1
|
Wang QL, Gong C, Meng XY, Fu M, Yang H, Zhou F, Wu Q, Zhou Y. TPP1 is associated with risk of advanced precursors and cervical cancer survival. PLoS One 2024; 19:e0298118. [PMID: 38722833 PMCID: PMC11081309 DOI: 10.1371/journal.pone.0298118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 01/16/2024] [Indexed: 05/13/2024] Open
Abstract
It is unclear how telomere-binding protein TPP1 interacts with human telomerase reverse transcriptase (hTERT) and influences cervical cancer development and progression. This study included all eligible 156 cervical cancers diagnosed during 2003-2008 and followed up through 2014, 102 cervical intraepithelial neoplasia (CIN) patients, and 16 participants with normal cervix identified at the same period. Correlation of expression of TPP1 and hTERT in these lesions was assessed using Kappa statistics. TPP1 was knocked down by siRNA in three cervical cancer cell lines. We assessed mRNA expression using quantitative real-time polymerase chain reaction and protein expression using tissue microarray-based immunohistochemical staining. We further analyzed the impact of TPP1 expression on the overall survival of cervical cancer patients by calculating the hazard ratio (HR) with 95% confidence intervals (CIs) using the multivariable-adjusted Cox regression model. Compared to the normal cervix, high TPP1expression was significantly associated with CIN 3 and cervical cancers (P<0.001 for both). Expressions of TPP1 and hTERT were highly correlated in CIN 3 (Kappa statistics = 0.50, P = 0.005), squamous cell carcinoma (Kappa statistics = 0.22, P = 0.011), and adenocarcinoma/adenosquamous carcinoma (Kappa statistics = 0.77, P = 0.001). Mechanistically, knockdown of TPP1 inhibited the expression of hTERT in both mRNA and protein levels. High expression of TPP1 (HR = 2.61, 95% CI 1.23-5.51) and co-high expression of TPP1 and hTERT (HR = 2.38, 95% CI 1.28-4.43) were independently associated with worse survival in cervical cancer patients. TPP1 and hTERT expression was correlated and high expression of TPP1 was associated with high risk of CIN 3 and cervical cancer and could predict a worse survival in cervical cancer.
Collapse
Affiliation(s)
- Qiao-Li Wang
- Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Wuhan, Hubei, China
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, United States of America
| | - Caifeng Gong
- Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Wuhan, Hubei, China
- Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiang-Yu Meng
- Health Science Center, Hubei Minzu University, Enshi, China
| | - Min Fu
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hui Yang
- Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Wuhan, Hubei, China
| | - Fuxiang Zhou
- Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Wuhan, Hubei, China
| | - Qiuji Wu
- Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Wuhan, Hubei, China
| | - Yunfeng Zhou
- Department of Radiation and Medical Oncology, Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Wuhan, Hubei, China
| |
Collapse
|
2
|
Fernández-Varas B, Manguan-García C, Rodriguez-Centeno J, Mendoza-Lupiáñez L, Calatayud J, Perona R, Martín-Martínez M, Gutierrez-Rodriguez M, Benítez-Buelga C, Sastre L. Clinical mutations in the TERT and TERC genes coding for telomerase components induced oxidative stress, DNA damage at telomeres and cell apoptosis besides decreased telomerase activity. Hum Mol Genet 2024; 33:818-834. [PMID: 38641551 PMCID: PMC11031360 DOI: 10.1093/hmg/ddae015] [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: 10/02/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 04/21/2024] Open
Abstract
Telomeres are nucleoprotein structures at the end of chromosomes that maintain their integrity. Mutations in genes coding for proteins involved in telomere protection and elongation produce diseases such as dyskeratosis congenita or idiopathic pulmonary fibrosis known as telomeropathies. These diseases are characterized by premature telomere shortening, increased DNA damage and oxidative stress. Genetic diagnosis of telomeropathy patients has identified mutations in the genes TERT and TERC coding for telomerase components but the functional consequences of many of these mutations still have to be experimentally demonstrated. The activity of twelve TERT and five TERC mutants, five of them identified in Spanish patients, has been analyzed. TERT and TERC mutants were expressed in VA-13 human cells that express low telomerase levels and the activity induced was analyzed. The production of reactive oxygen species, DNA oxidation and TRF2 association at telomeres, DNA damage response and cell apoptosis were determined. Most mutations presented decreased telomerase activity, as compared to wild-type TERT and TERC. In addition, the expression of several TERT and TERC mutants induced oxidative stress, DNA oxidation, DNA damage, decreased recruitment of the shelterin component TRF2 to telomeres and increased apoptosis. These observations might indicate that the increase in DNA damage and oxidative stress observed in cells from telomeropathy patients is dependent on their TERT or TERC mutations. Therefore, analysis of the effect of TERT and TERC mutations of unknown function on DNA damage and oxidative stress could be of great utility to determine the possible pathogenicity of these variants.
Collapse
Affiliation(s)
- Beatriz Fernández-Varas
- Instituto de Investigaciones Biomedicas Sols/Morreale CSIC/UAM, Arturo Duperier 4, 28029 Madrid, Spain
| | - Cristina Manguan-García
- Instituto de Investigaciones Biomedicas Sols/Morreale CSIC/UAM, Arturo Duperier 4, 28029 Madrid, Spain
- Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III. C. Melchor Fernandez de Almagro, 3, 28029 Madrid, Spain
| | - Javier Rodriguez-Centeno
- Instituto de Investigaciones Biomedicas Sols/Morreale CSIC/UAM, Arturo Duperier 4, 28029 Madrid, Spain
| | - Lucía Mendoza-Lupiáñez
- Instituto de Investigaciones Biomedicas Sols/Morreale CSIC/UAM, Arturo Duperier 4, 28029 Madrid, Spain
| | - Joaquin Calatayud
- Departamento de Biología y Geología, Física y Química inorgánica. ESCET, Universidad Rey Juan Carlos, C/Tulipán s/n, Móstoles, C.P. 28933 Madrid, Spain
| | - Rosario Perona
- Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III. C. Melchor Fernandez de Almagro, 3, 28029 Madrid, Spain
- Instituto de Salud Carlos III. Calle Monforte de Lemos 5, 28029 Madrid, Spain
| | | | | | - Carlos Benítez-Buelga
- Instituto de Investigaciones Biomedicas Sols/Morreale CSIC/UAM, Arturo Duperier 4, 28029 Madrid, Spain
| | - Leandro Sastre
- Instituto de Investigaciones Biomedicas Sols/Morreale CSIC/UAM, Arturo Duperier 4, 28029 Madrid, Spain
- Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III. C. Melchor Fernandez de Almagro, 3, 28029 Madrid, Spain
| |
Collapse
|
3
|
Aureli S, Cardenas VB, Raniolo S, Limongelli V. Conformational plasticity and allosteric communication networks explain Shelterin protein TPP1 binding to human telomerase. Commun Chem 2023; 6:242. [PMID: 37935941 PMCID: PMC10630336 DOI: 10.1038/s42004-023-01040-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 10/24/2023] [Indexed: 11/09/2023] Open
Abstract
The Shelterin complex protein TPP1 interacts with human telomerase (TERT) by means of the TEL-patch region, controlling telomere homeostasis. Aberrations in the TPP1-TERT heterodimer formation might lead to short telomeres and severe diseases like dyskeratosis congenita and Hoyeraal-Hreidarsson syndrome. In the present study, we provide a thorough characterization of the structural properties of the TPP1's OB-domain by combining data coming from microsecond-long molecular dynamics calculations, time-series analyses, and graph-based networks. Our results show that the TEL-patch conformational freedom is influenced by a network of long-range amino acid communications that together determine the proper TPP1-TERT binding. Furthermore, we reveal that in TPP1 pathological variants Glu169Δ, Lys170Δ and Leu95Gln, the TEL-patch plasticity is reduced, affecting the correct binding to TERT and, in turn, telomere processivity, which eventually leads to accelerated aging of affected cells. Our study provides a structural basis for the design of TPP1-targeting ligands with therapeutic potential against cancer and telomeropathies.
Collapse
Affiliation(s)
- Simone Aureli
- Faculty of Biomedical Sciences, Euler Institute, Università della Svizzera italiana (USI), via G. Buffi 13, Lugano, CH-6900, Switzerland
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneve, Rue Michel-Servet 1, Geneva, CH-1211, Switzerland
- Swiss Institute of Bioinformatics, University of Geneve, Geneva, CH-1206, Switzerland
| | - Vince Bart Cardenas
- Faculty of Biomedical Sciences, Euler Institute, Università della Svizzera italiana (USI), via G. Buffi 13, Lugano, CH-6900, Switzerland
| | - Stefano Raniolo
- Faculty of Biomedical Sciences, Euler Institute, Università della Svizzera italiana (USI), via G. Buffi 13, Lugano, CH-6900, Switzerland
| | - Vittorio Limongelli
- Faculty of Biomedical Sciences, Euler Institute, Università della Svizzera italiana (USI), via G. Buffi 13, Lugano, CH-6900, Switzerland.
| |
Collapse
|
4
|
Padmanaban S, Tesmer VM, Nandakumar J. Interaction hub critical for telomerase recruitment and primer-template handling for catalysis. Life Sci Alliance 2023; 6:e202201727. [PMID: 36963832 PMCID: PMC10055720 DOI: 10.26508/lsa.202201727] [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: 09/16/2022] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 03/26/2023] Open
Abstract
Telomerase processively adds telomeric DNA repeats to chromosome ends using catalytic protein subunit TERT and a template on its RNA subunit TR. Mammalian telomerase is recruited to telomeres by the TEL patch and NOB regions of shelterin component TPP1. Recent cryo-EM structures of human telomerase reveal that a composite TERT TEN-(IFD-TRAP) domain interacts with TPP1. Here, we generate TERT mutants to demonstrate that a three-way TEN-(IFD-TRAP)-TPP1 interaction is critical for telomerase recruitment to telomeres and processive telomere repeat addition. Single mutations of IFD-TRAP at its interface with TR or the DNA primer impair telomerase catalysis. We further reveal the importance of TERT motif 3N and TEN domain loop 99FGF101 in telomerase action. Finally, we demonstrate that TPP1 TEL patch loop residue F172, which undergoes a structural rearrangement to bind telomerase, contributes to the human-mouse species specificity of the telomerase-TPP1 interaction. Our study provides insights into the multiple functions of TERT IFD-TRAP, reveals novel TERT and TPP1 elements critical for function, and helps explain how TPP1 binding licenses robust telomerase action at natural chromosome ends.
Collapse
Affiliation(s)
- Shilpa Padmanaban
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Valerie M Tesmer
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Jayakrishnan Nandakumar
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
5
|
Nelson N, Feurstein S, Niaz A, Truong J, Holien JK, Lucas S, Fairfax K, Dickinson J, Bryan TM. Functional genomics for curation of variants in telomere biology disorder associated genes: A systematic review. Genet Med 2023; 25:100354. [PMID: 36496180 DOI: 10.1016/j.gim.2022.11.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 11/28/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Patients with an underlying telomere biology disorder (TBD) have variable clinical presentations, and they can be challenging to diagnose clinically. A genomic diagnosis for patients presenting with TBD is vital for optimal treatment. Unfortunately, many variants identified during diagnostic testing are variants of uncertain significance. This complicates management decisions, delays treatment, and risks nonuptake of potentially curative therapies. Improved application of functional genomic evidence may reduce variants of uncertain significance classifications. METHODS We systematically searched the literature for published functional assays interrogating TBD gene variants. When possible, established likely benign/benign and likely pathogenic/pathogenic variants were used to estimate the assay sensitivity, specificity, positive predictive value, negative predictive value, and odds of pathogenicity. RESULTS In total, 3131 articles were screened and 151 met inclusion criteria. Sufficient data to enable a PS3/BS3 recommendation were available for TERT variants only. We recommend that PS3 and BS3 can be applied at a moderate and supportive level, respectively. PS3/BS3 application was limited by a lack of assay standardization and limited inclusion of benign variants. CONCLUSION Further assay standardization and assessment of benign variants are required for optimal use of the PS3/BS3 criterion for TBD gene variant classification.
Collapse
Affiliation(s)
- Niles Nelson
- The Menzies Institute for Medical Research, College of Health and Medicine, The University of Tasmania, Hobart, Tasmania, Australia; Department of Molecular Medicine, The Royal Hobart Hospital, Hobart, Tasmania, Australia; Department of Molecular Haematology, The Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.
| | - Simone Feurstein
- Section of Hematology, Oncology, and Rheumatology, Department of Internal Medicine, Heidelberg University Hospital, Heidelberg, Germany
| | - Aram Niaz
- Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, New South Wales, Australia
| | - Jia Truong
- School of Science, STEM College, RMIT University, Bundoora, Victoria, Australia
| | - Jessica K Holien
- School of Science, STEM College, RMIT University, Bundoora, Victoria, Australia
| | - Sionne Lucas
- The Menzies Institute for Medical Research, College of Health and Medicine, The University of Tasmania, Hobart, Tasmania, Australia
| | - Kirsten Fairfax
- The Menzies Institute for Medical Research, College of Health and Medicine, The University of Tasmania, Hobart, Tasmania, Australia
| | - Joanne Dickinson
- The Menzies Institute for Medical Research, College of Health and Medicine, The University of Tasmania, Hobart, Tasmania, Australia
| | - Tracy M Bryan
- Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, New South Wales, Australia
| |
Collapse
|
6
|
Revy P, Kannengiesser C, Bertuch AA. Genetics of human telomere biology disorders. Nat Rev Genet 2023; 24:86-108. [PMID: 36151328 DOI: 10.1038/s41576-022-00527-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2022] [Indexed: 01/24/2023]
Abstract
Telomeres are specialized nucleoprotein structures at the ends of linear chromosomes that prevent the activation of DNA damage response and repair pathways. Numerous factors localize at telomeres to regulate their length, structure and function, to avert replicative senescence or genome instability and cell death. In humans, Mendelian defects in several of these factors can result in abnormally short or dysfunctional telomeres, causing a group of rare heterogeneous premature-ageing diseases, termed telomeropathies, short-telomere syndromes or telomere biology disorders (TBDs). Here, we review the TBD-causing genes identified so far and describe their main functions associated with telomere biology. We present molecular aspects of TBDs, including genetic anticipation, phenocopy, incomplete penetrance and somatic genetic rescue, which underlie the complexity of these diseases. We also discuss the implications of phenotypic and genetic features of TBDs on fundamental aspects related to human telomere biology, ageing and cancer, as well as on diagnostic, therapeutic and clinical approaches.
Collapse
Affiliation(s)
- Patrick Revy
- INSERM UMR 1163, Laboratory of Genome Dynamics in the Immune System, Equipe Labellisée Ligue Nationale contre le Cancer, Paris, France.
- Université Paris Cité, Imagine Institute, Paris, France.
| | - Caroline Kannengiesser
- APHP Service de Génétique, Hôpital Bichat, Paris, France
- Inserm U1152, Université Paris Cité, Paris, France
| | - Alison A Bertuch
- Departments of Paediatrics and Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, USA
| |
Collapse
|
7
|
Dorgaleleh S, Naghipoor K, Hajimohammadi Z, Dastaviz F, Oladnabi M. Molecular insight of dyskeratosis congenita: Defects in telomere length homeostasis. J Clin Transl Res 2022; 8:20-30. [PMID: 35097237 PMCID: PMC8791241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 09/23/2021] [Accepted: 12/03/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Dyskeratosis congenita (DC) is a rare disease and is a heterogenous disorder, with its inheritance patterns as autosomal dominant, autosomal recessive, and X-linked recessive. This disorder occurs due to faulty maintenance of telomeres in stem cells. This congenital condition is diagnosed with three symptoms: oral leukoplakia, nail dystrophy, and abnormal skin pigmentation. However, because it has a wide range of symptoms, it may have phenotypes similar to other diseases. For this reason, it is necessary to use methods of measuring the Telomere Length (TL) and determining the shortness of the telomere in these patients so that it can be distinguished from other diseases. Today, the Next Generation Sequencing technique accurately detects mutations in the target genes. AIM This work aims to review and summarize how each of the DC genes is involved in TL, and how to diagnose and differentiate the disease using clinical signs and methods to measure TL. It also offers treatments for DC patients, such as Hematopoietic Stem Cell Transplantation and Androgen therapy. RELEVANCE FOR PATIENTS In DC patients, the genes involved in telomere homeostasis are mutated. Because these patients may have an overlapping phenotype with other diseases, it is best to perform whole-exome sequencing after genetics counseling to find the relevant mutation. As DC is a multi-systemic disease, we need to monitor patients frequently through annual lung function tests, ultrasounds, gynecological examinations, and skin examinations.
