1
|
Tsaalbi-Shtylik A, Mingard C, Räz M, Oka R, Manders F, Van Boxtel R, De Wind N, Sturla SJ. DNA mismatch repair controls the mutagenicity of Polymerase ζ-dependent translesion synthesis at methylated guanines. DNA Repair (Amst) 2024; 142:103755. [PMID: 39216121 DOI: 10.1016/j.dnarep.2024.103755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 07/27/2024] [Accepted: 08/16/2024] [Indexed: 09/04/2024]
Abstract
By replicating damaged nucleotides, error-prone DNA translesion synthesis (TLS) enables the completion of replication, albeit at the expense of fidelity. TLS of helix-distorting DNA lesions, that usually have reduced capacity of basepairing, comprises insertion opposite the lesion followed by extension, the latter in particular by polymerase ζ (Pol ζ). However, little is known about involvement of Pol ζ in TLS of non- or poorly-distorting, but miscoding, lesions such as O6-methyldeoxyguanosine (O6-medG). Using purified Pol ζ we describe that the enzyme can misincorporate thymidine opposite O6-medG and efficiently extend from terminal mismatches, suggesting its involvement in the mutagenicity of O6-medG. Surprisingly, O6-medG lesions induced by the methylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) appeared more, rather than less, mutagenic in Pol ζ-deficient mouse embryonic fibroblasts (MEFs) than in wild type MEFs. This suggested that in vivo Pol ζ participates in non-mutagenic TLS of O6-medG. However, we found that the Pol ζ-dependent misinsertions at O6-medG lesions are efficiently corrected by DNA mismatch repair (MMR), which masks the error-proneness of Pol ζ. We also found that the MNNG-induced mutational signature is determined by the adduct spectrum, and modulated by MMR. The signature mimicked single base substitution signature 11 in the catalogue of somatic mutations in cancer, associated with treatment with the methylating drug temozolomide. Our results unravel the individual roles of the major contributors to methylating drug-induced mutagenesis. Moreover, these results warrant caution as to the classification of TLS as mutagenic or error-free based on in vitro data or on the analysis of mutations induced in MMR-proficient cells.
Collapse
Affiliation(s)
| | - Cécile Mingard
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
| | - Michael Räz
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland
| | - Rurika Oka
- Princess Máxima Center for Pediatric Oncology, Oncode Institute, Utrecht, 3584CS, the Netherlands
| | - Freek Manders
- Princess Máxima Center for Pediatric Oncology, Oncode Institute, Utrecht, 3584CS, the Netherlands
| | - Ruben Van Boxtel
- Princess Máxima Center for Pediatric Oncology, Oncode Institute, Utrecht, 3584CS, the Netherlands
| | - Niels De Wind
- Department of Human Genetics, Leiden University Medical Center, Leiden 2333AL, the Netherlands.
| | - Shana J Sturla
- Department of Health Sciences and Technology, ETH Zürich, Zürich, 8092, Switzerland.
| |
Collapse
|
2
|
Venkadakrishnan J, Lahane G, Dhar A, Xiao W, Bhat KM, Pandita TK, Bhat A. Implications of Translesion DNA Synthesis Polymerases on Genomic Stability and Human Health. Mol Cell Biol 2023; 43:401-425. [PMID: 37439479 PMCID: PMC10448981 DOI: 10.1080/10985549.2023.2224199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 05/03/2023] [Accepted: 06/01/2023] [Indexed: 07/14/2023] Open
Abstract
Replication fork arrest-induced DNA double strand breaks (DSBs) caused by lesions are effectively suppressed in cells due to the presence of a specialized mechanism, commonly referred to as DNA damage tolerance (DDT). In eukaryotic cells, DDT is facilitated through translesion DNA synthesis (TLS) carried out by a set of DNA polymerases known as TLS polymerases. Another parallel mechanism, referred to as homology-directed DDT, is error-free and involves either template switching or fork reversal. The significance of the DDT pathway is well established. Several diseases have been attributed to defects in the TLS pathway, caused either by mutations in the TLS polymerase genes or dysregulation. In the event of a replication fork encountering a DNA lesion, cells switch from high-fidelity replicative polymerases to low-fidelity TLS polymerases, which are associated with genomic instability linked with several human diseases including, cancer. The role of TLS polymerases in chemoresistance has been recognized in recent years. In addition to their roles in the DDT pathway, understanding noncanonical functions of TLS polymerases is also a key to unraveling their importance in maintaining genomic stability. Here we summarize the current understanding of TLS pathway in DDT and its implication for human health.
Collapse
Affiliation(s)
| | - Ganesh Lahane
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad Campus, Hyderabad, India
| | - Arti Dhar
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad Campus, Hyderabad, India
| | - Wei Xiao
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada
| | - Krishna Moorthi Bhat
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, USA
| | - Tej K. Pandita
- Center for Genomics and Precision Medicine, Texas A&M College of Medicine, Houston, Texas, USA
| | - Audesh Bhat
- Center for Molecular Biology, Central University of Jammu, UT Jammu and Kashmir, India
| |
Collapse
|
3
|
Stekelenburg C, Blouin JL, Santoni F, Zaghloul N, O'Hare EA, Dusaulcy R, Maechler P, Schwitzgebel VM. Loss of Nexmif results in the expression of phenotypic variability and loss of genomic integrity. Sci Rep 2022; 12:13815. [PMID: 35970867 PMCID: PMC9378738 DOI: 10.1038/s41598-022-17845-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 08/02/2022] [Indexed: 11/17/2022] Open
Abstract
We identified two NEXMIF variants in two unrelated individuals with non-autoimmune diabetes and autistic traits, and investigated the expression of Nexmif in mouse and human pancreas and its function in pancreatic beta cells in vitro and in vivo. In insulin-secreting INS-1E cells, Nexmif expression increased strongly in response to oxidative stress. CRISPR Cas9-generated Nexmif knockout mice exhibited a reduced number of proliferating beta cells in pancreatic islets. RNA sequencing of pancreatic islets showed that the downregulated genes in Nexmif mutant islets are involved in stress response and the deposition of epigenetic marks. They include H3f3b, encoding histone H3.3, which is associated with the regulation of beta-cell proliferation and maintains genomic integrity by silencing transposable elements, particularly LINE1 elements. LINE1 activity has been associated with autism and neurodevelopmental disorders in which patients share characteristics with NEXMIF patients, and can cause genomic instability and genetic variation through retrotransposition. Nexmif knockout mice exhibited various other phenotypes. Mortality and phenotypic abnormalities increased in each generation in both Nexmif mutant and non-mutant littermates. In Nexmif mutant mice, LINE1 element expression was upregulated in the pancreas, brain, and testis, possibly inducing genomic instability in Nexmif mutant mice and causing phenotypic variability in their progeny.
Collapse
Affiliation(s)
- Caroline Stekelenburg
- Pediatric Endocrine and Diabetes Unit, Division of Development and Growth, Department of Pediatrics, Gynecology and Obstetrics, University Hospitals of Geneva, Children's University Hospital, 6, Rue Willy Donze, 1205, Geneva, Switzerland.,Faculty Diabetes Center, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Jean-Louis Blouin
- Department of Genetic Medicine and Laboratory, University Hospitals of Geneva, 1211, Geneva, Switzerland.,Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, 1211, Geneva, Switzerland
| | - Federico Santoni
- Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, 1211, Geneva, Switzerland
| | - Norann Zaghloul
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, USA
| | - Elisabeth A O'Hare
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimore, USA
| | - Rodolphe Dusaulcy
- Pediatric Endocrine and Diabetes Unit, Division of Development and Growth, Department of Pediatrics, Gynecology and Obstetrics, University Hospitals of Geneva, Children's University Hospital, 6, Rue Willy Donze, 1205, Geneva, Switzerland.,Faculty Diabetes Center, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Pierre Maechler
- Faculty Diabetes Center, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Department of Cell Physiology and Metabolism, University of Geneva Medical Center, 1206, Geneva, Switzerland
| | - Valerie M Schwitzgebel
- Pediatric Endocrine and Diabetes Unit, Division of Development and Growth, Department of Pediatrics, Gynecology and Obstetrics, University Hospitals of Geneva, Children's University Hospital, 6, Rue Willy Donze, 1205, Geneva, Switzerland. .,Faculty Diabetes Center, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
| |
Collapse
|
4
|
Ben Yamin B, Ahmed-Seghir S, Tomida J, Despras E, Pouvelle C, Yurchenko A, Goulas J, Corre R, Delacour Q, Droin N, Dessen P, Goidin D, Lange SS, Bhetawal S, Mitjavila-Garcia MT, Baldacci G, Nikolaev S, Cadoret JC, Wood RD, Kannouche PL. DNA polymerase zeta contributes to heterochromatin replication to prevent genome instability. EMBO J 2021; 40:e104543. [PMID: 34533226 PMCID: PMC8561639 DOI: 10.15252/embj.2020104543] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 08/20/2021] [Accepted: 08/28/2021] [Indexed: 02/06/2023] Open
Abstract
The DNA polymerase zeta (Polζ) plays a critical role in bypassing DNA damage. REV3L, the catalytic subunit of Polζ, is also essential in mouse embryonic development and cell proliferation for reasons that remain incompletely understood. In this study, we reveal that REV3L protein interacts with heterochromatin components including repressive histone marks and localizes in pericentromeric regions through direct interaction with HP1 dimer. We demonstrate that Polζ/REV3L ensures progression of replication forks through difficult‐to‐replicate pericentromeric heterochromatin, thereby preventing spontaneous chromosome break formation. We also find that Rev3l‐deficient cells are compromised in the repair of heterochromatin‐associated double‐stranded breaks, eliciting deletions in late‐replicating regions. Lack of REV3L leads to further consequences that may be ascribed to heterochromatin replication and repair‐associated functions of Polζ, with a disruption of the temporal replication program at specific loci. This is correlated with changes in epigenetic landscape and transcriptional control of developmentally regulated genes. These results reveal a new function of Polζ in preventing chromosome instability during replication of heterochromatic regions.
Collapse
Affiliation(s)
- Barbara Ben Yamin
- CNRS-UMR9019, Equipe labellisée Ligue Contre le Cancer, Gustave Roussy, Paris-Saclay Université, Villejuif, France
| | - Sana Ahmed-Seghir
- CNRS-UMR9019, Equipe labellisée Ligue Contre le Cancer, Gustave Roussy, Paris-Saclay Université, Villejuif, France
| | - Junya Tomida
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center and The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Emmanuelle Despras
- CNRS-UMR9019, Equipe labellisée Ligue Contre le Cancer, Gustave Roussy, Paris-Saclay Université, Villejuif, France
| | - Caroline Pouvelle
- CNRS-UMR9019, Equipe labellisée Ligue Contre le Cancer, Gustave Roussy, Paris-Saclay Université, Villejuif, France
| | - Andrey Yurchenko
- INSERM U981, Gustave Roussy, Université Paris Saclay, Villejuif, France
| | - Jordane Goulas
- CNRS-UMR9019, Equipe labellisée Ligue Contre le Cancer, Gustave Roussy, Paris-Saclay Université, Villejuif, France
| | - Raphael Corre
- CNRS-UMR9019, Equipe labellisée Ligue Contre le Cancer, Gustave Roussy, Paris-Saclay Université, Villejuif, France
| | - Quentin Delacour
- CNRS-UMR9019, Equipe labellisée Ligue Contre le Cancer, Gustave Roussy, Paris-Saclay Université, Villejuif, France
| | | | - Philippe Dessen
- Bioinformatics Core Facility, Gustave Roussy, Villejuif, France
| | - Didier Goidin
- Life Sciences and Diagnostics Group, Agilent Technologies France, Les Ulis, France
| | - Sabine S Lange
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center and The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Sarita Bhetawal
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center and The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, USA
| | | | - Giuseppe Baldacci
- Institut Jacques Monod, UMR7592, CNRS and University of Paris, Paris, France
| | - Sergey Nikolaev
- INSERM U981, Gustave Roussy, Université Paris Saclay, Villejuif, France
| | | | - Richard D Wood
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center and The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Patricia L Kannouche
- CNRS-UMR9019, Equipe labellisée Ligue Contre le Cancer, Gustave Roussy, Paris-Saclay Université, Villejuif, France
| |
Collapse
|
5
|
Martin SK, Tomida J, Wood RD. Disruption of DNA polymerase ζ engages an innate immune response. Cell Rep 2021; 34:108775. [PMID: 33626348 PMCID: PMC7990024 DOI: 10.1016/j.celrep.2021.108775] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 12/22/2020] [Accepted: 01/29/2021] [Indexed: 01/07/2023] Open
Abstract
In mammalian cells, specialized DNA polymerase ζ (pol ζ) contributes to genomic stability during normal DNA replication. Disruption of the catalytic subunit Rev3l is toxic and results in constitutive chromosome damage, including micronuclei. As manifestations of this genomic stress are unknown, we examined the transcriptome of pol ζ-defective cells by RNA sequencing (RNA-seq). Expression of 1,117 transcripts is altered by ≥4-fold in Rev3l-disrupted cells, with a pattern consistent with an induction of an innate immune response. Increased expression of interferon-stimulated genes at the mRNA and protein levels in pol ζ-defective cells is driven by the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-signaling partner stimulator of interferon genes (STING) pathway. Expression of key interferon-stimulated chemokines is elevated in basal epithelial mouse skin cells with a disruption of Rev3l. These results indicate that the disruption of pol ζ may simultaneously increase sensitivity to genotoxins and potentially engage parts of the innate immune response, which could add an additional benefit to targeting pol ζ in cancer therapies.
