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Borges G, Benslimane Y, Harrington L. A CRISPR base editing approach for the functional assessment of telomere biology disorder-related genes in human health and aging. Biogerontology 2024; 25:361-378. [PMID: 38310618 PMCID: PMC10998809 DOI: 10.1007/s10522-024-10094-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/06/2024] [Indexed: 02/06/2024]
Abstract
Telomere Biology Disorders (TBDs) are a group of rare diseases characterized by the presence of short and/or dysfunctional telomeres. They comprise a group of bone marrow failure syndromes, idiopathic pulmonary fibrosis, and liver disease, among other diseases. Genetic alterations (variants) in the genes responsible for telomere homeostasis have been linked to TBDs. Despite the number of variants already identified as pathogenic, an even more significant number must be better understood. The study of TBDs is challenging since identifying these variants is difficult due to their rareness, it is hard to predict their impact on the disease onset, and there are not enough samples to study. Most of our knowledge about pathogenic variants comes from assessing telomerase activity from patients and their relatives affected by a TBD. However, we still lack a cell-based model to identify new variants and to study the long-term impact of such variants on the genes involved in TBDs. Herein, we present a cell-based model using CRISPR base editing to mutagenize the endogenous alleles of 21 genes involved in telomere biology. We identified key residues in the genes encoding 17 different proteins impacting cell growth. We provide functional evidence for variants of uncertain significance in patients with TBDs. We also identified variants resistant to telomerase inhibition that, similar to cells expressing wild-type telomerase, exhibited increased tumorigenic potential using an in vitro tumour growth assay. We believe that such cell-based approaches will significantly advance our understanding of the biology of TBDs and may contribute to the development of new therapies for this group of diseases.
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Affiliation(s)
- Gustavo Borges
- Departments of Medicine and Biochemistry and Molecular Medicine, Molecular Biology Programme, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, H3T 1J4, Canada
| | - Yahya Benslimane
- Departments of Medicine and Biochemistry and Molecular Medicine, Molecular Biology Programme, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, H3T 1J4, Canada
| | - Lea Harrington
- Departments of Medicine and Biochemistry and Molecular Medicine, Molecular Biology Programme, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, H3T 1J4, Canada.
- Department of Biochemistry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5G 1L7, Canada.
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2
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Nandy K, Babu D, Rani S, Joshi G, Ijee S, George A, Palani D, Premkumar C, Rajesh P, Vijayanand S, David E, Murugesan M, Velayudhan SR. Efficient gene editing in induced pluripotent stem cells enabled by an inducible adenine base editor with tunable expression. Sci Rep 2023; 13:21953. [PMID: 38081875 PMCID: PMC10713686 DOI: 10.1038/s41598-023-42174-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 09/06/2023] [Indexed: 12/18/2023] Open
Abstract
The preferred method for disease modeling using induced pluripotent stem cells (iPSCs) is to generate isogenic cell lines by correcting or introducing pathogenic mutations. Base editing enables the precise installation of point mutations at specific genomic locations without the need for deleterious double-strand breaks used in the CRISPR-Cas9 gene editing methods. We created a bulk population of iPSCs that homogeneously express ABE8e adenine base editor enzyme under a doxycycline-inducible expression system at the AAVS1 safe harbor locus. These cells enabled fast, efficient and inducible gene editing at targeted genomic regions, eliminating the need for single-cell cloning and screening to identify those with homozygous mutations. We could achieve multiplex genomic editing by creating homozygous mutations in very high efficiencies at four independent genomic loci simultaneously in AAVS1-iABE8e iPSCs, which is highly challenging with previously described methods. The inducible ABE8e expression system allows editing of the genes of interest within a specific time window, enabling temporal control of gene editing to study the cell or lineage-specific functions of genes and their molecular pathways. In summary, the inducible ABE8e system provides a fast, efficient and versatile gene-editing tool for disease modeling and functional genomic studies.
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Affiliation(s)
- Krittika Nandy
- Center for Stem Cell Research (A Unit of inStem, Bengaluru, India), Christian Medical College, Tamil Nadu, Vellore, 632002, India
- Department of Biotechnology, Thiruvalluvar University, Vellore, Tamil Nadu, 632115, India
| | - Dinesh Babu
- Center for Stem Cell Research (A Unit of inStem, Bengaluru, India), Christian Medical College, Tamil Nadu, Vellore, 632002, India
| | - Sonam Rani
- Center for Stem Cell Research (A Unit of inStem, Bengaluru, India), Christian Medical College, Tamil Nadu, Vellore, 632002, India
- Department of Biotechnology, Thiruvalluvar University, Vellore, Tamil Nadu, 632115, India
| | - Gaurav Joshi
- Department of Haematology, Christian Medical College, Vellore, Tamil Nadu, 632004, India
- Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, 695011, India
| | - Smitha Ijee
- Center for Stem Cell Research (A Unit of inStem, Bengaluru, India), Christian Medical College, Tamil Nadu, Vellore, 632002, India
- Department of Biotechnology, Thiruvalluvar University, Vellore, Tamil Nadu, 632115, India
| | - Anila George
- Center for Stem Cell Research (A Unit of inStem, Bengaluru, India), Christian Medical College, Tamil Nadu, Vellore, 632002, India
- Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, 695011, India
| | - Dhavapriya Palani
- Center for Stem Cell Research (A Unit of inStem, Bengaluru, India), Christian Medical College, Tamil Nadu, Vellore, 632002, India
| | - Chitra Premkumar
- Center for Stem Cell Research (A Unit of inStem, Bengaluru, India), Christian Medical College, Tamil Nadu, Vellore, 632002, India
| | - Praveena Rajesh
- Center for Stem Cell Research (A Unit of inStem, Bengaluru, India), Christian Medical College, Tamil Nadu, Vellore, 632002, India
| | - S Vijayanand
- Department of Biotechnology, Thiruvalluvar University, Vellore, Tamil Nadu, 632115, India
| | - Ernest David
- Department of Biotechnology, Thiruvalluvar University, Vellore, Tamil Nadu, 632115, India
| | - Mohankumar Murugesan
- Center for Stem Cell Research (A Unit of inStem, Bengaluru, India), Christian Medical College, Tamil Nadu, Vellore, 632002, India
| | - Shaji R Velayudhan
- Center for Stem Cell Research (A Unit of inStem, Bengaluru, India), Christian Medical College, Tamil Nadu, Vellore, 632002, India.
- Department of Haematology, Christian Medical College, Vellore, Tamil Nadu, 632004, India.
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3
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Wolf SE, Shalev I. The shelterin protein expansion of telomere dynamics: Linking early life adversity, life history, and the hallmarks of aging. Neurosci Biobehav Rev 2023; 152:105261. [PMID: 37268182 PMCID: PMC10527177 DOI: 10.1016/j.neubiorev.2023.105261] [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: 01/27/2023] [Revised: 04/10/2023] [Accepted: 05/30/2023] [Indexed: 06/04/2023]
Abstract
Aging is characterized by functional decline occurring alongside changes to several hallmarks of aging. One of the hallmarks includes attrition of repeated DNA sequences found at the ends of chromosomes called telomeres. While telomere attrition is linked to morbidity and mortality, whether and how it causally contributes to lifelong rates of functional decline is unclear. In this review, we propose the shelterin-telomere hypothesis of life history, in which telomere-binding shelterin proteins translate telomere attrition into a range of physiological outcomes, the extent of which may be modulated by currently understudied variation in shelterin protein levels. Shelterin proteins may expand the breadth and timing of consequences of telomere attrition, e.g., by translating early life adversity into acceleration of the aging process. We consider how the pleiotropic roles of shelterin proteins provide novel insights into natural variation in physiology, life history, and lifespan. We highlight key open questions that encourage the integrative, organismal study of shelterin proteins that enhances our understanding of the contribution of the telomere system to aging.
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Affiliation(s)
- Sarah E Wolf
- Department of Biobehavioral Health, Penn State University, University Park, PA 16802, USA.
| | - Idan Shalev
- Department of Biobehavioral Health, Penn State University, University Park, PA 16802, USA
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4
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Chen B, Ge T, Jian M, Chen L, Fang Z, He Z, Huang C, An Y, Yin S, Xiong Y, Zhang J, Li R, Ye M, Li Y, Liu F, Ma W, Songyang Z. Transmembrane nuclease NUMEN/ENDOD1 regulates DNA repair pathway choice at the nuclear periphery. Nat Cell Biol 2023:10.1038/s41556-023-01165-1. [PMID: 37322289 DOI: 10.1038/s41556-023-01165-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/10/2023] [Indexed: 06/17/2023]
Abstract
Proper repair of DNA damage lesions is essential to maintaining genome integrity and preventing the development of human diseases, including cancer. Increasing evidence suggests the importance of the nuclear envelope in the spatial regulation of DNA repair, although the mechanisms of such regulatory processes remain poorly defined. Through a genome-wide synthetic viability screen for PARP-inhibitor resistance using an inducible CRISPR-Cas9 platform and BRCA1-deficient breast cancer cells, we identified a transmembrane nuclease (renamed NUMEN) that could facilitate compartmentalized and non-homologous end joining-dependent repair of double-stranded DNA breaks at the nuclear periphery. Collectively, our data demonstrate that NUMEN generates short 5' overhangs through its endonuclease and 3'→5' exonuclease activities, promotes the repair of DNA lesions-including heterochromatic lamina-associated domain breaks as well as deprotected telomeres-and functions as a downstream effector of DNA-dependent protein kinase catalytic subunit. These findings underline the role of NUMEN as a key player in DNA repair pathway choice and genome-stability maintenance, and have implications for ongoing research into the development and treatment of genome instability disorders.