Collapse
Affiliation(s)
- Saeed Dorgaleleh
- 1Student Research Committee, Golestan University of Medical Sciences, Gorgan, Iran
| | - Karim Naghipoor
- 1Student Research Committee, Golestan University of Medical Sciences, Gorgan, Iran
| | - Zahra Hajimohammadi
- 2Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Farzad Dastaviz
- 1Student Research Committee, Golestan University of Medical Sciences, Gorgan, Iran
| | - Morteza Oladnabi
- 3Ischemic Disorders Research Center, Golestan University of Medical Sciences, Gorgan, Iran,4Gorgan Congenital Malformations Research Center, Golestan University of Medical Sciences, Gorgan, Iran,
Corresponding author: Morteza Oladnabi Department of Medical Genetics, School of Advanced Technologies in Medicine, Golestan University of Medical Sciences, Gorgan, Iran. Tel: +981732459995
| |
Collapse
|
8
|
Graniel JV, Bisht K, Friedman A, White J, Perkey E, Vanderbeck A, Moroz A, Carrington LJ, Brandstadter JD, Allen F, Shami AN, Thomas P, Crayton A, Manzor M, Mychalowych A, Chase J, Hammoud SS, Keegan CE, Maillard I, Nandakumar J. Differential impact of a dyskeratosis congenita mutation in TPP1 on mouse hematopoiesis and germline. Life Sci Alliance 2021; 5:5/1/e202101208. [PMID: 34645668 PMCID: PMC8548261 DOI: 10.26508/lsa.202101208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/30/2021] [Accepted: 10/01/2021] [Indexed: 11/24/2022] Open
Abstract
A TPP1 mutation known to cause telomere shortening and bone marrow failure in humans recapitulates telomere loss but results in severe germline defects in mice without impacting murine hematopoiesis. Telomerase extends chromosome ends in somatic and germline stem cells to ensure continued proliferation. Mutations in genes critical for telomerase function result in telomeropathies such as dyskeratosis congenita, frequently resulting in spontaneous bone marrow failure. A dyskeratosis congenita mutation in TPP1 (K170∆) that specifically compromises telomerase recruitment to telomeres is a valuable tool to evaluate telomerase-dependent telomere length maintenance in mice. We used CRISPR-Cas9 to generate a mouse knocked in for the equivalent of the TPP1 K170∆ mutation (TPP1 K82∆) and investigated both its hematopoietic and germline compartments in unprecedented detail. TPP1 K82∆ caused progressive telomere erosion with increasing generation number but did not induce steady-state hematopoietic defects. Strikingly, K82∆ caused mouse infertility, consistent with gross morphological defects in the testis and sperm, the appearance of dysfunctional seminiferous tubules, and a decrease in germ cells. Intriguingly, both TPP1 K82∆ mice and previously characterized telomerase knockout mice show no spontaneous bone marrow failure but rather succumb to infertility at steady-state. We speculate that telomere length maintenance contributes differently to the evolutionary fitness of humans and mice.
Collapse
Affiliation(s)
- Jacqueline V Graniel
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.,Medical Scientist Training Program, University of Michigan, Ann Arbor, MI, USA.,Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Kamlesh Bisht
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.,Oncology Therapeutic Area, Sanofi, Cambridge, MA, USA
| | - Ann Friedman
- Department of Internal Medicine, Michigan Medicine, Ann Arbor, MI, USA
| | - James White
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA.,Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, USA
| | - Eric Perkey
- Medical Scientist Training Program, University of Michigan, Ann Arbor, MI, USA.,Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA.,Division of Hematology/Oncology, Department of Medicine; Abramson Family Cancer Research Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Ashley Vanderbeck
- Division of Hematology/Oncology, Department of Medicine; Abramson Family Cancer Research Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Alina Moroz
- Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, USA
| | - Léolène J Carrington
- Division of Hematology/Oncology, Department of Medicine; Abramson Family Cancer Research Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Joshua D Brandstadter
- Division of Hematology/Oncology, Department of Medicine; Abramson Family Cancer Research Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Frederick Allen
- Division of Hematology/Oncology, Department of Medicine; Abramson Family Cancer Research Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Adrienne Niederriter Shami
- Medical Scientist Training Program, University of Michigan, Ann Arbor, MI, USA.,Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Peedikayil Thomas
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA.,Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, USA
| | - Aniela Crayton
- Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, USA
| | - Mariel Manzor
- Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, USA
| | | | - Jennifer Chase
- Department of Internal Medicine, Michigan Medicine, Ann Arbor, MI, USA.,Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
| | - Saher S Hammoud
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Catherine E Keegan
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA .,Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, USA
| | - Ivan Maillard
- Division of Hematology/Oncology, Department of Medicine; Abramson Family Cancer Research Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Jayakrishnan Nandakumar
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
9
|
The structurally conserved TELR region on shelterin protein TPP1 is essential for telomerase processivity but not recruitment. Proc Natl Acad Sci U S A 2021; 118:2024889118. [PMID: 34282008 DOI: 10.1073/pnas.2024889118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The shelterin protein TPP1 is involved in both recruiting telomerase and stimulating telomerase processivity in human cells. Assessing the in vivo significance of the latter role of TPP1 has been difficult, because TPP1 mutations that perturb telomerase function tend to abolish both telomerase recruitment and processivity. The Saccharomyces cerevisiae telomerase-associated Est3 protein adopts a protein fold similar to the N-terminal region of TPP1. Interestingly, a previous structure-guided mutagenesis study of Est3 revealed a TELR surface region that regulates telomerase function via an unknown mechanism without affecting the interaction between Est3 and telomerase [T. Rao et al., Proc. Natl. Acad. Sci. U.S.A. 111, 214-218 (2014)]. Here, we show that mutations within the structurally conserved TELR region on human TPP1 impaired telomerase processivity while leaving telomerase recruitment unperturbed, hence uncoupling the two roles of TPP1 in regulating telomerase. Telomeres in cell lines containing homozygous TELR mutations progressively shortened to a critical length that caused cellular senescence, despite the presence of abundant telomerase in these cells. Our findings not only demonstrate that telomerase processivity can be regulated by TPP1 in a process separable from its role in recruiting telomerase, but also establish that the in vivo stimulation of telomerase processivity by TPP1 is critical for telomere length homeostasis and long-term viability of human cells.
Collapse
|
10
|
Grill S, Padmanaban S, Friedman A, Perkey E, Allen F, Tesmer VM, Chase J, Khoriaty R, Keegan CE, Maillard I, Nandakumar J. TPP1 mutagenesis screens unravel shelterin interfaces and functions in hematopoiesis. JCI Insight 2021; 6:138059. [PMID: 33822766 PMCID: PMC8262337 DOI: 10.1172/jci.insight.138059] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 03/31/2021] [Indexed: 02/06/2023] Open
Abstract
Telomerase catalyzes chromosome end replication in stem cells and other long-lived cells. Mutations in telomerase or telomere-related genes result in diseases known as telomeropathies. Telomerase is recruited to chromosome ends by the ACD/TPP1 protein (TPP1 hereafter), a component of the shelterin complex that protects chromosome ends from unwanted end joining. TPP1 facilitates end protection by binding shelterin proteins POT1 and TIN2. TPP1 variants have been associated with telomeropathies but remain poorly characterized in vivo. Disease variants and mutagenesis scans provide efficient avenues to interrogate the distinct physiological roles of TPP1. Here, we conduct mutagenesis in the TIN2- and POT1-binding domains of TPP1 to discover mutations that dissect TPP1's functions. Our results extend current structural data to reveal that the TPP1-TIN2 interface is more extensive than previously thought and highlight the robustness of the POT1-TPP1 interface. Introduction of separation-of-function mutants alongside known TPP1 telomeropathy mutations in mouse hematopoietic stem cells (mHSCs) lacking endogenous TPP1 demonstrated a clear phenotypic demarcation. TIN2- and POT1-binding mutants were unable to rescue mHSC failure resulting from end deprotection. In contrast, TPP1 telomeropathy mutations sustained mHSC viability, consistent with their selectively impacting end replication. These results highlight the power of scanning mutagenesis in revealing structural interfaces and dissecting multifunctional genes.