Collapse
Affiliation(s)
- Sara K Martin
- Department of Epigenetics & Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX 78507, USA; The University of Texas MD Anderson Cancer Center, UT Health Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Junya Tomida
- Department of Epigenetics & Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX 78507, USA
| | - Richard D Wood
- Department of Epigenetics & Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX 78507, USA; The University of Texas MD Anderson Cancer Center, UT Health Graduate School of Biomedical Sciences, Houston, TX, USA.
| |
Collapse
|
6
|
Shilkin ES, Boldinova EO, Stolyarenko AD, Goncharova RI, Chuprov-Netochin RN, Khairullin RF, Smal MP, Makarova AV. Translesion DNA Synthesis and Carcinogenesis. BIOCHEMISTRY (MOSCOW) 2021; 85:425-435. [PMID: 32569550 DOI: 10.1134/s0006297920040033] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Tens of thousands of DNA lesions are formed in mammalian cells each day. DNA translesion synthesis is the main mechanism of cell defense against unrepaired DNA lesions. DNA polymerases iota (Pol ι), eta (Pol η), kappa (Pol κ), and zeta (Pol ζ) have active sites that are less stringent toward the DNA template structure and efficiently incorporate nucleotides opposite DNA lesions. However, these polymerases display low accuracy of DNA synthesis and can introduce mutations in genomic DNA. Impaired functioning of these enzymes can lead to an increased risk of cancer.
Collapse
Affiliation(s)
- E S Shilkin
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia
| | - E O Boldinova
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia
| | - A D Stolyarenko
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia
| | - R I Goncharova
- Institute of Genetics and Cytology, National Academy of Sciences of Belarus, Minsk, 220072, Republic of Belarus
| | - R N Chuprov-Netochin
- Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, 141701, Russia
| | - R F Khairullin
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, 420012, Russia
| | - M P Smal
- Institute of Genetics and Cytology, National Academy of Sciences of Belarus, Minsk, 220072, Republic of Belarus.
| | - A V Makarova
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia.
| |
Collapse
|
7
|
Takezawa J, Shimazaki A, Takimoto H, Kajiwara K, Yamada K. A large intermediate domain of vertebrate REV3 protein is dispensable for ultraviolet-induced translesion replication. DNA Repair (Amst) 2020; 98:103031. [PMID: 33387704 DOI: 10.1016/j.dnarep.2020.103031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 11/24/2022]
Abstract
DNA polymerase ζ (pol ζ) is involved in translesion replication (translesion synthesis, TLS) and plays an essential role in embryogenesis. In adults, pol ζ triggers mutation as a result of error-prone TLS and causes carcinogenesis. The catalytic subunit of pol ζ, REV3, is evolutionarily conserved from yeast and plants to higher eukaryotes. However, the structures are notably different: unlike that in yeast REV3, a large intermediate domain is inserted in REV3 of humans and mice. The domain is mostly occupied with noncommittal structures (random coil…etc.); therefore, its role and function are yet to be resolved. Previously, we reported deficient levels of ultraviolet (UV)-induced TLS in fibroblasts derived from the Rev3-knockout mouse embryo (Rev3KO-MEF). Here, we constructed a mouse Rev3-expressing plasmid with a deleted intermediate domain (532-1793 a.a,) and transfected it into Rev3KO-MEF. The isolated stable transformants showed comparable levels of UV-sensitivity and UV-TLS activity to those in wild-type MEF, detected using an alkaline sucrose density gradient sedimentation. These results indicate that the intermediate domain is nonessential for UV-induced translesion replication in cultured mouse cells.
Collapse
Affiliation(s)
- Jun Takezawa
- Department of Genetic Biochemistry, The National Institutes of Biomedical Innovation, Health and Nutrition, Toyama 1-23-1, Shinjuku-ku, Tokyo, 162-8636, Japan
| | - Anna Shimazaki
- Department of Genetic Biochemistry, The National Institutes of Biomedical Innovation, Health and Nutrition, Toyama 1-23-1, Shinjuku-ku, Tokyo, 162-8636, Japan
| | - Hidemi Takimoto
- Department of Nutritional Epidemiology and Shoku-iku, The National Institutes of Biomedical Innovation, Health and Nutrition, Toyama 1-23-1, Shinjuku-ku, Tokyo, 162-8636, Japan
| | | | - Kouichi Yamada
- Department of Genetic Biochemistry, The National Institutes of Biomedical Innovation, Health and Nutrition, Toyama 1-23-1, Shinjuku-ku, Tokyo, 162-8636, Japan.
| |
Collapse
|
8
|
Wang F, Li P, Shao Y, Li Y, Zhang K, Li M, Wang R, Zheng S, Wang Y, Song S, Feng S, Liu F, Xiao W, Li X. Site-specific proteolytic cleavage prevents ubiquitination and degradation of human REV3L, the catalytic subunit of DNA polymerase ζ. Nucleic Acids Res 2020; 48:3619-3637. [PMID: 32064513 PMCID: PMC7144948 DOI: 10.1093/nar/gkaa096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/02/2020] [Accepted: 02/04/2020] [Indexed: 01/18/2023] Open
Abstract
REV3L, the catalytic subunit of DNA polymerase ζ (Pol ζ), is indispensable for translesion DNA synthesis, which protects cells from deleterious DNA lesions resulting from various intrinsic and environmental sources. However, REV3L lacks a proofreading exonuclease activity and consequently bypasses DNA lesions at the expense of increased mutations, which poses a severe threat to genome stability. Here we report a site-specific proteolytic event of human REV3L. We show that REV3L is cleaved by a threonine aspartase, Taspase1 (TASP1), to generate an N-terminal 70-kDa fragment (N70) and a polypeptide carrying the C-terminal polymerase catalytic domain in human cells. Strikingly, such a post-translational cleavage event plays a vital role in controlling REV3L stability by preventing ubiquitination and proteasome-mediated degradation of REV3L. Indicative of the biological importance of the above REV3L post-translational processing, cellular responses to UV and cisplatin-induced DNA lesions are markedly impaired in human HCT116 cell derivatives bearing defined point mutations in the endogenous REV3L gene that compromise REV3L cleavage. These findings establish a new paradigm in modulating the abundance of REV3L through site-specific proteolysis in human cells.
Collapse
Affiliation(s)
- Fengting Wang
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Pan Li
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Yuan Shao
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Yanyan Li
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Kai Zhang
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Miaomiao Li
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Rong Wang
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Shuo Zheng
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Yingying Wang
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Sen Song
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Shiguo Feng
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Fei Liu
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Wei Xiao
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| | - Xialu Li
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing, China
| |
Collapse
|
9
|
APIM-Mediated REV3L⁻PCNA Interaction Important for Error Free TLS Over UV-Induced DNA Lesions in Human Cells. Int J Mol Sci 2018; 20:ijms20010100. [PMID: 30597836 PMCID: PMC6337749 DOI: 10.3390/ijms20010100] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 12/22/2018] [Indexed: 12/23/2022] Open
Abstract
Proliferating cell nuclear antigen (PCNA) is essential for the organization of DNA replication and the bypass of DNA lesions via translesion synthesis (TLS). TLS is mediated by specialized DNA polymerases, which all interact, directly or indirectly, with PCNA. How interactions between the TLS polymerases and PCNA affects TLS specificity and/or coordination is not fully understood. Here we show that the catalytic subunit of the essential mammalian TLS polymerase POLζ, REV3L, contains a functional AlkB homolog 2 PCNA interacting motif, APIM. APIM from REV3L fused to YFP, and full-length REV3L-YFP colocalizes with PCNA in replication foci. Colocalization of REV3L-YFP with PCNA is strongly reduced when an APIM-CFP construct is overexpressed. We also found that overexpression of full-length REV3L with mutated APIM leads to significantly altered mutation frequencies and mutation spectra, when compared to overexpression of full-length REV3L wild-type (WT) protein in multiple cell lines. Altogether, these data suggest that APIM is a functional PCNA-interacting motif in REV3L, and that the APIM-mediated PCNA interaction is important for the function and specificity of POLζ in TLS. Finally, a PCNA-targeting cell-penetrating peptide, containing APIM, reduced the mutation frequencies and changed the mutation spectra in several cell lines, suggesting that efficient TLS requires coordination mediated by interactions with PCNA.
Collapse
|
10
|
Kochenova OV, Bezalel-Buch R, Tran P, Makarova AV, Chabes A, Burgers PMJ, Shcherbakova PV. Yeast DNA polymerase ζ maintains consistent activity and mutagenicity across a wide range of physiological dNTP concentrations. Nucleic Acids Res 2017; 45:1200-1218. [PMID: 28180291 PMCID: PMC5388397 DOI: 10.1093/nar/gkw1149] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 10/31/2016] [Accepted: 11/02/2016] [Indexed: 11/12/2022] Open
Abstract
In yeast, dNTP pools expand drastically during DNA damage response. We show that similar dNTP elevation occurs in strains, in which intrinsic replisome defects promote the participation of error-prone DNA polymerase ζ (Polζ) in replication of undamaged DNA. To understand the significance of dNTP pools increase for Polζ function, we studied the activity and fidelity of four-subunit Polζ (Polζ4) and Polζ4-Rev1 (Polζ5) complexes in vitro at ‘normal S-phase’ and ‘damage-response’ dNTP concentrations. The presence of Rev1 inhibited the activity of Polζ and greatly increased the rate of all three ‘X-dCTP’ mispairs, which Polζ4 alone made extremely inefficiently. Both Polζ4 and Polζ5 were most promiscuous at G nucleotides and frequently generated multiple closely spaced sequence changes. Surprisingly, the shift from ‘S-phase’ to ‘damage-response’ dNTP levels only minimally affected the activity, fidelity and error specificity of Polζ complexes. Moreover, Polζ-dependent mutagenesis triggered by replisome defects or UV irradiation in vivo was not decreased when dNTP synthesis was suppressed by hydroxyurea, indicating that Polζ function does not require high dNTP levels. The results support a model wherein dNTP elevation is needed to facilitate non-mutagenic tolerance pathways, while Polζ synthesis represents a unique mechanism of rescuing stalled replication when dNTP supply is low.