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Affiliation(s)
- Bohong Chen
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Tianyu Ge
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Meiqi Jian
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Liutao Chen
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhengwen Fang
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zibin He
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Chengjing Huang
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yan An
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Shanshan Yin
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yuanyuan Xiong
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - JingKai Zhang
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Ruofei Li
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Miaoman Ye
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yubing Li
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Feng Liu
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wenbing Ma
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhou Songyang
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
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5
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Wang H, Ma T, Zhang X, Chen W, Lan Y, Kuang G, Hsu SJ, He Z, Chen Y, Stewart J, Bhattacharjee A, Luo Z, Price C, Feng X. CTC1 OB-B interaction with TPP1 terminates telomerase and prevents telomere overextension. Nucleic Acids Res 2023; 51:4914-4928. [PMID: 37021555 PMCID: PMC10250220 DOI: 10.1093/nar/gkad237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 03/16/2023] [Accepted: 03/31/2023] [Indexed: 04/07/2023] Open
Abstract
CST (CTC1-STN1-TEN1) is a telomere associated complex that binds ssDNA and is required for multiple steps in telomere replication, including termination of G-strand extension by telomerase and synthesis of the complementary C-strand. CST contains seven OB-folds which appear to mediate CST function by modulating CST binding to ssDNA and the ability of CST to recruit or engage partner proteins. However, the mechanism whereby CST achieves its various functions remains unclear. To address the mechanism, we generated a series of CTC1 mutants and studied their effect on CST binding to ssDNA and their ability to rescue CST function in CTC1-/- cells. We identified the OB-B domain as a key determinant of telomerase termination but not C-strand synthesis. CTC1-ΔB expression rescued C-strand fill-in, prevented telomeric DNA damage signaling and growth arrest. However, it caused progressive telomere elongation and the accumulation of telomerase at telomeres, indicating an inability to limit telomerase action. The CTC1-ΔB mutation greatly reduced CST-TPP1 interaction but only modestly affected ssDNA binding. OB-B point mutations also weakened TPP1 association, with the deficiency in TPP1 interaction tracking with an inability to limit telomerase action. Overall, our results indicate that CTC1-TPP1 interaction plays a key role in telomerase termination.
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Affiliation(s)
- Huan Wang
- Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Tengfei Ma
- Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Xiaotong Zhang
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Wei Chen
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yina Lan
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Guotao Kuang
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Shih-Jui Hsu
- Department of Cancer Biology, University of Cincinnati, Cincinnati, OH, USA
| | - Zibin He
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yuxi Chen
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jason Stewart
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | | | - Zhenhua Luo
- Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Carolyn Price
- Department of Cancer Biology, University of Cincinnati, Cincinnati, OH, USA
| | - Xuyang Feng
- Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
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6
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Zade NH, Khattar E. POT1 mutations cause differential effects on telomere length leading to opposing disease phenotypes. J Cell Physiol 2023; 238:1237-1255. [PMID: 37183325 DOI: 10.1002/jcp.31034] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 03/28/2023] [Accepted: 04/17/2023] [Indexed: 05/16/2023]
Abstract
The protection of telomere protein (POT1) is a telomere-binding protein and is an essential component of the six-membered shelterin complex, which is associated with the telomeres. POT1 directly binds to the 3' single-stranded telomeric overhang and prevents the activation of DNA damage response at telomeres thus preventing the telomere-telomere fusions and genomic instability. POT1 also plays a pivotal role in maintaining telomere length by regulating telomerase-mediated telomere elongation. Mutations in POT1 proteins result in three different telomere phenotypes, which include long, short, or aberrant telomere length. Long telomeres predispose individuals to cancer, while short or aberrant telomere phenotypes result in pro-aging diseases referred to as telomeropathies. Here, we review the function of POT1 proteins in telomere length hemostasis and how the spectrum of mutations reported in POT1 can be segregated toward developing very distinct disease phenotypes of cancer and telomeropathies.
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Affiliation(s)
- Nikita Harish Zade
- Sunandan Divatia School of Science, SVKM's NMIMS (Deemed to be) University, Mumbai, India
| | - Ekta Khattar
- Sunandan Divatia School of Science, SVKM's NMIMS (Deemed to be) University, Mumbai, India
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7
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Yu X, Gray S, Ferreira H. POT-3 preferentially binds the terminal DNA-repeat on the telomeric G-overhang. Nucleic Acids Res 2023; 51:610-618. [PMID: 36583365 PMCID: PMC9881156 DOI: 10.1093/nar/gkac1203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 12/01/2022] [Accepted: 12/06/2022] [Indexed: 12/31/2022] Open
Abstract
Eukaryotic chromosomes typically end in 3' telomeric overhangs. The safeguarding of telomeric single-stranded DNA overhangs is carried out by factors related to the protection of telomeres 1 (POT1) protein in humans. Of the three POT1-like proteins in Caenorhabditis elegans, POT-3 was the only member thought to not play a role at telomeres. Here, we provide evidence that POT-3 is a bona fide telomere-binding protein. Using a new loss-of-function mutant, we show that the absence of POT-3 causes telomere lengthening and increased levels of telomeric C-circles. We find that POT-3 directly binds the telomeric G-strand in vitro and map its minimal DNA binding site to the six-nucleotide motif, GCTTAG. We further show that the closely related POT-2 protein binds the same motif, but that POT-3 shows higher sequence selectivity. Crucially, in contrast to POT-2, POT-3 prefers binding sites immediately adjacent to the 3' end of DNA. These differences are significant as genetic analyses reveal that pot-2 and pot-3 do not function redundantly with each other in vivo. Our work highlights the rapid evolution and specialisation of telomere binding proteins and places POT-3 in a unique position to influence activities that control telomere length.
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Affiliation(s)
- Xupeng Yu
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, UK
| | - Sean Gray
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, UK
| | - Helder C Ferreira
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, UK
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8
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Yin S, Zhang F, Lin S, Chen W, Weng K, Liu D, Wang C, He Z, Chen Y, Ma W, Huang J, Huang Y, Songyang Z. TIN2 deficiency leads to ALT-associated phenotypes and differentiation defects in embryonic stem cells. Stem Cell Reports 2022; 17:1183-1197. [PMID: 35395177 PMCID: PMC9120858 DOI: 10.1016/j.stemcr.2022.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 11/17/2022] Open
Abstract
Telomere integrity is critical for embryonic development, and core telomere-binding proteins, such as TIN2, are key to maintaining telomere stability. Here, we report that homozygous Tin2S341X resulted in embryonic lethality in mice and reduced expression of Tin2 in the derived mouse embryonic stem cells (mESCs). Homozygous mutant mESCs were able to self-renew and remain undifferentiated but displayed many phenotypes associated with alternative lengthening of telomeres (ALT), including excessively long and heterogeneous telomeres, increased ALT-associated promyelocytic leukemia (PML) bodies, and unstable chromosomal ends. These cells also showed upregulation of Zscan4 expression and elevated targeting of DAXX/ATRX and H3K9me3 marks on telomeres. Furthermore, the mutant mESCs were impeded in their differentiation capacity. Upon differentiation, DAXX/ATRX and PML bodies disassociated from telomeres in these cells, where elevated DNA damage was also apparent. Our results reveal differential responses to telomere dysfunction in mESCs versus differentiated cells and highlight the critical role of TIN2 in embryonic development.
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Affiliation(s)
- Shanshan Yin
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research, SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China; Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Fangyingnan Zhang
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research, SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Song Lin
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research, SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Wei Chen
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research, SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Kai Weng
- Shanghai Institute of Precision Medicine, Shanghai 200125, China
| | - Dan Liu
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Chuanle Wang
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research, SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Zibin He
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research, SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yuxi Chen
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research, SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Wenbin Ma
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research, SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Junjiu Huang
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research, SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yan Huang
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research, SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
| | - Zhou Songyang
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research, SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China; Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China; Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China.
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9
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CRISPR/Cas: A New Tool in the Research of Telomeres and Telomerase as Well as a Novel Form of Cancer Therapy. Int J Mol Sci 2022; 23:ijms23063002. [PMID: 35328421 PMCID: PMC8953708 DOI: 10.3390/ijms23063002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 02/28/2022] [Accepted: 03/08/2022] [Indexed: 02/01/2023] Open
Abstract
Due to their close connection with senescence, aging, and disease, telomeres and telomerase provide a unique and vital research route for boosting longevity and health span. Despite significant advances during the last three decades, earlier studies into these two biological players were impeded by the difficulty of achieving real-time changes inside living cells. As a result of the clustered regularly interspaced short palindromic repeats (CRISPR)-associated system’s (Cas) method, targeted genetic studies are now underway to change telomerase, the genes that govern it as well as telomeres. This review will discuss studies that have utilized CRISPR-related technologies to target and modify genes relevant to telomeres and telomerase as well as to develop targeted anti-cancer therapies. These studies greatly improve our knowledge and understanding of cellular and molecular mechanisms that underlie cancer development and aging.
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10
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Zhou Z, Li Y, Xu H, Xie X, He Z, Lin S, Li R, Jin S, Cui J, Hu H, Liu F, Wu S, Ma W, Songyang Z. An inducible CRISPR/Cas9 screen identifies DTX2 as a transcriptional regulator of human telomerase. iScience 2022; 25:103813. [PMID: 35198878 PMCID: PMC8844827 DOI: 10.1016/j.isci.2022.103813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/07/2021] [Accepted: 01/20/2022] [Indexed: 01/12/2023] Open
Abstract
Most tumor cells reactivate telomerase to ensure unlimited proliferation, whereas the expression of human telomerase reverse transcriptase (hTERT) is tightly regulated and rate-limiting for telomerase activity maintenance. Several general transcription factors (TFs) have been found in regulating hTERT transcription; however, a systematic study is lacking. Here we performed an inducible CRISPR/Cas9 KO screen using an hTERT core promoter-driven reporter. We identified numerous positive regulators including an E3 ligase DTX2. In telomerase-positive cancer cells, DTX2 depletion downregulated hTERT transcription and telomerase activity, contributing to progressive telomere shortening, growth arrest, and increased apoptosis. Utilizing BioID, we characterized multiple TFs as DTX2 proximal proteins, among which NFIC functioned corporately with DTX2 in promoting hTERT transcription. Further analysis demonstrated that DTX2 mediated K63-linked ubiquitination of NFIC, which facilitated NFIC binding to the hTERT promoter and enhanced hTERT expression. These findings highlight a new hTERT regulatory pathway that may be exploited for potential cancer therapeutics. An inducible CRISPR/Cas9 screen identifies regulators for hTERT transcription DTX2 deficiency leads to telomere shortening and cell growth arrest DTX2 mediates ubiquitination on NFIC, stabilizing NFIC binding on hTERT promoter DTX2-NFIC functions corporately to promote hTERT transcription and tumorigenesis
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Affiliation(s)
- Zhifen Zhou
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yujing Li
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Huimin Xu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Xiaowei Xie
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Zibin He
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Song Lin
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Ruofei Li
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Shouheng Jin
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Jun Cui
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Hai Hu
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Feng Liu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Su Wu
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
- Corresponding author
| | - Wenbin Ma
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
- Corresponding author
| | - Zhou Songyang
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, Institute of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China
- Corresponding author
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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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Plyasova AA, Zhdanov DD. Alternative Splicing of Human Telomerase Reverse Transcriptase (hTERT) and Its Implications in Physiological and Pathological Processes. Biomedicines 2021; 9:526. [PMID: 34065134 PMCID: PMC8150890 DOI: 10.3390/biomedicines9050526] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 12/24/2022] Open
Abstract
Alternative splicing (AS) of human telomerase catalytic subunit (hTERT, human telomerase reverse transcriptase) pre-mRNA strongly regulates telomerase activity. Several proteins can regulate AS in a cell type-specific manner and determine the functions of cells. In addition to being involved in telomerase activity regulation, AS provides cells with different splice variants that may have alternative biological activities. The modulation of telomerase activity through the induction of hTERT AS is involved in the development of different cancer types and embryos, and the differentiation of stem cells. Regulatory T cells may suppress the proliferation of target human and murine T and B lymphocytes and NK cells in a contact-independent manner involving activation of TERT AS. This review focuses on the mechanism of regulation of hTERT pre-mRNA AS and the involvement of splice variants in physiological and pathological processes.
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Affiliation(s)
| | - Dmitry D. Zhdanov
- Institute of Biomedical Chemistry, Pogodinskaya st 10/8, 119121 Moscow, Russia;
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14
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Wu Q, Shou J. Toward precise CRISPR DNA fragment editing and predictable 3D genome engineering. J Mol Cell Biol 2021; 12:828-856. [PMID: 33125070 PMCID: PMC7883824 DOI: 10.1093/jmcb/mjaa060] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/23/2020] [Accepted: 09/23/2020] [Indexed: 02/06/2023] Open
Abstract
Ever since gene targeting or specific modification of genome sequences in mice was achieved in the early 1980s, the reverse genetic approach of precise editing of any genomic locus has greatly accelerated biomedical research and biotechnology development. In particular, the recent development of the CRISPR/Cas9 system has greatly expedited genetic dissection of 3D genomes. CRISPR gene-editing outcomes result from targeted genome cleavage by ectopic bacterial Cas9 nuclease followed by presumed random ligations via the host double-strand break repair machineries. Recent studies revealed, however, that the CRISPR genome-editing system is precise and predictable because of cohesive Cas9 cleavage of targeting DNA. Here, we synthesize the current understanding of CRISPR DNA fragment-editing mechanisms and recent progress in predictable outcomes from precise genetic engineering of 3D genomes. Specifically, we first briefly describe historical genetic studies leading to CRISPR and 3D genome engineering. We then summarize different types of chromosomal rearrangements by DNA fragment editing. Finally, we review significant progress from precise 1D gene editing toward predictable 3D genome engineering and synthetic biology. The exciting and rapid advances in this emerging field provide new opportunities and challenges to understand or digest 3D genomes.
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Affiliation(s)
- Qiang Wu
- Center for Comparative Biomedicine, MOE Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jia Shou
- Center for Comparative Biomedicine, MOE Key Lab of Systems Biomedicine, State Key Laboratory of Oncogenes and Related Genes, Institute of Systems Biomedicine, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
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15
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Salimi-Jeda A, Badrzadeh F, Esghaei M, Abdoli A. The role of telomerase and viruses interaction in cancer development, and telomerase-dependent therapeutic approaches. Cancer Treat Res Commun 2021; 27:100323. [PMID: 33530025 DOI: 10.1016/j.ctarc.2021.100323] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 12/21/2022]
Abstract
Human telomerase reverse transcriptase (hTERT) is an enzyme that is critically involved in elongating and maintaining telomeres length to control cell life span and replicative potential. Telomerase activity is continuously expressed in human germ-line cells and most cancer cells, whereas it is suppressed in most somatic cells. In normal cells, by reducing telomerase activity and progressively shortening the telomeres, the cells progress to the senescence or apoptosis process. However, in cancer cells, telomere lengths remain constant due to telomerase's reactivation, and cells continue to proliferate and inhibit apoptosis, and ultimately lead to cancer development and human death due to metastasis. Studies demonstrated that several DNA and RNA oncoviruses could interact with telomerase by integrating their genome sequence within the host cell telomeres specifically. Through the activation of the hTERT promoter and lengthening the telomere, these cells contributes to cancer development. Since oncoviruses can activate telomerase and increase hTERT expression, there are several therapeutic strategies based on targeting the telomerase of cancer cells like telomerase-targeted peptide vaccines, hTERT-targeting dendritic cells (DCs), hTERT-targeting gene therapy, and hTERT-targeting CRISPR/Cas9 system that can overcome tumor-mediated toleration mechanisms and specifically apoptosis in cancer cells. This study reviews available data on the molecular structure of telomerase and the role of oncoviruses and telomerase interaction in cancer development and telomerase-dependent therapeutic approaches to conquest the cancer cells.
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Affiliation(s)
- Ali Salimi-Jeda
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Fariba Badrzadeh
- Faculti of Medicine, Golestan University of Medical sciences, Golestan, Iran.
| | - Maryam Esghaei
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Asghar Abdoli
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran.
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16
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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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17
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Glousker G, Briod A, Quadroni M, Lingner J. Human shelterin protein POT1 prevents severe telomere instability induced by homology-directed DNA repair. EMBO J 2020; 39:e104500. [PMID: 33073402 PMCID: PMC7705456 DOI: 10.15252/embj.2020104500] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 09/15/2020] [Accepted: 09/18/2020] [Indexed: 01/05/2023] Open
Abstract
The evolutionarily conserved POT1 protein binds single-stranded G-rich telomeric DNA and has been implicated in contributing to telomeric DNA maintenance and the suppression of DNA damage checkpoint signaling. Here, we explore human POT1 function through genetics and proteomics, discovering that a complete absence of POT1 leads to severe telomere maintenance defects that had not been anticipated from previous depletion studies in human cells. Conditional deletion of POT1 in HEK293E cells gives rise to rapid telomere elongation and length heterogeneity, branched telomeric DNA structures, telomeric R-loops, and telomere fragility. We determine the telomeric proteome upon POT1-loss, implementing an improved telomeric chromatin isolation protocol. We identify a large set of proteins involved in nucleic acid metabolism that engage with telomeres upon POT1-loss. Inactivation of the homology-directed repair machinery suppresses POT1-loss-mediated telomeric DNA defects. Our results unravel as major function of human POT1 the suppression of telomere instability induced by homology-directed repair.