Collapse
Affiliation(s)
- Sherilyn Grill
- Department of Molecular, Cellular, and Developmental Biology
| | | | - Ann Friedman
- Life Sciences Institute,,Department of Internal Medicine
| | - Eric Perkey
- Life Sciences Institute,,Graduate Program in Cellular and Molecular Biology, and,Medical Scientist Training Program, University of Michigan, Ann Arbor, Michigan, USA
| | - Frederick Allen
- Division of Hematology/Oncology, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | | | - Jennifer Chase
- Life Sciences Institute,,Graduate Program in Cellular and Molecular Biology, and
| | - Rami Khoriaty
- Department of Internal Medicine,,Department of Cell and Developmental Biology
| | - Catherine E. Keegan
- Department of Pediatrics, and,Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Ivan Maillard
- Life Sciences Institute,,Department of Internal Medicine,,Division of Hematology/Oncology, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA.,Department of Cell and Developmental Biology,,Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | | |
Collapse
|
11
|
Gavia-García G, Rosado-Pérez J, Arista-Ugalde TL, Aguiñiga-Sánchez I, Santiago-Osorio E, Mendoza-Núñez VM. Telomere Length and Oxidative Stress and Its Relation with Metabolic Syndrome Components in the Aging. BIOLOGY 2021; 10:253. [PMID: 33804844 PMCID: PMC8063797 DOI: 10.3390/biology10040253] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 12/20/2022]
Abstract
A great amount of scientific evidence supports that Oxidative Stress (OxS) can contribute to telomeric attrition and also plays an important role in the development of certain age-related diseases, among them the metabolic syndrome (MetS), which is characterised by clinical and biochemical alterations such as obesity, dyslipidaemia, arterial hypertension, hyperglycaemia, and insulin resistance, all of which are considered as risk factors for type 2 diabetes mellitus (T2DM) and cardiovascular diseases, which are associated in turn with an increase of OxS. In this sense, we review scientific evidence that supports the association between OxS with telomere length (TL) dynamics and the relationship with MetS components in aging. It was analysed whether each MetS component affects the telomere length separately or if they all affect it together. Likewise, this review provides a summary of the structure and function of telomeres and telomerase, the mechanisms of telomeric DNA repair, how telomere length may influence the fate of cells or be linked to inflammation and the development of age-related diseases, and finally, how the lifestyles can affect telomere length.
Collapse
Affiliation(s)
- Graciela Gavia-García
- Research Unit on Gerontology, FES Zaragoza, National Autonomous University of Mexico, Mexico City 09230, Mexico; (G.G.-G.); (J.R.-P.); (T.L.A.-U.)
| | - Juana Rosado-Pérez
- Research Unit on Gerontology, FES Zaragoza, National Autonomous University of Mexico, Mexico City 09230, Mexico; (G.G.-G.); (J.R.-P.); (T.L.A.-U.)
| | - Taide Laurita Arista-Ugalde
- Research Unit on Gerontology, FES Zaragoza, National Autonomous University of Mexico, Mexico City 09230, Mexico; (G.G.-G.); (J.R.-P.); (T.L.A.-U.)
| | - Itzen Aguiñiga-Sánchez
- Hematopoiesis and Leukemia Laboratory, Research Unit on Cell Differentiation and Cancer, FES Zaragoza, National Autonomous University of Mexico, Mexico City 09230, Mexico; (I.A.-S.); (E.S.-O.)
| | - Edelmiro Santiago-Osorio
- Hematopoiesis and Leukemia Laboratory, Research Unit on Cell Differentiation and Cancer, FES Zaragoza, National Autonomous University of Mexico, Mexico City 09230, Mexico; (I.A.-S.); (E.S.-O.)
| | - Víctor Manuel Mendoza-Núñez
- Research Unit on Gerontology, FES Zaragoza, National Autonomous University of Mexico, Mexico City 09230, Mexico; (G.G.-G.); (J.R.-P.); (T.L.A.-U.)
| |
Collapse
|
12
|
Lim CJ, Cech TR. Shaping human telomeres: from shelterin and CST complexes to telomeric chromatin organization. Nat Rev Mol Cell Biol 2021; 22:283-298. [PMID: 33564154 DOI: 10.1038/s41580-021-00328-y] [Citation(s) in RCA: 115] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2021] [Indexed: 01/14/2023]
Abstract
The regulation of telomere length in mammals is crucial for chromosome end-capping and thus for maintaining genome stability and cellular lifespan. This process requires coordination between telomeric protein complexes and the ribonucleoprotein telomerase, which extends the telomeric DNA. Telomeric proteins modulate telomere architecture, recruit telomerase to accessible telomeres and orchestrate the conversion of the newly synthesized telomeric single-stranded DNA tail into double-stranded DNA. Dysfunctional telomere maintenance leads to telomere shortening, which causes human diseases including bone marrow failure, premature ageing and cancer. Recent studies provide new insights into telomerase-related interactions (the 'telomere replisome') and reveal new challenges for future telomere structural biology endeavours owing to the dynamic nature of telomere architecture and the great number of structures that telomeres form. In this Review, we discuss recently determined structures of the shelterin and CTC1-STN1-TEN1 (CST) complexes, how they may participate in the regulation of telomere replication and chromosome end-capping, and how disease-causing mutations in their encoding genes may affect specific functions. Major outstanding questions in the field include how all of the telomere components assemble relative to each other and how the switching between different telomere structures is achieved.
Collapse
Affiliation(s)
- Ci Ji Lim
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA. .,Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA. .,BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA.
| | - Thomas R Cech
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA. .,BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA. .,Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA.
| |
Collapse
|
13
|
Henslee G, Williams CL, Liu P, Bertuch AA. Identification and characterization of novel ACD variants: modulation of TPP1 protein level offsets the impact of germline loss-of-function variants on telomere length. Cold Spring Harb Mol Case Stud 2021; 7:a005454. [PMID: 33446513 PMCID: PMC7903889 DOI: 10.1101/mcs.a005454] [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: 04/19/2020] [Accepted: 02/04/2021] [Indexed: 12/13/2022] Open
Abstract
Telomere biology disorders, largely characterized by telomere lengths below the first centile for age, are caused by variants in genes associated with telomere replication, structure, or function. One of these genes, ACD, which encodes the shelterin protein TPP1, is associated with both autosomal dominantly and autosomal recessively inherited telomere biology disorders. TPP1 recruits telomerase to telomeres and stimulates telomerase processivity. Several studies probing the effect of various synthetic or patient-derived variants have mapped specific residues and regions of TPP1 that are important for interaction with TERT, the catalytic component of telomerase. However, these studies have come to differing conclusions regarding ACD haploinsufficiency. Here, we report a proband with compound heterozygous novel variants in ACD (NM_001082486.1)-c.505_507delGAG, p.(Glu169del); and c.619delG, p.(Asp207Thrfs*22)-and a second proband with a heterozygous chromosomal deletion encompassing ACD: arr[hg19] 16q22.1(67,628,846-67,813,408)x1. Clinical data, including symptoms and telomere length within the pedigrees, suggested that loss of one ACD allele was insufficient to induce telomere shortening or confer clinical features. Further analyses of lymphoblastoid cell lines showed decreased nascent ACD RNA and steady-state mRNA, but normal TPP1 protein levels, in cells containing heterozygous ACD c.619delG, p.(Asp207Thrfs*22), or the ACD-encompassing chromosomal deletion compared to controls. Based on our results, we conclude that cells are able to compensate for loss of one ACD allele by activating a mechanism to maintain TPP1 protein levels, thus maintaining normal telomere length.