Collapse
Affiliation(s)
- Olga V Kochenova
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
| | - Rachel Bezalel-Buch
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
| | - Phong Tran
- Department of Medical Biochemistry and Biophysics and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Alena V Makarova
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
| | - Andrei Chabes
- Department of Medical Biochemistry and Biophysics and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Peter M J Burgers
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
| | - Polina V Shcherbakova
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
| |
Collapse
|
11
|
|
12
|
Krasich R, Copeland WC. DNA polymerases in the mitochondria: A critical review of the evidence. FRONT BIOSCI-LANDMRK 2017; 22:692-709. [PMID: 27814640 PMCID: PMC5485829 DOI: 10.2741/4510] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Since 1970, the DNA polymerase gamma (PolG) has been known to be the DNA polymerase responsible for replication and repair of mitochondrial DNA, and until recently it was generally accepted that this was the only polymerase present in mitochondria. However, recent data has challenged that opinion, as several polymerases are now proposed to have activity in mitochondria. To date, their exact role of these other DNA polymerases is unclear and the amount of evidence supporting their role in mitochondria varies greatly. Further complicating matters, no universally accepted standards have been set for definitive proof of the mitochondrial localization of a protein. To gain an appreciation of these newly proposed DNA polymerases in the mitochondria, we review the evidence and standards needed to establish the role of a polymerase in the mitochondria. Employing PolG as an example, we established a list of criteria necessary to verify the existence and function of new mitochondrial proteins. We then apply this criteria towards several other putative mitochondrial polymerases. While there is still a lot left to be done in this exciting new direction, it is clear that PolG is not acting alone in mitochondria, opening new doors for potential replication and repair mechanisms.
Collapse
Affiliation(s)
- Rachel Krasich
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - William C Copeland
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, 111 T.W. Alexander Dr., Bldg. 101, Rm. E316, Research Triangle Park, NC 27709,
| |
Collapse
|
13
|
Assessment of copy number variations in 120 patients with Poland syndrome. BMC MEDICAL GENETICS 2016; 17:89. [PMID: 27884122 PMCID: PMC5123256 DOI: 10.1186/s12881-016-0351-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 11/15/2016] [Indexed: 11/10/2022]
Abstract
BACKGROUND Poland Syndrome (PS) is a rare congenital disorder presenting with agenesis/hypoplasia of the pectoralis major muscle variably associated with thoracic and/or upper limb anomalies. Most cases are sporadic, but familial recurrence, with different inheritance patterns, has been observed. The genetic etiology of PS remains unknown. Karyotyping and array-comparative genomic hybridization (CGH) analyses can identify genomic imbalances that can clarify the genetic etiology of congenital and neurodevelopmental disorders. We previously reported a chromosome 11 deletion in twin girls with pectoralis muscle hypoplasia and skeletal anomalies, and a chromosome six deletion in a patient presenting a complex phenotype that included pectoralis muscle hypoplasia. However, the contribution of genomic imbalances to PS remains largely unknown. METHODS To investigate the prevalence of chromosomal imbalances in PS, standard cytogenetic and array-CGH analyses were performed in 120 PS patients. RESULTS Following the application of stringent filter criteria, 14 rare copy number variations (CNVs) were identified in 14 PS patients in different regions outside known common copy number variations: seven genomic duplications and seven genomic deletions, enclosing the two previously reported PS associated chromosomal deletions. These CNVs ranged from 0.04 to 4.71 Mb in size. Bioinformatic analysis of array-CGH data indicated gene enrichment in pathways involved in cell-cell adhesion, DNA binding and apoptosis processes. The analysis also provided a number of candidate genes possibly causing the developmental defects observed in PS patients, among others REV3L, a gene coding for an error-prone DNA polymerase previously associated with Möbius Syndrome with variable phenotypes including pectoralis muscle agenesis. CONCLUSIONS A number of rare CNVs were identified in PS patients, and these involve genes that represent candidates for further evaluation. Rare inherited CNVs may contribute to, or represent risk factors of PS in a multifactorial mode of inheritance.
Collapse
|
14
|
Fritzen R, Delbos F, De Smet A, Palancade B, Canman CE, Aoufouchi S, Weill JC, Reynaud CA, Storck S. A single aspartate mutation in the conserved catalytic site of Rev3L generates a hypomorphic phenotype in vivo and in vitro. DNA Repair (Amst) 2016; 46:37-46. [PMID: 27481099 DOI: 10.1016/j.dnarep.2016.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 12/29/2022]
Abstract
Rev3, the catalytic subunit of yeast DNA polymerase ζ, is required for UV resistance and UV-induced mutagenesis, while its mammalian ortholog, REV3L, plays further vital roles in cell proliferation and embryonic development. To assess the contribution of REV3L catalytic activity to its in vivo function, we generated mutant mouse strains in which one or two Ala residues were substituted to the Asp of the invariant catalytic YGDTDS motif. The simultaneous mutation of both Asp (ATA) phenocopies the Rev3l knockout, which proves that the catalytic activity is mandatory for the vital functions of Rev3L, as reported recently. Surprisingly, although the mutation of the first Asp severely impairs the enzymatic activity of other B-family DNA polymerases, the corresponding mutation of Rev3 (ATD) is hypomorphic in yeast and mouse, as it does not affect viability and proliferation and moderately impacts UVC-induced cell death and mutagenesis. Interestingly, Rev3l hypomorphic mutant mice display a distinct, albeit modest, alteration of the immunoglobulin gene mutation spectrum at G-C base pairs, further documenting its role in this process.
Collapse
Affiliation(s)
- Rémi Fritzen
- Institut Necker-Enfants Malades, INSERM U1151-CNRS UMR 8253, Faculté de Médecine Paris Descartes, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
| | - Frédéric Delbos
- Institut Necker-Enfants Malades, INSERM U1151-CNRS UMR 8253, Faculté de Médecine Paris Descartes, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
| | - Annie De Smet
- Institut Necker-Enfants Malades, INSERM U1151-CNRS UMR 8253, Faculté de Médecine Paris Descartes, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
| | - Benoît Palancade
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
| | | | - Said Aoufouchi
- Institut Gustave Roussy, CNRS UMR 8200, Villejuif, and Université Paris-Sud, Orsay, France.
| | - Jean-Claude Weill
- Institut Necker-Enfants Malades, INSERM U1151-CNRS UMR 8253, Faculté de Médecine Paris Descartes, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
| | - Claude-Agnès Reynaud
- Institut Necker-Enfants Malades, INSERM U1151-CNRS UMR 8253, Faculté de Médecine Paris Descartes, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
| | - Sébastien Storck
- Institut Necker-Enfants Malades, INSERM U1151-CNRS UMR 8253, Faculté de Médecine Paris Descartes, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
| |
Collapse
|
15
|
Singh B, Li X, Owens KM, Vanniarajan A, Liang P, Singh KK. Human REV3 DNA Polymerase Zeta Localizes to Mitochondria and Protects the Mitochondrial Genome. PLoS One 2015; 10:e0140409. [PMID: 26462070 PMCID: PMC4604079 DOI: 10.1371/journal.pone.0140409] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 09/24/2015] [Indexed: 12/29/2022] Open
Abstract
To date, mitochondrial DNA polymerase γ (POLG) is the only polymerase known to be present in mammalian mitochondria. A dogma in the mitochondria field is that there is no other polymerase present in the mitochondria of mammalian cells. Here we demonstrate localization of REV3 DNA polymerase in the mammalian mitochondria. We demonstrate localization of REV3 in the mitochondria of mammalian tissue as well as cell lines. REV3 associates with POLG and mitochondrial DNA and protects the mitochondrial genome from DNA damage. Inactivation of Rev3 leads to reduced mitochondrial membrane potential, reduced OXPHOS activity, and increased glucose consumption. Conversely, inhibition of the OXPHOS increases expression of Rev3. Rev3 expression is increased in human primary breast tumors and breast cancer cell lines. Inactivation of Rev3 decreases cell migration and invasion, and localization of Rev3 in mitochondria increases survival and the invasive potential of cancer cells. Taken together, we demonstrate that REV3 functions in mammalian mitochondria and that mitochondrial REV3 is associated with the tumorigenic potential of cells.
Collapse
Affiliation(s)
- Bhupendra Singh
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Xiurong Li
- Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, New York, United States of America
| | - Kjerstin M. Owens
- Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, New York, United States of America
| | - Ayyasamy Vanniarajan
- Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, New York, United States of America
| | - Ping Liang
- Department of Biological Sciences, Brock University, St. Catharine’s, Ontario, Canada
| | - Keshav K. Singh
- Departments of Genetics, Pathology, Environmental Health, Center for Free Radical Biology, Center for Aging and UAB Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Birmingham Veterans Affairs Medical Center, Birmingham, Alabama, United States of America
- * E-mail:
| |
Collapse
|
16
|
Luo H, Chen Z, Wang S, Zhang R, Qiu W, Zhao L, Peng C, Xu R, Chen W, Wang HW, Chen Y, Yang J, Zhang X, Zhang S, Chen D, Wu W, Zhao C, Cheng G, Jiang T, Lu D, You Y, Liu N, Wang H. c-Myc-miR-29c-REV3L signalling pathway drives the acquisition of temozolomide resistance in glioblastoma. Brain 2015; 138:3654-72. [PMID: 26450587 DOI: 10.1093/brain/awv287] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 08/09/2015] [Indexed: 01/09/2023] Open
Abstract
Resistance to temozolomide poses a major clinical challenge in glioblastoma multiforme treatment, and the mechanisms underlying the development of temozolomide resistance remain poorly understood. Enhanced DNA repair and mutagenesis can allow tumour cells to survive, contributing to resistance and tumour recurrence. Here, using recurrent temozolomide-refractory glioblastoma specimens, temozolomide-resistant cells, and resistant-xenograft models, we report that loss of miR-29c via c-Myc drives the acquisition of temozolomide resistance through enhancement of REV3L-mediated DNA repair and mutagenesis in glioblastoma. Importantly, disruption of c-Myc/miR-29c/REV3L signalling may have dual anticancer effects, sensitizing the resistant tumours to therapy as well as preventing the emergence of acquired temozolomide resistance. Our findings suggest a rationale for targeting the c-Myc/miR-29c/REV3L signalling pathway as a promising therapeutic approach for glioblastoma, even in recurrent, treatment-refractory settings.