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Affiliation(s)
- Galina Glousker
- School of Life SciencesSwiss Institute for Experimental Cancer Research (ISREC)Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Anna‐Sophia Briod
- School of Life SciencesSwiss Institute for Experimental Cancer Research (ISREC)Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | | | - Joachim Lingner
- School of Life SciencesSwiss Institute for Experimental Cancer Research (ISREC)Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
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18
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Wu Y, Poulos RC, Reddel RR. Role of POT1 in Human Cancer. Cancers (Basel) 2020; 12:cancers12102739. [PMID: 32987645 PMCID: PMC7598640 DOI: 10.3390/cancers12102739] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 09/20/2020] [Accepted: 09/22/2020] [Indexed: 12/11/2022] Open
Abstract
Simple Summary The segmentation of eukaryotic genomes into discrete linear chromosomes requires processes to solve several major biological problems, including prevention of the chromosome ends being recognized as DNA breaks and compensation for the shortening that occurs when linear DNA is replicated. A specialized set of six proteins, collectively referred to as shelterin, is involved in both of these processes, and mutations in several of these are now known to be involved in cancer. Here, we focus on Protection of Telomeres 1 (POT1), the shelterin protein that appears to be most commonly involved in cancer, and consider the clinical significance of findings about its biological functions and the prevalence of inherited and acquired mutations in the POT1 gene. Abstract Telomere abnormalities facilitate cancer development by contributing to genomic instability and cellular immortalization. The Protection of Telomeres 1 (POT1) protein is an essential subunit of the shelterin telomere binding complex. It directly binds to single-stranded telomeric DNA, protecting chromosomal ends from an inappropriate DNA damage response, and plays a role in telomere length regulation. Alterations of POT1 have been detected in a range of cancers. Here, we review the biological functions of POT1, the prevalence of POT1 germline and somatic mutations across cancer predisposition syndromes and tumor types, and the dysregulation of POT1 expression in cancers. We propose a framework for understanding how POT1 abnormalities may contribute to oncogenesis in different cell types. Finally, we summarize the clinical implications of POT1 alterations in the germline and in cancer, and possible approaches for the development of targeted cancer therapies.
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Affiliation(s)
- Yangxiu Wu
- Cancer Research Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead NSW 2145, Australia;
- ProCan® Cancer Data Science Group, Children’s Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead NSW 2145, Australia;
| | - Rebecca C. Poulos
- ProCan® Cancer Data Science Group, Children’s Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead NSW 2145, Australia;
| | - Roger R. Reddel
- Cancer Research Unit, Children’s Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead NSW 2145, Australia;
- Correspondence: ; Tel.: +61-2-8865-2901
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19
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Boyle JM, Hennick KM, Regalado SG, Vogan JM, Zhang X, Collins K, Hockemeyer D. Telomere length set point regulation in human pluripotent stem cells critically depends on the shelterin protein TPP1. Mol Biol Cell 2020; 31:2583-2596. [PMID: 32903138 PMCID: PMC7851873 DOI: 10.1091/mbc.e19-08-0447] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Telomere maintenance is essential for the long-term proliferation of human pluripotent stem cells, while their telomere length set point determines the proliferative capacity of their differentiated progeny. The shelterin protein TPP1 is required for telomere stability and elongation, but its role in establishing a telomere length set point remains elusive. Here, we characterize the contribution of the shorter isoform of TPP1 (TPP1S) and the amino acid L104 outside the TEL patch, TPP1’s telomerase interaction domain, to telomere length control. We demonstrate that cells deficient for TPP1S (TPP1S knockout [KO]), as well as the complete TPP1 KO cell lines, undergo telomere shortening. However, TPP1S KO cells are able to stabilize short telomeres, while TPP1 KO cells die. We compare these phenotypes with those of TPP1L104A/L104A mutant cells, which have short and stable telomeres similar to the TPP1S KO. In contrast to TPP1S KO cells, TPP1L104A/L104A cells respond to increased telomerase levels and maintain protected telomeres. However, TPP1L104A/L104A shows altered sensitivity to expression changes of shelterin proteins suggesting the mutation causes a defect in telomere length feedback regulation. Together this highlights TPP1L104A/L104A as the first shelterin mutant engineered at the endogenous locus of human stem cells with an altered telomere length set point.
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Affiliation(s)
- John M Boyle
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Kelsey M Hennick
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Samuel G Regalado
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Jacob M Vogan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Xiaozhu Zhang
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Kathleen Collins
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Dirk Hockemeyer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720.,Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720.,Chan Zuckerberg Biohub, San Francisco, CA 94158
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20
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Shi G, Hu Y, Zhu X, Jiang Y, Pang J, Wang C, Huang W, Zhao Y, Ma W, Liu D, Huang J, Songyang Z. A critical role of telomere chromatin compaction in ALT tumor cell growth. Nucleic Acids Res 2020; 48:6019-6031. [PMID: 32379321 PMCID: PMC7293046 DOI: 10.1093/nar/gkaa224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/17/2020] [Accepted: 04/18/2020] [Indexed: 01/15/2023] Open
Abstract
ALT tumor cells often contain abundant DNA damage foci at telomeres and rely on the alternative lengthening of telomeres (ALT) mechanism to maintain their telomeres. How the telomere chromatin is regulated and maintained in these cells remains largely unknown. In this study, we present evidence that heterochromatin protein 1 binding protein 3 (HP1BP3) can localize to telomeres and is particularly enriched on telomeres in ALT cells. HP1BP3 inhibition led to preferential growth inhibition of ALT cells, which was accompanied by telomere chromatin decompaction, increased presence of C-circles, more pronounced ALT-associated phenotypes and elongated telomeres. Furthermore, HP1BP3 appeared to participate in regulating telomere histone H3K9me3 epigenetic marks. Taken together, our data suggest that HP1BP3 functions on telomeres to maintain telomere chromatin and represents a novel target for inhibiting ALT cancer cells.
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Affiliation(s)
- Guang Shi
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.,Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Yang Hu
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Xing Zhu
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yuanling Jiang
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Junjie Pang
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Chuanle Wang
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Wenjun Huang
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yong Zhao
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Wenbin Ma
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Dan Liu
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, USA 77030
| | - Junjiu Huang
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.,Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Zhou Songyang
- MOE Key Laboratory of Gene Function and Regulation, Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.,Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.,Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, USA 77030.,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
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21
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Tang M, Feng X, Pei G, Srivastava M, Wang C, Chen Z, Li S, Zhang H, Zhao Z, Li X, Chen J. FOXK1 Participates in DNA Damage Response by Controlling 53BP1 Function. Cell Rep 2020; 32:108018. [PMID: 32783940 PMCID: PMC7458625 DOI: 10.1016/j.celrep.2020.108018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 06/09/2020] [Accepted: 07/17/2020] [Indexed: 01/28/2023] Open
Abstract
53BP1 plays a central role in dictating DNA repair choice between non-homologous end joining (NHEJ) and homologous recombination (HR), which is important for the sensitivity to poly(ADP-ribose) polymerase inhibitors (PARPis) of BRCA1-deficient cancers. In this study, we show that FOXK1 associates with 53BP1 and regulates 53BP1-dependent functions. FOXK1-53BP1 interaction is significantly enhanced upon DNA damage during the S phase in an ATM/CHK2-dependent manner, which reduces the association of 53BP1 with its downstream factors RIF1 and PTIP. Depletion of FOXK1 impairs DNA repair and induces compromised cell survival upon DNA damage. Overexpression of FOXK1 diminishes 53BP1 foci formation, which leads to resistance to PARPis and elevation of HR in BRCA1-deficient cells and decreased telomere fusion in TRF2-depleted cells. Collectively, our findings demonstrate that FOXK1 negatively regulates 53BP1 function by inhibiting 53BP1 localization to sites of DNA damage, which alters the DSB-induced protein complexes centering on 53BP1 and thus influences DNA repair choice.
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Affiliation(s)
- Mengfan Tang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Xu Feng
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Guangsheng Pei
- Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Mrinal Srivastava
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Chao Wang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Zhen Chen
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Siting Li
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Huimin Zhang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Zhongming Zhao
- Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Xu Li
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Junjie Chen
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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22
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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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23
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Lototska L, Yue J, Li J, Giraud‐Panis M, Songyang Z, Royle NJ, Liti G, Ye J, Gilson E, Mendez‐Bermudez A. Human RAP1 specifically protects telomeres of senescent cells from DNA damage. EMBO Rep 2020; 21:e49076. [PMID: 32096305 PMCID: PMC7132343 DOI: 10.15252/embr.201949076] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 01/26/2020] [Accepted: 01/29/2020] [Indexed: 12/31/2022] Open
Abstract
Repressor/activator protein 1 (RAP1) is a highly evolutionarily conserved protein found at telomeres. Although yeast Rap1 is a key telomere capping protein preventing non-homologous end joining (NHEJ) and consequently telomere fusions, its role at mammalian telomeres in vivo is still controversial. Here, we demonstrate that RAP1 is required to protect telomeres in replicative senescent human cells. Downregulation of RAP1 in these cells, but not in young or dividing pre-senescent cells, leads to telomere uncapping and fusions. The anti-fusion effect of RAP1 was further explored in a HeLa cell line where RAP1 expression was depleted through an inducible CRISPR/Cas9 strategy. Depletion of RAP1 in these cells gives rise to telomere fusions only when telomerase is inhibited. We further show that the fusions triggered by RAP1 loss are dependent upon DNA ligase IV. We conclude that human RAP1 is specifically involved in protecting critically short telomeres. This has important implications for the functions of telomeres in senescent cells.