Collapse
Affiliation(s)
- Gabrielle Henslee
- Baylor College of Medicine, Integrated Molecular and Biomedical Sciences Graduate Program, Houston, Texas 77030, USA
- Baylor College of Medicine, Department of Pediatrics, Hematology/Oncology, Houston, Texas 77030, USA
- Texas Children's Hospital, Cancer and Hematology Centers, Houston, Texas 77030, USA
| | - Christopher L Williams
- Baylor College of Medicine, Department of Pediatrics, Hematology/Oncology, Houston, Texas 77030, USA
- Texas Children's Hospital, Cancer and Hematology Centers, Houston, Texas 77030, USA
| | - Pengfei Liu
- Baylor College of Medicine, Department of Molecular and Human Genetics, Houston, Texas 77030, USA
- Baylor Genetics, Houston, Texas 77021, USA
| | - Alison A Bertuch
- Baylor College of Medicine, Integrated Molecular and Biomedical Sciences Graduate Program, Houston, Texas 77030, USA
- Baylor College of Medicine, Department of Pediatrics, Hematology/Oncology, Houston, Texas 77030, USA
- Texas Children's Hospital, Cancer and Hematology Centers, Houston, Texas 77030, USA
- Baylor College of Medicine, Department of Molecular and Human Genetics, Houston, Texas 77030, USA
| |
Collapse
|
14
|
Grill S, Nandakumar J. Molecular mechanisms of telomere biology disorders. J Biol Chem 2021; 296:100064. [PMID: 33482595 PMCID: PMC7948428 DOI: 10.1074/jbc.rev120.014017] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 11/11/2020] [Accepted: 11/12/2020] [Indexed: 12/20/2022] Open
Abstract
Genetic mutations that affect telomerase function or telomere maintenance result in a variety of diseases collectively called telomeropathies. This wide spectrum of disorders, which include dyskeratosis congenita, pulmonary fibrosis, and aplastic anemia, is characterized by severely short telomeres, often resulting in hematopoietic stem cell failure in the most severe cases. Recent work has focused on understanding the molecular basis of these diseases. Mutations in the catalytic TERT and TR subunits of telomerase compromise activity, while others, such as those found in the telomeric protein TPP1, reduce the recruitment of telomerase to the telomere. Mutant telomerase-associated proteins TCAB1 and dyskerin and the telomerase RNA maturation component poly(A)-specific ribonuclease affect the maturation and stability of telomerase. In contrast, disease-associated mutations in either CTC1 or RTEL1 are more broadly associated with telomere replication defects. Yet even with the recent surge in studies decoding the mechanisms underlying these diseases, a significant proportion of dyskeratosis congenita mutations remain uncharacterized or poorly understood. Here we review the current understanding of the molecular basis of telomeropathies and highlight experimental data that illustrate how genetic mutations drive telomere shortening and dysfunction in these patients. This review connects insights from both clinical and molecular studies to create a comprehensive view of the underlying mechanisms that drive these diseases. Through this, we emphasize recent advances in therapeutics and pinpoint disease-associated variants that remain poorly defined in their mechanism of action. Finally, we suggest future avenues of research that will deepen our understanding of telomere biology and telomere-related disease.
Collapse
Affiliation(s)
- Sherilyn Grill
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jayakrishnan Nandakumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA.
| |
Collapse
|
15
|
Grill S, Bisht K, Tesmer VM, Shami AN, Hammoud SS, Nandakumar J. Two Separation-of-Function Isoforms of Human TPP1 Dictate Telomerase Regulation in Somatic and Germ Cells. Cell Rep 2020; 27:3511-3521.e7. [PMID: 31216472 DOI: 10.1016/j.celrep.2019.05.073] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 03/07/2019] [Accepted: 05/17/2019] [Indexed: 12/13/2022] Open
Abstract
Telomerase replicates chromosome ends in germ and somatic stem cells to facilitate their continued proliferation. Telomerase action depends on the telomeric protein TPP1, which recruits telomerase to telomeres and facilitates processive DNA synthesis. Here, we identify separation-of-function long (TPP1-L) and short (TPP1-S) isoforms of TPP1 that appear to be generated from separate transcripts and differ only in 86 amino acids at their N terminus. Although both isoforms retain the ability to recruit telomerase, only TPP1-S facilitates efficient telomere synthesis. We find that TPP1-S is the predominant isoform in somatic cells, and strikingly, TPP1-L is the major isoform in differentiated male germ cells. We observed that TERT expression persists in these germ cells, suggesting that TPP1-L could restrain telomerase in this context. We show how differential expression of TPP1 isoforms determines telomerase function and demonstrate how alternative transcription start sites allow one gene to perform distinct functions in different biological contexts.
Collapse
Affiliation(s)
- Sherilyn Grill
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Kamlesh Bisht
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Valerie M Tesmer
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Saher S Hammoud
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jayakrishnan Nandakumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| |
Collapse
|
16
|
Insights into the structure and function of Est3 from the Hansenula polymorpha telomerase. Sci Rep 2020; 10:11109. [PMID: 32632130 PMCID: PMC7338525 DOI: 10.1038/s41598-020-68107-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 06/19/2020] [Indexed: 12/12/2022] Open
Abstract
Telomerase is a ribonucleoprotein enzyme, which maintains genome integrity in eukaryotes and ensures continuous cellular proliferation. Telomerase holoenzyme from the thermotolerant yeast Hansenula polymorpha, in addition to the catalytic subunit (TERT) and telomerase RNA (TER), contains accessory proteins Est1 and Est3, which are essential for in vivo telomerase function. Here we report the high-resolution structure of Est3 from Hansenula polymorpha (HpEst3) in solution, as well as the characterization of its functional relationships with other components of telomerase. The overall structure of HpEst3 is similar to that of Est3 from Saccharomyces cerevisiae and human TPP1. We have shown that telomerase activity in H. polymorpha relies on both Est3 and Est1 proteins in a functionally symmetrical manner. The absence of either Est3 or Est1 prevents formation of a stable ribonucleoprotein complex, weakens binding of a second protein to TER, and decreases the amount of cellular TERT, presumably due to the destabilization of telomerase RNP. NMR probing has shown no direct in vitro interactions of free Est3 either with the N-terminal domain of TERT or with DNA or RNA fragments mimicking the probable telomerase environment. Our findings corroborate the idea that telomerase possesses the evolutionarily variable functionality within the conservative structural context.
Collapse
|
17
|
Aramburu T, Plucinsky S, Skordalakes E. POT1-TPP1 telomere length regulation and disease. Comput Struct Biotechnol J 2020; 18:1939-1946. [PMID: 32774788 PMCID: PMC7385035 DOI: 10.1016/j.csbj.2020.06.040] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/24/2020] [Accepted: 06/27/2020] [Indexed: 12/27/2022] Open
Abstract
Telomeres are DNA repeats at the ends of linear chromosomes and are replicated by telomerase, a ribonucleoprotein reverse transcriptase. Telomere length regulation and chromosome end capping are essential for genome stability and are mediated primarily by the shelterin and CST complexes. POT1-TPP1, a subunit of shelterin, binds the telomeric overhang, suppresses ATR-dependent DNA damage response, and recruits telomerase to telomeres for DNA replication. POT1 localization to telomeres and chromosome end protection requires its interaction with TPP1. Therefore, the POT1-TPP1 complex is critical to telomere maintenance and full telomerase processivity. The aim of this mini-review is to summarize recent POT1-TPP1 structural studies and discuss how the complex contributes to telomere length regulation. In addition, we review how disruption of POT1-TPP1 function leads to human disease.