Collapse
Affiliation(s)
- Hui Luo
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Zhengxin Chen
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Shuai Wang
- 2 Department of Haematology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Rui Zhang
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Wenjin Qiu
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Lin Zhao
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Chenghao Peng
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Ran Xu
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Wanghao Chen
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Hong-Wei Wang
- 3 Department of Neurosurgery, The Fourth Affiliated Hospital of Harbin Medical University, Harbin 150001, China
| | - Yuanyuan Chen
- 4 Mouse Biology Unit, European Molecular Biology Laboratory, Monterotondo 00015, Italy
| | - Jingmin Yang
- 5 State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences and Institutes for Biomedical Sciences, Fudan University, Shanghai 200433, China
| | - Xiaotian Zhang
- 6 Department of Molecular Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Shuyu Zhang
- 7 School of Radiation Medicine and Protection, Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou 215123, China
| | - Dan Chen
- 8 Department of Immunology, Genetics and Pathology, Ministry of Education and Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Wenting Wu
- 9 Beyster Center for Genomics of Psychiatric Diseases, Department of Psychiatry, University of California San Diego, La Jolla, CA 92093, USA
| | - Chunsheng Zhao
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Gang Cheng
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Tao Jiang
- 10 Department of Neurosurgery, Tiantan Hospital, Capital Medical University, Beijing 100050, China 11 Chinese Glioma Cooperative Group (CGCG)
| | - Daru Lu
- 5 State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences and Institutes for Biomedical Sciences, Fudan University, Shanghai 200433, China
| | - Yongping You
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China 11 Chinese Glioma Cooperative Group (CGCG)
| | - Ning Liu
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China 11 Chinese Glioma Cooperative Group (CGCG)
| | - Huibo Wang
- 1 Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China 11 Chinese Glioma Cooperative Group (CGCG)
| |
Collapse
|
17
|
Tomas-Roca L, Tsaalbi-Shtylik A, Jansen JG, Singh MK, Epstein JA, Altunoglu U, Verzijl H, Soria L, van Beusekom E, Roscioli T, Iqbal Z, Gilissen C, Hoischen A, de Brouwer APM, Erasmus C, Schubert D, Brunner H, Pérez Aytés A, Marin F, Aroca P, Kayserili H, Carta A, de Wind N, Padberg GW, van Bokhoven H. De novo mutations in PLXND1 and REV3L cause Möbius syndrome. Nat Commun 2015; 6:7199. [PMID: 26068067 PMCID: PMC4648025 DOI: 10.1038/ncomms8199] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 04/17/2015] [Indexed: 11/17/2022] Open
Abstract
Möbius syndrome (MBS) is a neurological disorder that is characterized by paralysis of the facial nerves and variable other congenital anomalies. The aetiology of this syndrome has been enigmatic since the initial descriptions by von Graefe in 1880 and by Möbius in 1888, and it has been debated for decades whether MBS has a genetic or a non-genetic aetiology. Here, we report de novo mutations affecting two genes, PLXND1 and REV3L in MBS patients. PLXND1 and REV3L represent totally unrelated pathways involved in hindbrain development: neural migration and DNA translesion synthesis, essential for the replication of endogenously damaged DNA, respectively. Interestingly, analysis of Plxnd1 and Rev3l mutant mice shows that disruption of these separate pathways converge at the facial branchiomotor nucleus, affecting either motoneuron migration or proliferation. The finding that PLXND1 and REV3L mutations are responsible for a proportion of MBS patients suggests that de novo mutations in other genes might account for other MBS patients. lt has been debated for decades if there is a genetic aetiology underlying Möbius syndrome, a neurological disorder characterized by facial paralysis. Here Tomas-Roca et al. use exome sequencing and identify de novo mutations in PLXND1 and REV3L, representing converging pathways in hindbrain development.
Collapse
Affiliation(s)
- Laura Tomas-Roca
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands.,Department of Human Anatomy and Psychobiology, School of Medicine, University of Murcia, 30100 Espinardo (Murcia), Spain
| | - Anastasia Tsaalbi-Shtylik
- Department of Human Genetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands
| | - Jacob G Jansen
- Department of Human Genetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands
| | - Manvendra K Singh
- Department of Cell and Developmental Biology, Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, 9-105 SCTR, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania 19104, USA.,Signature Research Program in Cardiovascular and Metabolic Disorders, Duke-NUS Graduate Medical School Singapore, National Heart Center Singapore, 8 College Road, Singapore 169857, Singapore
| | - Jonathan A Epstein
- Department of Cell and Developmental Biology, Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, 9-105 SCTR, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania 19104, USA
| | - Umut Altunoglu
- Medical Genetics Department, Istanbul Medical Faculty, Istanbul University, Millet Caddesi, Capa, Fatih 34093, Turkey
| | - Harriette Verzijl
- Department of Neurology, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands
| | - Laura Soria
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands
| | - Ellen van Beusekom
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands
| | - Tony Roscioli
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands.,The Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, New South Wales 2010, Australia
| | - Zafar Iqbal
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands
| | - Alexander Hoischen
- Department of Human Genetics, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences (RIMLS), PO Box 9101, Nijmegen 6500 HB, The Netherlands
| | - Arjan P M de Brouwer
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands
| | - Corrie Erasmus
- Department of Neurology, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands
| | - Han Brunner
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands.,Department of Clinical Genetics, Maastricht University Medical Center, PO Box 5800, Maastricht 6200AZ, The Netherlands
| | - Antonio Pérez Aytés
- Dysmorphology and Reproductive Genetics Unit, Moebius Syndrome Foundation of Spain, University Hospital LA FE, Valencia 46540, Spain
| | - Faustino Marin
- Department of Human Anatomy and Psychobiology, School of Medicine, University of Murcia, 30100 Espinardo (Murcia), Spain
| | - Pilar Aroca
- Department of Human Anatomy and Psychobiology, School of Medicine, University of Murcia, 30100 Espinardo (Murcia), Spain
| | - Hülya Kayserili
- Medical Genetics Department, Istanbul Medical Faculty, Istanbul University, Millet Caddesi, Capa, Fatih 34093, Turkey
| | - Arturo Carta
- Ophthalmology Unit, Department of Biomedical, Biotechnological and Translational Sciences (S.Bi.Bi.T.), University of Parma, via Gramsci 14, 43126, Parma, Italy
| | - Niels de Wind
- Department of Human Genetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands
| | - George W Padberg
- Department of Neurology, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands
| | - Hans van Bokhoven
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, PO Box 9101, Nijmegen 6500 HB, The Netherlands
| |
Collapse
|
18
|
Makarova AV, Burgers PM. Eukaryotic DNA polymerase ζ. DNA Repair (Amst) 2015; 29:47-55. [PMID: 25737057 DOI: 10.1016/j.dnarep.2015.02.012] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 12/16/2022]
Abstract
This review focuses on eukaryotic DNA polymerase ζ (Pol ζ), the enzyme responsible for the bulk of mutagenesis in eukaryotic cells in response to DNA damage. Pol ζ is also responsible for a large portion of mutagenesis during normal cell growth, in response to spontaneous damage or to certain DNA structures and other blocks that stall DNA replication forks. Novel insights in mutagenesis have been derived from recent advances in the elucidation of the subunit structure of Pol ζ. The lagging strand DNA polymerase δ shares the small Pol31 and Pol32 subunits with the Rev3-Rev7 core assembly giving a four subunit Pol ζ complex that is the active form in mutagenesis. Furthermore, Pol ζ forms essential interactions with the mutasome assembly factor Rev1 and with proliferating cell nuclear antigen (PCNA). These interactions are modulated by posttranslational modifications such as ubiquitination and phosphorylation that enhance translesion synthesis (TLS) and mutagenesis.
Collapse
Affiliation(s)
- Alena V Makarova
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA; Institute of Molecular Genetics, Russian Academy of Sciences (IMG RAS), Kurchatov Sq. 2, Moscow 123182, Russia
| | - Peter M Burgers
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
| |
Collapse
|
19
|
Jansen JG, Tsaalbi-Shtylik A, de Wind N. Roles of mutagenic translesion synthesis in mammalian genome stability, health and disease. DNA Repair (Amst) 2015; 29:56-64. [PMID: 25655219 DOI: 10.1016/j.dnarep.2015.01.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 12/22/2014] [Accepted: 01/07/2015] [Indexed: 01/08/2023]
Abstract
Most spontaneous and DNA damage-induced nucleotide substitutions in eukaryotes depend on translesion synthesis polymerases Rev1 and Pol ζ, the latter consisting of the catalytic subunit Rev3 and the accessory protein Rev7. Here we review the regulation, and the biochemical and cellular functions, of Rev1/Pol ζ-dependent translesion synthesis. These are correlated with phenotypes of mouse models with defects in Rev1, Rev3 or Rev7. The data indicate that Rev1/Pol ζ-mediated translesion synthesis is important for adaptive immunity while playing paradoxical roles in oncogenesis. On the other hand, by enabling the replication of endogenously damaged templates, Rev1/Pol ζ -dependent translesion synthesis protects stem cells, thereby preventing features of ageing. In conclusion, Rev1/Pol ζ-dependent translesion synthesis at DNA helix-distorting nucleotide lesions orchestrates pleiotropic responses that determine organismal fitness and disease.
Collapse
Affiliation(s)
- Jacob G Jansen
- Department of Human Genetics, Leiden University Medical Center, PO Box 9600, 2300RC Leiden, The Netherlands
| | - Anastasia Tsaalbi-Shtylik
- Department of Human Genetics, Leiden University Medical Center, PO Box 9600, 2300RC Leiden, The Netherlands
| | - Niels de Wind
- Department of Human Genetics, Leiden University Medical Center, PO Box 9600, 2300RC Leiden, The Netherlands.
| |
Collapse
|
20
|
Maskey RS, Kim MS, Baker DJ, Childs B, Malureanu LA, Jeganathan KB, Machida Y, van Deursen JM, Machida YJ. Spartan deficiency causes genomic instability and progeroid phenotypes. Nat Commun 2014; 5:5744. [PMID: 25501849 PMCID: PMC4269170 DOI: 10.1038/ncomms6744] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 11/04/2014] [Indexed: 12/21/2022] Open
Abstract
Spartan (also known as DVC1 and C1orf124) is a PCNA-interacting protein implicated in translesion synthesis, a DNA damage tolerance process that allows the DNA replication machinery to replicate past nucleotide lesions. However, the physiological relevance of Spartan has not been established. Here we report that Spartan insufficiency in mice causes chromosomal instability, cellular senescence and early onset of age-related phenotypes. Whereas complete loss of Spartan causes early embryonic lethality, hypomorphic mice with low amounts of Spartan are viable. These mice are growth retarded and develop cataracts, lordokyphosis and cachexia at a young age. Cre-mediated depletion of Spartan from conditional knockout mouse embryonic fibroblasts results in impaired lesion bypass, incomplete DNA replication, formation of micronuclei and chromatin bridges and eventually cell death. These data demonstrate that Spartan plays a key role in maintaining structural and numerical chromosome integrity and suggest a link between Spartan insufficiency and progeria. Spartan/DVC1 is a translesion synthesis regulator with important roles in cellular DNA damage tolerance. Here, the authors report that Spartan is essential for DNA lesion bypass and that Spartan insufficiency in mice causes chromosomal instability, cellular senescence and early onset of age-related phenotypes.
Collapse
Affiliation(s)
- Reeja S Maskey
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA
| | - Myoung Shin Kim
- Department of Oncology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA
| | - Darren J Baker
- Department of Pediatric and Adolescent Medicine, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA
| | - Bennett Childs
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA
| | - Liviu A Malureanu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA
| | - Karthik B Jeganathan
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA
| | - Yuka Machida
- Department of Oncology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA
| | - Jan M van Deursen
- Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA
| | - Yuichi J Machida
- 1] Department of Oncology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA [2] Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA
| |
Collapse
|
21
|
Shivange G, Kodipelli N, Monisha M, Anindya R. A role for Saccharomyces cerevisiae Tpa1 protein in direct alkylation repair. J Biol Chem 2014; 289:35939-52. [PMID: 25381260 DOI: 10.1074/jbc.m114.590216] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Alkylating agents induce cytotoxic DNA base adducts. In this work, we provide evidence to suggest, for the first time, that Saccharomyces cerevisiae Tpa1 protein is involved in DNA alkylation repair. Little is known about Tpa1 as a repair protein beyond the initial observation from a high-throughput analysis indicating that deletion of TPA1 causes methyl methane sulfonate sensitivity in S. cerevisiae. Using purified Tpa1, we demonstrate that Tpa1 repairs both single- and double-stranded methylated DNA. Tpa1 is a member of the Fe(II) and 2-oxoglutarate-dependent dioxygenase family, and we show that mutation of the amino acid residues involved in cofactor binding abolishes the Tpa1 DNA repair activity. Deletion of TPA1 along with the base excision repair pathway DNA glycosylase MAG1 renders the tpa1Δmag1Δ double mutant highly susceptible to methylation-induced toxicity. We further demonstrate that the trans-lesion synthesis DNA polymerase Polζ (REV3) plays a key role in tolerating DNA methyl-base lesions and that tpa1Δmag1revΔ3 triple mutant is extremely susceptible to methylation-induced toxicity. Our results indicate a synergism between the base excision repair pathway and direct alkylation repair by Tpa1 in S. cerevisiae. We conclude that Tpa1 is a hitherto unidentified DNA repair protein in yeast and that it plays a crucial role in reverting alkylated DNA base lesions and cytotoxicity.