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Affiliation(s)
- Liudmyla Lototska
- Shanghai Ruijin HospitalShanghai Ruijin Hospital NorthShanghai Jiao Tong University School of MedicineUniversité Côte d'Azur, CNRSInsermInternational Research Laboratory in HematologyCancer and AgingState Key Laboratory of Medical GenomicsShanghaiChina
- Université Côte d'AzurCNRSINSERMIRCANMedical School of NiceNiceFrance
- Present address:
Institute of Molecular Biology gGmbH (IMB)MainzGermany
| | - Jia‐Xing Yue
- Université Côte d'AzurCNRSINSERMIRCANMedical School of NiceNiceFrance
- Present address:
State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineSun Yat‐sen University Cancer CenterGuangzhouChina
| | - Jing Li
- Université Côte d'AzurCNRSINSERMIRCANMedical School of NiceNiceFrance
- Present address:
State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineSun Yat‐sen University Cancer CenterGuangzhouChina
| | | | - Zhou Songyang
- Verna and Marrs McLean Department of Biochemistry and Molecular BiologyBaylor College of MedicineHoustonTXUSA
- School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
- Zhongshan Ophthalmic CenterSun Yat‐sen UniversityGuangzhouChina
| | - Nicola J Royle
- Department of GeneticsUniversity of LeicesterLeicesterUK
| | - Gianni Liti
- Université Côte d'AzurCNRSINSERMIRCANMedical School of NiceNiceFrance
| | - Jing Ye
- Shanghai Ruijin HospitalShanghai Ruijin Hospital NorthShanghai Jiao Tong University School of MedicineUniversité Côte d'Azur, CNRSInsermInternational Research Laboratory in HematologyCancer and AgingState Key Laboratory of Medical GenomicsShanghaiChina
| | - Eric Gilson
- Shanghai Ruijin HospitalShanghai Ruijin Hospital NorthShanghai Jiao Tong University School of MedicineUniversité Côte d'Azur, CNRSInsermInternational Research Laboratory in HematologyCancer and AgingState Key Laboratory of Medical GenomicsShanghaiChina
- Université Côte d'AzurCNRSINSERMIRCANMedical School of NiceNiceFrance
- Department of GeneticsCHUNiceFrance
| | - Aaron Mendez‐Bermudez
- Shanghai Ruijin HospitalShanghai Ruijin Hospital NorthShanghai Jiao Tong University School of MedicineUniversité Côte d'Azur, CNRSInsermInternational Research Laboratory in HematologyCancer and AgingState Key Laboratory of Medical GenomicsShanghaiChina
- Université Côte d'AzurCNRSINSERMIRCANMedical School of NiceNiceFrance
- Present address:
Lead author
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24
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Gong Y, Stock AJ, Liu Y. The enigma of excessively long telomeres in cancer: lessons learned from rare human POT1 variants. Curr Opin Genet Dev 2020; 60:48-55. [PMID: 32155570 DOI: 10.1016/j.gde.2020.02.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/17/2020] [Accepted: 02/02/2020] [Indexed: 01/10/2023]
Abstract
The discovery that rare POT1 variants are associated with extremely long telomeres and increased cancer predisposition has provided a framework to revisit the relationship between telomere length and cancer development. Telomere shortening is linked with increased risk for cancer. However, over the past decade, there is increasing evidence to show that extremely long telomeres caused by mutations in shelterin components (POT1, TPP1, and RAP1) also display an increased risk of cancer. Here, we will review current knowledge on germline mutations of POT1 identified from cancer-prone families. In particular, we will discuss some common features presented by the mutations through structure-function studies. We will further provide an overview of how POT1 mutations affect telomere length regulation and tumorigenesis.
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Affiliation(s)
- Yi Gong
- Biomedical Research Center, National Institute on Aging/National Institutes of Health, 251 Bayview Blvd, Baltimore, MD, USA.
| | - Amanda J Stock
- Biomedical Research Center, National Institute on Aging/National Institutes of Health, 251 Bayview Blvd, Baltimore, MD, USA
| | - Yie Liu
- Biomedical Research Center, National Institute on Aging/National Institutes of Health, 251 Bayview Blvd, Baltimore, MD, USA.
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25
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Robin JD, Jacome Burbano M, Peng H, Croce O, Thomas JL, Laberthonniere C, Renault V, Lototska L, Pousse M, Tessier F, Bauwens S, Leong W, Sacconi S, Schaeffer L, Magdinier F, Ye J, Gilson E. Mitochondrial function in skeletal myofibers is controlled by a TRF2-SIRT3 axis over lifetime. Aging Cell 2020; 19:e13097. [PMID: 31991048 PMCID: PMC7059141 DOI: 10.1111/acel.13097] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/23/2019] [Accepted: 12/10/2019] [Indexed: 12/15/2022] Open
Abstract
Telomere shortening follows a developmentally regulated process that leads to replicative senescence of dividing cells. However, whether telomere changes are involved in postmitotic cell function and aging remains elusive. In this study, we discovered that the level of the TRF2 protein, a key telomere-capping protein, declines in human skeletal muscle over lifetime. In cultured human myotubes, TRF2 downregulation did not trigger telomere dysfunction, but suppressed expression of the mitochondrial Sirtuin 3 gene (SIRT3) leading to mitochondrial respiration dysfunction and increased levels of reactive oxygen species. Importantly, restoring the Sirt3 level in TRF2-compromised myotubes fully rescued mitochondrial functions. Finally, targeted ablation of the Terf2 gene in mouse skeletal muscle leads to mitochondrial dysfunction and sirt3 downregulation similarly to those of TRF2-compromised human myotubes. Altogether, these results reveal a TRF2-SIRT3 axis controlling muscle mitochondrial function. We propose that this axis connects developmentally regulated telomere changes to muscle redox metabolism.
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Affiliation(s)
- Jérôme D. Robin
- Université Côte d'Azur CNRS Inserm Institut for Research on Cancer and Aging, Nice (IRCAN) Medical School of Nice Nice France
- Marseille Medical Genetics (MMG) U1251 Aix Marseille University Marseille France
| | - Maria‐Sol Jacome Burbano
- Université Côte d'Azur CNRS Inserm Institut for Research on Cancer and Aging, Nice (IRCAN) Medical School of Nice Nice France
| | - Han Peng
- International Research Laboratory in “Hematology, Cancer and Aging” 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 Shanghai China
| | - Olivier Croce
- Université Côte d'Azur CNRS Inserm Institut for Research on Cancer and Aging, Nice (IRCAN) Medical School of Nice Nice France
| | - Jean Luc Thomas
- Neuromuscular Differentiation Group Institut NeuroMyoGene (INMG) UMR5310 Inserm U1217 Ecole Normale Supérieure de Lyon Lyon France
| | | | - Valerie Renault
- Université Côte d'Azur CNRS Inserm Institut for Research on Cancer and Aging, Nice (IRCAN) Medical School of Nice Nice France
| | - Liudmyla Lototska
- Université Côte d'Azur CNRS Inserm Institut for Research on Cancer and Aging, Nice (IRCAN) Medical School of Nice Nice France
| | - Mélanie Pousse
- Université Côte d'Azur CNRS Inserm Institut for Research on Cancer and Aging, Nice (IRCAN) Medical School of Nice Nice France
| | - Florent Tessier
- Université Côte d'Azur CNRS Inserm Institut for Research on Cancer and Aging, Nice (IRCAN) Medical School of Nice Nice France
| | - Serge Bauwens
- Université Côte d'Azur CNRS Inserm Institut for Research on Cancer and Aging, Nice (IRCAN) Medical School of Nice Nice France
| | - Waiian Leong
- International Research Laboratory in “Hematology, Cancer and Aging” 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 Shanghai China
| | - Sabrina Sacconi
- Université Côte d'Azur CNRS Inserm Institut for Research on Cancer and Aging, Nice (IRCAN) Medical School of Nice Nice France
- Peripheral Nervous System, Muscle and ALS Neuromuscular & ALS Center of Reference FHU Oncoage Pasteur 2 Nice University Hospital Nice France
| | - Laurent Schaeffer
- Neuromuscular Differentiation Group Institut NeuroMyoGene (INMG) UMR5310 Inserm U1217 Ecole Normale Supérieure de Lyon Lyon France
| | - Frédérique Magdinier
- Marseille Medical Genetics (MMG) U1251 Aix Marseille University Marseille France
| | - Jing Ye
- International Research Laboratory in “Hematology, Cancer and Aging” 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 Shanghai China
| | - Eric Gilson
- Université Côte d'Azur CNRS Inserm Institut for Research on Cancer and Aging, Nice (IRCAN) Medical School of Nice Nice France
- International Research Laboratory in “Hematology, Cancer and Aging” 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 Shanghai China
- Department of Medical Genetics Archet 2 Hospital FHU Oncoage CHU of Nice Nice France
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26
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Srinivas N, Rachakonda S, Kumar R. Telomeres and Telomere Length: A General Overview. Cancers (Basel) 2020; 12:E558. [PMID: 32121056 PMCID: PMC7139734 DOI: 10.3390/cancers12030558] [Citation(s) in RCA: 126] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/24/2020] [Accepted: 02/26/2020] [Indexed: 02/06/2023] Open
Abstract
Telomeres are highly conserved tandem nucleotide repeats that include proximal double-stranded and distal single-stranded regions that in complex with shelterin proteins afford protection at chromosomal ends to maintain genomic integrity. Due to the inherent limitations of DNA replication and telomerase suppression in most somatic cells, telomeres undergo age-dependent incremental attrition. Short or dysfunctional telomeres are recognized as DNA double-stranded breaks, triggering cells to undergo replicative senescence. Telomere shortening, therefore, acts as a counting mechanism that drives replicative senescence by limiting the mitotic potential of cells. Telomere length, a complex hereditary trait, is associated with aging and age-related diseases. Epidemiological data, in general, support an association with varying magnitudes between constitutive telomere length and several disorders, including cancers. Telomere attrition is also influenced by oxidative damage and replicative stress caused by genetic, epigenetic, and environmental factors. Several single nucleotide polymorphisms at different loci, identified through genome-wide association studies, influence inter-individual variation in telomere length. In addition to genetic factors, environmental factors also influence telomere length during growth and development. Telomeres hold potential as biomarkers that reflect the genetic predisposition together with the impact of environmental conditions and as targets for anti-cancer therapies.
