenesis in xeroderma pigmentosum variant patients, who are deficient in Pol η. As these TLS polymerases also promote cell survival, they constitute an important mechanism by which cancer cells acquire resistance to genotoxic chemotherapy. Therefore, the TLS polymerases are new potential targets for improving therapy against tumors.
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Affiliation(s)
- Annabel Quinet
- Saint Louis University School of Medicine, St. Louis, MO, United States.
| | - Leticia K Lerner
- MRC Laboratory of Molecular Biology,Francis Crick Avenue, Cambridge CB2 0QH, UK.
| | - Davi J Martins
- Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Carlos F M Menck
- Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
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Analysis of DNA polymerase ν function in meiotic recombination, immunoglobulin class-switching, and DNA damage tolerance. PLoS Genet 2017; 13:e1006818. [PMID: 28570559 PMCID: PMC5472330 DOI: 10.1371/journal.pgen.1006818] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 06/15/2017] [Accepted: 05/13/2017] [Indexed: 11/20/2022] Open
Abstract
DNA polymerase ν (pol ν), encoded by the POLN gene, is an A-family DNA polymerase in vertebrates and some other animal lineages. Here we report an in-depth analysis of pol ν–defective mice and human cells. POLN is very weakly expressed in most tissues, with the highest relative expression in testis. We constructed multiple mouse models for Poln disruption and detected no anatomic abnormalities, alterations in lifespan, or changed causes of mortality. Mice with inactive Poln are fertile and have normal testis morphology. However, pol ν–disrupted mice have a modestly reduced crossover frequency at a meiotic recombination hot spot harboring insertion/deletion polymorphisms. These polymorphisms are suggested to generate a looped-out primer and a hairpin structure during recombination, substrates on which pol ν can operate. Pol ν-defective mice had no alteration in DNA end-joining during immunoglobulin class-switching, in contrast to animals defective in the related DNA polymerase θ (pol θ). We examined the response to DNA crosslinking agents, as purified pol ν has some ability to bypass major groove peptide adducts and residues of DNA crosslink repair. Inactivation of Poln in mouse embryonic fibroblasts did not alter cellular sensitivity to mitomycin C, cisplatin, or aldehydes. Depletion of POLN from human cells with shRNA or siRNA did not change cellular sensitivity to mitomycin C or alter the frequency of mitomycin C-induced radial chromosomes. Our results suggest a function of pol ν in meiotic homologous recombination in processing specific substrates. The restricted and more recent evolutionary appearance of pol ν (in comparison to pol θ) supports such a specialized role. The work described here fills a current gap in the study of the 16 known DNA polymerases in vertebrate genomes. Until now, experiments with genetically disrupted mice have been reported for all but pol ν, encoded by the POLN gene. To intensively analyze the role of mammalian pol ν we generated multiple Poln-deficient murine models. We discovered that Poln is uniquely upregulated during testicular development and that it is enriched in spermatocytes. This, and phylogenetic analysis indicate a testis-specific function. We observed a modest reduction in meiotic recombination at a recombination hotspot in Poln-deficient mice. Pol ν has been suggested to function in DNA crosslink repair. However, we found no increased DNA crosslink sensitivity in Poln-deficient mice or POLN-depleted human cells. This is a major difference from some previous findings, and we support our conclusion by multiple experimental approaches, and by the very low or absent expression of functional pol ν in mammalian somatic cells. The present work represents the first description and comprehensive analysis of mice deficient in pol ν, and the first thorough phenotypic analysis in human cells.
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McVey M, Khodaverdian VY, Meyer D, Cerqueira PG, Heyer WD. Eukaryotic DNA Polymerases in Homologous Recombination. Annu Rev Genet 2017; 50:393-421. [PMID: 27893960 DOI: 10.1146/annurev-genet-120215-035243] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Homologous recombination (HR) is a central process to ensure genomic stability in somatic cells and during meiosis. HR-associated DNA synthesis determines in large part the fidelity of the process. A number of recent studies have demonstrated that DNA synthesis during HR is conservative, less processive, and more mutagenic than replicative DNA synthesis. In this review, we describe mechanistic features of DNA synthesis during different types of HR-mediated DNA repair, including synthesis-dependent strand annealing, break-induced replication, and meiotic recombination. We highlight recent findings from diverse eukaryotic organisms, including humans, that suggest both replicative and translesion DNA polymerases are involved in HR-associated DNA synthesis. Our focus is to integrate the emerging literature about DNA polymerase involvement during HR with the unique aspects of these repair mechanisms, including mutagenesis and template switching.
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Affiliation(s)
- Mitch McVey
- Department of Biology, Tufts University, Medford, Massachusetts 02155;
| | | | - Damon Meyer
- Department of Microbiology and Molecular Genetics, University of California, Davis, California 95616; .,College of Health Sciences, California Northstate University, Rancho Cordova, California 95670
| | - Paula Gonçalves Cerqueira
- Department of Microbiology and Molecular Genetics, University of California, Davis, California 95616;
| | - Wolf-Dietrich Heyer
- Department of Microbiology and Molecular Genetics, University of California, Davis, California 95616; .,Department of Molecular and Cellular Biology, University of California, Davis, California 95616
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12
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Nikolova T, Roos WP, Krämer OH, Strik HM, Kaina B. Chloroethylating nitrosoureas in cancer therapy: DNA damage, repair and cell death signaling. Biochim Biophys Acta Rev Cancer 2017; 1868:29-39. [PMID: 28143714 DOI: 10.1016/j.bbcan.2017.01.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/25/2017] [Accepted: 01/26/2017] [Indexed: 01/20/2023]
Abstract
Chloroethylating nitrosoureas (CNU), such as lomustine, nimustine, semustine, carmustine and fotemustine are used for the treatment of malignant gliomas, brain metastases of different origin, melanomas and Hodgkin disease. They alkylate the DNA bases and give rise to the formation of monoadducts and subsequently interstrand crosslinks (ICL). ICL are critical cytotoxic DNA lesions that link the DNA strands covalently and block DNA replication and transcription. As a result, S phase progression is inhibited and cells are triggered to undergo apoptosis and necrosis, which both contribute to the effectiveness of CNU-based cancer therapy. However, tumor cells resist chemotherapy through the repair of CNU-induced DNA damage. The suicide enzyme O6-methylguanine-DNA methyltransferase (MGMT) removes the precursor DNA lesion O6-chloroethylguanine prior to its conversion into ICL. In cells lacking MGMT, the formed ICL evoke complex enzymatic networks to accomplish their removal. Here we discuss the mechanism of ICL repair as a survival strategy of healthy and cancer cells and DNA damage signaling as a mechanism contributing to CNU-induced cell death. We also discuss therapeutic implications and strategies based on sequential and simultaneous treatment with CNU and the methylating drug temozolomide.