Collapse
Affiliation(s)
- Gururaj Shivange
- From the Department of Biotechnology, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram 502205, Hyderabad, India
| | - Naveena Kodipelli
- From the Department of Biotechnology, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram 502205, Hyderabad, India
| | - Mohan Monisha
- From the Department of Biotechnology, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram 502205, Hyderabad, India
| | - Roy Anindya
- From the Department of Biotechnology, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram 502205, Hyderabad, India
| |
Collapse
|
22
|
Watanabe N, Mii S, Asai N, Asai M, Niimi K, Ushida K, Kato T, Enomoto A, Ishii H, Takahashi M, Murakumo Y. The REV7 subunit of DNA polymerase ζ is essential for primordial germ cell maintenance in the mouse. J Biol Chem 2013; 288:10459-71. [PMID: 23463509 DOI: 10.1074/jbc.m112.421966] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
REV7 (also known as MAD2L2 and MAD2B) is involved in DNA repair, cell cycle regulation, gene expression, and carcinogenesis. In vitro studies show that REV7 interacts with several proteins and regulates their function. It has been reported that human REV7 is highly expressed in the adult testis by Northern blot analysis. However, the significance of REV7 in mammalian development has not been elucidated. Here, we present analyses of REV7-deficient (Rev7(-/-)) mice to clarify the significance of Rev7 in mouse development. In WT mice (Rev7(+/+)), Rev7 expression was ubiquitously observed in the embryo and confined to germ cells in the testes after birth. Rev7(-/-) mice exhibited growth retardation and a partial embryonic lethal phenotype. Mice that survived to adulthood were infertile in both sexes and showed germ cell aplasia in the testes and ovaries. Analyses of Rev7(-/-) embryos revealed that primordial germ cells (PGCs) were present at embryonic day 8.5 (E8.5). However, progressive loss of PGCs was observed during migration, and PGCs were absent in the genital ridges at E13.5. An increase of apoptotic cells was detected not only among PGCs but also in the forebrain of the Rev7(-/-) embryo, whereas cell proliferation was unaffected. Moreover, DNA damage accumulation and increased levels of histone methylation were detected in Rev7(-/-) embryos, and expression of Oct4 and Nanog was deregulated by REV7 deficiency at E8.5. These findings indicate that Rev7 is essential for PGC maintenance by prevention of apoptotic cell death in the mouse.
Collapse
Affiliation(s)
- Naoki Watanabe
- Department of Pathology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
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.
Collapse
Affiliation(s)
- Julian E Sale
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom.
| |
Collapse
|
24
|
Dual role for mammalian DNA polymerase ζ in maintaining genome stability and proliferative responses. Proc Natl Acad Sci U S A 2013; 110:E687-96. [PMID: 23386725 DOI: 10.1073/pnas.1217425110] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
DNA polymerase ζ (polζ) is critical for bypass of DNA damage and the associated mutagenesis, but also has unique functions in mammals. It is required for embryonic development and for viability of hematopoietic cells, but, paradoxically, skin epithelia appear to survive polζ deletion. We wished to determine whether polζ functions in a tissue-specific manner and how polζ status influences skin tumorigenesis. Mice were produced in which Rev3L (the catalytic subunit of polζ) was deleted in tissues expressing keratin 5. Efficient epidermal deletion of Rev3L was tolerated but led to skin and hair abnormalities, accompanied by evidence of DNA breaks. Unchallenged mice developed tumors in keratin 5-expressing tissues with age, consistent with the chromosomal instability accompanying a polζ defect. Unexpectedly, mice with the Rev3L deletion were much more sensitive to UVB radiation than mice defective in other DNA repair genes. Following irradiation, polζ-defective mice failed to mount skin-regenerative responses and responded to stress by mobilizing melanocytes to the epidermis. However, they did not develop skin tumors after chronic UVB irradiation. To determine the proliferative potential of polζ-deficient skin epithelia, keratinocytes were isolated and examined. These keratinocytes harbored chromosomal gaps and breaks and exhibited a striking proliferation defect. These results can be unified by a model in which slowly dividing cells accumulate replication-associated DNA breaks but otherwise survive Rev3L deletion, but functional polζ is essential for responses requiring rapid proliferation, both in cell culture and in vivo. The results reveal a biological role for mammalian polζ in tolerating DNA damage and enabling proliferative responses in vivo.
Collapse
|
25
|
Sharma S, Helchowski CM, Canman CE. The roles of DNA polymerase ζ and the Y family DNA polymerases in promoting or preventing genome instability. Mutat Res 2012. [PMID: 23195997 DOI: 10.1016/j.mrfmmm.2012.11.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cancer cells display numerous abnormal characteristics which are initiated and maintained by elevated mutation rates and genome instability. Chromosomal DNA is continuously surveyed for the presence of damage or blocked replication forks by the DNA Damage Response (DDR) network. The DDR is complex and includes activation of cell cycle checkpoints, DNA repair, gene transcription, and induction of apoptosis. Duplicating a damaged genome is associated with elevated risks to fork collapse and genome instability. Therefore, the DNA damage tolerance (DDT) pathway is also employed to enhance survival and involves the recruitment of translesion DNA synthesis (TLS) polymerases to sites of replication fork blockade or single stranded DNA gaps left after the completion of replication in order to restore DNA to its double stranded form before mitosis. TLS polymerases are specialized for inserting nucleotides opposite DNA adducts, abasic sites, or DNA crosslinks. By definition, the DDT pathway is not involved in the actual repair of damaged DNA, but provides a mechanism to tolerate DNA lesions during replication thereby increasing survival and lessening the chance for genome instability. However this may be associated with increased mutagenesis. In this review, we will describe the specialized functions of Y family polymerases (Rev1, Polη, Polι and Polκ) and DNA polymerase ζ in lesion bypass, mutagenesis, and prevention of genome instability, the latter due to newly appreciated roles in DNA repair. The recently described role of the Fanconi anemia pathway in regulating Rev1 and Polζ-dependent TLS is also discussed in terms of their involvement in TLS, interstrand crosslink repair, and homologous recombination.
Collapse
Affiliation(s)
- Shilpy Sharma
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, United States
| | - Corey M Helchowski
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, United States
| | - Christine E Canman
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, United States.
| |
Collapse
|
26
|
Suzuki M, Takahashi T. Aberrant DNA replication in cancer. Mutat Res 2012; 743-744:111-117. [PMID: 22968031 DOI: 10.1016/j.mrfmmm.2012.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/26/2012] [Accepted: 07/31/2012] [Indexed: 12/11/2022]
Abstract
Genomic instability plays an important role in cancer susceptibility, though the mechanics of its development remain unclear. An often-stated hypothesis is that error-prone phenotypes in DNA replication or aberrations in translesion DNA synthesis lead to genomic instability and cancer. Mutations in core DNA replication proteins have been identified in human cancer, although DNA replication is essential for cell proliferation and most mutations eliminating this function are deleterious. With recent developments in this field we review and discuss the possible involvement of DNA replication proteins in carcinogenesis.
Collapse
Affiliation(s)
- Motoshi Suzuki
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan.
| | - Takashi Takahashi
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan
| |
Collapse
|
27
|
Genetic polymorphisms in translesion synthesis genes are associated with colorectal cancer risk and metastasis in Han Chinese. Gene 2012; 504:151-5. [DOI: 10.1016/j.gene.2012.05.042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 04/13/2012] [Accepted: 05/18/2012] [Indexed: 11/23/2022]
|
28
|
Temviriyanukul P, van Hees-Stuivenberg S, Delbos F, Jacobs H, de Wind N, Jansen JG. Temporally distinct translesion synthesis pathways for ultraviolet light-induced photoproducts in the mammalian genome. DNA Repair (Amst) 2012; 11:550-8. [PMID: 22521143 DOI: 10.1016/j.dnarep.2012.03.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 03/28/2012] [Accepted: 03/28/2012] [Indexed: 10/28/2022]
Abstract
Replicative polymerases (Pols) arrest at damaged DNA nucleotides, which induces ubiquitination of the DNA sliding clamp PCNA (PCNA-Ub) and DNA damage signaling. PCNA-Ub is associated with the recruitment or activation of translesion synthesis (TLS) DNA polymerases of the Y family that can bypass the lesions, thereby rescuing replication and preventing replication fork collapse and consequent formation of double-strand DNA breaks. Here, we have used gene-targeted mouse embryonic fibroblasts to perform a comprehensive study of the in vivo roles of PCNA-Ub and of the Y family TLS Pols η, ι, κ, Rev1 and the B family TLS Polζ in TLS and in the suppression of DNA damage signaling and genome instability after exposure to UV light. Our data indicate that TLS Pols ι and κ and the N-terminal BRCT domain of Rev1, that previously was implicated in the regulation of TLS, play minor roles in TLS of DNA photoproducts. PCNA-Ub is critical for an early TLS pathway that replicates both strongly helix-distorting (6-4) pyrimidine-pyrimidone ((6-4)PP) and mildly distorting cyclobutane pyrimidine dimer (CPD) photoproducts. The role of Polη is mainly restricted to early TLS of CPD photoproducts, whereas Rev1 and, in particular, Polζ are essential for the bypass of (6-4)PP photoproducts, both early and late after exposure. Thus, structurally distinct photoproducts at the mammalian genome are bypassed by different TLS Pols in temporally different, PCNA-Ub-dependent and independent fashions.
Collapse
Affiliation(s)
- Piya Temviriyanukul
- Department of Toxicogenetics, Leiden University Medical Center-LUMC, PO Box 9600, 2300 RC Leiden, The Netherlands.
| | | | | | | | | | | |
Collapse
|
29
|
Inhibition of REV3 expression induces persistent DNA damage and growth arrest in cancer cells. Neoplasia 2012; 13:961-70. [PMID: 22028621 DOI: 10.1593/neo.11828] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 08/23/2011] [Accepted: 08/26/2011] [Indexed: 02/02/2023] Open
Abstract
REV3 is the catalytic subunit of DNA translesion synthesis polymerase ζ. Inhibition of REV3 expression increases the sensitivity of human cells to a variety of DNA-damaging agents and reduces the formation of resistant cells. Surprisingly, we found that short hairpin RNA-mediated depletion of REV3 per se suppresses colony formation of lung (A549, Calu-3), breast (MCF-7, MDA-MB-231), mesothelioma (IL45 and ZL55), and colon (HCT116 +/-p53) tumor cell lines, whereas control cell lines (AD293, LP9-hTERT) and the normal mesothelial primary culture (SDM104) are less affected. Inhibition of REV3 expression in cancer cells leads to an accumulation of persistent DNA damage as indicated by an increase in phospho-ATM, 53BP1, and phospho-H2AX foci formation, subsequently leading to the activation of the ATM-dependent DNA damage response cascade. REV3 depletion in p53-proficient cancer cell lines results in a G(1) arrest and induction of senescence as indicated by the accumulation of p21 and an increase in senescence-associated β-galactosidase activity. In contrast, inhibition of REV3 expression in p53-deficient cells results in growth inhibition and a G(2)/M arrest. A small fraction of the p53-deficient cancer cells can overcome the G(2)/M arrest, which results in mitotic slippage and aneuploidy. Our findings reveal that REV3 depletion per se suppresses growth of cancer cell lines from different origin, whereas control cell lines and a mesothelial primary culture were less affected. Thus, our findings indicate that depletion of REV3 not only can amend cisplatin-based cancer therapy but also can be applied for susceptible cancers as a potential monotherapy.