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Affiliation(s)
| | | | - Rajiv Kumar
- Division of Functional Genome Analysis, German Cancer Research Center, Im Neunheimer Feld 580, 69120 Heidelberg, Germany; (N.S.); (S.R.)
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27
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Porreca RM, Herrera-Moyano E, Skourti E, Law PP, Gonzalez Franco R, Montoya A, Faull P, Kramer H, Vannier JB. TRF1 averts chromatin remodelling, recombination and replication dependent-break induced replication at mouse telomeres. eLife 2020; 9:49817. [PMID: 31934863 PMCID: PMC6986873 DOI: 10.7554/elife.49817] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 01/11/2020] [Indexed: 12/29/2022] Open
Abstract
Telomeres are a significant challenge to DNA replication and are prone to replication stress and telomere fragility. The shelterin component TRF1 facilitates telomere replication but the molecular mechanism remains uncertain. By interrogating the proteomic composition of telomeres, we show that mouse telomeres lacking TRF1 undergo protein composition reorganisation associated with the recruitment of DNA damage response and chromatin remodellers. Surprisingly, mTRF1 suppresses the accumulation of promyelocytic leukemia (PML) protein, BRCA1 and the SMC5/6 complex at telomeres, which is associated with increased Homologous Recombination (HR) and TERRA transcription. We uncovered a previously unappreciated role for mTRF1 in the suppression of telomere recombination, dependent on SMC5 and also POLD3 dependent Break Induced Replication at telomeres. We propose that TRF1 facilitates S-phase telomeric DNA synthesis to prevent illegitimate mitotic DNA recombination and chromatin rearrangement.
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Affiliation(s)
- Rosa Maria Porreca
- Telomere Replication and Stability group, Medical Research Council - London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Emilia Herrera-Moyano
- Telomere Replication and Stability group, Medical Research Council - London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Eleni Skourti
- Telomere Replication and Stability group, Medical Research Council - London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Pui Pik Law
- Telomere Replication and Stability group, Medical Research Council - London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Roser Gonzalez Franco
- Telomere Replication and Stability group, Medical Research Council - London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Alex Montoya
- Biological Mass Spectrometry and Proteomics, Medical Research Council - London Institute of Medical Sciences, London, United Kingdom
| | - Peter Faull
- Biological Mass Spectrometry and Proteomics, Medical Research Council - London Institute of Medical Sciences, London, United Kingdom.,The Francis Crick Institute, Proteomics Mass Spectrometry Science and Technology Platform, London, United Kingdom
| | - Holger Kramer
- Biological Mass Spectrometry and Proteomics, Medical Research Council - London Institute of Medical Sciences, London, United Kingdom
| | - Jean-Baptiste Vannier
- Telomere Replication and Stability group, Medical Research Council - London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
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28
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Zheng JT, Zhang N, Yu YH, Gong PT, Li XH, Wu N, Wang C, Wang XC, Li X, Li JH, Zhang XC. Identification of a TRBD zinc finger-interacting protein in Giardia duodenalis and its regulation of telomerase. Parasit Vectors 2019; 12:568. [PMID: 31783771 PMCID: PMC6884763 DOI: 10.1186/s13071-019-3821-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 11/21/2019] [Indexed: 11/10/2022] Open
Abstract
Background Giardia duodenalis causes giardiasis, with diarrhea as the primary symptom. The trophozoite proliferation of this zoonotic parasite is mainly affected by telomerase, although the mechanism of telomerase regulation has not been thoroughly analyzed. Methods This study was performed to identify the telomerase RNA-binding domain (TRBD)-interacting protein in G. duodenalis and its regulation of telomerase. Interaction between TRBD and interacting proteins was verified via pulldown assays and co-immunoprecipitation (co-IP) techniques, and the subcellular localization of the protein interactions was determined in vivo via split SNAP-tag labeling. The hammerhead ribozyme was designed to deplete the mRNA of TRBD-interacting proteins. Results Using TRBD as bait, we identified zinc-finger domain (ZFD)-containing proteins and verified it via pulldown and co-IP experiments. Protein-protein interaction occurred in the nuclei of 293T cells and both nuclei of G. duodenalis. The hammerhead ribozyme depleted ZFD mRNA levels, which reduced the reproduction rate of G. duodenalis, telomerase activity and telomere length. Conclusions Our findings suggest that ZFD may regulate telomere function in G. duodenalis nuclei.
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Affiliation(s)
- Jing-Tong Zheng
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Institute of Zoonosis, Jilin University, Changchun, 130062, China.,Department of Pathogenobiology, College of Basic Medicine, Jilin University, Changchun, 130021, Jilin, China
| | - Nan Zhang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Institute of Zoonosis, Jilin University, Changchun, 130062, China.,State and Local Joint Engineering Laboratory for Animal Models of Human Diseases, Academy of Translational Medicine, First Hospital, Jilin University, Changchun, 130021, China
| | - Yan-Hui Yu
- Clinical Laboratory of Second Hospital, Jilin University, Changchun, 130021, China
| | - Peng-Tao Gong
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Institute of Zoonosis, Jilin University, Changchun, 130062, China
| | - Xian-He Li
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Institute of Zoonosis, Jilin University, Changchun, 130062, China
| | - Na Wu
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Institute of Zoonosis, Jilin University, Changchun, 130062, China
| | - Can Wang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Institute of Zoonosis, Jilin University, Changchun, 130062, China
| | - Xiao-Cen Wang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Institute of Zoonosis, Jilin University, Changchun, 130062, China
| | - Xin Li
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Institute of Zoonosis, Jilin University, Changchun, 130062, China
| | - Jian-Hua Li
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Institute of Zoonosis, Jilin University, Changchun, 130062, China.
| | - Xi-Chen Zhang
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Institute of Zoonosis, Jilin University, Changchun, 130062, China.
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29
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Pike AM, Strong MA, Ouyang JPT, Greider CW. TIN2 Functions with TPP1/POT1 To Stimulate Telomerase Processivity. Mol Cell Biol 2019; 39:e00593-18. [PMID: 31383750 PMCID: PMC6791651 DOI: 10.1128/mcb.00593-18] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 02/10/2019] [Accepted: 07/30/2019] [Indexed: 12/20/2022] Open
Abstract
TIN2 is an important regulator of telomere length, and mutations in TINF2, the gene encoding TIN2, cause short-telomere syndromes. While the genetics underscore the importance of TIN2, the mechanism through which TIN2 regulates telomere length remains unclear. Here, we tested the effects of human TIN2 on telomerase activity. We identified a new isoform in human cells, TIN2M, that is expressed at levels similar to those of previously studied TIN2 isoforms. All three TIN2 isoforms localized to and maintained telomere integrity in vivo, and localization was not disrupted by telomere syndrome mutations. Using direct telomerase activity assays, we discovered that TIN2 stimulated telomerase processivity in vitro All of the TIN2 isoforms stimulated telomerase to similar extents. Mutations in the TPP1 TEL patch abrogated this stimulation, suggesting that TIN2 functions with TPP1/POT1 to stimulate telomerase processivity. We conclude from our data and previously published work that TIN2/TPP1/POT1 is a functional shelterin subcomplex.