Collapse
Key Words
- ATM, Ataxia Telangiectasia Mutated protein
- ATR, Ataxia Telangiectasia and Rad3-related Protein
- CST, CTC1, Stn1 and Ten1
- CTC1, Conserved Telomere Capping Protein 1
- POT1
- POT1, Protection of telomere 1
- RAP1, Repressor/Activator Protein 1
- RPA, Replication Protein A
- SMCHD1, Structural Maintenance Of Chromosomes Flexible Hinge Domain Containing 1
- Shelterin
- Stn1, Suppressor of Cdc Thirteen
- TERC, Telomerase RNA
- TERT, Telomerase Reverse Transcriptase
- TIN2, TRF1- and TRF2-Interacting Nuclear Protein 2
- TPP1
- TPP1 also known as ACD, Adrenocortical Dysplasia Protein Homolog
- TRF1, Telomere Repeat binding Factor 1
- TRF2, Telomere Repeat binding Factor 2
- TSPYL5, Testis-specific Y-encoded-like protein 5
- Telomerase
- Telomeres
- Ten1, Telomere Length Regulation Protein
- USP7, ubiquitin-specific-processing protease 7
Collapse
|
18
|
Smith EM, Pendlebury DF, Nandakumar J. Structural biology of telomeres and telomerase. Cell Mol Life Sci 2020; 77:61-79. [PMID: 31728577 PMCID: PMC6986361 DOI: 10.1007/s00018-019-03369-x] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 10/11/2019] [Accepted: 10/31/2019] [Indexed: 01/16/2023]
Abstract
Telomeres are protein-DNA complexes that protect chromosome ends from illicit ligation and resection. Telomerase is a ribonucleoprotein enzyme that synthesizes telomeric DNA to counter telomere shortening. Human telomeres are composed of complexes between telomeric DNA and a six-protein complex known as shelterin. The shelterin proteins TRF1 and TRF2 provide the binding affinity and specificity for double-stranded telomeric DNA, while the POT1-TPP1 shelterin subcomplex coats the single-stranded telomeric G-rich overhang that is characteristic of all our chromosome ends. By capping chromosome ends, shelterin protects telomeric DNA from unwanted degradation and end-to-end fusion events. Structures of the human shelterin proteins reveal a network of constitutive and context-specific interactions. The shelterin protein-DNA structures reveal the basis for both the high affinity and DNA sequence specificity of these interactions, and explain how shelterin efficiently protects chromosome ends from genome instability. Several protein-protein interactions, many provided by the shelterin component TIN2, are critical for upholding the end-protection function of shelterin. A survey of these protein-protein interfaces within shelterin reveals a series of "domain-peptide" interactions that allow for efficient binding and adaptability towards new functions. While the modular nature of shelterin has facilitated its part-by-part structural characterization, the interdependence of subunits within telomerase has made its structural solution more challenging. However, the exploitation of several homologs in combination with recent advancements in cryo-EM capabilities has led to an exponential increase in our knowledge of the structural biology underlying telomerase function. Telomerase homologs from a wide range of eukaryotes show a typical retroviral reverse transcriptase-like protein core reinforced with elements that deliver telomerase-specific functions including recruitment to telomeres and high telomere-repeat addition processivity. In addition to providing the template for reverse transcription, the RNA component of telomerase provides a scaffold for the catalytic and accessory protein subunits, defines the limits of the telomeric repeat sequence, and plays a critical role in RNP assembly, stability, and trafficking. While a high-resolution definition of the human telomerase structure is only beginning to emerge, the quick pace of technical progress forecasts imminent breakthroughs in this area. Here, we review the structural biology surrounding telomeres and telomerase to provide a molecular description of mammalian chromosome end protection and end replication.
Collapse
Affiliation(s)
- Eric M Smith
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Devon F Pendlebury
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Jayakrishnan Nandakumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
19
|
Hoffman TW, van der Vis JJ, van der Smagt JJ, Massink MPG, Grutters JC, van Moorsel CHM. Pulmonary fibrosis linked to variants in the ACD gene, encoding the telomere protein TPP1. Eur Respir J 2019; 54:13993003.00809-2019. [PMID: 31515401 DOI: 10.1183/13993003.00809-2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 08/17/2019] [Indexed: 11/05/2022]
Affiliation(s)
- Thijs W Hoffman
- Dept of Pulmonology, Interstitial Lung Diseases Center of Excellence, St Antonius Hospital, Nieuwegein, The Netherlands
| | - Joanne J van der Vis
- Dept of Pulmonology, Interstitial Lung Diseases Center of Excellence, St Antonius Hospital, Nieuwegein, The Netherlands.,Dept of Clinical Chemistry, St Antonius Hospital, Nieuwegein, The Netherlands
| | | | - Maarten P G Massink
- Dept of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jan C Grutters
- Dept of Pulmonology, Interstitial Lung Diseases Center of Excellence, St Antonius Hospital, Nieuwegein, The Netherlands.,Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Coline H M van Moorsel
- Dept of Pulmonology, Interstitial Lung Diseases Center of Excellence, St Antonius Hospital, Nieuwegein, The Netherlands .,Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands
| |
Collapse
|
20
|
Combining conservation and species-specific differences to determine how human telomerase binds telomeres. Proc Natl Acad Sci U S A 2019; 116:26505-26515. [PMID: 31822618 DOI: 10.1073/pnas.1911912116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Telomerase catalyzes telomeric DNA synthesis at chromosome ends to allow for continued cell division. The telomeric protein TPP1 is essential for enhancing the processivity of telomerase and recruiting the enzyme to telomeres. The telomerase interaction surface on human TPP1 has been mapped to 2 regions of the N-terminal oligosaccharide/oligonucleotide-binding (OB) domain, namely the TPP1 glutamate (E) and leucine (L)-rich (TEL) patch and the N terminus of TPP1-oligosaccharide/oligonucleotide-binding (NOB) region. To map the telomerase side of the interface, we exploited the predicted structural similarities for human and Tetrahymena thermophila telomerase as well as the species specificity of human and mouse telomerase for their cognate TPP1 partners. We show that swapping in the telomerase essential N-terminal (TEN) and insertions in fingers domain (IFD)-TRAP regions of the human telomerase catalytic protein subunit TERT into the mouse TERT backbone is sufficient to bias the species specificity toward human TPP1. Employing a structural homology-based mutagenesis screen focused on surface residues of the TEN and IFD regions, we identified TERT residues that are critical for contacting TPP1 but dispensable for other aspects of telomerase structure or function. We present a functionally validated structural model for how human telomerase engages TPP1 at telomeres, setting the stage for a high-resolution structure of this interface.
Collapse
|
21
|
Yu Y, Jia W, Lyu Y, Su D, Bai M, Shen J, Qiao J, Han T, Liu W, Chen J, Chen W, Ye D, Guo X, Zhu S, Xi J, Zhu R, Wan X, Gao S, Zhu J, Kang J. Pwp1 regulates telomere length by stabilizing shelterin complex and maintaining histone H4K20 trimethylation. Cell Discov 2019; 5:47. [PMID: 31754456 PMCID: PMC6868014 DOI: 10.1038/s41421-019-0116-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 07/24/2019] [Indexed: 01/02/2023] Open
Abstract
Telomere maintenance is critical for chromosome stability. Here we report that periodic tryptophan protein 1 (PWP1) is involved in regulating telomere length homeostasis. Pwp1 appears to be essential for mouse development and embryonic stem cell (ESC) survival, as homozygous Pwp1-knockout mice and ESCs have never been obtained. Heterozygous Pwp1-knockout mice had shorter telomeres and decreased reproductive capacity. Pwp1 depletion induced rapid telomere shortening accompanied by reduced shelterin complex and increased DNA damage in telomeric regions. Mechanistically, PWP1 bound and stabilized the shelterin complex via its WD40 domains and regulated the overall level of H4K20me3. The rescue of telomere length in Pwp1-deficient cells by PWP1 overexpression depended on SUV4-20H2 co-expression and increased H4K20me3. Therefore, our study revealed a novel protein involved in telomere homeostasis in both mouse and human cells. This knowledge will improve our understanding of how chromatin structure and histone modifications are involved in maintaining telomere integrity.