Collapse
|
30
|
Takezawa J, Aiba N, Kajiwara K, Yamada K. Caffeine abolishes the ultraviolet-induced REV3 translesion replication pathway in mouse cells. Int J Mol Sci 2011; 12:8513-29. [PMID: 22272088 PMCID: PMC3257085 DOI: 10.3390/ijms12128513] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 11/08/2011] [Accepted: 11/17/2011] [Indexed: 11/26/2022] Open
Abstract
When a replicative DNA polymerase stalls upon encountering a photoproduct on the template strand, it is relieved by other low-processivity polymerase(s), which insert nucleotide(s) opposite the lesion. Using an alkaline sucrose density gradient sedimentation technique, we previously classified this process termed UV-induced translesion replication (UV-TLS) into two types. In human cancer cells or xeroderma pigmentosum variant (XP-V) cells, UV-TLS was inhibited by caffeine or proteasome inhibitors. However, in normal human cells, the process was insensitive to these reagents. Reportedly, in yeast or mammalian cells, REV3 protein (a catalytic subunit of DNA polymerase ζ) is predominantly involved in the former type of TLS. Here, we studied UV-TLS in fibroblasts derived from the Rev3-knockout mouse embryo (Rev3KO-MEF). In the wild-type MEF, UV-TLS was slow (similar to that of human cancer cells or XP-V cells), and was abolished by caffeine or MG-262. In 2 cell lines of Rev3KO-MEF (Rev3−/−p53−/−), UV-TLS was not observed. In p53KO-MEF, which is a strict control for Rev3KO-MEF, the UV-TLS response was similar to that of the wild-type. Introduction of the Rev3 expression plasmid into Rev3KO-MEF restored the UV-TLS response in selected stable transformants. In some transformants, viability to UV was the same as that in the wild-type, and the death rate was increased by caffeine. Our findings indicate that REV3 is predominantly involved in UV-TLS in mouse cells, and that the REV3 translesion pathway is suppressed by caffeine or proteasome inhibitors.
Collapse
Affiliation(s)
- Jun Takezawa
- Division of Genetic Biochemistry, The National Institute of Health and Nutrition, Shinjuku-ku, Tokyo 162-8636, Japan; E-Mail: (J.T.)
| | - Naomi Aiba
- Division of Genetic Biochemistry, The National Institute of Health and Nutrition, Shinjuku-ku, Tokyo 162-8636, Japan; E-Mail: (J.T.)
| | - Kagemasa Kajiwara
- School of Medicine, Tokai University, Isehara-shi, Kanagawa-ken 259-1193, Japan
| | - Kouichi Yamada
- Division of Genetic Biochemistry, The National Institute of Health and Nutrition, Shinjuku-ku, Tokyo 162-8636, Japan; E-Mail: (J.T.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-3-3203-5723; Fax: +81-3-3203-0335
| |
Collapse
|
31
|
Kochenova OV, Soshkina JV, Stepchenkova EI, Inge-Vechtomov SG, Shcherbakova PV. Participation of translesion synthesis DNA polymerases in the maintenance of chromosome integrity in yeast Saccharomyces cerevisiae. BIOCHEMISTRY (MOSCOW) 2011; 76:49-60. [PMID: 21568839 DOI: 10.1134/s000629791101007x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We employed a genetic assay based on illegitimate hybridization of heterothallic Saccharomyces cerevisiae strains (the α-test) to analyze the consequences for genome stability of inactivating translesion synthesis (TLS) DNA polymerases. The α-test is the only assay that measures the frequency of different types of mutational changes (point mutations, recombination, chromosome or chromosome arm loss) and temporary changes in genetic material simultaneously. All these events are manifested as illegitimate hybridization and can be distinguished by genetic analysis of the hybrids and cytoductants. We studied the effect of Polζ, Polη, and Rev1 deficiency on the genome stability in the absence of genotoxic treatment and in UV-irradiated cells. We show that, in spite of the increased percent of accurately repaired primary lesions, chromosome fragility, rearrangements, and loss occur in the absence of Polζ and Polη. Our findings contribute to further refinement of the current models of translesion synthesis and the organization of eukaryotic replication fork.
Collapse
Affiliation(s)
- O V Kochenova
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, 68198, USA.
| | | | | | | | | |
Collapse
|
32
|
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.
Collapse
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
| |
Collapse
|
33
|
O'Donnell L, Panier S, Wildenhain J, Tkach JM, Al-Hakim A, Landry MC, Escribano-Diaz C, Szilard RK, Young JTF, Munro M, Canny MD, Kolas NK, Zhang W, Harding SM, Ylanko J, Mendez M, Mullin M, Sun T, Habermann B, Datti A, Bristow RG, Gingras AC, Tyers MD, Brown GW, Durocher D. The MMS22L-TONSL complex mediates recovery from replication stress and homologous recombination. Mol Cell 2010; 40:619-31. [PMID: 21055983 DOI: 10.1016/j.molcel.2010.10.024] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 09/30/2010] [Accepted: 10/19/2010] [Indexed: 01/07/2023]
Abstract
Genome integrity is jeopardized each time DNA replication forks stall or collapse. Here we report the identification of a complex composed of MMS22L (C6ORF167) and TONSL (NFKBIL2) that participates in the recovery from replication stress. MMS22L and TONSL are homologous to yeast Mms22 and plant Tonsoku/Brushy1, respectively. MMS22L-TONSL accumulates at regions of ssDNA associated with distressed replication forks or at processed DNA breaks, and its depletion results in high levels of endogenous DNA double-strand breaks caused by an inability to complete DNA synthesis after replication fork collapse. Moreover, cells depleted of MMS22L are highly sensitive to camptothecin, a topoisomerase I poison that impairs DNA replication progression. Finally, MMS22L and TONSL are necessary for the efficient formation of RAD51 foci after DNA damage, and their depletion impairs homologous recombination. These results indicate that MMS22L and TONSL are genome caretakers that stimulate the recombination-dependent repair of stalled or collapsed replication forks.
Collapse
Affiliation(s)
- Lara O'Donnell
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Hirota K, Sonoda E, Kawamoto T, Motegi A, Masutani C, Hanaoka F, Szüts D, Iwai S, Sale JE, Lehmann A, Takeda S. Simultaneous disruption of two DNA polymerases, Polη and Polζ, in Avian DT40 cells unmasks the role of Polη in cellular response to various DNA lesions. PLoS Genet 2010; 6. [PMID: 20949111 PMCID: PMC2951353 DOI: 10.1371/journal.pgen.1001151] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Accepted: 09/08/2010] [Indexed: 12/18/2022] Open
Abstract
Replicative DNA polymerases are frequently stalled by DNA lesions. The resulting replication blockage is released by homologous recombination (HR) and translesion DNA synthesis (TLS). TLS employs specialized TLS polymerases to bypass DNA lesions. We provide striking in vivo evidence of the cooperation between DNA polymerase η, which is mutated in the variant form of the cancer predisposition disorder xeroderma pigmentosum (XP-V), and DNA polymerase ζ by generating POLη−/−/POLζ−/− cells from the chicken DT40 cell line. POLζ−/− cells are hypersensitive to a very wide range of DNA damaging agents, whereas XP-V cells exhibit moderate sensitivity to ultraviolet light (UV) only in the presence of caffeine treatment and exhibit no significant sensitivity to any other damaging agents. It is therefore widely believed that Polη plays a very specific role in cellular tolerance to UV-induced DNA damage. The evidence we present challenges this assumption. The phenotypic analysis of POLη−/−/POLζ−/− cells shows that, unexpectedly, the loss of Polη significantly rescued all mutant phenotypes of POLζ−/− cells and results in the restoration of the DNA damage tolerance by a backup pathway including HR. Taken together, Polη contributes to a much wide range of TLS events than had been predicted by the phenotype of XP-V cells. DNA replication is a fragile biochemical reaction, as the replicative DNA polymerases are readily stalled by DNA lesions. The resulting replication blockage is released by translesion DNA synthesis (TLS), which employs specialized TLS polymerases to bypass DNA lesions. There are at least seven TLS polymerases known in vertebrates. However, how they cooperate in vivo remains one of central questions in the field. We analyzed this functional interaction by genetically disrupting two of major TLS polymerases, Polη and Polζ, in the unique genetic model organism, chicken DT40 cells. Currently, it is widely believed that Polη plays a very specific role in cellular tolerance to ultraviolet light–induced DNA damage. Polζ, on the other hand, plays a key role in cellular tolerance to a very wide range of DNA–damaging agents, as POLζ−/− cells are hypersensitivity to a number of DNA damaging agents. Our phenotypic analysis of POLη−/−/POLζ−/− cells shows that, unexpectedly, the loss of Polη significantly rescued all mutant phenotypes of POLζ−/− cells. The genetic interaction shown here reveals a previously unappreciated role of human Polη in cellular response to a wide variety of DNA lesions and two-step collaborative action of Polymerase η and ζ.
Collapse
Affiliation(s)
- Kouji Hirota
- CREST Research Project, Japan Science and Technology, Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Eiichiro Sonoda
- CREST Research Project, Japan Science and Technology, Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Takuo Kawamoto
- CREST Research Project, Japan Science and Technology, Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Akira Motegi
- CREST Research Project, Japan Science and Technology, Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Chikahide Masutani
- Solution-Oriented Research for Science and Technology (SORST), Japan Science and Technology Agency, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Fumio Hanaoka
- Solution-Oriented Research for Science and Technology (SORST), Japan Science and Technology Agency, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Dávid Szüts
- St. George's, University of London, London, United Kingdom
| | - Shigenori Iwai
- Division of Chemistry, Graduate School of Engineering Science, Osaka University, Osaka, Japan
| | - Julian E. Sale
- Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Alan Lehmann
- Genome Damage and Stability Centre, University of Sussex, Brighton, United Kingdom
| | - Shunichi Takeda
- CREST Research Project, Japan Science and Technology, Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- * E-mail:
| |
Collapse
|
35
|
Stallons LJ, McGregor WG. Translesion synthesis polymerases in the prevention and promotion of carcinogenesis. J Nucleic Acids 2010; 2010. [PMID: 20936171 PMCID: PMC2945679 DOI: 10.4061/2010/643857] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Accepted: 08/13/2010] [Indexed: 12/29/2022] Open
Abstract
A critical step in the transformation of cells to the malignant state of cancer is the induction of mutations in the DNA of cells damaged by genotoxic agents. Translesion DNA synthesis (TLS) is the process by which cells copy DNA containing unrepaired damage that blocks progression of the replication fork. The DNA polymerases that catalyze TLS in mammals have been the topic of intense investigation over the last decade. DNA polymerase η (Pol η) is best understood and is active in error-free bypass of UV-induced DNA damage. The other TLS polymerases (Pol ι, Pol κ, REV1, and Pol ζ) have been studied extensively in vitro, but their in vivo role is only now being investigated using knockout mouse models of carcinogenesis. This paper will focus on the studies of mice and humans with altered expression of TLS polymerases and the effects on cancer induced by environmental agents.
Collapse
Affiliation(s)
- L Jay Stallons
- Department of Pharmacology and Toxicology, James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | | |
Collapse
|
36
|
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: 4.5] [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.
Collapse
Affiliation(s)
- The Vinh Ho
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York 11794-3400, USA
| | | |
Collapse
|
37
|
Hermo L, Pelletier RM, Cyr DG, Smith CE. Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 5: intercellular junctions and contacts between germs cells and Sertoli cells and their regulatory interactions, testicular cholesterol, and genes/proteins associated with more than one germ cell generation. Microsc Res Tech 2010; 73:409-94. [PMID: 19941291 DOI: 10.1002/jemt.20786] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In the testis, cell adhesion and junctional molecules permit specific interactions and intracellular communication between germ and Sertoli cells and apposed Sertoli cells. Among the many adhesion family of proteins, NCAM, nectin and nectin-like, catenins, and cadherens will be discussed, along with gap junctions between germ and Sertoli cells and the many members of the connexin family. The blood-testis barrier separates the haploid spermatids from blood borne elements. In the barrier, the intercellular junctions consist of many proteins such as occludin, tricellulin, and claudins. Changes in the expression of cell adhesion molecules are also an essential part of the mechanism that allows germ cells to move from the basal compartment of the seminiferous tubule to the adluminal compartment thus crossing the blood-testis barrier and well-defined proteins have been shown to assist in this process. Several structural components show interactions between germ cells to Sertoli cells such as the ectoplasmic specialization which are more closely related to Sertoli cells and tubulobulbar complexes that are processes of elongating spermatids embedded into Sertoli cells. Germ cells also modify several Sertoli functions and this also appears to be the case for residual bodies. Cholesterol plays a significant role during spermatogenesis and is essential for germ cell development. Lastly, we list genes/proteins that are expressed not only in any one specific generation of germ cells but across more than one generation.
Collapse
Affiliation(s)
- Louis Hermo
- Faculty of Medicine, Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada H3A 2B2.
| | | | | | | |
Collapse
|
38
|
Wittschieben JP, Patil V, Glushets V, Robinson LJ, Kusewitt DF, Wood RD. Loss of DNA polymerase zeta enhances spontaneous tumorigenesis. Cancer Res 2010; 70:2770-8. [PMID: 20215524 DOI: 10.1158/0008-5472.can-09-4267] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mammalian genomes encode at least 15 distinct DNA polymerases, functioning as specialists in DNA replication, DNA repair, recombination, or bypass of DNA damage. Although the DNA polymerase zeta (polzeta) catalytic subunit REV3L is important in defense against genotoxins, little is known of its biological function. This is because REV3L is essential during embryogenesis, unlike other translesion DNA polymerases. Outstanding questions include whether any adult cells are viable in the absence of polzeta and whether polzeta status influences tumorigenesis. REV3L-deficient cells have properties that could influence the development of neoplasia in opposing ways: markedly reduced damage-induced point mutagenesis and extensive chromosome instability. To answer these questions, Rev3L was conditionally deleted from tissues of adult mice using MMTV-Cre. Loss of REV3L was tolerated in epithelial tissues but not in the hematopoietic lineage. Thymic lymphomas in Tp53(-/-) Rev3L conditional mice occurred with decreased latency and higher incidence. The lymphomas were populated predominantly by Rev3L-null T cells, showing that loss of Rev3L can promote tumorigenesis. Remarkably, the tumors were frequently oligoclonal, consistent with accelerated genetic changes in the absence of Rev3L. Mammary tumors could also arise from Rev3L-deleted cells in both Tp53(+/+) and Tp53(+/-) backgrounds. Mammary tumors in Tp53(+/-) mice deleting Rev3L formed months earlier than mammary tumors in Tp53(+/-) control mice. Prominent preneoplastic changes in glandular tissue adjacent to these tumors occurred only in mice deleting Rev3L and were associated with increased tumor multiplicity. Polzeta is the only specialized DNA polymerase yet identified that inhibits spontaneous tumor development.
Collapse
Affiliation(s)
- John P Wittschieben
- Department of Pharmacology, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania, USA
| | | | | | | | | | | |
Collapse
|
39
|
Wang H, Zhang SY, Wang S, Lu J, Wu W, Weng L, Chen D, Zhang Y, Lu Z, Yang J, Chen Y, Zhang X, Chen X, Xi C, Lu D, Zhao S. REV3L confers chemoresistance to cisplatin in human gliomas: the potential of its RNAi for synergistic therapy. Neuro Oncol 2010; 11:790-802. [PMID: 19289490 DOI: 10.1215/15228517-2009-015] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The REV3L gene, encoding the catalytic subunit of human polymerase zeta, plays a significant role in the cytotoxicity, mutagenicity, and chemoresistance of certain tumors. However, the role of REV3L in regulating the sensitivity of glioma cells to chemotherapy remains unknown. In this study, we investigated the expression of the REV3L gene in 10 normal brain specimens and 30 human glioma specimens and examined the value of REV3L as a potential modulator of cellular response to various DNA-damaging agents. Reverse transcriptase PCR/real-time PCR analysis revealed that REV3L was overexpressed in human gliomas compared with normal brain tissues. A glioma cell model with stable overexpression of REV3L was used to probe the role of REV3L in cisplatin treatment; upregulation of REV3L markedly attenuated cisplatin-induced apoptosis of the mitochondrial apoptotic pathway. We therefore assessed the REV3L-targeted treatment modality that combines suppression of REV3L expression using RNA interference (RNAi) with the cytotoxic effects of DNA-damaging agents. Downregulation of REV3L expression significantly enhanced the sensitivity of glioma cells to cisplatin, as evidenced by the increased apoptosis rate and marked alterations in the anti-apoptotic proteins B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl) and proapoptotic Bcl-2-associated x protein (Bax) expression levels, and reduced mutation frequencies in surviving glioma cells. These results suggest that REV3L may potentially contribute to gliomagenesis and play a crucial role in regulating cellular response to the DNA cross-linking agent cisplatin. Our findings indicate that RNAi targeting REV3L combined with chemotherapy has synergistic therapeutic effects on glioma cells, which warrants further investigation as an effective novel therapeutic regimen for patients with this malignancy.
Collapse
Affiliation(s)
- Huibo Wang
- Department of Neurological Surgery, Brain Tumor Research Center, First Affliated Hospital, Harbin Medical University, Harbin 150001, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Ogawara D, Muroya T, Yamauchi K, Iwamoto TA, Yagi Y, Yamashita Y, Waga S, Akiyama M, Maki H. Near-full-length REV3L appears to be a scarce maternal factor in Xenopus laevis eggs that changes qualitatively in early embryonic development. DNA Repair (Amst) 2009; 9:90-5. [PMID: 19896909 DOI: 10.1016/j.dnarep.2009.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 10/07/2009] [Accepted: 10/08/2009] [Indexed: 11/17/2022]
Abstract
REV3 is the catalytic subunit of DNA polymerase zeta (pol zeta), which is responsible for the damage-induced mutagenesis that arises during error-prone translesion synthesis in eukaryotes. The related REV3L genes in human and mouse encode proteins of approximately 350kDa, twice as large as yeast REV3, but full-length REV3L has not been identified in any vertebrate cell. We report that Xenopus laevisREV3L encodes a 352-kDa protein that has high overall amino acid sequence similarity to its mammalian counterparts, and, for the first time in a vertebrate species, we have detected putative REV3L polypeptides of 300 and 340kDa in X. laevis oocytes. Only the 300-kDa form is stored in eggs, where its concentration of about 65pM is much lower than those of other replication and repair proteins including the accessory pol zeta subunit REV7. In fertilized eggs, the levels of this polypeptide did not change until neurula; the larger 340-kDa form first appeared at stages after gastrula, suggesting a pattern of regulation during development. These observations indicate the existence of REV3L as a scarce protein, of approximately the full predicted size, whose level may impose severe constraints on the assembly of pol zeta in X. laevis.
Collapse
Affiliation(s)
- Daichi Ogawara
- Division of Molecular Biology, Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Participation of DNA polymerase zeta in replication of undamaged DNA in Saccharomyces cerevisiae. Genetics 2009; 184:27-42. [PMID: 19841096 DOI: 10.1534/genetics.109.107482] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Translesion synthesis DNA polymerases contribute to DNA damage tolerance by mediating replication of damaged templates. Due to the low fidelity of these enzymes, lesion bypass is often mutagenic. We have previously shown that, in Saccharomyces cerevisiae, the contribution of the error-prone DNA polymerase zeta (Polzeta) to replication and mutagenesis is greatly enhanced if the normal replisome is defective due to mutations in replication genes. Here we present evidence that this defective-replisome-induced mutagenesis (DRIM) results from the participation of Polzeta in the copying of undamaged DNA rather than from mutagenic lesion bypass. First, DRIM is not elevated in strains that have a high level of endogenous DNA lesions due to defects in nucleotide excision repair or base excision repair pathways. Second, DRIM remains unchanged when the level of endogenous oxidative DNA damage is decreased by using anaerobic growth conditions. Third, analysis of the spectrum of mutations occurring during DRIM reveals the characteristic error signature seen during replication of undamaged DNA by Polzeta in vitro. These results extend earlier findings in Escherichia coli indicating that Y-family DNA polymerases can contribute to the copying of undamaged DNA. We also show that exposure of wild-type yeast cells to the replication inhibitor hydroxyurea causes a Polzeta-dependent increase in mutagenesis. This suggests that DRIM represents a response to replication impediment per se rather than to specific defects in the replisome components.
Collapse
|
42
|
Roos WP, Tsaalbi-Shtylik A, Tsaryk R, Güvercin F, de Wind N, Kaina B. The translesion polymerase Rev3L in the tolerance of alkylating anticancer drugs. Mol Pharmacol 2009; 76:927-34. [PMID: 19641035 DOI: 10.1124/mol.109.058131] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Temozolomide and fotemustine, representing methylating and chloroethylating agents, respectively, are used in the treatment of glioma and malignant melanoma. Because chemoresistance of these tumors is a common phenomenon, identification of the underlying mechanisms is needed. Here we show that Rev3L, the catalytic subunit of the translesion DNA polymerase zeta, mediates resistance to both temozolomide and fotemustine. Rev3L knockout cells are hypersensitive to both agents. It is remarkable that cells heterozygous for Rev3L showed an intermediate sensitivity. Rev3L is not involved in the tolerance of the toxic O6-methylguanine lesion. However, a possible role of Rev3L in the tolerance of O6-chloroethylguanine or the subsequently formed N1-guanine-N3-cytosine interstrand cross-link is shown. Rev3L had no influence on base excision repair (BER) of the N-alkylation lesions but is very likely to be involved in the tolerance of N-alkylations or apurinic/apyrimidinic sites originating from them. We also show that Rev3L exerts its protective effect in replicating cells and that loss of Rev3L leads to a significant increase in DNA double-strand breaks after temozolomide and fotemustine treatment. These data show that Rev3L contributes to temozolomide and fotemustine resistance, thus acting in concert with O6-methylguanine-DNA methyltransferase, BER, mismatch repair, and double-strand break repair in defense against simple alkylating anticancer drugs.
Collapse
Affiliation(s)
- Wynand Paul Roos
- Institute of Toxicology, University Medicine Mainz, Mainz D-55131, Germany
| | | | | | | | | | | |
Collapse
|
43
|
Jansen JG, Tsaalbi-Shtylik A, Hendriks G, Verspuy J, Gali H, Haracska L, de Wind N. Mammalian polymerase zeta is essential for post-replication repair of UV-induced DNA lesions. DNA Repair (Amst) 2009; 8:1444-51. [PMID: 19783229 DOI: 10.1016/j.dnarep.2009.09.006] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 08/17/2009] [Accepted: 09/10/2009] [Indexed: 01/11/2023]
Abstract
DNA polymerase zeta is believed to be an essential constituent of DNA damage tolerance, comprising several pathways that allow the replication of DNA templates containing unrepaired damage. We wanted to better define the role of polymerase zeta in DNA damage tolerance in mammalian cells. To this aim we have investigated replication of ultraviolet light-damaged DNA templates in mouse embryonic fibroblasts deficient for Rev3, the catalytic subunit of polymerase zeta. We found that Rev3 is important for a post-replication repair pathway of helix-distorting [6-4]pyrimidine-pyrimidone photoproducts and, to a lesser extent, of cyclobutane pyrimidine dimers. Unlike its partner Rev1, Rev3 appears not to be involved in an immediate translesion synthesis pathway at a stalled replication fork. The deficiency of Rev3(-/-) MEFs in post-replication repair of different photoproducts contributes to the extreme sensitivity of these cells to UV light.