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Affiliation(s)
- Alexandra M Pike
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Margaret A Strong
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - John Paul T Ouyang
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Graduate Program in Biochemistry Cell and Molecular Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Carol W Greider
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Graduate Program in Biochemistry Cell and Molecular Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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30
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Billard P, Poncet DA. Replication Stress at Telomeric and Mitochondrial DNA: Common Origins and Consequences on Ageing. Int J Mol Sci 2019; 20:ijms20194959. [PMID: 31597307 PMCID: PMC6801922 DOI: 10.3390/ijms20194959] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/04/2019] [Accepted: 10/05/2019] [Indexed: 12/12/2022] Open
Abstract
Senescence is defined as a stress-induced durable cell cycle arrest. We herein revisit the origin of two of these stresses, namely mitochondrial metabolic compromise, associated with reactive oxygen species (ROS) production, and replicative senescence, activated by extreme telomere shortening. We discuss how replication stress-induced DNA damage of telomeric DNA (telDNA) and mitochondrial DNA (mtDNA) can be considered a common origin of senescence in vitro, with consequences on ageing in vivo. Unexpectedly, mtDNA and telDNA share common features indicative of a high degree of replicative stress, such as G-quadruplexes, D-loops, RNA:DNA heteroduplexes, epigenetic marks, or supercoiling. To avoid these stresses, both compartments use similar enzymatic strategies involving, for instance, endonucleases, topoisomerases, helicases, or primases. Surprisingly, many of these replication helpers are active at both telDNA and mtDNA (e.g., RNAse H1, FEN1, DNA2, RecQ helicases, Top2α, Top2β, TOP3A, DNMT1/3a/3b, SIRT1). In addition, specialized telomeric proteins, such as TERT (telomerase reverse transcriptase) and TERC (telomerase RNA component), or TIN2 (shelterin complex), shuttle from telomeres to mitochondria, and, by doing so, modulate mitochondrial metabolism and the production of ROS, in a feedback manner. Hence, mitochondria and telomeres use common weapons and cooperate to resist/prevent replication stresses, otherwise producing common consequences, namely senescence and ageing.
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Affiliation(s)
- Pauline Billard
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de recherche en cancérologie de Lyon, 69008 Lyon, France.
- Institut de Biopathologie moléculaire, Centre de Bio-Pathologie Est, Groupement hospitalier Est, Hospices Civils de Lyon, 69500 Bron, France.
| | - Delphine A Poncet
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de recherche en cancérologie de Lyon, 69008 Lyon, France.
- Institut de Biopathologie moléculaire, Centre de Bio-Pathologie Est, Groupement hospitalier Est, Hospices Civils de Lyon, 69500 Bron, France.
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31
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Udroiu I, Marinaccio J, Sgura A. Epigallocatechin-3-gallate induces telomere shortening and clastogenic damage in glioblastoma cells. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:683-692. [PMID: 31026358 DOI: 10.1002/em.22295] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 03/11/2019] [Accepted: 04/24/2019] [Indexed: 06/09/2023]
Abstract
Epigallocatechingallate (EGCG) is the major polyphenol in green tea, to which many anticancer features, such as antioxidative, antigenotoxic, and antiangiogenetic properties, are attributed. Moreover, it is also well known as a telomerase inhibitor. In this work, we have chronically treated U251 glioblastoma cells with low, physiologically realistic concentrations, of EGCG, in order to investigate its effects both on telomeres and on genome integrity. Inhibition of telomerase activity caused telomere shortening, ultimately leading to senescence and telomere dysfunction at 98 days. Remarkably, we have observed DNA damage through an increase of phosphorylation of γ-H2AX histone and micronuclei also with doses and at timepoints when telomere shortening was not present. Therefore, we concluded that this DNA damage was not correlated with telomere shortening and that EGCG treatment induced not only an increase of telomere-shortening-induced senescence but also telomere-independent genotoxicity. This study questions the common knowledge about EGCG properties, but confirms the few works that indicated the clastogenic properties of this molecule, probably due to DNA reductive damage and topoisomerase II poisoning. Environ. Mol. Mutagen., 60:683-692, 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Ion Udroiu
- Department of Science, University "Roma Tre", Rome, Italy
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32
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Deng T, Huang Y, Weng K, Lin S, Li Y, Shi G, Chen Y, Huang J, Liu D, Ma W, Songyang Z. TOE1 acts as a 3' exonuclease for telomerase RNA and regulates telomere maintenance. Nucleic Acids Res 2019; 47:391-405. [PMID: 30371886 PMCID: PMC6326811 DOI: 10.1093/nar/gky1019] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 10/14/2018] [Indexed: 12/14/2022] Open
Abstract
In human cells, telomeres are elongated by the telomerase complex that contains the reverse transcriptase hTERT and RNA template TERC/hTR. Poly(A)-specific ribonuclease (PARN) is known to trim hTR precursors by removing poly(A) tails. However, the precise mechanism of hTR 3′ maturation remains largely unknown. Target of Egr1 (TOE1) is an Asp-Glu-Asp-Asp (DEDD) domain containing deadenylase that is mutated in the human disease Pontocerebella Hypoplasia Type 7 (PCH7) and implicated in snRNA and hTR processing. We have previously found TOE1 to localize specifically in Cajal bodies, where telomerase RNP complex assembly takes place. In this study, we showed that TOE1 could interact with hTR and the telomerase complex. TOE1-deficient cells accumulated hTR precursors, including oligoadenylated and 3′-extended forms, which was accompanied by impaired telomerase activity and shortened telomeres. Telomerase activity in TOE1-deficient cells could be rescued by wild-type TOE1 but not the catalytically inactive mutant. Our results suggest that hTR 3′ end processing likely involves multiple exonucleases that work in parallel and/or sequentially, where TOE1 may function non-redundantly as a 3′-to-5′ exonuclease in conjunction with PARN. Our study highlights a mechanistic link between TOE1 mutation, improper hTR processing and telomere dysfunction in diseases such as PCH7.
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Affiliation(s)
- Tingting Deng
- State Key Laboratory of Oncology in South China, Cancer Center, Collaborative Innovation Center for Cancer Medicine, MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.,Guangzhou Regenerative Medicine and Health-Guangdong Laboratory (GRMH-GDL), Institute of Healthy Aging Research, Sun Yat-sen University, Guangzhou 510006, China
| | - Yan Huang
- State Key Laboratory of Oncology in South China, Cancer Center, Collaborative Innovation Center for Cancer Medicine, MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.,Guangzhou Regenerative Medicine and Health-Guangdong Laboratory (GRMH-GDL), Institute of Healthy Aging Research, Sun Yat-sen University, Guangzhou 510006, China
| | - Kai Weng
- Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Centre, Guangzhou 510623, China
| | - Song Lin
- State Key Laboratory of Oncology in South China, Cancer Center, Collaborative Innovation Center for Cancer Medicine, MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.,Guangzhou Regenerative Medicine and Health-Guangdong Laboratory (GRMH-GDL), Institute of Healthy Aging Research, Sun Yat-sen University, Guangzhou 510006, China
| | - Yujing Li
- State Key Laboratory of Oncology in South China, Cancer Center, Collaborative Innovation Center for Cancer Medicine, MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.,Guangzhou Regenerative Medicine and Health-Guangdong Laboratory (GRMH-GDL), Institute of Healthy Aging Research, Sun Yat-sen University, Guangzhou 510006, China
| | - Guang Shi
- State Key Laboratory of Oncology in South China, Cancer Center, Collaborative Innovation Center for Cancer Medicine, MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.,Guangzhou Regenerative Medicine and Health-Guangdong Laboratory (GRMH-GDL), Institute of Healthy Aging Research, Sun Yat-sen University, Guangzhou 510006, China
| | - Yali Chen
- State Key Laboratory of Oncology in South China, Cancer Center, Collaborative Innovation Center for Cancer Medicine, MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.,Guangzhou Regenerative Medicine and Health-Guangdong Laboratory (GRMH-GDL), Institute of Healthy Aging Research, Sun Yat-sen University, Guangzhou 510006, China
| | - Junjiu Huang
- State Key Laboratory of Oncology in South China, Cancer Center, Collaborative Innovation Center for Cancer Medicine, MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.,Guangzhou Regenerative Medicine and Health-Guangdong Laboratory (GRMH-GDL), Institute of Healthy Aging Research, Sun Yat-sen University, Guangzhou 510006, China
| | - Dan Liu
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Wenbin Ma
- State Key Laboratory of Oncology in South China, Cancer Center, Collaborative Innovation Center for Cancer Medicine, MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.,Guangzhou Regenerative Medicine and Health-Guangdong Laboratory (GRMH-GDL), Institute of Healthy Aging Research, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhou Songyang
- State Key Laboratory of Oncology in South China, Cancer Center, Collaborative Innovation Center for Cancer Medicine, MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.,Guangzhou Regenerative Medicine and Health-Guangdong Laboratory (GRMH-GDL), Institute of Healthy Aging Research, Sun Yat-sen University, Guangzhou 510006, China.,Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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33
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The role of telomere-binding modulators in pluripotent stem cells. Protein Cell 2019; 11:60-70. [PMID: 31350723 PMCID: PMC6949317 DOI: 10.1007/s13238-019-0651-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 05/07/2019] [Indexed: 01/24/2023] Open
Abstract
Pluripotent stem cells (PSCs) such as embryonic stem cells (ESCs), ESCs derived by somatic cell nuclear transfer (ntESCs), and induced pluripotent stem cells (iPSCs) have unlimited capacity for self-renewal and pluripotency and can give rise to all types of somatic cells. In order to maintain their self-renewal and pluripotency, PSCs need to preserve their telomere length and homeostasis. In recent years, increasing studies have shown that telomere reprogramming is essential for stem cell pluripotency maintenance and its induced pluripotency process. Telomere-associated proteins are not only required for telomere maintenance in both stem cells, their extra-telomeric functions have also been found to be critical as well. Here, we will discuss how telomeres and telomere-associated factors participate and regulate the maintenance of stem cell pluripotency.
