1
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Singh M, Raseley K, Perez AM, MacKenzie D, Kosiyatrakul ST, Desai S, Batista N, Guru N, Loomba KK, Abid HZ, Wang Y, Udo-Bellner L, Stout RF, Schildkraut CL, Xiao M, Zhang D. Elucidation of the molecular mechanism of the breakage-fusion-bridge (BFB) cycle using a CRISPR-dCas9 cellular model. Nucleic Acids Res 2024:gkae747. [PMID: 39193906 DOI: 10.1093/nar/gkae747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 08/04/2024] [Accepted: 08/19/2024] [Indexed: 08/29/2024] Open
Abstract
Chromosome instability (CIN) is frequently observed in many tumors. The breakage-fusion-bridge (BFB) cycle has been proposed to be one of the main drivers of CIN during tumorigenesis and tumor evolution. However, the detailed mechanism for the individual steps of the BFB cycle warrants further investigation. Here, we demonstrate that a nuclease-dead Cas9 (dCas9) coupled with a telomere-specific single-guide RNA (sgTelo) can be used to model the BFB cycle. First, we show that targeting dCas9 to telomeres using sgTelo impedes DNA replication at telomeres and induces a pronounced increase of replication stress and DNA damage. Using Single-Molecule Telomere Assay via Optical Mapping (SMTA-OM), we investigate the genome-wide features of telomeres in the dCas9/sgTelo cells and observe a dramatic increase of chromosome end fusions, including fusion/ITS+ and fusion/ITS-. Consistently, we also observe an increase in the formation of dicentric chromosomes, anaphase bridges, and intercellular telomeric chromosome bridges (ITCBs). Utilizing the dCas9/sgTelo system, we uncover many interesting molecular and structural features of the ITCB and demonstrate that multiple DNA repair pathways are implicated in the formation of ITCBs. Our studies shed new light on the molecular mechanisms of the BFB cycle, which will advance our understanding of tumorigenesis, tumor evolution, and drug resistance.
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Affiliation(s)
- Manrose Singh
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
| | - Kaitlin Raseley
- School of Biomedical Engineering, Science and Health System, Drexel University, Philadelphia, PA 19104, USA
| | - Alexis M Perez
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
| | - Danny MacKenzie
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
| | | | - Sanket Desai
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
| | - Noelle Batista
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
| | - Navjot Guru
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
| | - Katherine K Loomba
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
| | - Heba Z Abid
- School of Biomedical Engineering, Science and Health System, Drexel University, Philadelphia, PA 19104, USA
| | - Yilin Wang
- School of Biomedical Engineering, Science and Health System, Drexel University, Philadelphia, PA 19104, USA
| | - Lars Udo-Bellner
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
| | - Randy F Stout
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
| | - Carl L Schildkraut
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ming Xiao
- School of Biomedical Engineering, Science and Health System, Drexel University, Philadelphia, PA 19104, USA
- Center for Genomic Sciences and Center for Advanced Microbial Processing, Institute of Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Dong Zhang
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
- Center for Cancer Research, New York Institute of Technology, Old Westbury, NY 11568, USA
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2
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Shi G, Pang Q, Lin Z, Zhang X, Huang K. Repetitive Sequence Stability in Embryonic Stem Cells. Int J Mol Sci 2024; 25:8819. [PMID: 39201503 PMCID: PMC11354519 DOI: 10.3390/ijms25168819] [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: 07/10/2024] [Revised: 08/07/2024] [Accepted: 08/12/2024] [Indexed: 09/02/2024] Open
Abstract
Repetitive sequences play an indispensable role in gene expression, transcriptional regulation, and chromosome arrangements through trans and cis regulation. In this review, focusing on recent advances, we summarize the epigenetic regulatory mechanisms of repetitive sequences in embryonic stem cells. We aim to bridge the knowledge gap by discussing DNA damage repair pathway choices on repetitive sequences and summarizing the significance of chromatin organization on repetitive sequences in response to DNA damage. By consolidating these insights, we underscore the critical relationship between the stability of repetitive sequences and early embryonic development, seeking to provide a deeper understanding of repetitive sequence stability and setting the stage for further research and potential therapeutic strategies in developmental biology and regenerative medicine.
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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; (Q.P.); (Z.L.); (X.Z.)
| | - Qianwen 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; (Q.P.); (Z.L.); (X.Z.)
| | - Zhancheng Lin
- 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; (Q.P.); (Z.L.); (X.Z.)
| | - Xinyi Zhang
- 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; (Q.P.); (Z.L.); (X.Z.)
| | - Kaimeng Huang
- Division of Radiation and Genome Stability, Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA;
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
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3
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Rodrigues J, Alfieri R, Bione S, Azzalin CM. TERRA ONTseq: a long-read-based sequencing pipeline to study the human telomeric transcriptome. RNA (NEW YORK, N.Y.) 2024; 30:955-966. [PMID: 38777382 PMCID: PMC11251519 DOI: 10.1261/rna.079906.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 05/05/2024] [Indexed: 05/25/2024]
Abstract
The long noncoding RNA TERRA is transcribed from telomeres in virtually all eukaryotes with linear chromosomes. In humans, TERRA transcription is driven in part by promoters comprising CpG dinucleotide-rich repeats of 29 bp repeats, believed to be present in half of the subtelomeres. Thus far, TERRA expression has been analyzed mainly using molecular biology-based approaches that only generate partial and somehow biased results. Here, we present a novel experimental pipeline to study human TERRA based on long-read sequencing (TERRA ONTseq). By applying TERRA ONTseq to different cell lines, we show that the vast majority of human telomeres produce TERRA and that the cellular levels of TERRA transcripts vary according to their chromosomes of origin. Using TERRA ONTseq, we also identified regions containing TERRA transcription start sites (TSSs) in more than half of human subtelomeres. TERRA TSS regions are generally found immediately downstream from 29 bp repeat-related sequences, which appear to be more widespread than previously estimated. Finally, we isolated a novel TERRA promoter from the highly expressed subtelomere of the long arm of Chromosome 7. With the development of TERRA ONTseq, we provide a refined picture of human TERRA biogenesis and expression and we equip the scientific community with an invaluable tool for future studies.
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Affiliation(s)
- Joana Rodrigues
- Instituto de Medicina Molecular João Lobo Antunes (iMM), Faculdade de Medicina da Universidade de Lisboa, Lisbon 1649-028, Portugal
| | - Roberta Alfieri
- Istituto di Genetica Molecolare Luigi Luca Cavalli-Sforza, Consiglio Nazionale delle Ricerche, Pavia 27100, Italy
- Istituto di Tecnologie Biomediche, Consiglio Nazionale delle Ricerche, Segrate (MI) 20054, Italy
| | - Silvia Bione
- Istituto di Genetica Molecolare Luigi Luca Cavalli-Sforza, Consiglio Nazionale delle Ricerche, Pavia 27100, Italy
| | - Claus M Azzalin
- Instituto de Medicina Molecular João Lobo Antunes (iMM), Faculdade de Medicina da Universidade de Lisboa, Lisbon 1649-028, Portugal
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4
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Kieft R, Reynolds D, Sabatini R. Epigenetic regulation of TERRA transcription and metacyclogenesis by base J in Leishmania major. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.27.601056. [PMID: 38979290 PMCID: PMC11230386 DOI: 10.1101/2024.06.27.601056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The hyper-modified DNA base J helps control termination of Pol II transcription at polycistronic transcription units (PTUs) in T. brucei and L. major , allowing epigenetic control of gene expression. The Telomere Repeat-containing RNA (TERRA) is synthesized in T. brucei by Pol I readthrough transcription of a telomeric PTU. While little is understood regarding TERRA synthesis and function, the hyper-modified DNA base J is highly enriched at telomeres in L. major promastigotes. We now show that TERRA is synthesized by Pol II in L. major and loss of base J leads to increased TERRA. For at least one site, the increased TERRA is by Pol II readthrough transcription from an adjacent PTU. Furthermore, Pol II readthrough defects and increased TERRA correlate with increased differentiation of promastigotes to the infectious metacyclic life stage and decreased cell viability. These results help explain the essential nature of base J in Leishmania and provide insight regarding epigenetic control of coding and non-coding RNA expression and parasite development during the life cycle of L. major .
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5
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Bettin N, Querido E, Gialdini I, Grupelli GP, Goretti E, Cantarelli M, Andolfato M, Soror E, Sontacchi A, Jurikova K, Chartrand P, Cusanelli E. TERRA transcripts localize at long telomeres to regulate telomerase access to chromosome ends. SCIENCE ADVANCES 2024; 10:eadk4387. [PMID: 38865460 PMCID: PMC11168465 DOI: 10.1126/sciadv.adk4387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 05/08/2024] [Indexed: 06/14/2024]
Abstract
The function of TERRA in the regulation of telomerase in human cells is still debated. While TERRA interacts with telomerase, how it regulates telomerase function remains unknown. Here, we show that TERRA colocalizes with the telomerase RNA subunit hTR in the nucleoplasm and at telomeres during different phases of the cell cycle. We report that TERRA transcripts relocate away from chromosome ends during telomere lengthening, leading to a reduced number of telomeric TERRA-hTR molecules and consequent increase in "TERRA-free" telomerase molecules at telomeres. Using live-cell imaging and super-resolution microscopy, we show that upon transcription, TERRA relocates from its telomere of origin to long chromosome ends. Furthermore, TERRA depletion by antisense oligonucleotides promoted hTR localization to telomeres, leading to increased residence time and extended half-life of hTR molecules at telomeres. Overall, our findings indicate that telomeric TERRA transcripts inhibit telomere elongation by telomerase acting in trans, impairing telomerase access to telomeres that are different from their chromosome end of origin.
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Affiliation(s)
- Nicole Bettin
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Emmanuelle Querido
- Department of Biochemistry and Molecular Medicine, University of Montreal, 2900 boul. Edouard Montpetit, H3T1J4 Montreal, Canada
| | - Irene Gialdini
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Glenda Paola Grupelli
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Elena Goretti
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Marta Cantarelli
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Marta Andolfato
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Eslam Soror
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Alessandra Sontacchi
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Katarina Jurikova
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina, 84215 Bratislava, Slovakia
| | - Pascal Chartrand
- Department of Biochemistry and Molecular Medicine, University of Montreal, 2900 boul. Edouard Montpetit, H3T1J4 Montreal, Canada
| | - Emilio Cusanelli
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
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6
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Karimian K, Groot A, Huso V, Kahidi R, Tan KT, Sholes S, Keener R, McDyer JF, Alder JK, Li H, Rechtsteiner A, Greider CW. Human telomere length is chromosome end-specific and conserved across individuals. Science 2024; 384:533-539. [PMID: 38603523 DOI: 10.1126/science.ado0431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 03/30/2024] [Indexed: 04/13/2024]
Abstract
Short telomeres cause age-related disease, and long telomeres contribute to cancer; however, the mechanisms regulating telomere length are unclear. We developed a nanopore-based method, which we call Telomere Profiling, to determine telomere length at nearly single-nucleotide resolution. Mapping telomere reads to chromosome ends showed chromosome end-specific length distributions that could differ by more than six kilobases. Examination of telomere lengths in 147 individuals revealed that certain chromosome ends were consistently longer or shorter. The same rank order was found in newborn cord blood, suggesting that telomere length is determined at birth and that chromosome end-specific telomere length differences are maintained as telomeres shorten with age. Telomere Profiling makes precision investigation of telomere length widely accessible for laboratory, clinical, and drug discovery efforts and will allow deeper insights into telomere biology.
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Affiliation(s)
- Kayarash Karimian
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Aljona Groot
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
| | - Vienna Huso
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ramin Kahidi
- Health Sciences Program, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Kar-Tong Tan
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Cancer Program, The Broad Institute, Cambridge, MA, USA
| | - Samantha Sholes
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rebecca Keener
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - John F McDyer
- Pulmonary, Allergy, Critical Care, and Sleep Medicine Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jonathan K Alder
- Pulmonary, Allergy, Critical Care, and Sleep Medicine Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Heng Li
- Department of Data Sciences, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Andreas Rechtsteiner
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
| | - Carol W Greider
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
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7
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Singh M, Raseley K, Perez AM, MacKenzie D, Kosiyatrakul ST, Desai S, Batista N, Guru N, Loomba KK, Abid HZ, Wang Y, Udo-Bellner L, Stout RF, Schildkraut CL, Xiao M, Zhang D. Elucidation of the molecular mechanism of the breakage-fusion-bridge (BFB) cycle using a CRISPR-dCas9 cellular model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.03.587951. [PMID: 38617299 PMCID: PMC11014597 DOI: 10.1101/2024.04.03.587951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Chromosome instability (CIN) is frequently observed in many tumors. The breakage-fusion-bridge (BFB) cycle has been proposed to be one of the main drivers of CIN during tumorigenesis and tumor evolution. However, the detailed mechanisms for the individual steps of the BFB cycle warrants further investigation. Here, we demonstrated that a nuclease-dead Cas9 (dCas9) coupled with a telomere-specific single-guide RNA (sgTelo) can be used to model the BFB cycle. First, we showed that targeting dCas9 to telomeres using sgTelo impeded DNA replication at telomeres and induced a pronounced increase of replication stress and DNA damage. Using Single-Molecule Telomere Assay via Optical Mapping (SMTA-OM), we investigated the genome-wide features of telomeres in the dCas9/sgTelo cells and observed a dramatic increase of chromosome end fusions, including fusion/ITS+ and fusion/ITS-.Consistently, we also observed an increase in the formation of dicentric chromosomes, anaphase bridges, and intercellular telomeric chromosome bridges (ITCBs). Utilizing the dCas9/sgTelo system, we uncovered many novel molecular and structural features of the ITCB and demonstrated that multiple DNA repair pathways are implicated in the formation of ITCBs. Our studies shed new light on the molecular mechanisms of the BFB cycle, which will advance our understanding of tumorigenesis, tumor evolution, and drug resistance.
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8
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Rivosecchi J, Jurikova K, Cusanelli E. Telomere-specific regulation of TERRA and its impact on telomere stability. Semin Cell Dev Biol 2024; 157:3-23. [PMID: 38088000 DOI: 10.1016/j.semcdb.2023.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 11/02/2023] [Indexed: 01/08/2024]
Abstract
TERRA is a class of telomeric repeat-containing RNAs that are expressed from telomeres in multiple organisms. TERRA transcripts play key roles in telomere maintenance and their physiological levels are essential to maintain the integrity of telomeric DNA. Indeed, deregulated TERRA expression or its altered localization can impact telomere stability by multiple mechanisms including fueling transcription-replication conflicts, promoting resection of chromosome ends, altering the telomeric chromatin, and supporting homologous recombination. Therefore, a fine-tuned control of TERRA is important to maintain the integrity of the genome. Several studies have reported that different cell lines express substantially different levels of TERRA. Most importantly, TERRA levels markedly vary among telomeres of a given cell type, indicating the existence of telomere-specific regulatory mechanisms which may help coordinate TERRA functions. TERRA molecules contain distinct subtelomeric sequences, depending on their telomere of origin, which may instruct specific post-transcriptional modifications or mediate distinct functions. In addition, all TERRA transcripts share a repetitive G-rich sequence at their 3' end which can form DNA:RNA hybrids and fold into G-quadruplex structures. Both structures are involved in TERRA functions and can critically affect telomere stability. In this review, we examine the mechanisms controlling TERRA levels and the impact of their telomere-specific regulation on telomere stability. We compare evidence obtained in different model organisms, discussing recent advances as well as controversies in the field. Furthermore, we discuss the importance of DNA:RNA hybrids and G-quadruplex structures in the context of TERRA biology and telomere maintenance.
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Affiliation(s)
- Julieta Rivosecchi
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Katarina Jurikova
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy; Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina, 84215 Bratislava, Slovakia
| | - Emilio Cusanelli
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy.
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9
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Vaid R, Thombare K, Mendez A, Burgos-Panadero R, Djos A, Jachimowicz D, Lundberg K, Bartenhagen C, Kumar N, Tümmler C, Sihlbom C, Fransson S, Johnsen J, Kogner P, Martinsson T, Fischer M, Mondal T. METTL3 drives telomere targeting of TERRA lncRNA through m6A-dependent R-loop formation: a therapeutic target for ALT-positive neuroblastoma. Nucleic Acids Res 2024; 52:2648-2671. [PMID: 38180812 PMCID: PMC10954483 DOI: 10.1093/nar/gkad1242] [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: 12/06/2022] [Revised: 12/08/2023] [Accepted: 12/18/2023] [Indexed: 01/07/2024] Open
Abstract
Telomerase-negative tumors maintain telomere length by alternative lengthening of telomeres (ALT), but the underlying mechanism behind ALT remains poorly understood. A proportion of aggressive neuroblastoma (NB), particularly relapsed tumors, are positive for ALT (ALT+), suggesting that a better dissection of the ALT mechanism could lead to novel therapeutic opportunities. TERRA, a long non-coding RNA (lncRNA) derived from telomere ends, localizes to telomeres in a R-loop-dependent manner and plays a crucial role in telomere maintenance. Here we present evidence that RNA modification at the N6 position of internal adenosine (m6A) in TERRA by the methyltransferase METTL3 is essential for telomere maintenance in ALT+ cells, and the loss of TERRA m6A/METTL3 results in telomere damage. We observed that m6A modification is abundant in R-loop enriched TERRA, and the m6A-mediated recruitment of hnRNPA2B1 to TERRA is critical for R-loop formation. Our findings suggest that m6A drives telomere targeting of TERRA via R-loops, and this m6A-mediated R-loop formation could be a widespread mechanism employed by other chromatin-interacting lncRNAs. Furthermore, treatment of ALT+ NB cells with a METTL3 inhibitor resulted in compromised telomere targeting of TERRA and accumulation of DNA damage at telomeres, indicating that METTL3 inhibition may represent a therapeutic approach for ALT+ NB.
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Affiliation(s)
- Roshan Vaid
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Ketan Thombare
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Akram Mendez
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Rebeca Burgos-Panadero
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Anna Djos
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Daniel Jachimowicz
- Translational Genomics, Discovery Biology, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Kristina Ihrmark Lundberg
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institute, and Pediatric Oncology, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Christoph Bartenhagen
- Department of Experimental Pediatric Oncology, University Children's Hospital of Cologne, Medical Faculty, Cologne, Germany, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany; Department of Pediatric Oncology and Hematology, University of Cologne, Cologne, Germany
| | - Navinder Kumar
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Conny Tümmler
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institute, and Pediatric Oncology, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Carina Sihlbom
- Proteomics Core Facility, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Susanne Fransson
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - John Inge Johnsen
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institute, and Pediatric Oncology, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Per Kogner
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institute, and Pediatric Oncology, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Tommy Martinsson
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Matthias Fischer
- Department of Experimental Pediatric Oncology, University Children's Hospital of Cologne, Medical Faculty, Cologne, Germany, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany; Department of Pediatric Oncology and Hematology, University of Cologne, Cologne, Germany
| | - Tanmoy Mondal
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Chemistry, Sahlgrenska University Hospital, University of Gothenburg, Gothenburg, 41345 Sweden
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10
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Karimian K, Groot A, Huso V, Kahidi R, Tan KT, Sholes S, Keener R, McDyer JF, Alder JK, Li H, Rechtsteiner A, Greider CW. Human telomere length is chromosome specific and conserved across individuals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.21.572870. [PMID: 38187739 PMCID: PMC10769321 DOI: 10.1101/2023.12.21.572870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Short telomeres cause age-related disease and long telomeres predispose to cancer; however, the mechanisms regulating telomere length are unclear. To probe these mechanisms, we developed a nanopore sequencing method, Telomere Profiling, that is easy to implement, precise, and cost effective with broad applications in research and the clinic. We sequenced telomeres from individuals with short telomere syndromes and found similar telomere lengths to the clinical FlowFISH assay. We mapped telomere reads to specific chromosome end and identified both chromosome end-specific and haplotype-specific telomere length distributions. In the T2T HG002 genome, where the average telomere length is 5kb, we found a remarkable 6kb difference in lengths between some telomeres. Further, we found that specific chromosome ends were consistently shorter or longer than the average length across 147 individuals. The presence of conserved chromosome end-specific telomere lengths suggests there are new paradigms in telomere biology that are yet to be explored. Understanding the mechanisms regulating length will allow deeper insights into telomere biology that can lead to new approaches to disease.
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Affiliation(s)
- Kayarash Karimian
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Aljona Groot
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz
| | - Vienna Huso
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | | | - Kar-Tong Tan
- Harvard Medical School, Department of Genetics, Boston, MA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
- Broad Institute, Cancer Program, Cambridge, MA
| | - Samantha Sholes
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Present address Merck & Co., 770 Sumneytown Pike, West Point, PA 19486
| | - Rebecca Keener
- Department of Biomedical Engineering, Johns Hopkins University
| | - John F. McDyer
- Pulmonary, Allergy, Critical Care, and Sleep Medicine Division, Department of Medicine, University of Pittsburgh
| | - Jonathan K. Alder
- Pulmonary, Allergy, Critical Care, and Sleep Medicine Division, Department of Medicine, University of Pittsburgh
| | - Heng Li
- Dana-Farber Cancer Institute, Department of Data Sciences, Boston, MA
- Harvard Medical School, Department of Biomedical Informatics, Boston, MA
| | - Andreas Rechtsteiner
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz
| | - Carol W. Greider
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz
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11
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Wang Y, Zhu W, Jang Y, Sommers JA, Yi G, Puligilla C, Croteau DL, Yang Y, Kai M, Liu Y. The RNA-binding motif protein 14 regulates telomere integrity at the interface of TERRA and telomeric R-loops. Nucleic Acids Res 2023; 51:12242-12260. [PMID: 37930826 PMCID: PMC10711441 DOI: 10.1093/nar/gkad967] [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: 02/09/2023] [Accepted: 10/13/2023] [Indexed: 11/08/2023] Open
Abstract
Telomeric repeat-containing RNA (TERRA) and its formation of RNA:DNA hybrids (or TERRA R-loops), influence telomere maintenance, particularly in human cancer cells that use homologous recombination-mediated alternative lengthening of telomeres. Here, we report that the RNA-binding motif protein 14 (RBM14) is associated with telomeres in human cancer cells. RBM14 negatively regulates TERRA expression. It also binds to TERRA and inhibits it from forming TERRA R-loops at telomeres. RBM14 depletion has several effects, including elevated TERRA levels, telomeric R-loops, telomere dysfunction-induced DNA damage foci formation, particularly in the presence of DNA replication stress, pRPA32 accumulation at telomeres and telomere signal-free ends. Thus, RBM14 protects telomere integrity via modulating TERRA levels and its R-loop formation at telomeres.
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Affiliation(s)
- Yajun Wang
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Wei Zhu
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
| | - Yumi Jang
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Joshua A Sommers
- Translational Gerontology Branch, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
| | - Gong Yi
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
| | - Chandrakala Puligilla
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
| | - Deborah L Croteau
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
| | - Yibin Yang
- Blood Cell Development and Function Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Mihoko Kai
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Yie Liu
- Laboratory of Genetics and Genomics, 251 Bayview Blvd, National Institute on Aging/National Institutes of Health, Baltimore, MD 21224, USA
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12
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Melnikova L, Golovnin A. Multiple Roles of dXNP and dADD1- Drosophila Orthologs of ATRX Chromatin Remodeler. Int J Mol Sci 2023; 24:16486. [PMID: 38003676 PMCID: PMC10671109 DOI: 10.3390/ijms242216486] [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: 10/09/2023] [Revised: 11/11/2023] [Accepted: 11/16/2023] [Indexed: 11/26/2023] Open
Abstract
The Drosophila melanogaster dADD1 and dXNP proteins are orthologues of the ADD and SNF2 domains of the vertebrate ATRX (Alpha-Thalassemia with mental Retardation X-related) protein. ATRX plays a role in general molecular processes, such as regulating chromatin status and gene expression, while dADD1 and dXNP have similar functions in the Drosophila genome. Both ATRX and dADD1/dXNP interact with various protein partners and participate in various regulatory complexes. Disruption of ATRX expression in humans leads to the development of α-thalassemia and cancer, especially glioma. However, the mechanisms that allow ATRX to regulate various cellular processes are poorly understood. Studying the functioning of dADD1/dXNP in the Drosophila model may contribute to understanding the mechanisms underlying the multifunctional action of ATRX and its connection with various cellular processes. This review provides a brief overview of the currently available information in mammals and Drosophila regarding the roles of ATRX, dXNP, and dADD1. It discusses possible mechanisms of action of complexes involving these proteins.
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Affiliation(s)
- Larisa Melnikova
- Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
| | - Anton Golovnin
- Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
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13
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Manzato C, Larini L, Oss Pegorar C, Dello Stritto MR, Jurikova K, Jantsch V, Cusanelli E. TERRA expression is regulated by the telomere-binding proteins POT-1 and POT-2 in Caenorhabditis elegans. Nucleic Acids Res 2023; 51:10681-10699. [PMID: 37713629 PMCID: PMC10602879 DOI: 10.1093/nar/gkad742] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/23/2023] [Accepted: 08/31/2023] [Indexed: 09/17/2023] Open
Abstract
Several aspects of telomere biology are regulated by the telomeric repeat-containing RNA TERRA. While TERRA expression is conserved through evolution, species-specific mechanisms regulate its biogenesis and function. Here we report on the expression of TERRA in Caenorhabditis elegans. We show that C. elegans TERRA is regulated by the telomere-binding proteins POT-1 and POT-2 which repress TERRA in a telomere-specific manner. C. elegans TERRA transcripts are heterogeneous in length and form discrete nuclear foci, as detected by RNA FISH, in both postmitotic and germline cells; a fraction of TERRA foci localizes to telomeres. Interestingly, in germ cells, TERRA is expressed in all stages of meiotic prophase I, and it increases during pachytene, a stage in meiosis when homologous recombination is ongoing. We used the MS2-GFP system to study the spatiotemporal dynamics of single-telomere TERRA molecules. Single particle tracking revealed different types of motilities, suggesting complex dynamics of TERRA transcripts. Finally, we unveiled distinctive features of C. elegans TERRA, which is regulated by telomere shortening in a telomere-specific manner, and it is upregulated in the telomerase-deficient trt-1; pot-2 double mutant prior to activation of the alternative lengthening mechanism ALT. Interestingly, in these worms TERRA displays distinct dynamics with a higher fraction of fast-moving particles.
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Affiliation(s)
- Caterina Manzato
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, 38123, Trento, Italy
| | - Luca Larini
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, 38123, Trento, Italy
| | - Claudio Oss Pegorar
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, 38123, Trento, Italy
| | - Maria Rosaria Dello Stritto
- Department of Chromosome Biology, Max Perutz Laboratories, University of Vienna, Vienna Biocenter 1030, Vienna, Austria
| | - Katarina Jurikova
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, 38123, Trento, Italy
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina 84215, Bratislava, Slovakia
| | - Verena Jantsch
- Department of Chromosome Biology, Max Perutz Laboratories, University of Vienna, Vienna Biocenter 1030, Vienna, Austria
| | - Emilio Cusanelli
- Laboratory of Cell Biology and Molecular Genetics, Department CIBIO, University of Trento, 38123, Trento, Italy
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14
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Sutterlüty H, Bargl M, Holzmann K. Quantifying telomere transcripts as tool to improve risk assessment for genetic instability and genotoxicity. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2023; 891:503690. [PMID: 37770147 DOI: 10.1016/j.mrgentox.2023.503690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/18/2023] [Accepted: 09/04/2023] [Indexed: 10/03/2023]
Abstract
Telomere repeat-containing RNAs (TERRA) are transcribed from telomeres as long non-coding RNAs and are part of the telomere structure with protective function. The genetic stability of cells requires telomeric repeats at the ends of chromosomes. Maintenance of telomere length (TL) is essential for proliferative capacity and chromosomal integrity. In contrast, telomere shortening is a recognized risk factor for carcinogenesis and a biomarker of aging due to the cumulative effects of environmental exposures and life experiences such as trauma or stress. In this context, telomere repeats are lost due to cell proliferation, but are also susceptible to stress factors including reactive oxygen species (ROS) inducing oxidative base damage. Quantitative PCR (qPCR) of genomic DNA is an established method to analyze TL as a tool to detect genotoxic events. That same qPCR method can be applied to RNA converted into cDNA to quantify TERRA as a useful tool to perform high-throughput screenings. This short review summarizes relevant qPCR studies using both TL and TERRA quantification, provides an overall view of the molecular mechanisms of telomere protection against ROS by TERRA, and summarizes the presented studies comparing the results at DNA and RNA levels, which indicate that fluctuations at transcript level might reflect a short-term response. Therefore, we conclude that performing both of these measurements together will improve genotoxicity studies.
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Affiliation(s)
- Hedwig Sutterlüty
- Center for Cancer Research, Comprehensive Cancer Center, Medical University Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Maximilian Bargl
- Center for Cancer Research, Comprehensive Cancer Center, Medical University Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Klaus Holzmann
- Center for Cancer Research, Comprehensive Cancer Center, Medical University Vienna, Borschkegasse 8a, A-1090 Vienna, Austria.
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15
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Iyer SS, Sun Y, Seyfferth J, Manjunath V, Samata M, Alexiadis A, Kulkarni T, Gutierrez N, Georgiev P, Shvedunova M, Akhtar A. The NSL complex is required for piRNA production from telomeric clusters. Life Sci Alliance 2023; 6:e202302194. [PMID: 37399316 PMCID: PMC10313855 DOI: 10.26508/lsa.202302194] [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: 05/31/2023] [Revised: 06/15/2023] [Accepted: 06/20/2023] [Indexed: 07/05/2023] Open
Abstract
The NSL complex is a transcriptional activator. Germline-specific knockdown of NSL complex subunits NSL1, NSL2, and NSL3 results in reduced piRNA production from a subset of bidirectional piRNA clusters, accompanied by widespread transposon derepression. The piRNAs most transcriptionally affected by NSL2 and NSL1 RNAi map to telomeric piRNA clusters. At the chromatin level, these piRNA clusters also show decreased levels of H3K9me3, HP1a, and Rhino after NSL2 depletion. Using NSL2 ChIP-seq in ovaries, we found that this protein specifically binds promoters of telomeric transposons HeT-A, TAHRE, and TART Germline-specific depletion of NSL2 also led to a reduction in nuclear Piwi in nurse cells. Our findings thereby support a role for the NSL complex in promoting the transcription of piRNA precursors from telomeric piRNA clusters and in regulating Piwi levels in the Drosophila female germline.
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Affiliation(s)
- Shantanu S Iyer
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg im Breisgau, Germany
- Faculty of Biology, University of Freiburg, Freiburg im Breisgau, Germany
| | - Yidan Sun
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Janine Seyfferth
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Vinitha Manjunath
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Maria Samata
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Anastasios Alexiadis
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Tanvi Kulkarni
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Noel Gutierrez
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Plamen Georgiev
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Maria Shvedunova
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Asifa Akhtar
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
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16
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Rivosecchi J, