1
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Rai R, Sodeinde T, Boston A, Chang S. Telomeres cooperate with the nuclear envelope to maintain genome stability. Bioessays 2024; 46:e2300184. [PMID: 38047499 DOI: 10.1002/bies.202300184] [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: 09/25/2023] [Revised: 11/12/2023] [Accepted: 11/14/2023] [Indexed: 12/05/2023]
Abstract
Mammalian telomeres have evolved safeguards to prevent their recognition as DNA double-stranded breaks by suppressing the activation of various DNA sensing and repair proteins. We have shown that the telomere-binding proteins TRF2 and RAP1 cooperate to prevent telomeres from undergoing aberrant homology-directed recombination by mediating t-loop protection. Our recent findings also suggest that mammalian telomere-binding proteins interact with the nuclear envelope to maintain chromosome stability. RAP1 interacts with nuclear lamins through KU70/KU80, and disruption of RAP1 and TRF2 function result in nuclear envelope rupture, promoting telomere-telomere recombination to form structures termed ultrabright telomeres. In this review, we discuss the importance of the interactions between shelterin components and the nuclear envelope to maintain telomere homeostasis and genome stability.
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Affiliation(s)
- Rekha Rai
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Tori Sodeinde
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Molecular, Cellular and Developmental Biology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Ava Boston
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Molecular, Cellular and Developmental Biology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Sandy Chang
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, USA
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2
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Wong SY, Soman A, Korolev N, Surya W, Chen Q, Shum W, van Noort J, Nordenskiöld L. The shelterin component TRF2 mediates columnar stacking of human telomeric chromatin. EMBO J 2024; 43:87-111. [PMID: 38177309 PMCID: PMC10883271 DOI: 10.1038/s44318-023-00002-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 01/06/2024] Open
Abstract
Telomere repeat binding factor 2 (TRF2) is an essential component of the telomeres and also plays an important role in a number of other non-telomeric processes. Detailed knowledge of the binding and interaction of TRF2 with telomeric nucleosomes is limited. Here, we study the binding of TRF2 to in vitro-reconstituted kilobasepair-long human telomeric chromatin fibres using electron microscopy, single-molecule force spectroscopy and analytical ultracentrifugation sedimentation velocity. Our electron microscopy results revealed that full-length and N-terminally truncated TRF2 promote the formation of a columnar structure of the fibres with an average width and compaction larger than that induced by the addition of Mg2+, in agreement with the in vivo observations. Single-molecule force spectroscopy showed that TRF2 increases the mechanical and thermodynamic stability of the telomeric fibres when stretched with magnetic tweezers. This was in contrast to the result for fibres reconstituted on the 'Widom 601' high-affinity nucleosome positioning sequence, where minor effects on fibre stability were observed. Overall, TRF2 binding induces and stabilises columnar fibres, which may play an important role in telomere maintenance.
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Affiliation(s)
- Sook Yi Wong
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
- Department of Emerging Infectious Diseases, Duke-NUS, Medical School, Singapore, 169857, Singapore
| | - Aghil Soman
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
| | - Nikolay Korolev
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
| | - Wahyu Surya
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
| | - Qinming Chen
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
- M Diagnostics PTE. LTD, 30 Biopolis Street, Matrix, Singapore, 138671, Singapore
| | - Wayne Shum
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
| | - John van Noort
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
- Huygens-Kamerlingh Ones Laboratory, Leiden University, Leiden, 2333 AL, The Netherlands
| | - Lars Nordenskiöld
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore.
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3
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Chang Y, Zhou Y, Zhou J, Li W, Cao J, Jing Y, Zhang S, Shen Y, Lin Q, Fan X, Yang H, Dong X, Zhang S, Yi X, Shuai L, Shi L, Liu Z, Yang J, Ma X, Hao J, Chen K, Li MJ, Wang F, Huang D. Unraveling the causal genes and transcriptomic determinants of human telomere length. Nat Commun 2023; 14:8517. [PMID: 38129441 PMCID: PMC10739845 DOI: 10.1038/s41467-023-44355-z] [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: 01/18/2023] [Accepted: 12/11/2023] [Indexed: 12/23/2023] Open
Abstract
Telomere length (TL) shortening is a pivotal indicator of biological aging and is associated with many human diseases. The genetic determinates of human TL have been widely investigated, however, most existing studies were conducted based on adult tissues which are heavily influenced by lifetime exposure. Based on the analyses of terminal restriction fragment (TRF) length of telomere, individual genotypes, and gene expressions on 166 healthy placental tissues, we systematically interrogate TL-modulated genes and their potential functions. We discover that the TL in the placenta is comparatively longer than in other adult tissues, but exhibiting an intra-tissue homogeneity. Trans-ancestral TL genome-wide association studies (GWASs) on 644,553 individuals identify 20 newly discovered genetic associations and provide increased polygenic determination of human TL. Next, we integrate the powerful TL GWAS with placental expression quantitative trait locus (eQTL) mapping to prioritize 23 likely causal genes, among which 4 are functionally validated, including MMUT, RRM1, KIAA1429, and YWHAZ. Finally, modeling transcriptomic signatures and TRF-based TL improve the prediction performance of human TL. This study deepens our understanding of causal genes and transcriptomic determinants of human TL, promoting the mechanistic research on fine-grained TL regulation.
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Affiliation(s)
- Ying Chang
- Tianjin Key Lab of Human Development and Reproductive Regulation, Tianjin Central Hospital of Obstetrics and Gynecology, Nankai University, Tianjin, China
| | - Yao Zhou
- Department of Bioinformatics, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Junrui Zhou
- Department of Genetics and Tianjin Key Laboratory of Cellular and Molecular Immunology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
- Department of Clinical Laboratory, Shanghai Children's Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Wen Li
- Tianjin Key Lab of Human Development and Reproductive Regulation, Tianjin Central Hospital of Obstetrics and Gynecology, Nankai University, Tianjin, China
| | - Jiasong Cao
- Tianjin Key Lab of Human Development and Reproductive Regulation, Tianjin Central Hospital of Obstetrics and Gynecology, Nankai University, Tianjin, China
| | - Yaqing Jing
- Department of Genetics and Tianjin Key Laboratory of Cellular and Molecular Immunology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Shan Zhang
- Department of Genetics and Tianjin Key Laboratory of Cellular and Molecular Immunology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Yongmei Shen
- Tianjin Key Lab of Human Development and Reproductive Regulation, Tianjin Central Hospital of Obstetrics and Gynecology, Nankai University, Tianjin, China
| | - Qimei Lin
- Tianjin Key Lab of Human Development and Reproductive Regulation, Tianjin Central Hospital of Obstetrics and Gynecology, Nankai University, Tianjin, China
| | - Xutong Fan
- Department of Bioinformatics, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Hongxi Yang
- Department of Bioinformatics, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
- Department of Pharmacology, Tianjin Key Laboratory of Inflammation Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Xiaobao Dong
- Department of Genetics and Tianjin Key Laboratory of Cellular and Molecular Immunology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Shijie Zhang
- Department of Pharmacology, Tianjin Key Laboratory of Inflammation Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Xianfu Yi
- Department of Bioinformatics, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Ling Shuai
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Central Hospital of Gynecology Obstetrics/Tianjin Key Laboratory of Human Development and Reproductive Regulation, Nankai University, Tianjin, China
| | - Lei Shi
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Zhe Liu
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Jie Yang
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Xin Ma
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Jihui Hao
- Department of Pancreatic Cancer, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Kexin Chen
- Department of Epidemiology and Biostatistics, Tianjin Key Laboratory of Molecular Cancer Epidemiology, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin Medical University, Tianjin, China
| | - Mulin Jun Li
- Department of Bioinformatics, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China.
- Department of Epidemiology and Biostatistics, Tianjin Key Laboratory of Molecular Cancer Epidemiology, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin Medical University, Tianjin, China.
| | - Feng Wang
- Department of Genetics and Tianjin Key Laboratory of Cellular and Molecular Immunology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China.
- Tianjin Medical University School of Stomatology, Tianjin Medical University, Tianjin, China.
- Department of Geriatrics, Tianjin Medical University General Hospital; Tianjin Geriatrics Institute, Tianjin, China.
| | - Dandan Huang
- Department of Pharmacology, Tianjin Key Laboratory of Inflammation Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China.
- Wuxi School of Medicine, Jiangnan University, Wuxi, China.
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4
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Jacome Burbano MS, Robin JD, Bauwens S, Martin M, Donati E, Martínez L, Lin P, Sacconi S, Magdinier F, Gilson E. Non-canonical telomere protection role of FOXO3a of human skeletal muscle cells regulated by the TRF2-redox axis. Commun Biol 2023; 6:561. [PMID: 37231173 DOI: 10.1038/s42003-023-04903-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 05/02/2023] [Indexed: 05/27/2023] Open
Abstract
Telomeric repeat binding factor 2 (TRF2) binds to telomeres and protects chromosome ends against the DNA damage response and senescence. Although the expression of TRF2 is downregulated upon cellular senescence and in various aging tissues, including skeletal muscle tissues, very little is known about the contribution of this decline to aging. We previously showed that TRF2 loss in myofibers does not trigger telomere deprotection but mitochondrial dysfunction leading to an increased level of reactive oxygen species. We show here that this oxidative stress triggers the binding of FOXO3a to telomeres where it protects against ATM activation, revealing a previously unrecognized telomere protective function of FOXO3a, to the best of our knowledge. We further showed in transformed fibroblasts and myotubes that the telomere properties of FOXO3a are dependent on the C-terminal segment of its CR2 domain (CR2C) but independent of its Forkhead DNA binding domain and of its CR3 transactivation domain. We propose that these non-canonical properties of FOXO3a at telomeres play a role downstream of the mitochondrial signaling induced by TRF2 downregulation to regulate skeletal muscle homeostasis and aging.
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Affiliation(s)
| | - Jérôme D Robin
- Université Côte d'Azur, CNRS, Inserm, IRCAN, Faculté de médecine Nice, Nice, France
| | - Serge Bauwens
- Université Côte d'Azur, CNRS, Inserm, IRCAN, Faculté de médecine Nice, Nice, France
| | - Marjorie Martin
- Université Côte d'Azur, CNRS, Inserm, IRCAN, Faculté de médecine Nice, Nice, France
| | - Emma Donati
- Université Côte d'Azur, CNRS, Inserm, IRCAN, Faculté de médecine Nice, Nice, France
| | - Lucia Martínez
- Université Côte d'Azur, CNRS, Inserm, IRCAN, Faculté de médecine Nice, Nice, France
| | - Peipei Lin
- Université Côte d'Azur, CNRS, Inserm, IRCAN, Faculté de médecine Nice, Nice, France
- Department of Geriatrics, Medical center on Aging of Shanghai Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, International Research Project in Hematology, Cancer and Aging, RuiJin Hospital, Shanghai Jiao Tong University School, Shanghai, China
| | - Sabrina Sacconi
- Université Côte d'Azur, CNRS, Inserm, IRCAN, Faculté de médecine Nice, Nice, France
- Peripheral Nervous System, Muscle and ALS, Neuromuscular & ALS Center of Reference, FHU Oncoage, Nice University Hospital, Pasteur 2, Nice, France
| | | | - Eric Gilson
- Université Côte d'Azur, CNRS, Inserm, IRCAN, Faculté de médecine Nice, Nice, France.
- Department of Geriatrics, Medical center on Aging of Shanghai Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
- Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, International Research Project in Hematology, Cancer and Aging, RuiJin Hospital, Shanghai Jiao Tong University School, Shanghai, China.
- Department of Genetics, CHU; FHU OncoAge, Nice, France.
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5
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Rai R, Biju K, Sun W, Sodeinde T, Al-Hiyasat A, Morgan J, Ye X, Li X, Chen Y, Chang S. Homology directed telomere clustering, ultrabright telomere formation and nuclear envelope rupture in cells lacking TRF2 B and RAP1. Nat Commun 2023; 14:2144. [PMID: 37059728 PMCID: PMC10104862 DOI: 10.1038/s41467-023-37761-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 03/30/2023] [Indexed: 04/16/2023] Open
Abstract
Double-strand breaks (DSBs) due to genotoxic stress represent potential threats to genome stability. Dysfunctional telomeres are recognized as DSBs and are repaired by distinct DNA repair mechanisms. RAP1 and TRF2 are telomere binding proteins essential to protect telomeres from engaging in homology directed repair (HDR), but how this occurs remains unclear. In this study, we examined how the basic domain of TRF2 (TRF2B) and RAP1 cooperate to repress HDR at telomeres. Telomeres lacking TRF2B and RAP1 cluster into structures termed ultrabright telomeres (UTs). HDR factors localize to UTs, and UT formation is abolished by RNaseH1, DDX21 and ADAR1p110, suggesting that they contain DNA-RNA hybrids. Interaction between the BRCT domain of RAP1 and KU70/KU80 is also required to repress UT formation. Expressing TRF2∆B in Rap1-/- cells resulted in aberrant lamin A localization in the nuclear envelope and dramatically increased UT formation. Expressing lamin A phosphomimetic mutants induced nuclear envelope rupturing and aberrant HDR-mediated UT formation. Our results highlight the importance of shelterin and proteins in the nuclear envelope in repressing aberrant telomere-telomere recombination to maintain telomere homeostasis.
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Affiliation(s)
- Rekha Rai
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA.
| | - Kevin Biju
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
- Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Wenqi Sun
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Tori Sodeinde
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
| | - Amer Al-Hiyasat
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
| | - Jaida Morgan
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
| | - Xianwen Ye
- University of Chinese Academy of Sciences, 100049, Beijing, China
- School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai, 201210, China
| | - Xueqing Li
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yong Chen
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
- School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai, 201210, China
| | - Sandy Chang
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA.
- Department of Pathology, Yale University School of Medicine, 330 Cedar Street, New Haven, CT, 06520, USA.
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, 330 Cedar Street, New Haven, CT, 06520, USA.
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6
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Higa M, Matsuda Y, Fujii J, Sugimoto N, Yoshida K, Fujita M. TRF2-mediated ORC recruitment underlies telomere stability upon DNA replication stress. Nucleic Acids Res 2021; 49:12234-12251. [PMID: 34761263 PMCID: PMC8643664 DOI: 10.1093/nar/gkab1004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 10/07/2021] [Accepted: 10/12/2021] [Indexed: 12/12/2022] Open
Abstract
Telomeres are intrinsically difficult-to-replicate region of eukaryotic chromosomes. Telomeric repeat binding factor 2 (TRF2) binds to origin recognition complex (ORC) to facilitate the loading of ORC and the replicative helicase MCM complex onto DNA at telomeres. However, the biological significance of the TRF2–ORC interaction for telomere maintenance remains largely elusive. Here, we employed a TRF2 mutant with mutations in two acidic acid residues (E111A and E112A) that inhibited the TRF2–ORC interaction in human cells. The TRF2 mutant was impaired in ORC recruitment to telomeres and showed increased replication stress-associated telomeric DNA damage and telomere instability. Furthermore, overexpression of an ORC1 fragment (amino acids 244–511), which competitively inhibited the TRF2–ORC interaction, increased telomeric DNA damage under replication stress conditions. Taken together, these findings suggest that TRF2-mediated ORC recruitment contributes to the suppression of telomere instability.
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Affiliation(s)
- Mitsunori Higa
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yukihiro Matsuda
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Jumpei Fujii
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Nozomi Sugimoto
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Kazumasa Yoshida
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Masatoshi Fujita
- Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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7
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Myler LR, Kinzig CG, Sasi NK, Zakusilo G, Cai SW, de Lange T. The evolution of metazoan shelterin. Genes Dev 2021; 35:1625-1641. [PMID: 34764137 PMCID: PMC8653790 DOI: 10.1101/gad.348835.121] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 10/05/2021] [Indexed: 12/11/2022]
Abstract
In this study, Myler et al. investigated the evolutionary origins of shelterin complex, which is comprised of TRF1, TRF2, Rap1, TIN2, TPP1, and POT1; blocks the DNA damage response at chromosome ends; and interacts with telomerase and the CST complex to regulate telomere length. They describe the evolution of metazoan shelterin, showing that TRF1 emerged in vertebrates upon duplication of a TRF2-like ancestor, and providing insights into the biology of shelterin and its evolution from ancestral telomeric DNA-binding proteins. The mammalian telomeric shelterin complex—comprised of TRF1, TRF2, Rap1, TIN2, TPP1, and POT1—blocks the DNA damage response at chromosome ends and interacts with telomerase and the CST complex to regulate telomere length. The evolutionary origins of shelterin are unclear, partly because unicellular organisms have distinct telomeric proteins. Here, we describe the evolution of metazoan shelterin, showing that TRF1 emerged in vertebrates upon duplication of a TRF2-like ancestor. TRF1 and TRF2 diverged rapidly during vertebrate evolution through the acquisition of new domains and interacting factors. Vertebrate shelterin is also distinguished by the presence of an HJRL domain in the split C-terminal OB fold of POT1, whereas invertebrate POT1s carry inserts of variable nature. Importantly, the data reveal that, apart from the primate and rodent POT1 orthologs, all metazoan POT1s are predicted to have a fourth OB fold at their N termini. Therefore, we propose that POT1 arose from a four-OB-fold ancestor, most likely an RPA70-like protein. This analysis provides insights into the biology of shelterin and its evolution from ancestral telomeric DNA-binding proteins.
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Affiliation(s)
- Logan R Myler
- Laboratory for Cell Biology and Genetics, The Rockefeller University, New York, New York 10021, USA
| | - Charles G Kinzig
- Laboratory for Cell Biology and Genetics, The Rockefeller University, New York, New York 10021, USA
| | - Nanda K Sasi
- Laboratory for Cell Biology and Genetics, The Rockefeller University, New York, New York 10021, USA
| | - George Zakusilo
- Laboratory for Cell Biology and Genetics, The Rockefeller University, New York, New York 10021, USA
| | - Sarah W Cai
- Laboratory for Cell Biology and Genetics, The Rockefeller University, New York, New York 10021, USA
| | - Titia de Lange
- Laboratory for Cell Biology and Genetics, The Rockefeller University, New York, New York 10021, USA
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8
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Payliss BJ, Patel A, Sheppard AC, Wyatt HDM. Exploring the Structures and Functions of Macromolecular SLX4-Nuclease Complexes in Genome Stability. Front Genet 2021; 12:784167. [PMID: 34804132 PMCID: PMC8599992 DOI: 10.3389/fgene.2021.784167] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 10/21/2021] [Indexed: 12/15/2022] Open
Abstract
All organisms depend on the ability of cells to accurately duplicate and segregate DNA into progeny. However, DNA is frequently damaged by factors in the environment and from within cells. One of the most dangerous lesions is a DNA double-strand break. Unrepaired breaks are a major driving force for genome instability. Cells contain sophisticated DNA repair networks to counteract the harmful effects of genotoxic agents, thus safeguarding genome integrity. Homologous recombination is a high-fidelity, template-dependent DNA repair pathway essential for the accurate repair of DNA nicks, gaps and double-strand breaks. Accurate homologous recombination depends on the ability of cells to remove branched DNA structures that form during repair, which is achieved through the opposing actions of helicases and structure-selective endonucleases. This review focuses on a structure-selective endonuclease called SLX1-SLX4 and the macromolecular endonuclease complexes that assemble on the SLX4 scaffold. First, we discuss recent developments that illuminate the structure and biochemical properties of this somewhat atypical structure-selective endonuclease. We then summarize the multifaceted roles that are fulfilled by human SLX1-SLX4 and its associated endonucleases in homologous recombination and genome stability. Finally, we discuss recent work on SLX4-binding proteins that may represent integral components of these macromolecular nuclease complexes, emphasizing the structure and function of a protein called SLX4IP.
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Affiliation(s)
- Brandon J Payliss
- Department of Biochemistry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Ayushi Patel
- Department of Biochemistry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Anneka C Sheppard
- Department of Biochemistry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Haley D M Wyatt
- Department of Biochemistry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.,Canada Research Chairs Program, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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9
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Imran SAM, Yazid MD, Cui W, Lokanathan Y. The Intra- and Extra-Telomeric Role of TRF2 in the DNA Damage Response. Int J Mol Sci 2021; 22:ijms22189900. [PMID: 34576063 PMCID: PMC8470803 DOI: 10.3390/ijms22189900] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/06/2021] [Accepted: 09/09/2021] [Indexed: 12/12/2022] Open
Abstract
Telomere repeat binding factor 2 (TRF2) has a well-known function at the telomeres, which acts to protect the telomere end from being recognized as a DNA break or from unwanted recombination. This protection mechanism prevents DNA instability from mutation and subsequent severe diseases caused by the changes in DNA, such as cancer. Since TRF2 actively inhibits the DNA damage response factors from recognizing the telomere end as a DNA break, many more studies have also shown its interactions outside of the telomeres. However, very little has been discovered on the mechanisms involved in these interactions. This review aims to discuss the known function of TRF2 and its interaction with the DNA damage response (DDR) factors at both telomeric and non-telomeric regions. In this review, we will summarize recent progress and findings on the interactions between TRF2 and DDR factors at telomeres and outside of telomeres.
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Affiliation(s)
- Siti A. M. Imran
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.)
| | - Muhammad Dain Yazid
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.)
| | - Wei Cui
- Institute of Reproductive and Developmental Biology, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK;
| | - Yogeswaran Lokanathan
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.)
- Correspondence: ; Tel.: +603-9145-7704
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10
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Wang Z, Wu X. Abnormal function of telomere protein TRF2 induces cell mutation and the effects of environmental tumor‑promoting factors (Review). Oncol Rep 2021; 46:184. [PMID: 34278498 PMCID: PMC8273685 DOI: 10.3892/or.2021.8135] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/14/2021] [Indexed: 01/30/2023] Open
Abstract
Recent studies have found that somatic gene mutations and environmental tumor-promoting factors are both indispensable for tumor formation. Telomeric repeat-binding factor (TRF)2 is the core component of the telomere shelterin complex, which plays an important role in chromosome stability and the maintenance of normal cell physiological states. In recent years, TRF2 and its role in tumor formation have gradually become a research hot topic, which has promoted in-depth discussions into tumorigenesis and treatment strategies, and has achieved promising results. Some cells bypass elimination, due to either aging, apoptosis via mutations or abnormal prolongation of the mitotic cycle, and enter the telomere crisis period, where large-scale DNA reorganization occurs repeatedly, which manifests as the precancerous cell cycle. Finally, at the end of the crisis cycle, the mutation activates either the expression level of telomerase or activates the alternative lengthening of telomere mechanism to extend the local telomeres. Under the protection of TRF2, chromosomes are gradually stabilized, immortal cells are formed and the stagewise mutation-driven transformation of normal cells to cancer cells is completed. In addition, TRF2 also shares the characteristics of environmental tumor-promoting factors. It acts on multiple signal transduction pathway-related proteins associated with cell proliferation, and affects peripheral angiogenesis, inhibits the immune recognition and killing ability of the microenvironment, and maintains the stemness characteristics of tumor cells. TRF2 levels are abnormally elevated by a variety of tumor control proteins, which are more conducive to the protection of telomeres and the survival of tumor cells. In brief, the various regulatory mechanisms which tumor cells rely on to survive are organically integrated around TRF2, forming a regulatory network, which is conducive to the optimization of the survival direction of heterogeneous tumor cells, and promotes their survival and adaptability. In terms of clinical application, TRF2 is expected to become a new type of cancer prognostic marker and a new tumor treatment target. Inhibition of TRF2 overexpression could effectively cut off the core network regulating tumor cell survival, reduce drug resistance, or bypass the mutation under the pressure of tumor treatment selection, which may represent a promising therapeutic strategy for the complete eradication of tumors in the clinical setting. Based on recent research, the aim of the present review was to systematically elaborate on the basic structure and functional characteristics of TRF2 and its role in tumor formation, and to analyze the findings indicating that TRF2 deficiency or overexpression could cause severe damage to telomere function and telomere shortening, and induce DNA damage response and chromosomal instability.
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Affiliation(s)
- Zhengyi Wang
- Good Clinical Practice Center, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610071, P.R. China
| | - Xiaoying Wu
- Ministry of Education and Training, Chengdu Second People's Hospital, Chengdu, Sichuan 610000, P.R. China
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11
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Multifunctionality of the Telomere-Capping Shelterin Complex Explained by Variations in Its Protein Composition. Cells 2021; 10:cells10071753. [PMID: 34359923 PMCID: PMC8305809 DOI: 10.3390/cells10071753] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/03/2021] [Accepted: 07/09/2021] [Indexed: 12/31/2022] Open
Abstract
Protecting telomere from the DNA damage response is essential to avoid the entry into cellular senescence and organismal aging. The progressive telomere DNA shortening in dividing somatic cells, programmed during development, leads to critically short telomeres that trigger replicative senescence and thereby contribute to aging. In several organisms, including mammals, telomeres are protected by a protein complex named Shelterin that counteract at various levels the DNA damage response at chromosome ends through the specific function of each of its subunits. The changes in Shelterin structure and function during development and aging is thus an intense area of research. Here, we review our knowledge on the existence of several Shelterin subcomplexes and the functional independence between them. This leads us to discuss the possibility that the multifunctionality of the Shelterin complex is determined by the formation of different subcomplexes whose composition may change during aging.
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12
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The Power of Stress: The Telo-Hormesis Hypothesis. Cells 2021; 10:cells10051156. [PMID: 34064566 PMCID: PMC8151059 DOI: 10.3390/cells10051156] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/29/2021] [Accepted: 05/06/2021] [Indexed: 02/06/2023] Open
Abstract
Adaptative response to stress is a strategy conserved across evolution to promote survival. In this context, the groundbreaking findings of Miroslav Radman on the adaptative value of changing mutation rates opened new avenues in our understanding of stress response. Inspired by this work, we explore here the putative beneficial effects of changing the ends of eukaryotic chromosomes, the telomeres, in response to stress. We first summarize basic principles in telomere biology and then describe how various types of stress can alter telomere structure and functions. Finally, we discuss the hypothesis of stress-induced telomere signaling with hormetic effects.
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13
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Bauwens S, Lototska L, Koundrioukoff S, Debatisse M, Ye J, Gilson E, Mendez-Bermudez A. The Telomeric Protein TRF2 Regulates Replication Origin Activity within Pericentromeric Heterochromatin. Life (Basel) 2021; 11:life11040267. [PMID: 33804994 PMCID: PMC8063955 DOI: 10.3390/life11040267] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/12/2021] [Accepted: 03/22/2021] [Indexed: 12/12/2022] Open
Abstract
Heterochromatic regions render the replication process particularly difficult due to the high level of chromatin compaction and the presence of repeated DNA sequences. In humans, replication through pericentromeric heterochromatin requires the binding of a complex formed by the telomeric factor TRF2 and the helicase RTEL1 in order to relieve topological barriers blocking fork progression. Since TRF2 is known to bind the Origin Replication Complex (ORC), we hypothesized that this factor could also play a role at the replication origins (ORI) of these heterochromatin regions. By performing DNA combing analysis, we found that the ORI density is higher within pericentromeric satellite DNA repeats than within bulk genomic DNA and decreased upon TRF2 downregulation. Moreover, we showed that TRF2 and ORC2 interact in pericentromeric DNA, providing a mechanism by which TRF2 is involved in ORI activity. Altogether, our findings reveal an essential role for TRF2 in pericentromeric heterochromatin replication by regulating both replication initiation and elongation.
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Affiliation(s)
- Serge Bauwens
- Faculty of Medicine Nice, Institute for Research on Cancer and Aging (IRCAN), CNRS, INSERM, Université Côte d’Azur, 06107 Nice, France; (S.B.); (L.L.)
| | - Liudmyla Lototska
- Faculty of Medicine Nice, Institute for Research on Cancer and Aging (IRCAN), CNRS, INSERM, Université Côte d’Azur, 06107 Nice, France; (S.B.); (L.L.)
| | - Stephane Koundrioukoff
- Institut Gustave Roussy, Sorbonne Université, UPMC University, 94805 Villejuif, France; (S.K.); (M.D.)
| | - Michelle Debatisse
- Institut Gustave Roussy, Sorbonne Université, UPMC University, 94805 Villejuif, France; (S.K.); (M.D.)
| | - Jing Ye
- International Laboratory in Hematology, Cancer and Aging, Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China;
| | - Eric Gilson
- Faculty of Medicine Nice, Institute for Research on Cancer and Aging (IRCAN), CNRS, INSERM, Université Côte d’Azur, 06107 Nice, France; (S.B.); (L.L.)
- International Laboratory in Hematology, Cancer and Aging, Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China;
- Correspondence: (E.G.); (A.M.-B.)
| | - Aaron Mendez-Bermudez
- Faculty of Medicine Nice, Institute for Research on Cancer and Aging (IRCAN), CNRS, INSERM, Université Côte d’Azur, 06107 Nice, France; (S.B.); (L.L.)
- International Laboratory in Hematology, Cancer and Aging, Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China;
- Correspondence: (E.G.); (A.M.-B.)
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14
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TERRA G-quadruplex RNA interaction with TRF2 GAR domain is required for telomere integrity. Sci Rep 2021; 11:3509. [PMID: 33568696 PMCID: PMC7876106 DOI: 10.1038/s41598-021-82406-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 01/13/2021] [Indexed: 12/15/2022] Open
Abstract
Telomere dysfunction causes chromosomal instability which is associated with many cancers and age-related diseases. The non-coding telomeric repeat-containing RNA (TERRA) forms a structural and regulatory component of the telomere that is implicated in telomere maintenance and chromosomal end protection. The basic N-terminal Gly/Arg-rich (GAR) domain of telomeric repeat-binding factor 2 (TRF2) can bind TERRA but the structural basis and significance of this interaction remains poorly understood. Here, we show that TRF2 GAR recognizes G-quadruplex features of TERRA. We show that small molecules that disrupt the TERRA-TRF2 GAR complex, such as N-methyl mesoporphyrin IX (NMM) or genetic deletion of TRF2 GAR domain, result in the loss of TERRA, and the induction of γH2AX-associated telomeric DNA damage associated with decreased telomere length, and increased telomere aberrations, including telomere fragility. Taken together, our data indicates that the G-quadruplex structure of TERRA is an important recognition element for TRF2 GAR domain and this interaction between TRF2 GAR and TERRA is essential to maintain telomere stability.
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15
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Lim CJ, Cech TR. Shaping human telomeres: from shelterin and CST complexes to telomeric chromatin organization. Nat Rev Mol Cell Biol 2021; 22:283-298. [PMID: 33564154 DOI: 10.1038/s41580-021-00328-y] [Citation(s) in RCA: 115] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2021] [Indexed: 01/14/2023]
Abstract
The regulation of telomere length in mammals is crucial for chromosome end-capping and thus for maintaining genome stability and cellular lifespan. This process requires coordination between telomeric protein complexes and the ribonucleoprotein telomerase, which extends the telomeric DNA. Telomeric proteins modulate telomere architecture, recruit telomerase to accessible telomeres and orchestrate the conversion of the newly synthesized telomeric single-stranded DNA tail into double-stranded DNA. Dysfunctional telomere maintenance leads to telomere shortening, which causes human diseases including bone marrow failure, premature ageing and cancer. Recent studies provide new insights into telomerase-related interactions (the 'telomere replisome') and reveal new challenges for future telomere structural biology endeavours owing to the dynamic nature of telomere architecture and the great number of structures that telomeres form. In this Review, we discuss recently determined structures of the shelterin and CTC1-STN1-TEN1 (CST) complexes, how they may participate in the regulation of telomere replication and chromosome end-capping, and how disease-causing mutations in their encoding genes may affect specific functions. Major outstanding questions in the field include how all of the telomere components assemble relative to each other and how the switching between different telomere structures is achieved.
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Affiliation(s)
- Ci Ji Lim
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA. .,Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA. .,BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA.
| | - Thomas R Cech
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA. .,BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA. .,Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA.
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16
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Shen M, Young A, Autexier C. PCNA, a focus on replication stress and the alternative lengthening of telomeres pathway. DNA Repair (Amst) 2021; 100:103055. [PMID: 33581499 DOI: 10.1016/j.dnarep.2021.103055] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 01/25/2021] [Indexed: 12/16/2022]
Abstract
The maintenance of telomeres, which are specialized stretches of DNA found at the ends of linear chromosomes, is a crucial step for the immortalization of cancer cells. Approximately 10-15 % of cancer cells use a homologous recombination-based mechanism known as the Alternative Lengthening of Telomeres (ALT) pathway to maintain their telomeres. Telomeres in general pose a challenge to DNA replication owing to their repetitive nature and potential for forming secondary structures. Telomeres in ALT+ cells especially are subject to elevated levels of replication stress compared to telomeres that are maintained by the enzyme telomerase, in part due to the incorporation of telomeric variant repeats at ALT+ telomeres, their on average longer lengths, and their modified chromatin states. Many DNA metabolic strategies exist to counter replication stress and to protect stalled replication forks. The role of proliferating cell nuclear antigen (PCNA) as a platform for recruiting protein partners that participate in several of these DNA replication and repair pathways has been well-documented. We propose that many of these pathways may be active at ALT+ telomeres, either to facilitate DNA replication, to manage replication stress, or during telomere extension. Here, we summarize recent evidence detailing the role of PCNA in pathways including DNA secondary structure resolution, DNA damage bypass, replication fork restart, and DNA damage synthesis. We propose that an examination of PCNA and its post-translational modifications (PTMs) may offer a unique lens by which we might gain insight into the DNA metabolic landscape that is distinctively present at ALT+ telomeres.
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Affiliation(s)
- Michelle Shen
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, H3A 0C7, Canada; Jewish General Hospital, Lady Davis Institute, Montreal, Quebec, H3T 1E2, Canada
| | - Adrian Young
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, H3A 0C7, Canada; Jewish General Hospital, Lady Davis Institute, Montreal, Quebec, H3T 1E2, Canada
| | - Chantal Autexier
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, H3A 0C7, Canada; Jewish General Hospital, Lady Davis Institute, Montreal, Quebec, H3T 1E2, Canada.
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17
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Abstract
In this perspective, we introduce shelterin and the mechanisms of ATM activation and NHEJ at telomeres, before discussing the following questions: How are t-loops proposed to protect chromosome ends and what is the evidence for this model? Can other models explain how TRF2 mediates end protection? Could t-loops be pathological structures? How is end protection achieved in pluripotent cells? What do the insights into telomere end protection in pluripotent cells mean for the t-loop model of end protection? Why might different cell states have evolved different mechanisms of end protection? Finally, we offer support for an updated t-loop model of end protection, suggesting that the data is supportive of a critical role for t-loops in protecting chromosome ends from NHEJ and ATM activation, but that other mechanisms are involved. Finally, we propose that t-loops are likely dynamic, rather than static, structures.
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Affiliation(s)
- Phil Ruis
- The Francis Crick Institute, London NW1 1AT, United Kingdom
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18
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Saccharomyces cerevisiae Mus81-Mms4 prevents accelerated senescence in telomerase-deficient cells. PLoS Genet 2020; 16:e1008816. [PMID: 32469862 PMCID: PMC7286520 DOI: 10.1371/journal.pgen.1008816] [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: 12/31/2019] [Revised: 06/10/2020] [Accepted: 04/30/2020] [Indexed: 01/31/2023] Open
Abstract
Alternative lengthening of telomeres (ALT) in human cells is a conserved process that is often activated in telomerase-deficient human cancers. This process exploits components of the recombination machinery to extend telomere ends, thus allowing for increased proliferative potential. Human MUS81 (Mus81 in Saccharomyces cerevisiae) is the catalytic subunit of structure-selective endonucleases involved in recombination and has been implicated in the ALT mechanism. However, it is unclear whether MUS81 activity at the telomere is specific to ALT cells or if it is required for more general aspects of telomere stability. In this study, we use S. cerevisiae to evaluate the contribution of the conserved Mus81-Mms4 endonuclease in telomerase-deficient yeast cells that maintain their telomeres by mechanisms akin to human ALT. Similar to human cells, we find that yeast Mus81 readily localizes to telomeres and its activity is important for viability after initial loss of telomerase. Interestingly, our analysis reveals that yeast Mus81 is not required for the survival of cells undergoing recombination-mediated telomere lengthening, i.e. for ALT itself. Rather we infer from genetic analysis that Mus81-Mms4 facilitates telomere replication during times of telomere instability. Furthermore, combining mus81 mutants with mutants of a yeast telomere replication factor, Rrm3, reveals that the two proteins function in parallel to promote normal growth during times of telomere stress. Combined with previous reports, our data can be interpreted in a consistent model in which both yeast and human MUS81-dependent nucleases participate in the recovery of stalled replication forks within telomeric DNA. Furthermore, this process becomes crucial under conditions of additional replication stress, such as telomere replication in telomerase-deficient cells. Cancer cell divisions require active chromosome lengthening through extension of their highly repetitive ends, called telomeres. This process is accomplished through two main mechanisms: the activity of an RNA-protein complex, telomerase, or through a telomerase-independent process termed alternative lengthening of telomeres (ALT). Human MUS81, the catalytic subunit of a set of structure-selective endonucleases, was found to be essential in human cells undergoing ALT and proposed to be directly involved in telomere lengthening. Using telomerase-deficient Saccharomyces cerevisiae cells as a model for ALT, we tested the hypothesis that Mus81-Mms4, the budding yeast homolog of human MUS81-dependent nucleases, is essential for telomere lengthening as proposed for human cells. Using genetic and molecular assays we confirm that Mus81-Mms4 is involved in telomere metabolism in yeast. However, to our surprise, we find that Mus81-Mms4 is not directly involved in recombination-based mechanisms of telomere lengthening. Rather it appears that Mus81-Mms4 is involved in resolving replication stress at telomeres, which is augmented in cells undergoing telomere instability. This model is consistent with observations in mammalian cells and suggest that cells undergoing telomere shortening experience replication stress at telomeres.
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19
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Long-lived post-mitotic cell aging: is a telomere clock at play? Mech Ageing Dev 2020; 189:111256. [PMID: 32380018 DOI: 10.1016/j.mad.2020.111256] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/25/2020] [Accepted: 04/27/2020] [Indexed: 12/27/2022]
Abstract
Senescence is a cellular response to stress for both dividing and post-mitotic cells. Noteworthy, long-lived post-mitotic cells (collectively named LLPMCs), which can live for decades in the organism, can exhibit a distinct type of cellular aging characterized by a progressive functional decline not associated to an overt senescence phenotype. The age-related drivers of senescence and aging in LLPMCs remain largely unknown. There is evidence that an increased production of reactive oxygen species (ROS) due to dysfunctional mitochondria, coupled with an inherent inability of cellular-degradation mechanisms to remove damaged molecules, is responsible for senescence and aging in LLPMC. Although telomeric DNA shortening, by nature linked to cell division, is generally not considered as a driver of LLPMC aging and senescence, we discuss recent reports revealing the existence of age-related telomere changes in LLPMC. These findings reveal unexpected roles for telomeres in LLPMC function and invite us to consider the hypothesis of a complex telomere clock involved in both dividing and non-dividing cell aging.
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20
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Panier S, Maric M, Hewitt G, Mason-Osann E, Gali H, Dai A, Labadorf A, Guervilly JH, Ruis P, Segura-Bayona S, Belan O, Marzec P, Gaillard PHL, Flynn RL, Boulton SJ. SLX4IP Antagonizes Promiscuous BLM Activity during ALT Maintenance. Mol Cell 2019; 76:27-43.e11. [PMID: 31447390 PMCID: PMC6863466 DOI: 10.1016/j.molcel.2019.07.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 06/03/2019] [Accepted: 07/08/2019] [Indexed: 12/18/2022]
Abstract
Cancer cells acquire unlimited proliferative capacity by either re-expressing telomerase or inducing alternative lengthening of telomeres (ALT), which relies on telomere recombination. Here, we show that ALT recombination requires coordinate regulation of the SMX and BTR complexes to ensure the appropriate balance of resolution and dissolution activities at recombining telomeres. Critical to this control is SLX4IP, which accumulates at ALT telomeres and interacts with SLX4, XPF, and BLM. Loss of SLX4IP increases ALT-related phenotypes, which is incompatible with cell growth following concomitant loss of SLX4. Inactivation of BLM is sufficient to rescue telomere aggregation and the synthetic growth defect in this context, suggesting that SLX4IP favors SMX-dependent resolution by antagonizing promiscuous BLM activity during ALT recombination. Finally, we show that SLX4IP is inactivated in a subset of ALT-positive osteosarcomas. Collectively, our findings uncover an SLX4IP-dependent regulatory mechanism critical for telomere maintenance in ALT cancer cells.
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Affiliation(s)
| | - Marija Maric
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Graeme Hewitt
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Emily Mason-Osann
- Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Himabindu Gali
- Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Anqi Dai
- Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Adam Labadorf
- Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Jean-Hugues Guervilly
- Centre de Recherche en Cancérologie de Marseille, CRCM, CNRS, Aix Marseille Université, INSERM, Institut Paoli-Calmettes, 27 Boulevard Leï Roure, 13009 Marseille, France
| | - Philip Ruis
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | | | - Ondrej Belan
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Paulina Marzec
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Pierre-Henri L Gaillard
- Centre de Recherche en Cancérologie de Marseille, CRCM, CNRS, Aix Marseille Université, INSERM, Institut Paoli-Calmettes, 27 Boulevard Leï Roure, 13009 Marseille, France
| | - Rachel L Flynn
- Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Simon J Boulton
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
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21
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Genome-wide Control of Heterochromatin Replication by the Telomere Capping Protein TRF2. Mol Cell 2019; 70:449-461.e5. [PMID: 29727617 DOI: 10.1016/j.molcel.2018.03.036] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 02/20/2018] [Accepted: 03/29/2018] [Indexed: 11/22/2022]
Abstract
Hard-to-replicate regions of chromosomes (e.g., pericentromeres, centromeres, and telomeres) impede replication fork progression, eventually leading, in the event of replication stress, to chromosome fragility, aging, and cancer. Our knowledge of the mechanisms controlling the stability of these regions is essentially limited to telomeres, where fragility is counteracted by the shelterin proteins. Here we show that the shelterin subunit TRF2 ensures progression of the replication fork through pericentromeric heterochromatin, but not centromeric chromatin. In a process involving its N-terminal basic domain, TRF2 binds to pericentromeric Satellite III sequences during S phase, allowing the recruitment of the G-quadruplex-resolving helicase RTEL1 to facilitate fork progression. We also show that TRF2 is required for the stability of other heterochromatic regions localized throughout the genome, paving the way for future research on heterochromatic replication and its relationship with aging and cancer.
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22
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Abstract
The SLX4/FANCP tumor suppressor has emerged as a key player in the maintenance of genome stability, making pivotal contributions to the repair of interstrand cross-links, homologous recombination, and in response to replication stress genome-wide as well as at specific loci such as common fragile sites and telomeres. SLX4 does so in part by acting as a scaffold that controls and coordinates the XPF-ERCC1, MUS81-EME1, and SLX1 structure-specific endonucleases in different DNA repair and recombination mechanisms. It also interacts with other important DNA repair and cell cycle control factors including MSH2, PLK1, TRF2, and TOPBP1 as well as with ubiquitin and SUMO. This review aims at providing an up-to-date and comprehensive view on the key functions that SLX4 fulfills to maintain genome stability as well as to highlight and discuss areas of uncertainty and emerging concepts.
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Affiliation(s)
- Jean-Hugues Guervilly
- a CRCM, CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes , Marseille , France
| | - Pierre Henri Gaillard
- a CRCM, CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes , Marseille , France
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23
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Abstract
For more than a decade, it has been known that mammalian cells use shelterin to protect chromosome ends. Much progress has been made on the mechanism by which shelterin prevents telomeres from inadvertently activating DNA damage signaling and double-strand break (DSB) repair pathways. Shelterin averts activation of three DNA damage response enzymes [the ataxia-telangiectasia-mutated (ATM) and ataxia telangiectasia and Rad3-related (ATR) kinases and poly(ADP-ribose) polymerase 1 (PARP1)], blocks three DSB repair pathways [classical nonhomologous end joining (c-NHEJ), alternative (alt)-NHEJ, and homology-directed repair (HDR)], and prevents hyper-resection at telomeres. For several of these functions, mechanistic insights have emerged. In addition, much has been learned about how shelterin maintains the telomeric 3' overhang, forms and protects the t-loop structure, and promotes replication through telomeres. These studies revealed that shelterin is compartmentalized, with individual subunits dedicated to distinct aspects of the end-protection problem. This review focuses on the current knowledge of shelterin-mediated telomere protection, highlights differences between human and mouse shelterin, and discusses some of the questions that remain.
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Affiliation(s)
- Titia de Lange
- Laboratory of Cell Biology and Genetics, Rockefeller University, New York, NY 10065, USA;
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24
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Zheng Q, Xu J, Lin Z, Lu Y, Xin X, Li X, Yang Y, Meng Q, Wang C, Xiong W, Lu D. Inflammatory factor receptor Toll-like receptor 4 controls telomeres through heterochromatin protein 1 isoforms in liver cancer stem cell. J Cell Mol Med 2018; 22:3246-3258. [PMID: 29602239 PMCID: PMC5980149 DOI: 10.1111/jcmm.13606] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 02/06/2018] [Indexed: 12/15/2022] Open
Abstract
Toll-like receptor 4 (TLR4) which acts as a receptor for lipopolysaccharide (LPS) has been reported to be involved in carcinogenesis. However, the regulatory mechanism of it has not been elucidated. Herein, we demonstrate that TLR4 promotes the malignant growth of liver cancer stem cells. Mechanistically, TLR4 promotes the expression of histone-lysine N-methyltransferase (SUV39 h2) and increases the formation of trimethyl histone H3 lysine 9-heterochromatin protein 1-telomere repeat binding factor 2 (H3K9me3-HP1-TRF2) complex at the telomeric locus under mediation by long non coding RNA urothelial cancer-associated 1 (CUDR). At the telomeric locus, this complex promotes binding of POT1, pPOT1, Exo1, pExo1, SNM1B and pSNM1B but prevents binding of CST/AAF to telomere, thus controlling telomere and maintaining telomere length. Furthermore, TLR4 enhances interaction between HP1α and DNA methyltransferase (DNMT3b), which limits RNA polymerase II deposition on the telomeric repeat-containing RNA (TERRA) promoter region and its elongation, thus inhibiting transcription of TERRA. Ultimately, TLR4 enhances the telomerase activity by reducing the interplay between telomerase reverse transcriptase catalytic subunit (TERT) and TERRA. More importantly, our results reveal that tri-complexes of HP1 isoforms (α, β and γ) are required for the oncogenic action of TLR4. This study elucidates a novel protection mechanism of TLR4 in liver cancer stem cells and suggests that TLR4 can be used as a novel therapeutic target for liver cancer.
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Affiliation(s)
- Qidi Zheng
- Research Center for Translational Medicine at Shanghai East HospitalSchool of Life Science and TechnologyTongji UniversityShanghaiChina
| | - Jie Xu
- Research Center for Translational Medicine at Shanghai East HospitalSchool of Life Science and TechnologyTongji UniversityShanghaiChina
| | - Zhuojia Lin
- Research Center for Translational Medicine at Shanghai East HospitalSchool of Life Science and TechnologyTongji UniversityShanghaiChina
| | - Yanan Lu
- Research Center for Translational Medicine at Shanghai East HospitalSchool of Life Science and TechnologyTongji UniversityShanghaiChina
| | - Xiaoru Xin
- Research Center for Translational Medicine at Shanghai East HospitalSchool of Life Science and TechnologyTongji UniversityShanghaiChina
| | - Xiaonan Li
- Research Center for Translational Medicine at Shanghai East HospitalSchool of Life Science and TechnologyTongji UniversityShanghaiChina
| | - Yuxin Yang
- Research Center for Translational Medicine at Shanghai East HospitalSchool of Life Science and TechnologyTongji UniversityShanghaiChina
| | - Qiuyu Meng
- Research Center for Translational Medicine at Shanghai East HospitalSchool of Life Science and TechnologyTongji UniversityShanghaiChina
| | - Chen Wang
- Research Center for Translational Medicine at Shanghai East HospitalSchool of Life Science and TechnologyTongji UniversityShanghaiChina
| | - Wujun Xiong
- Department of HepatologyShanghai East HospitalTongji University School of MedicineShanghaiChina
| | - Dongdong Lu
- Research Center for Translational Medicine at Shanghai East HospitalSchool of Life Science and TechnologyTongji UniversityShanghaiChina
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25
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An J, Wu M, Xin X, Lin Z, Li X, Zheng Q, Gui X, Li T, Pu H, Li H, Lu D. Inflammatory related gene IKKα, IKKβ, IKKγ cooperates to determine liver cancer stem cells progression by altering telomere via heterochromatin protein 1-HOTAIR axis. Oncotarget 2018; 7:50131-50149. [PMID: 27367027 PMCID: PMC5226573 DOI: 10.18632/oncotarget.10321] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/13/2016] [Indexed: 12/12/2022] Open
Abstract
Cancer stem cells are associated with tumor recurrence. IKK is a protein kinase that is composed of IKKα, IKKβ, IKKγ. Herein, we demonstrate that IKKα plus IKKβ promoted and IKKγ inhibited liver cancer stem cell growth in vitro and in vivo. Mechanistically, IKKα plus IKKβ enhanced and IKKγ inhibited the interplay among HP1α, HP1β and HP1γ that competes for the interaction among HP1α, SUZ12, HEZ2. Therefore, IKKα plus IKKβ inhibited and IKKγ enhanced the activity of H3K27 methyltransferase SUZ12 and EZH2, which methylates H3K27 immediately sites on HOTAIR promoter region. Therefore, IKKα plus IKKβ increased and IKKγ decreased the HOTAIR expression. Strikingly, IKKα plus IKKβ decreases and IKKγ increases the HP1α interplays with DNA methyltransferase DNMT3b, which increases or decreases TERRA promoter DNA methylation. Thus IKKα plus IKKβ reduces and IKKγ increases to recruit TRF1 and RNA polymerase II deposition and elongation on the TERRA promoter locus, which increases or decreases TERRA expression. Furthermore, IKKα plus IKKβ decreases/increases and IKKγ increases/decreases the interplay between TERT and TRRRA/between TERT and TREC. Ultimately, IKKα plus IKKβ increases and IKKγ decreases the telomerase activity. On the other hand, at the telomere locus, IKKα plus IKKβ increases/drcreases and IKKγ decreases/increases TRF2, POT1, pPOT1, Exo1, pExo1, SNM1B, pSNM1B/CST-AAF binding, which keep active telomere regulatory genes and poised for telomere length. Strikingly, HOTAIR is required for IKKα plus IKKβ and IKKγ to control telomerase activity and telomere length. These observations suggest that HOTAIR operates the action of IKKα, IKKβ, IKKγ in liver cancer stem cells. This study provides a novel basis to elucidate the oncogenic action of IKKα, IKKβ, IKKγ and prompts that IKKα, IKKβ, IKKγ cooperate to HOTAR to be used as a novel therapeutic targets for liver cancer.
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Affiliation(s)
- Jiahui An
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Mengying Wu
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Xiaoru Xin
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Zhuojia Lin
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Xiaonan Li
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Qidi Zheng
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Xin Gui
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Tianming Li
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Hu Pu
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Haiyan Li
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
| | - Dongdong Lu
- School of Life Science and Technology, Tongji University, Shanghai 200092, China
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26
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Necasová I, Janoušková E, Klumpler T, Hofr C. Basic domain of telomere guardian TRF2 reduces D-loop unwinding whereas Rap1 restores it. Nucleic Acids Res 2017; 45:12170-12180. [PMID: 28981702 PMCID: PMC5716094 DOI: 10.1093/nar/gkx812] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 09/09/2017] [Indexed: 01/06/2023] Open
Abstract
Telomeric repeat binding factor 2 (TRF2) folds human telomeres into loops to prevent unwanted DNA repair and chromosome end-joining. The N-terminal basic domain of TRF2 (B-domain) protects the telomeric displacement loop (D-loop) from cleavage by endonucleases. Repressor activator protein 1 (Rap1) binds TRF2 and improves telomeric DNA recognition. We found that the B-domain of TRF2 stabilized the D-loop and thus reduced unwinding by BLM and RPA, whereas the formation of the Rap1–TRF2 complex restored DNA unwinding. To understand how the B-domain of TRF2 affects DNA binding and D-loop processing, we analyzed DNA binding of full-length TRF2 and a truncated TRF2 construct lacking the B-domain. We quantified how the B-domain improves TRF2’s interaction with DNA via enhanced long-range electrostatic interactions. We developed a structural envelope model of the B-domain bound on DNA. The model revealed that the B-domain is flexible in solution but becomes rigid upon binding to telomeric DNA. We proposed a mechanism for how the B-domain stabilizes the D-loop.
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Affiliation(s)
- Ivona Necasová
- LifeB, Chromatin Molecular Complexes, CEITEC and Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno CZ-62500, Czech Republic
| | - Eliška Janoušková
- LifeB, Chromatin Molecular Complexes, CEITEC and Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno CZ-62500, Czech Republic
| | - Tomáš Klumpler
- Structural Biology of Gene Regulation, CEITEC, Masaryk University, Brno CZ-62500, Czech Republic
| | - Ctirad Hofr
- LifeB, Chromatin Molecular Complexes, CEITEC and Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno CZ-62500, Czech Republic
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27
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Rizzo A, Iachettini S, Salvati E, Zizza P, Maresca C, D'Angelo C, Benarroch-Popivker D, Capolupo A, Del Gaudio F, Cosconati S, Di Maro S, Merlino F, Novellino E, Amoreo CA, Mottolese M, Sperduti I, Gilson E, Biroccio A. SIRT6 interacts with TRF2 and promotes its degradation in response to DNA damage. Nucleic Acids Res 2017; 45:1820-1834. [PMID: 27923994 PMCID: PMC5389694 DOI: 10.1093/nar/gkw1202] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 11/18/2016] [Indexed: 12/29/2022] Open
Abstract
Telomere repeat binding factor 2 (TRF2) has been increasingly recognized to be involved in telomere maintenance and DNA damage response. Here, we show that TRF2 directly binds SIRT6 in a DNA independent manner and that this interaction is increased upon replication stress. Knockdown of SIRT6 up-regulates TRF2 protein levels and counteracts its down-regulation during DNA damage response, leading to cell survival. Moreover, we report that SIRT6 deactetylates in vivo the TRFH domain of TRF2, which in turn, is ubiquitylated in vivo activating the ubiquitin-dependent proteolysis. Notably, overexpression of the TRF2cT mutant failed to be stabilized by SIRT6 depletion, demonstrating that the TRFH domain is required for its post-transcriptional modification. Finally, we report an inverse correlation between SIRT6 and TRF2 protein expression levels in a cohort of colon rectal cancer patients. Taken together our findings describe TRF2 as a novel SIRT6 substrate and demonstrate that acetylation of TRF2 plays a crucial role in the regulation of TRF2 protein stability, thus providing a new route for modulating its expression level during oncogenesis and damage response.
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Affiliation(s)
- Angela Rizzo
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Sara Iachettini
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Erica Salvati
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Pasquale Zizza
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Carmen Maresca
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Carmen D'Angelo
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Delphine Benarroch-Popivker
- Université Côte d'Azur, INSERM U1081 CNRS UMR7284, Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, France
| | - Angela Capolupo
- Department of Pharmacy, PhD Program in Drug Discovery and Development, University of Salerno, Via Giovanni Paolo II 132, Fisciano (SA) 84084, Italy
| | - Federica Del Gaudio
- Department of Pharmacy, PhD Program in Drug Discovery and Development, University of Salerno, Via Giovanni Paolo II 132, Fisciano (SA) 84084, Italy
| | - Sandro Cosconati
- DiSTABiF, Seconda Università di Napoli, Via Vivaldi 43, Caserta 81100, Italy
| | - Salvatore Di Maro
- DiSTABiF, Seconda Università di Napoli, Via Vivaldi 43, Caserta 81100, Italy
| | - Francesco Merlino
- Department of Pharmacy, University of Naples Federico II, Via Montesano 49, Naples 80131, Italy
| | - Ettore Novellino
- Department of Pharmacy, University of Naples Federico II, Via Montesano 49, Naples 80131, Italy
| | - Carla Azzurra Amoreo
- Department of Pathology, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Marcella Mottolese
- Department of Pathology, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Isabella Sperduti
- Biostatistics Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Eric Gilson
- Université Côte d'Azur, INSERM U1081 CNRS UMR7284, Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, France.,Department of Medical Genetics, Archet 2 Hospital, CHU of Nice, France
| | - Annamaria Biroccio
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
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28
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TRF2 binds branched DNA to safeguard telomere integrity. Nat Struct Mol Biol 2017; 24:734-742. [PMID: 28805810 DOI: 10.1038/nsmb.3451] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/11/2017] [Indexed: 12/16/2022]
Abstract
Although t-loops protect telomeres, they are at risk of cleavage by Holliday junction (HJ) resolvases if branch migration converts the three-way t-loop junction into four-way HJs. T-loop cleavage is repressed by the TRF2 basic domain, which binds three- and four-way junctions and protects HJs in vitro. By replacing the basic domain with bacterial-protein domains binding three- and four-way junctions, we demonstrated the in vivo relevance of branched-DNA binding. Branched-DNA binding also repressed PARP1, presumably by masking the PARP1 site in the t-loop junction. Although PARP1 recruits HJ resolvases and promotes t-loop cleavage, PARP1 activation alone did not result in t-loop cleavage, thus suggesting that the basic domain also prevents formation of HJs. Concordantly, removal of HJs by BLM helicase mitigated t-loop cleavage in response to loss of the basic domain. We propose that TRF2 masks and stabilizes the t-loop three-way junction, thereby protecting telomeres from detrimental deletions and PARP1 activation.
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29
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Charif R, Granotier-Beckers C, Bertrand HC, Poupon J, Ségal-Bendirdjian E, Teulade-Fichou MP, Boussin FD, Bombard S. Association of a Platinum Complex to a G-Quadruplex Ligand Enhances Telomere Disruption. Chem Res Toxicol 2017; 30:1629-1640. [DOI: 10.1021/acs.chemrestox.7b00131] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Razan Charif
- Université
Paris Descartes, INSERM UMR-S-1007, 45 rue des Saints-Pères, 75006 Paris, France
| | - Christine Granotier-Beckers
- CEA/DRF/IRCM,
Laboratoire de RadioPathologie, INSERM U967, Université Paris
VII, Université Paris XI, 18
route du Panorama, 92265 Fontenay-aux-Roses Cedex, France
| | - Hélène Charlotte Bertrand
- Institut
Curie,
Centre Universitaire Paris Saclay, CNRS UMR9187/INSERM U1196, Bâtiments 110-112, 91405 Orsay, France
- Département
de Chimie, Ecole Normale Supérieure, PSL Research University,
UPMC Univ Paris 06, CNRS, Laboratoire des Biomolécules (LBM), 24 rue Lhomond, 75005 Paris, France
- Sorbonne Universités,
UPMC Univ Paris 06, Ecole Normale Supérieure, CNRS, Laboratoire
des Biomolécules (LBM), 24 rue
Lhomond, 75005 Paris, France
| | - Joël Poupon
- Laboratoire
de Toxicologie-Biologique, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris, France
| | | | - Marie-Paule Teulade-Fichou
- Institut
Curie,
Centre Universitaire Paris Saclay, CNRS UMR9187/INSERM U1196, Bâtiments 110-112, 91405 Orsay, France
| | - François D. Boussin
- CEA/DRF/IRCM,
Laboratoire de RadioPathologie, INSERM U967, Université Paris
VII, Université Paris XI, 18
route du Panorama, 92265 Fontenay-aux-Roses Cedex, France
| | - Sophie Bombard
- Université
Paris Descartes, INSERM UMR-S-1007, 45 rue des Saints-Pères, 75006 Paris, France
- Institut
Curie,
Centre Universitaire Paris Saclay, CNRS UMR9187/INSERM U1196, Bâtiments 110-112, 91405 Orsay, France
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30
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DNA Replication Origins and Fork Progression at Mammalian Telomeres. Genes (Basel) 2017; 8:genes8040112. [PMID: 28350373 PMCID: PMC5406859 DOI: 10.3390/genes8040112] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/23/2017] [Accepted: 03/24/2017] [Indexed: 12/20/2022] Open
Abstract
Telomeres are essential chromosomal regions that prevent critical shortening of linear chromosomes and genomic instability in eukaryotic cells. The bulk of telomeric DNA is replicated by semi-conservative DNA replication in the same way as the rest of the genome. However, recent findings revealed that replication of telomeric repeats is a potential cause of chromosomal instability, because DNA replication through telomeres is challenged by the repetitive telomeric sequences and specific structures that hamper the replication fork. In this review, we summarize current understanding of the mechanisms by which telomeres are faithfully and safely replicated in mammalian cells. Various telomere-associated proteins ensure efficient telomere replication at different steps, such as licensing of replication origins, passage of replication forks, proper fork restart after replication stress, and dissolution of post-replicative structures. In particular, shelterin proteins have central roles in the control of telomere replication. Through physical interactions, accessory proteins are recruited to maintain telomere integrity during DNA replication. Dormant replication origins and/or homology-directed repair may rescue inappropriate fork stalling or collapse that can cause defects in telomere structure and functions.
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31
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Dehé PM, Gaillard PHL. Control of structure-specific endonucleases to maintain genome stability. Nat Rev Mol Cell Biol 2017; 18:315-330. [PMID: 28327556 DOI: 10.1038/nrm.2016.177] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Structure-specific endonucleases (SSEs) have key roles in DNA replication, recombination and repair, and emerging roles in transcription. These enzymes have specificity for DNA secondary structure rather than for sequence, and therefore their activity must be precisely controlled to ensure genome stability. In this Review, we discuss how SSEs are controlled as part of genome maintenance pathways in eukaryotes, with an emphasis on the elaborate mechanisms that regulate the members of the major SSE families - including the xeroderma pigmentosum group F-complementing protein (XPF) and MMS and UV-sensitive protein 81 (MUS81)-dependent nucleases, and the flap endonuclease 1 (FEN1), XPG and XPG-like endonuclease 1 (GEN1) enzymes - during processes such as DNA adduct repair, Holliday junction processing and replication stress. We also discuss newly characterized connections between SSEs and other classes of DNA-remodelling enzymes and cell cycle control machineries, which reveal the importance of SSE scaffolds such as the synthetic lethal of unknown function 4 (SLX4) tumour suppressor for the maintenance of genome stability.
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Affiliation(s)
- Pierre-Marie Dehé
- Centre de Recherche en Cancérologie de Marseille, CRCM, CNRS, Aix Marseille Université, INSERM, Institut Paoli-Calmettes, 27 Boulevard Leï Roure, 13009 Marseille, France
| | - Pierre-Henri L Gaillard
- Centre de Recherche en Cancérologie de Marseille, CRCM, CNRS, Aix Marseille Université, INSERM, Institut Paoli-Calmettes, 27 Boulevard Leï Roure, 13009 Marseille, France
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32
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Hu L, Yang F, Lu L, Dai W. Arsenic-induced sumoylation of Mus81 is involved in regulating genomic stability. Cell Cycle 2017; 16:802-811. [PMID: 28318385 DOI: 10.1080/15384101.2017.1302628] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Chronic environmental exposure to metal toxicants such as chromium and arsenic is closely related to the development of several types of common cancers. Genetic and epigenetic studies in the past decade reveal that post-translational modifications of histones play a role in metal carcinogenesis. However, exact molecular mechanisms of metal carcinogenesis remain to be elucidated. In this study we found that As2O3, an environmental metal toxicant, upregulated overall modifications of many cellular proteins by SUMO2/3. Sumoylated proteins from arsenic-treated cells constitutively expressing His6-SUMO2 were pulled down by Ni-IDA resin under denaturing conditions. Mass spectrometric analysis revealed over 100 proteins that were potentially modified by sumoylation. Mus81, a DNA endonuclease involved in homologous recombination repair, was among the identified proteins whose sumoylation was increased after treatment with As2O3. We further showed that K10 and K524 were 2 lysine residues essential for Mus81 sumoylation. Moreover, we demonstrated that Mus81 sumoylation is important for normal mitotic chromosome congression and that cells expressing SUMO-resistant Mus81 mutants displayed compromised DNA damage responses after exposure to metal toxins such as Cr(VI) and arsenic.
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Affiliation(s)
- Liyan Hu
- a Department of Environmental Medicine , New York University Langone Medical Center , Tuxedo , NY , USA
| | - Feikun Yang
- b University of Pennsylvania , Philadelphia , PA , USA
| | - Lou Lu
- c Division of Molecular Medicine, Department of Medicine , David Geffen School of Medicine, University of California Los Angeles , Torrance , CA , USA
| | - Wei Dai
- a Department of Environmental Medicine , New York University Langone Medical Center , Tuxedo , NY , USA
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33
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HULC cooperates with MALAT1 to aggravate liver cancer stem cells growth through telomere repeat-binding factor 2. Sci Rep 2016; 6:36045. [PMID: 27782152 PMCID: PMC5080550 DOI: 10.1038/srep36045] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 09/26/2016] [Indexed: 12/29/2022] Open
Abstract
The dysregulation of lncRNAs has increasingly been linked to many human diseases, especially in cancers. Our results demonstrate HULC, MALAT1 and TRF2 are highly expressed in human hepatocellular carcinoma tissues, and HULC plus MALAT1 overexpression drastically promotes the growth of liver cancer stem cells. Mechanistically, both HULC and MALAT1 overexpression enhanced RNA polII, P300, CREPT to load on the promoter region of telomere repeat-binding factor 2(TRF2), triggering the overexpression, phosphorylation and SUMOylation of TRF2. Strikingly, the excessive TRF2 interacts with HULC or MALAT1 to form the complex that loads on the telomeric region, replacing the CST/AAF and recruiting POT1, pPOT1, ExoI, SNM1B, HP1 α. Accordingly, the telomere is greatly protected and enlonged. Furthermore, the excessive HULC plus MALAT1 reduced the methylation of the TERC promoter dependent on TRF2, increasing the TERC expression that causes the increase of interplay between TRET and TERC. Ultimately, the interaction between RFC and PCNA or between CDK2 and CyclinE, the telomerase activity and the microsatellite instability (MSI) are significantly increased in the liver cancer stem cells. Our demonstrations suggest that haploinsufficiency of HULC/MALAT1 plays an important role in malignant growth of liver cancer stem cell.
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34
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Grammatikakis I, Zhang P, Mattson MP, Gorospe M. The long and the short of TRF2 in neurogenesis. Cell Cycle 2016; 15:3026-3032. [PMID: 27565210 DOI: 10.1080/15384101.2016.1222339] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Gene expression patterns change dramatically during neuronal development. Proliferating cells, including neural stem cells (NSCs), express telomere repeat-binding factor 2 (TRF2), a nuclear protein that associates with telomeric proteins, DNA, and RNA telomeres. In NSCs TRF2 also binds to the transcription regulator REST to facilitate repression of numerous neuron-specific genes, thereby keeping the NSCs in a self-renewing state. Upon neuronal differentiation, TRF2 levels decline, REST-regulated neuronal genes are derepressed, and a short isoform of TRF2 arises (TRF2-S) which localizes in the cytoplasm, associates with different subsets of proteins and transcripts, and mobilizes axonal G-rich mRNAs. We recently identified two RNA-binding proteins, HNRNPH1 and H2 (referred to jointly as HNRNPH due to their high homology), which mediate the alternative splicing of an exon required for the expression of full-length TRF2. As HNRNPH levels decline during neurogenesis, TRF2 abundance decreases and TRF2-S accumulates. Here, we discuss the shared and unique functions of TRF2 and TRF2-S, the distinct subcellular compartment in which each isoform resides, the subsets of proteins and nucleic acids with which each interacts, and the functional consequences of these ribonucleoprotein interactions. This paradigm illustrates the dynamic mechanisms through which splicing regulation by factors like HNRNPH enable distinct protein functions as cells adapt to developmental programs such as neurogenesis.
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Affiliation(s)
- Ioannis Grammatikakis
- a Laboratory of Genetics, National Institute on Aging, National Institutes of Health , Baltimore , MD , USA
| | - Peisu Zhang
- b Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health , Baltimore , MD , USA
| | - Mark P Mattson
- b Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health , Baltimore , MD , USA
| | - Myriam Gorospe
- a Laboratory of Genetics, National Institute on Aging, National Institutes of Health , Baltimore , MD , USA
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35
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Abstract
Telomeres at chromosome ends are nucleoprotein structures consisting of tandem TTAGGG repeats and a complex of proteins termed shelterin. DNA damage and repair at telomeres is uniquely influenced by the ability of telomeric DNA to form alternate structures including loops and G-quadruplexes, coupled with the ability of shelterin proteins to interact with and regulate enzymes in every known DNA repair pathway. The role of shelterin proteins in preventing telomeric ends from being falsely recognized and processed as DNA double strand breaks is well established. Here we focus instead on recent developments in understanding the roles of shelterin proteins and telomeric DNA sequence and structure in processing genuine damage at telomeres induced by endogenous and exogenous DNA damage agents. We will highlight advances in double strand break repair, base excision repair and nucleotide excision repair at telomeres, and will discuss important questions remaining in the field.
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Affiliation(s)
- Elise Fouquerel
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, University of Pittsburgh Cancer Institute Research Pavilion, 5117 Centre Avenue, University of Pittsburgh, Pittsburgh, PA 15213, United States
| | - Dhvani Parikh
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, University of Pittsburgh Cancer Institute Research Pavilion, 5117 Centre Avenue, University of Pittsburgh, Pittsburgh, PA 15213, United States
| | - Patricia Opresko
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, University of Pittsburgh Cancer Institute Research Pavilion, 5117 Centre Avenue, University of Pittsburgh, Pittsburgh, PA 15213, United States.
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36
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Yin J, Wan B, Sarkar J, Horvath K, Wu J, Chen Y, Cheng G, Wan K, Chin P, Lei M, Liu Y. Dimerization of SLX4 contributes to functioning of the SLX4-nuclease complex. Nucleic Acids Res 2016; 44:4871-80. [PMID: 27131364 PMCID: PMC4889959 DOI: 10.1093/nar/gkw354] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/05/2016] [Accepted: 04/21/2016] [Indexed: 11/16/2022] Open
Abstract
The Fanconi anemia protein SLX4 assembles a genome and telomere maintenance toolkit, consisting of the nucleases SLX1, MUS81 and XPF. Although it is known that SLX4 acts as a scaffold for building this complex, the molecular basis underlying this function of SLX4 remains unclear. Here, we report that functioning of SLX4 is dependent on its dimerization via an oligomerization motif called the BTB domain. We solved the crystal structure of the SLX4BTB dimer, identifying key contacts (F681 and F708) that mediate dimerization. Disruption of BTB dimerization abrogates nuclear foci formation and telomeric localization of not only SLX4 but also of its associated nucleases. Furthermore, dimerization-deficient SLX4 mutants cause defective cellular response to DNA interstrand crosslinking agent and telomere maintenance, underscoring the contribution of BTB domain-mediated dimerization of SLX4 in genome and telomere maintenance.
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Affiliation(s)
- Jinhu Yin
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institutes of Health, 251 Bayview Blvd, Baltimore, MD 21044, USA
| | - Bingbing Wan
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 333 Haike Road, Shanghai 200031, China Shanghai Research Center, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jaya Sarkar
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institutes of Health, 251 Bayview Blvd, Baltimore, MD 21044, USA
| | - Kent Horvath
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institutes of Health, 251 Bayview Blvd, Baltimore, MD 21044, USA
| | - Jian Wu
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 333 Haike Road, Shanghai 200031, China
| | - Yong Chen
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 333 Haike Road, Shanghai 200031, China
| | - Guangjuan Cheng
- Shanghai Research Center, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ke Wan
- Shanghai Research Center, Chinese Academy of Sciences, Shanghai 200031, China
| | - Peiju Chin
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institutes of Health, 251 Bayview Blvd, Baltimore, MD 21044, USA
| | - Ming Lei
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 333 Haike Road, Shanghai 200031, China Department of Biological Chemistry, University of Michigan Medical School, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA Shanghai Research Center, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yie Liu
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institutes of Health, 251 Bayview Blvd, Baltimore, MD 21044, USA
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37
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Complex interactions between the DNA-damage response and mammalian telomeres. Nat Struct Mol Biol 2016; 22:859-66. [PMID: 26581520 DOI: 10.1038/nsmb.3092] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/23/2015] [Indexed: 12/28/2022]
Abstract
Natural chromosome ends resemble double-stranded DNA breaks, but they do not activate a damage response in healthy cells. Telomeres therefore have evolved to solve the 'end-protection problem' by inhibiting multiple DNA damage-response pathways. During the past decade, the view of telomeres has progressed from simple caps that hide chromosome ends to complex machineries that have an active role in organizing the genome. Here we focus on mammalian telomeres and summarize and interpret recent discoveries in detail, focusing on how repair pathways are inhibited, how resection and replication are controlled and how these mechanisms govern cell fate during senescence, crisis and transformation.
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TRF2-RAP1 is required to protect telomeres from engaging in homologous recombination-mediated deletions and fusions. Nat Commun 2016; 7:10881. [PMID: 26941064 PMCID: PMC4785230 DOI: 10.1038/ncomms10881] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 01/29/2016] [Indexed: 12/27/2022] Open
Abstract
Repressor/activator protein 1 (RAP1) is a highly conserved telomere-interacting protein. Yeast Rap1 protects telomeres from non-homologous end joining (NHEJ), plays important roles in telomere length control and is involved in transcriptional gene regulation. However, a role for mammalian RAP1 in telomere end protection remains controversial. Here we present evidence that mammalian RAP1 is essential to protect telomere from homology directed repair (HDR) of telomeres. RAP1 cooperates with the basic domain of TRF2 (TRF2B) to repress PARP1 and SLX4 localization to telomeres. Without RAP1 and TRF2B, PARP1 and SLX4 HR factors promote rapid telomere resection, resulting in catastrophic telomere loss and the generation of telomere-free chromosome fusions in both mouse and human cells. The RAP1 Myb domain is required to repress both telomere loss and formation of telomere-free fusions. Our results highlight the importance of the RAP1-TRF2 heterodimer in protecting telomeres from inappropriate processing by the HDR pathway. While yeast Rap1 regulates telomere length and protects telomeres from non-homologous end joining, its role in higher eukaryotes is controversial. Here the authors present evidence that in mammals, RAP1 cooperates with TRF2 to prevent homologous recombination-mediated repair of telomeres.
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Noce A, Canale MP, Capria A, Rovella V, Tesauro M, Splendiani G, Annicchiarico-Petruzzelli M, Manzuoli M, Simonetti G, Di Daniele N. Coronary artery calcifications predict long term cardiovascular events in non diabetic Caucasian hemodialysis patients. Aging (Albany NY) 2016; 7:269-79. [PMID: 26131456 PMCID: PMC4429091 DOI: 10.18632/aging.100740] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Vascular calcifications are frequent in chronic renal disease and are associated to significant cardiovascular morbidity and mortality. The long term predictive value of coronary artery calcifications detected by multi-layer spiral computed tomography for major cardiovascular events was evaluated in non-diabetic Caucasian patients on maintenance hemodialysis free of clinical cardiovascular disease. Two-hundred and five patients on maintenance hemodialysis were enrolled into this observational, prospective cohort study. Patients underwent a single cardiac multi-layer spiral computed tomography. Calcium load was quantified and patients grouped according to the Agatston score: group 1 (Agatston score: 0), group 2 (Agatston score 1-400), group 3 (Agatston score 401-1000) and group 4 (Agatston score >1000). Follow-up was longer than seven years. Primary endpoint was death from a major cardiovascular event. Actuarial survival was calculated separately in the four groups with Kaplan-Meier method. Patients who died from causes other than cardiovascular disease and transplanted patients were censored. The “log rank” test was employed to compare survival curves. One-hundred two patients (49.7%) died for a major cardiovascular event during the follow-up period. Seven-year actuarial survival was more than 90% for groups 1 and 2, but failed to about 50% for group 3 and to <10% for group 4. Hence, Agatston score >400 predicts a significantly higher cardiovascular mortality compared with Agatston score <400 (p<0.0001); furthermore, serum Parathyroid hormone levels > 300 pg/l were associated to a lower survival (p < 0.05). Extended coronary artery calcifications detected by cardiac multi-layer spiral computed tomography, strongly predicted long term cardiovascular mortality in non-diabetic Caucasian patients on maintenance hemodialysis. Moreover, it was not related to conventional indices of atherosclerosis, but to other non-traditional risk factors, as serum Parathyroid hormone levels. A full cost-benefit analysis is however necessary to justify a widespread use of cardiac multi-layer spiral computed tomography in clinical practice.
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40
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Benarroch-Popivker D, Pisano S, Mendez-Bermudez A, Lototska L, Kaur P, Bauwens S, Djerbi N, Latrick CM, Fraisier V, Pei B, Gay A, Jaune E, Foucher K, Cherfils-Vicini J, Aeby E, Miron S, Londoño-Vallejo A, Ye J, Le Du MH, Wang H, Gilson E, Giraud-Panis MJ. TRF2-Mediated Control of Telomere DNA Topology as a Mechanism for Chromosome-End Protection. Mol Cell 2016; 61:274-86. [PMID: 26774283 DOI: 10.1016/j.molcel.2015.12.009] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 10/14/2015] [Accepted: 11/30/2015] [Indexed: 02/07/2023]
Abstract
The shelterin proteins protect telomeres against activation of the DNA damage checkpoints and recombinational repair. We show here that a dimer of the shelterin subunit TRF2 wraps ∼ 90 bp of DNA through several lysine and arginine residues localized around its homodimerization domain. The expression of a wrapping-deficient TRF2 mutant, named Top-less, alters telomeric DNA topology, decreases the number of terminal loops (t-loops), and triggers the ATM checkpoint, while still protecting telomeres against non-homologous end joining (NHEJ). In Top-less cells, the protection against NHEJ is alleviated if the expression of the TRF2-interacting protein RAP1 is reduced. We conclude that a distinctive topological state of telomeric DNA, controlled by the TRF2-dependent DNA wrapping and linked to t-loop formation, inhibits both ATM activation and NHEJ. The presence of RAP1 at telomeres appears as a backup mechanism to prevent NHEJ when topology-mediated telomere protection is impaired.
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Affiliation(s)
- Delphine Benarroch-Popivker
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Sabrina Pisano
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Aaron Mendez-Bermudez
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France; International Laboratory in Hematology and Cancer, Shanghai Jiao Tong University School of Medicine/Ruijin Hospital/CNRS/INSERM/Nice University, Pôle Sino-Français de Recherche en Sciences du Vivant et Génomique, Shanghai Ruijin Hospital, Huangpu, Shanghai 200025, P.R. China
| | - Liudmyla Lototska
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Parminder Kaur
- Physics Department, North Carolina State University at Raleigh, Raleigh, NC 27695, USA
| | - Serge Bauwens
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Nadir Djerbi
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Chrysa M Latrick
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Vincent Fraisier
- Cell and Tissue Imaging Platform (PICT-IBiSA), Nikon Imaging Centre, UMR 144 CNRS Institut Curie, 75248 Paris Cedex 05, France
| | - Bei Pei
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Alexandre Gay
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Emilie Jaune
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Kevin Foucher
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Julien Cherfils-Vicini
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France
| | - Eric Aeby
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Simona Miron
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Bâtiment 144, CEA Saclay, Gif-sur-Yvette F-91191, France
| | | | - Jing Ye
- International Laboratory in Hematology and Cancer, Shanghai Jiao Tong University School of Medicine/Ruijin Hospital/CNRS/INSERM/Nice University, Pôle Sino-Français de Recherche en Sciences du Vivant et Génomique, Shanghai Ruijin Hospital, Huangpu, Shanghai 200025, P.R. China
| | - Marie-Hélène Le Du
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Bâtiment 144, CEA Saclay, Gif-sur-Yvette F-91191, France
| | - Hong Wang
- Physics Department, North Carolina State University at Raleigh, Raleigh, NC 27695, USA
| | - Eric Gilson
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France; International Laboratory in Hematology and Cancer, Shanghai Jiao Tong University School of Medicine/Ruijin Hospital/CNRS/INSERM/Nice University, Pôle Sino-Français de Recherche en Sciences du Vivant et Génomique, Shanghai Ruijin Hospital, Huangpu, Shanghai 200025, P.R. China; Department of Genetics, CHU Nice, Nice 06202, France.
| | - Marie-Josèphe Giraud-Panis
- Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, CNRS UMR7284, INSERM U1081, University of Nice Sophia Antipolis, Nice, France.
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Abstract
The ends of linear chromosomes are capped by nucleoprotein structures called telomeres. A dysfunctional telomere may resemble a DNA double-strand break (DSB), which is a severe form of DNA damage. The presence of one DSB is sufficient to drive cell cycle arrest and cell death. Therefore cells have evolved mechanisms to repair DSBs such as homologous recombination (HR). HR-mediated repair of telomeres can lead to genome instability, a hallmark of cancer cells, which is why such repair is normally inhibited. However, some HR-mediated processes are required for proper telomere function. The need for some recombination activities at telomeres but not others necessitates careful and complex regulation, defects in which can lead to catastrophic consequences. Furthermore, some cell types can maintain telomeres via telomerase-independent, recombination-mediated mechanisms. In humans, these mechanisms are called alternative lengthening of telomeres (ALT) and are used in a subset of human cancer cells. In this review, we summarize the different recombination activities occurring at telomeres and discuss how they are regulated. Much of the current knowledge is derived from work using yeast models, which is the focus of this review, but relevant studies in mammals are also included.
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Affiliation(s)
- Clémence Claussin
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Michael Chang
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Sarkar J, Wan B, Yin J, Vallabhaneni H, Horvath K, Kulikowicz T, Bohr VA, Zhang Y, Lei M, Liu Y. SLX4 contributes to telomere preservation and regulated processing of telomeric joint molecule intermediates. Nucleic Acids Res 2015; 43:5912-23. [PMID: 25990736 PMCID: PMC4499145 DOI: 10.1093/nar/gkv522] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 05/07/2015] [Indexed: 11/14/2022] Open
Abstract
SLX4 assembles a toolkit of endonucleases SLX1, MUS81 and XPF, which is recruited to telomeres via direct interaction of SLX4 with TRF2. Telomeres present an inherent obstacle for DNA replication and repair due to their high propensity to form branched DNA intermediates. Here we provide novel insight into the mechanism and regulation of the SLX4 complex in telomere preservation. SLX4 associates with telomeres throughout the cell cycle, peaking in late S phase and under genotoxic stress. Disruption of SLX4's interaction with TRF2 or SLX1 and SLX1's nuclease activity independently causes telomere fragility, suggesting a requirement of the SLX4 complex for nucleolytic resolution of branched intermediates during telomere replication. Indeed, the SLX1-SLX4 complex processes a variety of telomeric joint molecules in vitro. The nucleolytic activity of SLX1-SLX4 is negatively regulated by telomeric DNA-binding proteins TRF1 and TRF2 and is suppressed by the RecQ helicase BLM in vitro. In vivo, in the presence of functional BLM, telomeric circle formation and telomere sister chromatid exchange, both arising out of nucleolytic processing of telomeric homologous recombination intermediates, are suppressed. We propose that the SLX4-toolkit is a telomere accessory complex that, in conjunction with other telomere maintenance proteins, ensures unhindered, but regulated telomere maintenance.
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Affiliation(s)
- Jaya Sarkar
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institute of Health, 251 Bayview Blvd, Baltimore, MD 21224, USA
| | - Bingbing Wan
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 333 Haike Road, Shanghai 200031, China Department of Biological Chemistry, University of Michigan Medical School, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA
| | - Jinhu Yin
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institute of Health, 251 Bayview Blvd, Baltimore, MD 21224, USA
| | - Haritha Vallabhaneni
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institute of Health, 251 Bayview Blvd, Baltimore, MD 21224, USA
| | - Kent Horvath
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institute of Health, 251 Bayview Blvd, Baltimore, MD 21224, USA
| | - Tomasz Kulikowicz
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institute of Health, 251 Bayview Blvd, Baltimore, MD 21224, USA
| | - Vilhelm A Bohr
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institute of Health, 251 Bayview Blvd, Baltimore, MD 21224, USA
| | - Yanbin Zhang
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Ming Lei
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institute of Health, 251 Bayview Blvd, Baltimore, MD 21224, USA National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 333 Haike Road, Shanghai 200031, China
| | - Yie Liu
- Laboratory of Molecular Gerontology, National Institute on Aging/National Institute of Health, 251 Bayview Blvd, Baltimore, MD 21224, USA
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43
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Feuerhahn S, Chen LY, Luke B, Porro A. No DDRama at chromosome ends: TRF2 takes centre stage. Trends Biochem Sci 2015; 40:275-85. [DOI: 10.1016/j.tibs.2015.03.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/06/2015] [Accepted: 03/06/2015] [Indexed: 12/13/2022]
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44
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Ilicheva NV, Podgornaya OI, Voronin AP. Telomere Repeat-Binding Factor 2 Is Responsible for the Telomere Attachment to the Nuclear Membrane. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2015; 101:67-96. [DOI: 10.1016/bs.apcsb.2015.06.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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45
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Bower BD, Griffith JD. TRF1 and TRF2 differentially modulate Rad51-mediated telomeric and nontelomeric displacement loop formation in vitro. Biochemistry 2014; 53:5485-95. [PMID: 25115914 PMCID: PMC4151696 DOI: 10.1021/bi5006249] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
A growing
body of literature suggests that the homologous recombination/repair
(HR) pathway cooperates with components of the shelterin complex to
promote both telomere maintenance and nontelomeric HR. This may be
due to the ability of both HR and shelterin proteins to promote strand
invasion, wherein a single-stranded DNA (ssDNA) substrate base pairs
with a homologous double-stranded DNA (dsDNA) template displacing
a loop of ssDNA (D-loop). Rad51 recombinase catalyzes D-loop formation
during HR, and telomere repeat binding factor 2 (TRF2) catalyzes the
formation of a telomeric D-loop that stabilizes a looped structure
in telomeric DNA (t-loop) that may facilitate telomere protection.
We have characterized this functional interaction in vitro using a fluorescent D-loop assay measuring the incorporation of
Cy3-labeled 90-nucleotide telomeric and nontelomeric substrates into
telomeric and nontelomeric plasmid templates. We report that preincubation
of a telomeric template with TRF2 inhibits the ability of Rad51 to
promote telomeric D-loop formation upon preincubation with a telomeric
substrate. This suggests Rad51 does not facilitate t-loop formation
and suggests a mechanism whereby TRF2 can inhibit HR at telomeres.
We also report a TRF2 mutant lacking the dsDNA binding domain promotes
Rad51-mediated nontelomeric D-loop formation, possibly explaining
how TRF2 promotes nontelomeric HR. Finally, we report telomere repeat
binding factor 1 (TRF1) promotes Rad51-mediated telomeric D-loop formation,
which may facilitate HR-mediated replication fork restart and explain
why TRF1 is required for efficient telomere replication.
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Affiliation(s)
- Brian D Bower
- Curriculum in Genetics and Molecular Biology, University of North Carolina , Chapel Hill, North Carolina 27599, United States
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