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34
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Liu T, Gonzalez De Los Santos F, Zhao Y, Wu Z, Rinke AE, Kim KK, Phan SH. Telomerase reverse transcriptase ameliorates lung fibrosis by protecting alveolar epithelial cells against senescence. J Biol Chem 2019; 294:8861-8871. [PMID: 31000627 DOI: 10.1074/jbc.ra118.006615] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 04/11/2019] [Indexed: 11/06/2022] Open
Abstract
Mutations in the genes encoding telomerase reverse transcriptase (TERT) and telomerase's RNA components as well as shortened telomeres are risk factors for idiopathic pulmonary fibrosis, where repetitive injury to the alveolar epithelium is considered a key factor in pathogenesis. Given the importance of TERT in stem cells, we hypothesized that TERT plays an important role in epithelial repair and that its deficiency results in exacerbation of fibrosis by impairing this repair/regenerative process. To evaluate the role of TERT in epithelial cells, we generated type II alveolar epithelial cell (AECII)-specific TERT conditional knockout (SPC-Tert cKO) mice by crossing floxed Tert mice with inducible SPC-driven Cre mice. SPC-Tert cKO mice did not develop pulmonary fibrosis spontaneously up to 9 months of TERT deficiency. However, upon bleomycin treatment, they exhibited enhanced lung injury, inflammation, and fibrosis compared with control mice, accompanied by increased pro-fibrogenic cytokine expression but without a significant effect on AECII telomere length. Moreover, selective TERT deficiency in AECII diminished their proliferation and induced cellular senescence. These findings suggest that AECII-specific TERT deficiency enhances pulmonary fibrosis by heightening susceptibility to bleomycin-induced epithelial injury and diminishing epithelial regenerative capacity because of increased cellular senescence. We confirmed evidence for increased AECII senescence in idiopathic pulmonary fibrosis lungs, suggesting potential clinical relevance of the findings from our animal model. Our results suggest that TERT has a protective role in AECII, unlike its pro-fibrotic activity, observed previously in fibroblasts, indicating that TERT's role in pulmonary fibrosis is cell type-specific.
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Affiliation(s)
| | | | | | - Zhe Wu
- From the Departments of Pathology and
| | | | - Kevin K Kim
- Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
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35
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Zhang X, Liu Z, Liu X, Wang S, Zhang Y, He X, Sun S, Ma S, Shyh-Chang N, Liu F, Wang Q, Wang X, Liu L, Zhang W, Song M, Liu GH, Qu J. Telomere-dependent and telomere-independent roles of RAP1 in regulating human stem cell homeostasis. Protein Cell 2019; 10:649-667. [PMID: 30796637 PMCID: PMC6711945 DOI: 10.1007/s13238-019-0610-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 01/03/2019] [Indexed: 01/19/2023] Open
Abstract
RAP1 is a well-known telomere-binding protein, but its functions in human stem cells have remained unclear. Here we generated RAP1-deficient human embryonic stem cells (hESCs) by using CRISPR/Cas9 technique and obtained RAP1-deficient human mesenchymal stem cells (hMSCs) and neural stem cells (hNSCs) via directed differentiation. In both hMSCs and hNSCs, RAP1 not only negatively regulated telomere length but also acted as a transcriptional regulator of RELN by tuning the methylation status of its gene promoter. RAP1 deficiency enhanced self-renewal and delayed senescence in hMSCs, but not in hNSCs, suggesting complicated lineage-specific effects of RAP1 in adult stem cells. Altogether, these results demonstrate for the first time that RAP1 plays both telomeric and nontelomeric roles in regulating human stem cell homeostasis.
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Affiliation(s)
- Xing Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital Capital Medical University, Beijing, 100053, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zunpeng Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaoqian Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Si Wang
- Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital Capital Medical University, Beijing, 100053, China.,National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,Institute for Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yiyuan Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaojuan He
- Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital Capital Medical University, Beijing, 100053, China
| | - Shuhui Sun
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shuai Ma
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ng Shyh-Chang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,Institute for Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
| | - Feng Liu
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,Institute for Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
| | - Qiang Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,Institute for Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiaoqun Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,Institute for Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
| | - Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China
| | - Weiqi Zhang
- Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital Capital Medical University, Beijing, 100053, China. .,National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Institute for Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Moshi Song
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Institute for Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Guang-Hui Liu
- Advanced Innovation Center for Human Brain Protection, National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital Capital Medical University, Beijing, 100053, China. .,National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Institute for Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China. .,Key Laboratory of Regenerative Medicine of Ministry of Education, Institute of Aging and Regenerative Medicine, Jinan University, Guangzhou, 510632, China. .,Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China.
| | - Jing Qu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Institute for Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
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36
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Shishkin SS, Kovalev LI, Pashintseva NV, Kovaleva MA, Lisitskaya K. Heterogeneous Nuclear Ribonucleoproteins Involved in the Functioning of Telomeres in Malignant Cells. Int J Mol Sci 2019; 20:ijms20030745. [PMID: 30744200 PMCID: PMC6387250 DOI: 10.3390/ijms20030745] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/31/2019] [Accepted: 02/04/2019] [Indexed: 12/12/2022] Open
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) are structurally and functionally distinct proteins containing specific domains and motifs that enable the proteins to bind certain nucleotide sequences, particularly those found in human telomeres. In human malignant cells (HMCs), hnRNP-A1-the most studied hnRNP-is an abundant multifunctional protein that interacts with telomeric DNA and affects telomerase function. In addition, it is believed that other hnRNPs in HMCs may also be involved in the maintenance of telomere length. Accordingly, these proteins are considered possible participants in the processes associated with HMC immortalization. In our review, we discuss the results of studies on different hnRNPs that may be crucial to solving molecular oncological problems and relevant to further investigations of these proteins in HMCs.
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Affiliation(s)
- Sergey S Shishkin
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Leonid I Kovalev
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Natalya V Pashintseva
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Marina A Kovaleva
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
| | - Ksenia Lisitskaya
- Laboratory of Biomedical Research, Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospekt, 33, bld. 2, 119071 Moscow, Russia.
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37
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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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38
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Nelson ND, Dodson LM, Escudero L, Sukumar AT, Williams CL, Mihalek I, Baldan A, Baird DM, Bertuch AA. The C-Terminal Extension Unique to the Long Isoform of the Shelterin Component TIN2 Enhances Its Interaction with TRF2 in a Phosphorylation- and Dyskeratosis Congenita Cluster-Dependent Fashion. Mol Cell Biol 2018; 38:e00025-18. [PMID: 29581185 PMCID: PMC5974431 DOI: 10.1128/mcb.00025-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 03/18/2018] [Indexed: 01/08/2023] Open
Abstract
TIN2 is central to the shelterin complex, linking the telomeric proteins TRF1 and TRF2 with TPP1/POT1. Mutations in TINF2, which encodes TIN2, that are found in dyskeratosis congenita (DC) result in very short telomeres and cluster in a region shared by the two TIN2 isoforms, TIN2S (short) and TIN2L (long). Here we show that TIN2L, but not TIN2S, is phosphorylated. TRF2 interacts more with TIN2L than TIN2S, and both the DC cluster and phosphorylation promote this enhanced interaction. The binding of TIN2L, but not TIN2S, is affected by TRF2-F120, which is also required for TRF2's interaction with end processing factors such as Apollo. Conversely, TRF1 interacts more with TIN2S than with TIN2L. A DC-associated mutation further reduces TIN2L-TRF1, but not TIN2S-TRF1, interaction. Cells overexpressing TIN2L or phosphomimetic TIN2L are permissive to telomere elongation, whereas cells overexpressing TIN2S or phosphodead TIN2L are not. Telomere lengths are unchanged in cell lines in which TIN2L expression has been eliminated by clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9-mediated mutation. These results indicate that TIN2 isoforms are biochemically and functionally distinguishable and that shelterin composition could be fundamentally altered in patients with TINF2 mutations.
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Affiliation(s)
- Nya D Nelson
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- Division of Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Lois M Dodson
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- Division of Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Laura Escudero
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Ann T Sukumar
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- Division of Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Christopher L Williams
- Division of Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Ivana Mihalek
- Bioinformatics Institute, Agency for Science Technology and Research, Singapore, Singapore
| | - Alessandro Baldan
- Division of Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Duncan M Baird
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Alison A Bertuch
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- Division of Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
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