Collapse
Affiliation(s)
- Jacob G Jansen
- Department of Toxicogenetics, Leiden University Medical Center, Einthovenweg 20, PO Box 9600, 2300 RC Leiden, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
44
|
Waters LS, Minesinger BK, Wiltrout ME, D'Souza S, Woodruff RV, Walker GC. Eukaryotic translesion polymerases and their roles and regulation in DNA damage tolerance. Microbiol Mol Biol Rev 2009; 73:134-54. [PMID: 19258535 PMCID: PMC2650891 DOI: 10.1128/mmbr.00034-08] [Citation(s) in RCA: 451] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
DNA repair and DNA damage tolerance machineries are crucial to overcome the vast array of DNA damage that a cell encounters during its lifetime. In this review, we summarize the current state of knowledge about the eukaryotic DNA damage tolerance pathway translesion synthesis (TLS), a process in which specialized DNA polymerases replicate across from DNA lesions. TLS aids in resistance to DNA damage, presumably by restarting stalled replication forks or filling in gaps that remain in the genome due to the presence of DNA lesions. One consequence of this process is the potential risk of introducing mutations. Given the role of these translesion polymerases in mutagenesis, we discuss the significant regulatory mechanisms that control the five known eukaryotic translesion polymerases: Rev1, Pol zeta, Pol kappa, Pol eta, and Pol iota.
Collapse
Affiliation(s)
- Lauren S Waters
- Department of Biology, Massachusetts Institute of Technology, Building 68, Room 653, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | | | | | | | | | | |
Collapse
|
45
|
Brondello JM, Pillaire MJ, Rodriguez C, Gourraud PA, Selves J, Cazaux C, Piette J. Novel evidences for a tumor suppressor role of Rev3, the catalytic subunit of Pol zeta. Oncogene 2008; 27:6093-101. [PMID: 18622427 DOI: 10.1038/onc.2008.212] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cell cycle checkpoints and DNA repair act in concert to ensure DNA integrity during perturbation of normal replication or in response to genotoxic agents. Deficiencies in these protective mechanisms can lead to cellular transformation and ultimately tumorigenesis. Here we focused on Rev3, the catalytic subunit of the low-fidelity DNA repair polymerase zeta. Rev3 is believed to play a role in double-strand break (DSB)-induced DNA repair by homologous recombination. In line with this hypothesis, we show the accumulation of chromatin-bound Rev3 protein in late S-G2 of untreated cells and in response to clastogenic DNA damage as well as an gamma-H2AX accumulation in Rev3-depleted cells. Moreover, serine 995 of Rev3 is in vitro phosphorylated by the DSB-inducible checkpoint kinase, Chk2. Our data also disclose a significant reduction of rev3 gene expression in 74 colon carcinomas when compared to the normal adjacent tissues. This reduced expression is independent of the carcinoma stages, suggesting that the downregulation of rev3 might have occurred early during tumorigenesis.
Collapse
Affiliation(s)
- J-M Brondello
- Centre Régional de Cancérologie de Montpellier (INSERM-Université de Montpellier I Unité 868) Identité et Plasticité Tumorale, CRCM Val d'Aurelle-Lamarque, Montpellier cedex 5, France.
| | | | | | | | | | | | | |
Collapse
|
46
|
Gan GN, Wittschieben JP, Wittschieben BØ, Wood RD. DNA polymerase zeta (pol zeta) in higher eukaryotes. Cell Res 2008; 18:174-83. [PMID: 18157155 DOI: 10.1038/cr.2007.117] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Most current knowledge about DNA polymerase zeta (pol zeta) comes from studies of the enzyme in the budding yeast Saccharomyces cerevisiae, where pol zeta consists of a complex of the catalytic subunit Rev3 with Rev7, which associates with Rev1. Most spontaneous and induced mutagenesis in yeast is dependent on these gene products, and yeast pol zeta can mediate translesion DNA synthesis past some adducts in DNA templates. Study of the homologous gene products in higher eukaryotes is in a relatively early stage, but additional functions for the eukaryotic proteins are already apparent. Suppression of vertebrate REV3L function not only reduces induced point mutagenesis but also causes larger-scale genome instability by raising the frequency of spontaneous chromosome translocations. Disruption of Rev3L function is tolerated in Drosophila, Arabidopsis, and in vertebrate cell lines under some conditions, but is incompatible with mouse embryonic development. Functions for REV3L and REV7(MAD2B) in higher eukaryotes have been suggested not only in translesion DNA synthesis but also in some forms of homologous recombination, repair of interstrand DNA crosslinks, somatic hypermutation of immunoglobulin genes and cell-cycle control. This review discusses recent developments in these areas.
Collapse
Affiliation(s)
- Gregory N Gan
- Department of Pharmacology, University of Pittsburgh Medical School, Pittsburgh, PA 15213, USA
| | | | | | | |
Collapse
|
47
|
Saberi A, Hochegger H, Szuts D, Lan L, Yasui A, Sale JE, Taniguchi Y, Murakawa Y, Zeng W, Yokomori K, Helleday T, Teraoka H, Arakawa H, Buerstedde JM, Takeda S. RAD18 and poly(ADP-ribose) polymerase independently suppress the access of nonhomologous end joining to double-strand breaks and facilitate homologous recombination-mediated repair. Mol Cell Biol 2007; 27:2562-71. [PMID: 17242200 PMCID: PMC1899888 DOI: 10.1128/mcb.01243-06] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The Saccharomyces cerevisiae RAD18 gene is essential for postreplication repair but is not required for homologous recombination (HR), which is the major double-strand break (DSB) repair pathway in yeast. Accordingly, yeast rad18 mutants are tolerant of camptothecin (CPT), a topoisomerase I inhibitor, which induces DSBs by blocking replication. Surprisingly, mammalian cells and chicken DT40 cells deficient in Rad18 display reduced HR-dependent repair and are hypersensitive to CPT. Deletion of nonhomologous end joining (NHEJ), a major DSB repair pathway in vertebrates, in rad18-deficient DT40 cells completely restored HR-mediated DSB repair, suggesting that vertebrate Rad18 regulates the balance between NHEJ and HR. We previously reported that loss of NHEJ normalized the CPT sensitivity of cells deficient in poly(ADP-ribose) polymerase 1 (PARP1). Concomitant deletion of Rad18 and PARP1 synergistically increased CPT sensitivity, and additional inactivation of NHEJ normalized this hypersensitivity, indicating their parallel actions. In conclusion, higher-eukaryotic cells separately employ PARP1 and Rad18 to suppress the toxic effects of NHEJ during the HR reaction at stalled replication forks.
Collapse
Affiliation(s)
- Alihossein Saberi
- CREST Research Project, Radiation Genetics, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Cheung HW, Chun ACS, Wang Q, Deng W, Hu L, Guan XY, Nicholls JM, Ling MT, Chuan Wong Y, Tsao SW, Jin DY, Wang X. Inactivation of human MAD2B in nasopharyngeal carcinoma cells leads to chemosensitization to DNA-damaging agents. Cancer Res 2006; 66:4357-67. [PMID: 16618761 DOI: 10.1158/0008-5472.can-05-3602] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Rev7p has been suggested to play an important role in regulating DNA damage response in yeast, and recently, the human homologue (i.e., MAD2B) has been identified, which shares significant homology to the mitotic checkpoint protein MAD2. In this study, we investigated whether MAD2B played a key role in cellular sensitivity to DNA-damaging anticancer drugs by suppressing its expression using RNA interference in nasopharyngeal carcinoma cells. Using colony formation assay, we found that suppression of MAD2B conferred hypersensitivity to a range of DNA-damaging agents, especially DNA cross-linkers, such as cisplatin, and gamma-irradiation. This effect was associated with reduced frequencies of spontaneous and drug-induced mutations, elevated phosphorylation of histone H2AX, and markedly increased chromosomal aberrations in response to DNA damage. In addition, there was also a significant decrease in cisplatin-induced sister chromatid exchange rate, a marker for homologous recombination-mediated post-replication repair in MAD2B-depleted cells. These results indicate that MAD2B may be a key factor in regulating cellular response to DNA damage in cancer cells. Our findings reveal a novel strategy for cancer therapy, in which cancer cells are sensitized to DNA-damaging anticancer drugs through inactivation of the MAD2B gene.
Collapse
Affiliation(s)
- Hiu Wing Cheung
- Department of Anatomy, Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Wittschieben JP, Reshmi SC, Gollin SM, Wood RD. Loss of DNA polymerase zeta causes chromosomal instability in mammalian cells. Cancer Res 2006; 66:134-42. [PMID: 16397225 DOI: 10.1158/0008-5472.can-05-2982] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Rev3L encodes the catalytic subunit of DNA polymerase zeta (pol zeta) in mammalian cells. In yeast, pol zeta helps cells bypass sites of DNA damage that can block replication enzymes. Targeted disruption of the mouse Rev3L gene causes lethality midway through embryonic gestation, and Rev3L-/- mouse embryonic fibroblasts (MEFs) remain in a quiescent state in culture. This suggests that pol zeta may be necessary for tolerance of endogenous DNA damage during normal cell growth. We report the generation of mitotically active Rev3L-/- MEFs on a p53-/- genetic background. Rev3L null MEFs exhibited striking chromosomal instability, with a large increase in translocation frequency. Many complex genetic aberrations were found only in Rev3L null cells. Rev3L null cells had increased chromosome numbers, most commonly near pentaploid, and double minute chromosomes were frequently found. This chromosomal instability associated with loss of a DNA polymerase activity in mammalian cells is similar to the instability associated with loss of homologous recombination capacity. Rev3L null MEFs were also moderately sensitive to mitomycin C, methyl methanesulfonate, and UV and gamma-radiation, indicating that mammalian pol zeta helps cells tolerate diverse types of DNA damage. The increased occurrence of chromosomal translocations in Rev3L-/- MEFs suggests that loss of Rev3L expression could contribute to genome instability during neoplastic transformation and progression.
Collapse
Affiliation(s)
- John P Wittschieben
- Department of Pharmacology, University of Pittsburgh Medical School and University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, USA
| | | | | | | |
Collapse
|
50
|
Seki M, Gearhart PJ, Wood RD. DNA polymerases and somatic hypermutation of immunoglobulin genes. EMBO Rep 2006; 6:1143-8. [PMID: 16319960 PMCID: PMC1369213 DOI: 10.1038/sj.embor.7400582] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Accepted: 10/17/2005] [Indexed: 11/08/2022] Open
Abstract
Somatic hypermutation of immunoglobulin variable genes, which increases antibody diversity, is initiated by the activation-induced cytosine deaminase (AID) protein. The current DNA-deamination model posits that AID deaminates cytosine to uracil in DNA, and that mutations are generated by DNA polymerases during replication or repair of the uracil residue. Mutations could arise as follows: by DNA replicating past the uracil; by removing the uracil with a uracil glycosylase and replicating past the resulting abasic site with a low-fidelity polymerase; or by repairing the uracil and synthesizing a DNA-repair patch downstream using a low-fidelity polymerase. In this review, we summarize the biochemical properties of specialized DNA polymerases in mammalian cells and discuss their participation in the mechanisms of hypermutation. Many recent studies have examined mice deficient in the genes that encode various DNA polymerases, and have shown that DNA polymerase H (POLH) contributes to hypermutation, whereas POLI, POLK and several other enzymes do not have major roles. The low-fidelity enzyme POLQ has been proposed as another candidate polymerase because it can efficiently bypass abasic sites and recent evidence indicates that it might participate in hypermutation.
Collapse
Affiliation(s)
- Mineaki Seki
- Suite 2.6, Research Pavilion, Hillman Cancer Center, University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, Pennsylvania 15213, USA
| | - Patricia J Gearhart
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Drive, Baltimore, Maryland 21224, USA
| | - Richard D Wood
- Suite 2.6, Research Pavilion, Hillman Cancer Center, University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, Pennsylvania 15213, USA
- Tel: +1 412 623 7766; Fax: +1 412 623 7761; E-mail:
| |
Collapse
|