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Affiliation(s)
- Teodora Nikolova
- Institute of Toxicology, University Medical Center, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany.
| | - Wynand P Roos
- Institute of Toxicology, University Medical Center, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany
| | - Oliver H Krämer
- Institute of Toxicology, University Medical Center, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany
| | - Herwig M Strik
- Department of Neurology, University Medical Center, Baldinger Strasse, 35033 Marburg, Germany
| | - Bernd Kaina
- Institute of Toxicology, University Medical Center, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany.
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13
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Prakasha Gowda AS, Spratt TE. DNA Polymerase ν Rapidly Bypasses O 6-Methyl-dG but Not O 6-[4-(3-Pyridyl)-4-oxobutyl-dG and O 2-Alkyl-dTs. Chem Res Toxicol 2016; 29:1894-1900. [PMID: 27741574 PMCID: PMC5673091 DOI: 10.1021/acs.chemrestox.6b00318] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent tobacco carcinogen that forms mutagenic DNA adducts including O6-methyl-2'-deoxyguanosine (O6-Me-dG), O6-[4-(3-pyridyl)-4-oxobut-1-yl]-dG (O6-POB-dG), O2-methylthymidine (O2-Me-dT), and O2-POB-dT. We evaluated the ability of human DNA polymerase ν to bypass this damage to evaluate the structural constraints on substrates for pol ν and to evaluate if there is kinetic evidence suggesting the in vivo activity of pol ν on tobacco-induced DNA damage. Presteady-state kinetic analysis has indicated that O6-Me-dG is a good substrate for pol ν, while O6-POB-dG and the O2-alkyl-dT adducts are poor substrates for pol ν. The reactivity with O6-Me-dG is high with a preference for dCTP > dGTP > dATP > dTTP. The catalytic activity of pol ν toward O6-Me-dG is high and can potentially be involved in its bypass in vivo. In contrast, pol ν is unlikely to bypass O6-POB-dG or the O2-alkyl-dTs in vivo.
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Affiliation(s)
- A. S. Prakasha Gowda
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Pennsylvania State University, Hershey, Pennsylvania 17033, United States
| | - Thomas E. Spratt
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Pennsylvania State University, Hershey, Pennsylvania 17033, United States
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14
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Roy U, Mukherjee S, Sharma A, Frank EG, Schärer OD. The structure and duplex context of DNA interstrand crosslinks affects the activity of DNA polymerase η. Nucleic Acids Res 2016; 44:7281-91. [PMID: 27257072 PMCID: PMC5009737 DOI: 10.1093/nar/gkw485] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/20/2016] [Indexed: 12/18/2022] Open
Abstract
Several important anti-tumor agents form DNA interstrand crosslinks (ICLs), but their clinical efficiency is counteracted by multiple complex DNA repair pathways. All of these pathways require unhooking of the ICL from one strand of a DNA duplex by nucleases, followed by bypass of the unhooked ICL by translesion synthesis (TLS) polymerases. The structures of the unhooked ICLs remain unknown, yet the position of incisions and processing of the unhooked ICLs significantly influence the efficiency and fidelity of bypass by TLS polymerases. We have synthesized a panel of model unhooked nitrogen mustard ICLs to systematically investigate how the state of an unhooked ICL affects pol η activity. We find that duplex distortion induced by a crosslink plays a crucial role in translesion synthesis, and length of the duplex surrounding an unhooked ICL critically affects polymerase efficiency. We report the synthesis of a putative ICL repair intermediate that mimics the complete processing of an unhooked ICL to a single crosslinked nucleotide, and find that it provides only a minimal obstacle for DNA polymerases. Our results raise the possibility that, depending on the structure and extent of processing of an ICL, its bypass may not absolutely require TLS polymerases.
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Affiliation(s)
- Upasana Roy
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Shivam Mukherjee
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Anjali Sharma
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Ekaterina G Frank
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-3371, USA
| | - Orlando D Schärer
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794-3400, USA
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15
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Roy U, Schärer OD. Involvement of translesion synthesis DNA polymerases in DNA interstrand crosslink repair. DNA Repair (Amst) 2016; 44:33-41. [PMID: 27311543 DOI: 10.1016/j.dnarep.2016.05.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
DNA interstrand crosslinks (ICLs) covalently join the two strands of a DNA duplex and block essential processes such as DNA replication and transcription. Several important anti-tumor drugs such as cisplatin and nitrogen mustards exert their cytotoxicity by forming ICLs. However, multiple complex pathways repair ICLs and these are thought to contribute to the development of resistance towards ICL-inducing agents. While the understanding of many aspects of ICL repair is still rudimentary, studies in recent years have provided significant insights into the pathways of ICL repair. In this perspective we review the recent advances made in elucidating the mechanisms of ICL repair with a focus on the role of TLS polymerases. We describe the emerging models for how these enzymes contribute to and are regulated in ICL repair, discuss the key open questions and examine the implications for this pathway in anti-cancer therapy.
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Affiliation(s)
- Upasana Roy
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Orlando D Schärer
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA; Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794-3400, USA.
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16
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Beagan K, McVey M. Linking DNA polymerase theta structure and function in health and disease. Cell Mol Life Sci 2016; 73:603-15. [PMID: 26514729 PMCID: PMC4715478 DOI: 10.1007/s00018-015-2078-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/10/2015] [Accepted: 10/19/2015] [Indexed: 10/22/2022]
Abstract
DNA polymerase theta (Pol θ) is an error-prone A-family polymerase that is highly conserved among multicellular eukaryotes and plays multiple roles in DNA repair and the regulation of genome integrity. Studies conducted in several model organisms have shown that Pol θ can be utilized during DNA interstrand crosslink repair and during alternative end-joining repair of double-strand breaks. Recent genetic and biochemical studies have begun to elucidate the unique structural features of Pol θ that promote alternative end-joining repair. Importantly, Pol θ-dependent end joining appears to be important for overall genome stability, as it affects chromosome translocation formation in murine and human cell lines. Pol θ has also been suggested to act as a modifier of replication timing in human cells, though the mechanism of action remains unknown. Pol θ is highly upregulated in a number of human cancer types, which could indicate that mutagenic Pol θ-dependent end joining is used during cancer cell proliferation. Here, we review the various roles of Pol θ across species and discuss how these roles may be relevant to cancer therapy.
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Affiliation(s)
- Kelly Beagan
- Department of Biology, Tufts University, 200 Boston Avenue, Suite 4700, Medford, MA, 02155, USA
| | - Mitch McVey
- Department of Biology, Tufts University, 200 Boston Avenue, Suite 4700, Medford, MA, 02155, USA.
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17
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Xu W, Ouellette A, Ghosh S, O'Neill TC, Greenberg MM, Zhao L. Mutagenic Bypass of an Oxidized Abasic Lesion-Induced DNA Interstrand Cross-Link Analogue by Human Translesion Synthesis DNA Polymerases. Biochemistry 2015; 54:7409-22. [PMID: 26626537 DOI: 10.1021/acs.biochem.5b01027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
5'-(2-Phosphoryl-1,4-dioxobutane) (DOB) is an oxidized abasic site that is produced by several antitumor agents and γ-radiolysis. DOB reacts reversibly with a dA opposite the 3'-adjacent nucleotide to form DNA interstrand cross-links (ICLs), genotoxic DNA lesions that can block DNA replication and transcription. Translesion synthesis (TLS) is an important step in several ICL repair pathways to bypass unhooked intermediates generated by endonucleolytic incision. The instability of DOB-ICLs has made it difficult to learn about their TLS-mediated repair capability and mutagenic potential. We recently developed a method for chemically synthesizing oligonucleotides containing a modified DOB-ICL analogue. Herein, we examined the capabilities of several highly relevant eukaryotic TLS DNA polymerases (pols), including human pol η, pol κ, pol ι, pol ν, REV1, and yeast pol ζ, to bypass this DOB-ICL analogue. The prelesion, translesion, and postlesion replication efficiency and fidelity were examined. Pol η showed moderate bypass activity when encountering the DOB-ICL, giving major products one or two nucleotides beyond the cross-linked template nucleotide. In contrast, DNA synthesis by the other pols was stalled at the position before the cross-linked nucleotide. Steady-state kinetic data and liquid chromatography-mass spectrometry sequencing of primer extension products by pol η unambiguously revealed that pol η-mediated bypass is highly error-prone. Together, our study provides the first set of in vitro evidence that the DOB-ICL is a replication-blocking and highly miscoding lesion. Compared to several other TLS pols examined, pol η is likely to contribute to the TLS-mediated repair of the DOB-ICL in vivo.
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Affiliation(s)
| | | | - Souradyuti Ghosh
- Department of Chemistry, Johns Hopkins University , Baltimore, Maryland 21218, United States
| | | | - Marc M Greenberg
- Department of Chemistry, Johns Hopkins University , Baltimore, Maryland 21218, United States
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18
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Takata KI, Tomida J, Reh S, Swanhart LM, Takata M, Hukriede NA, Wood RD. Conserved overlapping gene arrangement, restricted expression, and biochemical activities of DNA polymerase ν (POLN). J Biol Chem 2015; 290:24278-93. [PMID: 26269593 PMCID: PMC4591814 DOI: 10.1074/jbc.m115.677419] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Indexed: 12/12/2022] Open
Abstract
DNA polymerase ν (POLN) is one of 16 DNA polymerases encoded in vertebrate genomes. It is important to determine its gene expression patterns, biological roles, and biochemical activities. By quantitative analysis of mRNA expression, we found that POLN from the zebrafish Danio rerio is expressed predominantly in testis. POLN is not detectably expressed in zebrafish embryos or in mouse embryonic stem cells. Consistent with this, injection of POLN-specific morpholino antisense oligonucleotides did not interfere with zebrafish embryonic development. Analysis of transcripts revealed that vertebrate POLN has an unusual gene expression arrangement, sharing a first exon with HAUS3, the gene encoding augmin-like complex subunit 3. HAUS3 is broadly expressed in embryonic and adult tissues, in contrast to POLN. Differential expression of POLN and HAUS3 appears to arise by alternate splicing of transcripts in mammalian cells and zebrafish. When POLN was ectopically overexpressed in human cells, it specifically coimmunoprecipitated with the homologous recombination factors BRCA1 and FANCJ, but not with previously suggested interaction partners (HELQ and members of the Fanconi anemia core complex). Purified zebrafish POLN protein is capable of thymine glycol bypass and strand displacement, with activity dependent on a basic amino acid residue known to stabilize the primer-template. These properties are conserved with the human enzyme. Although the physiological function of pol ν remains to be clarified, this study uncovers distinctive aspects of its expression control and evolutionarily conserved properties of this DNA polymerase.
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Affiliation(s)
- Kei-Ichi Takata
- From the Department of Epigenetics and Molecular Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Smithville, Texas 78957, the University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030,
| | - Junya Tomida
- From the Department of Epigenetics and Molecular Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Smithville, Texas 78957, the University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030
| | - Shelley Reh
- From the Department of Epigenetics and Molecular Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Smithville, Texas 78957, the University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030
| | - Lisa M Swanhart
- the Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, and
| | - Minoru Takata
- the Laboratory of DNA Damage Signaling, Department of Late Effects Studies, Radiation Biology Center, Kyoto University, Kyoto 606-8501, Japan
| | - Neil A Hukriede
- the Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, and
| | - Richard D Wood
- From the Department of Epigenetics and Molecular Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Smithville, Texas 78957, the University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030
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19
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Abstract
Although the two B-family human DNA polymerases, pol δ and pol ε, are responsible for the bulk of nuclear genome replication, at least 14 additional polymerases have roles in nuclear DNA repair and replication. In this issue, newly reported crystal structures of two specialized A-family polymerases, pol δ and pol ε, expose these enzymes’ strategies for handling aberrant DNA ends.
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20
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Gowda ASP, Moldovan GL, Spratt TE. Human DNA Polymerase ν Catalyzes Correct and Incorrect DNA Synthesis with High Catalytic Efficiency. J Biol Chem 2015; 290:16292-303. [PMID: 25963146 DOI: 10.1074/jbc.m115.653287] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Indexed: 01/04/2023] Open
Abstract
DNA polymerase ν (pol ν) is a low fidelity A-family polymerase with a putative role in interstrand cross-link repair and homologous recombination. We carried out pre-steady-state kinetic analysis to elucidate the kinetic mechanism of this enzyme. We found that the mechanism consists of seven steps, similar that of other A-family polymerases. pol ν binds to DNA with a Kd for DNA of 9.2 nm, with an off-rate constant of 0.013 s(-1)and an on-rate constant of 14 μm(-1) s(-1). dNTP binding is rapid with Kd values of 20 and 476 μm for the correct and incorrect dNTP, respectively. Pyrophosphorylation occurs with a Kd value for PPi of 3.7 mm and a maximal rate constant of 11 s(-1). Pre-steady-state kinetics, examination of the elemental effect using dNTPαS, and pulse-chase experiments indicate that a rapid phosphodiester bond formation step is flanked by slow conformational changes for both correct and incorrect base pair formation. These experiments in combination with computer simulations indicate that the first conformational change occurs with rate constants of 75 and 20 s(-1); rapid phosphodiester bond formation occurs with a Keq of 2.2 and 1.7, and the second conformational change occurs with rate constants of 2.1 and 0.5 s(-1), for correct and incorrect base pair formation, respectively. The presence of a mispair does not induce the polymerase to adopt a low catalytic conformation. pol ν catalyzes both correct and mispair formation with high catalytic efficiency.
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Affiliation(s)
- A S Prakasha Gowda
- From the Department of Biochemistry and Molecular Biology, Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033
| | - George-Lucian Moldovan
- From the Department of Biochemistry and Molecular Biology, Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033
| | - Thomas E Spratt
- From the Department of Biochemistry and Molecular Biology, Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033
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21
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Naryshkin NA, Weetall M, Dakka A, Narasimhan J, Zhao X, Feng Z, Ling KKY, Karp GM, Qi H, Woll MG, Chen G, Zhang N, Gabbeta V, Vazirani P, Bhattacharyya A, Furia B, Risher N, Sheedy J, Kong R, Ma J, Turpoff A, Lee CS, Zhang X, Moon YC, Trifillis P, Welch EM, Colacino JM, Babiak J, Almstead NG, Peltz SW, Eng LA, Chen KS, Mull JL, Lynes MS, Rubin LL, Fontoura P, Santarelli L, Haehnke D, McCarthy KD, Schmucki R, Ebeling M, Sivaramakrishnan M, Ko CP, Paushkin SV, Ratni H, Gerlach I, Ghosh A, Metzger F. Motor neuron disease. SMN2 splicing modifiers improve motor function and longevity in mice with spinal muscular atrophy. Science 2014; 345:688-93. [PMID: 25104390 DOI: 10.1126/science.1250127] [Citation(s) in RCA: 346] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Spinal muscular atrophy (SMA) is a genetic disease caused by mutation or deletion of the survival of motor neuron 1 (SMN1) gene. A paralogous gene in humans, SMN2, produces low, insufficient levels of functional SMN protein due to alternative splicing that truncates the transcript. The decreased levels of SMN protein lead to progressive neuromuscular degeneration and high rates of mortality. Through chemical screening and optimization, we identified orally available small molecules that shift the balance of SMN2 splicing toward the production of full-length SMN2 messenger RNA with high selectivity. Administration of these compounds to Δ7 mice, a model of severe SMA, led to an increase in SMN protein levels, improvement of motor function, and protection of the neuromuscular circuit. These compounds also extended the life span of the mice. Selective SMN2 splicing modifiers may have therapeutic potential for patients with SMA.
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Affiliation(s)
| | - Marla Weetall
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Amal Dakka
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Jana Narasimhan
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Xin Zhao
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Zhihua Feng
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Karen K Y Ling
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Gary M Karp
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Hongyan Qi
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Matthew G Woll
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Guangming Chen
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Nanjing Zhang
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | | | - Priya Vazirani
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | | | - Bansri Furia
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Nicole Risher
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Josephine Sheedy
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Ronald Kong
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Jiyuan Ma
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Anthony Turpoff
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Chang-Sun Lee
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Xiaoyan Zhang
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Young-Choon Moon
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | | | - Ellen M Welch
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Joseph M Colacino
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - John Babiak
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Neil G Almstead
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Stuart W Peltz
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA.
| | - Loren A Eng
- SMA Foundation, 888 Seventh Avenue, Suite 400, New York, NY 10019, USA
| | - Karen S Chen
- SMA Foundation, 888 Seventh Avenue, Suite 400, New York, NY 10019, USA
| | - Jesse L Mull
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Maureen S Lynes
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Lee L Rubin
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Paulo Fontoura
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Luca Santarelli
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Daniel Haehnke
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | | | - Roland Schmucki
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Martin Ebeling
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Manaswini Sivaramakrishnan
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Chien-Ping Ko
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Sergey V Paushkin
- SMA Foundation, 888 Seventh Avenue, Suite 400, New York, NY 10019, USA
| | - Hasane Ratni
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Irene Gerlach
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Anirvan Ghosh
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Friedrich Metzger
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland.
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22
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Clauson C, Schärer OD, Niedernhofer L. Advances in understanding the complex mechanisms of DNA interstrand cross-link repair. Cold Spring Harb Perspect Biol 2013; 5:a012732. [PMID: 24086043 DOI: 10.1101/cshperspect.a012732] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
DNA interstrand cross-links (ICLs) are lesions caused by a variety of endogenous metabolites, environmental exposures, and cancer chemotherapeutic agents that have two reactive groups. The common feature of these diverse lesions is that two nucleotides on opposite strands are covalently joined. ICLs prevent the separation of two DNA strands and therefore essential cellular processes including DNA replication and transcription. ICLs are mainly detected in S phase when a replication fork stalls at an ICL. Damage signaling and repair of ICLs are promoted by the Fanconi anemia pathway and numerous posttranslational modifications of DNA repair and chromatin structural proteins. ICLs are also detected and repaired in nonreplicating cells, although the mechanism is less clear. A unique feature of ICL repair is that both strands of DNA must be incised to completely remove the lesion. This is accomplished in sequential steps to prevent creating multiple double-strand breaks. Unhooking of an ICL from one strand is followed by translesion synthesis to fill the gap and create an intact duplex DNA, harboring a remnant of the ICL. Removal of the lesion from the second strand is likely accomplished by nucleotide excision repair. Inadequate repair of ICLs is particularly detrimental to rapidly dividing cells, explaining the bone marrow failure characteristic of Fanconi anemia and why cross-linking agents are efficacious in cancer therapy. Herein, recent advances in our understanding of ICLs and the biological responses they trigger are discussed.
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Affiliation(s)
- Cheryl Clauson
- Department of Microbiology and Molecular Genetics, The University of Pittsburgh, Pittsburgh, Pennsylvania 15219
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23
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Abstract
The structural features that enable replicative DNA polymerases to synthesize DNA rapidly and accurately also limit their ability to copy damaged DNA. Direct replication of DNA damage is termed translesion synthesis (TLS), a mechanism conserved from bacteria to mammals and executed by an array of specialized DNA polymerases. This chapter examines how these translesion polymerases replicate damaged DNA and how they are regulated to balance their ability to replicate DNA lesions with the risk of undesirable mutagenesis. It also discusses how TLS is co-opted to increase the diversity of the immunoglobulin gene hypermutation and the contribution it makes to the mutations that sculpt the genome of cancer cells.
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Affiliation(s)
- Julian E Sale
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom.
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24
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Sharma S, Canman CE. REV1 and DNA polymerase zeta in DNA interstrand crosslink repair. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2012; 53:725-40. [PMID: 23065650 PMCID: PMC5543726 DOI: 10.1002/em.21736] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 08/09/2012] [Accepted: 08/15/2012] [Indexed: 05/06/2023]
Abstract
DNA interstrand crosslinks (ICLs) are covalent linkages between two strands of DNA, and their presence interferes with essential metabolic processes such as transcription and replication. These lesions are extremely toxic, and their repair is essential for genome stability and cell survival. In this review, we will discuss how the removal of ICLs requires interplay between multiple genome maintenance pathways and can occur in the absence of replication (replication-independent ICL repair) or during S phase (replication-coupled ICL repair), the latter being the predominant pathway used in mammalian cells. It is now well recognized that translesion DNA synthesis (TLS), especially through the activities of REV1 and DNA polymerase zeta (Polζ), is necessary for both ICL repair pathways operating throughout the cell cycle. Recent studies suggest that the convergence of two replication forks upon an ICL initiates a cascade of events including unhooking of the lesion through the actions of structure-specific endonucleases, thereby creating a DNA double-stranded break (DSB). TLS across the unhooked lesion is necessary for restoring the sister chromatid before homologous recombination repair. Biochemical and genetic studies implicate REV1 and Polζ as being essential for performing lesion bypass across the unhooked crosslink, and this step appears to be important for subsequent events to repair the intermediate DSB. The potential role of Fanconi anemia pathway in the regulation of REV1 and Polζ-dependent TLS and the involvement of additional polymerases, including DNA polymerases kappa, nu, and theta, in the repair of ICLs is also discussed in this review.
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Affiliation(s)
- Shilpy Sharma
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA
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25
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Duquette ML, Zhu Q, Taylor ER, Tsay AJ, Shi LZ, Berns MW, McGowan CH. CtIP is required to initiate replication-dependent interstrand crosslink repair. PLoS Genet 2012; 8:e1003050. [PMID: 23144634 PMCID: PMC3493458 DOI: 10.1371/journal.pgen.1003050] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 09/12/2012] [Indexed: 11/26/2022] Open
Abstract
DNA interstrand crosslinks (ICLs) are toxic lesions that block the progression of replication and transcription. CtIP is a conserved DNA repair protein that facilitates DNA end resection in the double-strand break (DSB) repair pathway. Here we show that CtIP plays a critical role during initiation of ICL processing in replicating human cells that is distinct from its role in DSB repair. CtIP depletion sensitizes human cells to ICL inducing agents and significantly impairs the accumulation of DNA damage response proteins RPA, ATR, FANCD2, γH2AX, and phosphorylated ATM at sites of laser generated ICLs. In contrast, the appearance of γH2AX and phosphorylated ATM at sites of laser generated double strand breaks (DSBs) is CtIP-independent. We present a model in which CtIP functions early in ICL repair in a BRCA1– and FANCM–dependent manner prior to generation of DSB repair intermediates. One of the most lethal forms of DNA damage is the interstrand crosslink (ICL). An ICL is a chemical bridge between two nucleotides on complementary strands of DNA. An unrepaired ICL is toxic because it poses an unsurpassable block to DNA replication and transcription. Certain forms of cancer treatment exploit the toxicity of ICL generating agents to target rapidly dividing cells. Sensitivity to crosslinking agents is a defining characteristic of Fanconi Anemia (FA), a hereditary syndrome characterized by an increased risk in cancer development and hematopoietic abnormalities frequently resulting in bone marrow failure. The mechanism underlying ICL repair is important to human health; however, the sequence of molecular events governing ICL repair is poorly understood. Here we describe how the repair protein CtIP functions to initiate ICL repair in replicating cells in a manner distinct from its previously described role in other forms of DNA repair.
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Affiliation(s)
- Michelle L Duquette
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, United States of America.
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26
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Smith LA, Makarova AV, Samson L, Thiesen KE, Dhar A, Bessho T. Bypass of a psoralen DNA interstrand cross-link by DNA polymerases β, ι, and κ in vitro. Biochemistry 2012; 51:8931-8. [PMID: 23106263 DOI: 10.1021/bi3008565] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Repair of DNA interstrand cross-links in mammalian cells involves several biochemically distinctive processes, including the release of one of the cross-linked strands and translesion DNA synthesis (TLS). In this report, we investigated the in vitro TLS activity of a psoralen DNA interstrand cross-link by three DNA repair polymerases, DNA polymerases β, κ, and ι. DNA polymerase β is capable of bypassing a psoralen cross-link with a low efficiency. Cell extracts prepared from DNA polymerase β knockout mouse embryonic fibroblasts showed a reduced bypass activity of the psoralen cross-link, and purified DNA polymerase β restored the bypass activity. In addition, DNA polymerase ι misincorporated thymine across the psoralen cross-link and DNA polymerase κ extended these mispaired primer ends, suggesting that DNA polymerase ι may serve as an inserter and DNA polymerase κ may play a role as an extender in the repair of psoralen DNA interstrand cross-links. The results demonstrated here indicate that multiple DNA polymerases could participate in TLS steps in mammalian DNA interstrand cross-link repair.
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Affiliation(s)
- Leigh A Smith
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
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27
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Abstract
The maintenance of genome stability is critical for survival, and its failure is often associated with tumorigenesis. The Fanconi anemia (FA) pathway is essential for the repair of DNA interstrand cross-links (ICLs), and a germline defect in the pathway results in FA, a cancer predisposition syndrome driven by genome instability. Central to this pathway is the monoubiquitination of FANCD2, which coordinates multiple DNA repair activities required for the resolution of ICLs. Recent studies have demonstrated how the FA pathway coordinates three critical DNA repair processes, including nucleolytic incision, translesion DNA synthesis (TLS), and homologous recombination (HR). Here, we review recent advances in our understanding of the downstream ICL repair steps initiated by ubiquitin-mediated FA pathway activation.
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28
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A strategy for the expression of recombinant proteins traditionally hard to purify. Anal Biochem 2012; 429:132-9. [PMID: 22828411 DOI: 10.1016/j.ab.2012.07.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 07/06/2012] [Accepted: 07/13/2012] [Indexed: 11/22/2022]
Abstract
We have developed a series of plasmid vectors for the soluble expression and subsequent purification of recombinant proteins that have historically proven to be extremely difficult to purify from Escherichia coli. Instead of dramatically overproducing the target protein, it is expressed at a low basal level that facilitates the correct folding of the recombinant protein and increases its solubility. Highly active recombinant proteins that are traditionally difficult to purify are readily purified using standard affinity tags and conventional chromatography. To demonstrate the utility of these vectors, we have expressed and purified full-length human DNA polymerases η, ι, and ν from E. coli and show that the purified DNA polymerases are catalytically active in vitro.
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29
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Knobel PA, Marti TM. Translesion DNA synthesis in the context of cancer research. Cancer Cell Int 2011; 11:39. [PMID: 22047021 PMCID: PMC3224763 DOI: 10.1186/1475-2867-11-39] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 11/02/2011] [Indexed: 11/17/2022] Open
Abstract
During cell division, replication of the genomic DNA is performed by high-fidelity DNA polymerases but these error-free enzymes can not synthesize across damaged DNA. Specialized DNA polymerases, so called DNA translesion synthesis polymerases (TLS polymerases), can replicate damaged DNA thereby avoiding replication fork breakdown and subsequent chromosomal instability. We focus on the involvement of mammalian TLS polymerases in DNA damage tolerance mechanisms. In detail, we review the discovery of TLS polymerases and describe the molecular features of all the mammalian TLS polymerases identified so far. We give a short overview of the mechanisms that regulate the selectivity and activity of TLS polymerases. In addition, we summarize the current knowledge how different types of DNA damage, relevant either for the induction or treatment of cancer, are bypassed by TLS polymerases. Finally, we elucidate the relevance of TLS polymerases in the context of cancer therapy.
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Affiliation(s)
- Philip A Knobel
- Laboratory of Molecular Oncology, Clinic and Polyclinic of Oncology, University Hospital Zürich, Häldeliweg 4, CH-8044 Zürich, Switzerland.
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30
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Arana ME, Potapova O, Kunkel TA, Joyce CM. Kinetic analysis of the unique error signature of human DNA polymerase ν. Biochemistry 2011; 50:10126-35. [PMID: 22008035 DOI: 10.1021/bi201197p] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The fidelity of DNA synthesis by A-family DNA polymerases ranges from very accurate for bacterial, bacteriophage, and mitochondrial family members to very low for certain eukaryotic homologues. The latter include DNA polymerase ν (Pol ν) which, among all A-family polymerases, is uniquely prone to misincorporating dTTP opposite template G in a highly sequence-dependent manner. Here we present a kinetic analysis of this unusual error specificity, in four different sequence contexts and in comparison to Pol ν's more accurate A-family homologue, the Klenow fragment of Escherichia coli DNA polymerase I. The kinetic data strongly correlate with rates of stable misincorporation during gap-filling DNA synthesis. The lower fidelity of Pol ν compared to that of Klenow fragment can be attributed primarily to a much lower catalytic efficiency for correct dNTP incorporation, whereas both enzymes have similar kinetic parameters for G-dTTP misinsertion. The major contributor to sequence-dependent differences in Pol ν error rates is the reaction rate, k(pol). In the sequence context where fidelity is highest, k(pol) for correct G-dCTP incorporation by Pol ν is ~15-fold faster than k(pol) for G-dTTP misinsertion. However, in sequence contexts where the error rate is higher, k(pol) is the same for both correct and mismatched dNTPs, implying that the transition state does not provide additional discrimination against misinsertion. The results suggest that Pol ν may be fine-tuned to function when high enzyme activity is not a priority and may even be disadvantageous and that the relaxed active-site specificity toward the G-dTTP mispair may be associated with its cellular function(s).
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Affiliation(s)
- Mercedes E Arana
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina 27709, USA
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31
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Sczepanski JT, Hiemstra CN, Greenberg MM. Probing DNA interstrand cross-link formation by an oxidized abasic site using nonnative nucleotides. Bioorg Med Chem 2011; 19:5788-93. [PMID: 21903404 DOI: 10.1016/j.bmc.2011.08.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Revised: 08/08/2011] [Accepted: 08/11/2011] [Indexed: 11/17/2022]
Abstract
The C4'-oxidized abasic site (C4-AP) forms two types of interstrand cross-links with the adjacent nucleotides in DNA. Previous experiments revealed that dG does not react with the lesion and that formation of one type of cross-link is catalyzed by the opposing dA. iso-Guanosine·dC and 2-aminopurine·dT base pairs were used to determine why dG does not cross-link with C4-AP despite its well known reactivity with other bis-electrophiles. 7-Deaza-2'-deoxyadenosine was used to probe the role of the nucleotide opposite C4-AP in the catalysis of interstrand cross-link formation.
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Affiliation(s)
- Jonathan T Sczepanski
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
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32
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Inoue H. Exploring the processes of DNA repair and homologous integration in Neurospora. Mutat Res 2011; 728:1-11. [PMID: 21757027 DOI: 10.1016/j.mrrev.2011.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2011] [Indexed: 12/23/2022]
Abstract
This review offers a personal perspective on historical developments related to our current understanding of DNA repair, recombination, and homologous integration in Neurospora crassa. Previous reviews have summarized and analyzed the characteristics of Neurospora DNA repair mutants. The early history is reviewed again here as a prelude to a discussion of the molecular cloning, annotation, gene disruption and reverse genetics of Neurospora DNA repair genes. The classical studies and molecular analysis are then linked in a perspective on new directions in research on mutagen-sensitive mutants.
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Affiliation(s)
- Hirokazu Inoue
- Laboratory of Genetics, Department of Regulation Biology, Faculty of Science, Saitama University, Urawa 338-8570, Japan.
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33
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Abstract
There are 15 different DNA polymerases encoded in mammalian genomes, which are specialized for replication, repair or the tolerance of DNA damage. New evidence is emerging for lesion-specific and tissue-specific functions of DNA polymerases. Many point mutations that occur in cancer cells arise from the error-generating activities of DNA polymerases. However, the ability of some of these enzymes to bypass DNA damage may actually defend against chromosome instability in cells, and at least one DNA polymerase, Pol ζ, is a suppressor of spontaneous tumorigenesis. Because DNA polymerases can help cancer cells tolerate DNA damage, some of these enzymes might be viable targets for therapeutic strategies.
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Affiliation(s)
| | | | - Richard D. Wood
- Correspondence to: 1808 Park Road 1C, P.O. Box 389, Smithville, TX, USA, 78957 Tel: (512) 237-9431 Fax: (512) 237-6532
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34
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Efimov VA, Fedyunin SV. Cross-linked nucleic acids: isolation, structure, and biological role. BIOCHEMISTRY (MOSCOW) 2011; 75:1606-27. [DOI: 10.1134/s0006297910130079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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35
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Smogorzewska A, Desetty R, Saito TT, Schlabach M, Lach FP, Sowa ME, Clark AB, Kunkel TA, Harper JW, Colaiácovo MP, Elledge SJ. A genetic screen identifies FAN1, a Fanconi anemia-associated nuclease necessary for DNA interstrand crosslink repair. Mol Cell 2010; 39:36-47. [PMID: 20603073 DOI: 10.1016/j.molcel.2010.06.023] [Citation(s) in RCA: 256] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 06/07/2010] [Accepted: 06/09/2010] [Indexed: 01/13/2023]
Abstract
The Fanconi anemia (FA) pathway is responsible for interstrand crosslink repair. At the heart of this pathway is the FANCI-FAND2 (ID) complex, which, upon ubiquitination by the FA core complex, travels to sites of damage to coordinate repair that includes nucleolytic modification of the DNA surrounding the lesion and translesion synthesis. How the ID complex regulates these events is unknown. Here we describe a shRNA screen that led to the identification of two nucleases necessary for crosslink repair, FAN1 (KIAA1018) and EXDL2. FAN1 colocalizes at sites of DNA damage with the ID complex in a manner dependent on FAN1's ubiquitin-binding domain (UBZ), the ID complex, and monoubiquitination of FANCD2. FAN1 possesses intrinsic 5'-3' exonuclease activity and endonuclease activity that cleaves nicked and branched structures. We propose that FAN1 is a repair nuclease that is recruited to sites of crosslink damage in part through binding the ubiquitinated ID complex through its UBZ domain.
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Affiliation(s)
- Agata Smogorzewska
- Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, and Brigham and Women's Hospital, Boston, MA 02115, USA.
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36
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Ho TV, Schärer OD. Translesion DNA synthesis polymerases in DNA interstrand crosslink repair. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2010; 51:552-566. [PMID: 20658647 DOI: 10.1002/em.20573] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
DNA interstrand crosslinks (ICLs) are induced by a number of bifunctional antitumor drugs such as cisplatin, mitomycin C, or the nitrogen mustards as well as endogenous agents formed by lipid peroxidation. The repair of ICLs requires the coordinated interplay of a number of genome maintenance pathways, leading to the removal of ICLs through at least two distinct mechanisms. The major pathway of ICL repair is dependent on replication, homologous recombination, and the Fanconi anemia (FA) pathway, whereas a minor, G0/G1-specific and recombination-independent pathway depends on nucleotide excision repair. A central step in both pathways in vertebrates is translesion synthesis (TLS) and mutants in the TLS polymerases Rev1 and Pol zeta are exquisitely sensitive to crosslinking agents. Here, we review the involvement of Rev1 and Pol zeta as well as additional TLS polymerases, in particular, Pol eta, Pol kappa, Pol iota, and Pol nu, in ICL repair. Biochemical studies suggest that multiple TLS polymerases have the ability to bypass ICLs and that the extent ofbypass depends upon the structure as well as the extent of endo- or exonucleolytic processing of the ICL. As has been observed for lesions that affect only one strand of DNA, TLS polymerases are recruited by ubiquitinated proliferating nuclear antigen (PCNA) to repair ICLs in the G0/G1 pathway. By contrast, this data suggest that a different mechanism involving the FA pathway is operative in coordinating TLS in the context of replication-dependent ICL repair.
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Affiliation(s)
- The Vinh Ho
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York 11794-3400, USA
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37
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Kohzaki M, Nishihara K, Hirota K, Sonoda E, Yoshimura M, Ekino S, Butler JE, Watanabe M, Halazonetis TD, Takeda S. DNA polymerases nu and theta are required for efficient immunoglobulin V gene diversification in chicken. J Cell Biol 2010; 189:1117-27. [PMID: 20584917 PMCID: PMC2894443 DOI: 10.1083/jcb.200912012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 05/26/2010] [Indexed: 01/10/2023] Open
Abstract
The chicken DT40 B lymphocyte line diversifies its immunoglobulin (Ig) V genes through translesion DNA synthesis-dependent point mutations (Ig hypermutation) and homologous recombination (HR)-dependent Ig gene conversion. The error-prone biochemical characteristic of the A family DNA polymerases Polnu and Pol led us to explore the role of these polymerases in Ig gene diversification in DT40 cells. Disruption of both polymerases causes a significant decrease in Ig gene conversion events, although POLN(-/-)/POLQ(-/-) cells exhibit no prominent defect in HR-mediated DNA repair, as indicated by no increase in sensitivity to camptothecin. Poleta has also been previously implicated in Ig gene conversion. We show that a POLH(-/-)/POLN(-/-)/POLQ(-/-) triple mutant displays no Ig gene conversion and reduced Ig hypermutation. Together, these data define a role for Polnu and Pol in recombination and suggest that the DNA synthesis associated with Ig gene conversion is accounted for by three specialized DNA polymerases.
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Affiliation(s)
- Masaoki Kohzaki
- Department of Radiation Genetics and Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
- Research Reactor Institute, Kyoto University, Sennan-gun, Osaka 590-0494, Japan
- Department of Molecular Biology, University of Geneva, Geneva 4 CH-1211, Switzerland
| | - Kana Nishihara
- Department of Radiation Genetics and Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
- Department of Food and Nutrition, Kyoto Women’s University, Higashiyama-ku, Kyoto 606-8501, Japan
| | - Kouji Hirota
- Department of Radiation Genetics and Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Eiichiro Sonoda
- Department of Radiation Genetics and Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Michio Yoshimura
- Department of Radiation Genetics and Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shigeo Ekino
- Department of Histology, Graduate School of Medical Sciences, Kumamoto University, Honjo, Kumamoto 860-8556, Japan
| | - John E. Butler
- Department of Microbiology, University of Iowa Medical School, Iowa City, IA 52242
| | - Masami Watanabe
- Research Reactor Institute, Kyoto University, Sennan-gun, Osaka 590-0494, Japan
| | - Thanos D. Halazonetis
- Department of Molecular Biology, University of Geneva, Geneva 4 CH-1211, Switzerland
| | - Shunichi Takeda
- Department of Radiation Genetics and Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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38
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Wilson DM, Seidman MM. A novel link to base excision repair? Trends Biochem Sci 2010; 35:247-52. [PMID: 20172733 DOI: 10.1016/j.tibs.2010.01.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 01/07/2010] [Accepted: 01/15/2010] [Indexed: 01/04/2023]
Abstract
DNA interstrand crosslinks (ICLs) can arise from reactions with endogenous chemicals, such as malondialdehyde - a lipid peroxidation product - or from exposure to various clinical anti-cancer drugs, most notably bifunctional alkylators and platinum compounds. Because they covalently link the two strands of DNA, ICLs completely block transcription and replication, and, as a result, are lethal to the cell. It is well established that proteins that function in nucleotide excision repair and homologous recombination are involved in ICL resolution. Recent work, coupled with a much earlier report, now suggest an emerging link between proteins of the base excision repair pathway and crosslink processing.
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Affiliation(s)
- David M Wilson
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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39
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Takata KI, Arana ME, Seki M, Kunkel TA, Wood RD. Evolutionary conservation of residues in vertebrate DNA polymerase N conferring low fidelity and bypass activity. Nucleic Acids Res 2010; 38:3233-44. [PMID: 20144948 PMCID: PMC2879524 DOI: 10.1093/nar/gkq048] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
POLN is a nuclear A-family DNA polymerase encoded in vertebrate genomes. POLN has unusual fidelity and DNA lesion bypass properties, including strong strand displacement activity, low fidelity favoring incorporation of T for template G and accurate translesion synthesis past a 5S-thymine glycol (5S-Tg). We searched for conserved features of the polymerase domain that distinguish it from prokaryotic pol I-type DNA polymerases. A Lys residue (679 in human POLN) of particular interest was identified in the conserved ‘O-helix’ of motif 4 in the fingers sub-domain. The corresponding residue is one of the most important for controlling fidelity of prokaryotic pol I and is a nonpolar Ala or Thr in those enzymes. Kinetic measurements show that K679A or K679T POLN mutant DNA polymerases have full activity on nondamaged templates, but poorly incorporate T opposite template G and do not bypass 5S-Tg efficiently. We also found that a conserved Tyr residue in the same motif not only affects sensitivity to dideoxynucleotides, but also greatly influences enzyme activity, fidelity and bypass. Protein sequence alignment reveals that POLN has three specific insertions in the DNA polymerase domain. The results demonstrate that residues have been strictly retained during evolution that confer unique bypass and fidelity properties on POLN.
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Affiliation(s)
- Kei-ichi Takata
- Department of Carcinogenesis, The University of Texas Graduate School of Biomedical Sciences at Houston, USA
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40
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Muniandy PA, Liu J, Majumdar A, Liu ST, Seidman MM. DNA interstrand crosslink repair in mammalian cells: step by step. Crit Rev Biochem Mol Biol 2010; 45:23-49. [PMID: 20039786 PMCID: PMC2824768 DOI: 10.3109/10409230903501819] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Interstrand DNA crosslinks (ICLs) are formed by natural products of metabolism and by chemotherapeutic reagents. Work in E. coli identified a two cycle repair scheme involving incisions on one strand on either side of the ICL (unhooking) producing a gapped intermediate with the incised oligonucleotide attached to the intact strand. The gap is filled by recombinational repair or lesion bypass synthesis. The remaining monoadduct is then removed by nucleotide excision repair (NER). Despite considerable effort, our understanding of each step in mammalian cells is still quite limited. In part this reflects the variety of crosslinking compounds, each with distinct structural features, used by different investigators. Also, multiple repair pathways are involved, variably operative during the cell cycle. G(1) phase repair requires functions from NER, although the mechanism of recognition has not been determined. Repair can be initiated by encounters with the transcriptional apparatus, or a replication fork. In the case of the latter, the reconstruction of a replication fork, stalled or broken by collision with an ICL, adds to the complexity of the repair process. The enzymology of unhooking, the identity of the lesion bypass polymerases required to fill the first repair gap, and the functions involved in the second repair cycle are all subjects of active inquiry. Here we will review current understanding of each step in ICL repair in mammalian cells.
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Affiliation(s)
- Parameswary A Muniandy
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
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