Collapse
Affiliation(s)
- Yangyang Yu
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Wenwen Jia
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China.,2Institute for Regenerative Medicine, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, 200123 China
| | - Yao Lyu
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Dingwen Su
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Mingliang Bai
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Junwei Shen
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Jing Qiao
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Tong Han
- 3Department of Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 201204 P. R. China
| | - Wenqiang Liu
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Jiayu Chen
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Wen Chen
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Dan Ye
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Xudong Guo
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Songcheng Zhu
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Jiajie Xi
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Ruixin Zhu
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Xiaoping Wan
- 3Department of Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 201204 P. R. China
| | - Shaorong Gao
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China
| | - Jiyue Zhu
- 4Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Spokane, WA 99210 USA
| | - Jiuhong Kang
- 1Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science; School of Life Sciences and Technology, Tongji University, Shanghai, 200092 China.,2Institute for Regenerative Medicine, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, 200123 China
| |
Collapse
|
22
|
Grill S, Tesmer VM, Nandakumar J. The N Terminus of the OB Domain of Telomere Protein TPP1 Is Critical for Telomerase Action. Cell Rep 2019; 22:1132-1140. [PMID: 29386102 DOI: 10.1016/j.celrep.2018.01.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 12/19/2017] [Accepted: 01/03/2018] [Indexed: 01/15/2023] Open
Abstract
Telomerase recruitment to telomeres and enzymatic processivity are mediated by TPP1, an essential component of telomere integrity and telomerase function. A surface on the OB domain of TPP1 called the TEL patch is critical for TPP1's telomerase-associated functions. Here, we identify a separate region in the N terminus of the OB domain (termed NOB) of TPP1 that, like the TEL patch, is essential for telomerase repeat addition processivity in vitro as well as telomerase recruitment to telomeres and telomere lengthening in cells. Although well-conserved among most mammalian TPP1 homologs, the NOB region in mice is distinct. Swapping the sequence of human NOB into mouse TPP1 allows it to stimulate human telomerase, qualifying NOB as an important determinant of species specificity for TPP1-telomerase interaction. Our studies show that TPP1 NOB is critical for telomerase function and demonstrate that the telomerase interaction surface on TPP1 is more elaborate than previously appreciated.
Collapse
Affiliation(s)
- Sherilyn Grill
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Valerie M Tesmer
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jayakrishnan Nandakumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| |
Collapse
|
23
|
An N-terminal Flag-tag impairs TPP1 regulation of telomerase function. Biochem Biophys Res Commun 2019; 512:230-235. [PMID: 30885434 DOI: 10.1016/j.bbrc.2019.03.050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 10/27/2022]
Abstract
The shelterin protein complex protects natural chromosome ends from being recognized as DNA damage sites and also regulates the synthesis of telomeric repeats by telomerase. TPP1, a shelterin subunit that is essential for telomerase extension of telomeres, has been studied intensively in recent years. Many such studies utilize epitope tagged TPP1, but it is unclear how the tags may affect the multiple cellular functions of TPP1. Here we analyzed the effect of adding a 3x Flag epitope tag to the N- or C-terminus of TPP1. While the position of the tag did not affect TPP1's interaction within the shelterin complex or its localization to telomeres, the N-terminal Flag tag on TPP1 impaired telomerase function, resulting in reduced telomerase processivity in vitro and a failure to stimulate telomere elongation in vivo. The C-terminally Flag-tagged TPP1, in contrast, behaved similarly to untagged TPP1 in all functional aspects examined. These findings suggest that caution is required when utilizing epitope tagged TPP1 to study its regulation of telomerase function.
Collapse
|
24
|
Huang Y, Dai W, Li Y. Potential associations of testosterone/estradiol ratio, leukocyte hTERT expression and PBMC telomerase activity with aging and the presence of coronary artery disease in men. Exp Gerontol 2019; 117:38-44. [DOI: 10.1016/j.exger.2018.08.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 12/26/2022]
|
25
|
Gu P, Jia S, Takasugi T, Smith E, Nandakumar J, Hendrickson E, Chang S. CTC1-STN1 coordinates G- and C-strand synthesis to regulate telomere length. Aging Cell 2018; 17:e12783. [PMID: 29774655 PMCID: PMC6052479 DOI: 10.1111/acel.12783] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2018] [Indexed: 02/01/2023] Open
Abstract
Coats plus (CP) is a rare autosomal recessive disorder caused by mutations in CTC1, a component of the CST (CTC1, STN1, and TEN1) complex important for telomere length maintenance. The molecular basis of how CP mutations impact upon telomere length remains unclear. The CP CTC1L1142H mutation has been previously shown to disrupt telomere maintenance. In this study, we used CRISPR/Cas9 to engineer this mutation into both alleles of HCT116 and RPE cells to demonstrate that CTC1:STN1 interaction is required to repress telomerase activity. CTC1L1142H interacts poorly with STN1, leading to telomerase‐mediated telomere elongation. Impaired interaction between CTC1L1142H:STN1 and DNA Pol‐α results in increased telomerase recruitment to telomeres and further telomere elongation, revealing that C:S binding to DNA Pol‐α is required to fully repress telomerase activity. CP CTC1 mutants that fail to interact with DNA Pol‐α resulted in loss of C‐strand maintenance and catastrophic telomere shortening. Our findings place the CST complex as an important regulator of both G‐strand extensions by telomerase and C‐strand synthesis by DNA Pol‐α.
Collapse
Affiliation(s)
- Peili Gu
- Department of Laboratory Medicine; Yale University School of Medicine; New Haven Connecticut
| | - Shuting Jia
- Lab of Molecular Genetics of Aging and Tumor; Faculty of Medicine; Kunming University of Science and Technology; Kunming Yunnan Province China
| | - Taylor Takasugi
- Department of Laboratory Medicine; Yale University School of Medicine; New Haven Connecticut
- Department of Biochemistry, Molecular Biology and Biophysics; University of Minnesota Medical School; Minneapolis Minnesota
| | - Eric Smith
- Department of Molecular, Cellular, and Developmental Biology; University of Michigan; Ann Arbor Michigan
| | - Jayakrishnan Nandakumar
- Department of Molecular, Cellular, and Developmental Biology; University of Michigan; Ann Arbor Michigan
- Program in Chemical Biology; University of Michigan; Ann Arbor Michigan
| | - Eric Hendrickson
- Department of Biochemistry, Molecular Biology and Biophysics; University of Minnesota Medical School; Minneapolis Minnesota
| | - Sandy Chang
- Department of Laboratory Medicine; Yale University School of Medicine; New Haven Connecticut
- Department of Pathology; Yale University School of Medicine; New Haven Connecticut
- Molecular Biophysics and Biochemistry; Yale University School of Medicine; New Haven Connecticut
| |
Collapse
|
26
|
Homozygous OB-fold variants in telomere protein TPP1 are associated with dyskeratosis congenita-like phenotypes. Blood 2018; 132:1349-1353. [PMID: 30064976 DOI: 10.1182/blood-2018-03-837799] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
|
27
|
Mariasina SS, Efimov SV, Petrova OA, Rodina EV, Malyavko AN, Zvereva MI, Klochkov VV, Dontsova OA, Polshakov VI. Chemical shift assignments and the secondary structure of the Est3 telomerase subunit in the yeast Hansenula polymorpha. BIOMOLECULAR NMR ASSIGNMENTS 2018; 12:57-62. [PMID: 28916982 DOI: 10.1007/s12104-017-9780-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 09/13/2017] [Indexed: 06/07/2023]
Abstract
Telomerase is a multisubunit ribonucleoprotein enzyme that is essential for continuous cellular proliferation. A key role of telomerase in cancer and ageing makes it a promising target for the development of cancer therapies and treatments of other age-associated diseases, since telomerase allows unlimited proliferation potential of cells in the majority of cancer types. However, the structure and molecular mechanism of telomerase action are still poorly understood. In budding yeast, telomerase consists of the catalytic subunit, the telomerase reverse transcriptase or Est2 protein, telomerase RNA (TLC1) and two regulatory subunits, Est1 and Est3. Each of the four subunits is essential for in vivo telomerase function. Est3 interacts directly with Est1 and Est2, and stimulates Est2 catalytic activity. However, the exact role of the Est3 protein in telomerase function is still unknown. Determination of the structure, dynamic and functional properties of Est3 can bring new insights into the molecular mechanism of telomerase activity. Here we report nearly complete 1H, 13C and 15N resonance assignments of Est3 from the yeast Hansenula polymorpha. Analysis of the assigned chemical shifts allowed us to identify the protein's secondary structure and backbone dynamic properties. Structure-based sequence alignment revealed similarities in the structural organization of yeast Est3 and mammalian TPP1 proteins.
Collapse
Affiliation(s)
- Sofia S Mariasina
- Center for Magnetic Tomography and Spectroscopy, Faculty of Fundamental Medicine, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991
- Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991
| | - Sergey V Efimov
- NMR Laboratory, Institute of Physics, Kazan Federal University, 18 Kremlevskaya, Kazan, Russia, 420008
| | - Olga A Petrova
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991
| | - Elena V Rodina
- Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991
| | - Alexander N Malyavko
- Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Maria I Zvereva
- Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991
| | - Vladimir V Klochkov
- NMR Laboratory, Institute of Physics, Kazan Federal University, 18 Kremlevskaya, Kazan, Russia, 420008
| | - Olga A Dontsova
- Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Vladimir I Polshakov
- Center for Magnetic Tomography and Spectroscopy, Faculty of Fundamental Medicine, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991.
| |
Collapse
|
28
|
Shao Y, Feng S, Huang J, Huo J, You Y, Zheng Y. A unique homozygous WRAP53 Arg298Trp mutation underlies dyskeratosis congenita in a Chinese Han family. BMC MEDICAL GENETICS 2018. [PMID: 29514627 PMCID: PMC5842585 DOI: 10.1186/s12881-018-0549-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Dyskeratosis congenita (DC) is an inherited telomeropathy characterized by mucocutaneous dysplasia, bone marrow failure, cancer predisposition, and other somatic abnormalities. Cells from patients with DC exhibit short telomere. The genetic basis of the majority of DC cases remains unknown. METHODS A 2 generational Chinese Han family with DC was studied using targeted capture and next-generation sequencing to identify the underlying DC-related mutations. RESULTS In this study, we identified a unique homozygous WD repeat containing antisense to TP53 (WRAP53) Arg298Trp mutation in the proband with DC and heterozygous WRAP53 Arg298Trp mutations in his asymptomatic, consanguineous parents and his sister, indicating an autosomal recessive inheritance mode. The proband with the homozygous WRAP53 Arg298Trp mutation had short telomere, classic clinical symptoms, and no response to danazol, glucocorticoid or cyclosporin A. CONCLUSIONS Thus, we reported for the first time that a unique homozygous WRAP53 mutation site underlies the development of DC.
Collapse
Affiliation(s)
- Yingqi Shao
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China
| | - Sizhou Feng
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China.
| | - Jinbo Huang
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China
| | - Jiali Huo
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China
| | - Yahong You
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China
| | - Yizhou Zheng
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China.
| |
Collapse
|
29
|
Liu Y, Liu F, Cao Y, Xu H, Wu Y, Wu S, Liu D, Zhao Y, Songyang Z, Ma W. Shwachman-Diamond Syndrome Protein SBDS Maintains Human Telomeres by Regulating Telomerase Recruitment. Cell Rep 2018; 22:1849-1860. [PMID: 29444436 PMCID: PMC5844287 DOI: 10.1016/j.celrep.2018.01.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/20/2017] [Accepted: 01/19/2018] [Indexed: 01/15/2023] Open
Abstract
Shwachman-Diamond syndrome (SDS) is a rare pediatric disease characterized by various systemic disorders, including hematopoietic dysfunction. The mutation of Shwachman-Bodian-Diamond syndrome (SBDS) gene has been proposed to be a major causative reason for SDS. Although SBDS patients were reported to have shorter telomere length in granulocytes, the underlying mechanism is still unclear. Here we provide data to elucidate the role of SBDS in telomere protection. We demonstrate that SBDS deficiency leads to telomere shortening. We found that overexpression of disease-associated SBDS mutants or knockdown of SBDS hampered the recruitment of telomerase onto telomeres, while the overall reverse transcriptase activity of telomerase remained unaffected. Moreover, we show that SBDS could specifically bind to TPP1 during the S phase of cell cycle, likely functioning as a stabilizer for TPP1-telomerase interaction. Our findings suggest that SBDS is a telomere-protecting protein that participates in regulating telomerase recruitment.
Collapse
Affiliation(s)
- Yi Liu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Oncology in South China, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Feng Liu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Oncology in South China, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.
| | - Yizhao Cao
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Oncology in South China, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Huimin Xu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Oncology in South China, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Yangxiu Wu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Oncology in South China, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Su Wu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Oncology in South China, School of Life Sciences, 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
| | - Yong Zhao
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Oncology in South China, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhou Songyang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Oncology in South China, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China; Collaborative Innovation Center for Cancer Medicine, 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.
| | - Wenbin Ma
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Oncology in South China, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China; Collaborative Innovation Center for Cancer Medicine, Institute of Healthy Aging Research, Sun Yat-sen University, Guangzhou 510006, China.
| |
Collapse
|
30
|
Wang Y, Feigon J. Structural biology of telomerase and its interaction at telomeres. Curr Opin Struct Biol 2017; 47:77-87. [PMID: 28732250 PMCID: PMC5564310 DOI: 10.1016/j.sbi.2017.06.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 06/29/2017] [Indexed: 12/21/2022]
Abstract
Telomerase is an RNP that synthesizes the 3' ends of linear chromosomes and is an important regulator of telomere length. It contains a single long non-coding telomerase RNA (TER), telomerase reverse transcriptase (TERT), and other proteins that vary among organisms. Recent progress in structural biology of telomerase includes reports of the first cryo-electron microscopy structure of telomerase, from Tetrahymena, new crystal structures of TERT domains, telomerase RNA structures and models, and identification in Tetrahymena telomerase holoenzyme of human homologues of telomere-associated proteins that have provided a more unified view of telomerase interaction at telomeres as well as insights into the role of telomerase RNA in activity and assembly.
Collapse
Affiliation(s)
- Yaqiang Wang
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA 90095-1569, USA
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA 90095-1569, USA.
| |
Collapse
|
31
|
Bisht K, Grill S, Graniel J, Nandakumar J. A lentivirus-free inducible CRISPR-Cas9 system for efficient targeting of human genes. Anal Biochem 2017; 530:40-49. [PMID: 28477963 PMCID: PMC5501077 DOI: 10.1016/j.ab.2017.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/11/2017] [Accepted: 05/01/2017] [Indexed: 01/29/2023]
Abstract
CRISPR-Cas9 is a cutting-edge tool for modifying genomes. The efficacy with which Cas9 recognizes its target has revolutionized the engineering of knockouts. However this efficacy complicates the knocking out of important genes in cultured cells. Unedited cells holding a survival advantage within an edited population can confound the knockout phenotype. Here we develop a HeLa-based system that overcomes this limitation, incorporating several attractive features. First, we use Flp-recombinase to generate clones stably integrated for Cas9 and guide RNAs, eliminating the possibility of unedited cells. Second, Cas9 can be induced uniformly in the clonal cultures using doxycycline to measure the knockout phenotype. Third, two genes can be simultaneously knocked out using this approach. Finally, by not involving lentiviruses, our method is appealing to a broad research audience. Using this methodology we generated an inducible AGO2-knockout cell line showing normal RNA interference in the absence of doxycycline. Upon induction of Cas9, the AGO2 locus was cleaved, the AGO2 protein was depleted, and RNA interference was compromised. In addition to generating inducible knockouts, our technology can be adapted to improve other applications of Cas9, including transcriptional/epigenetic modulation and visualization of cellular DNA loci.
Collapse
Affiliation(s)
- Kamlesh Bisht
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sherilyn Grill
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jacqueline Graniel
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jayakrishnan Nandakumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| |
Collapse
|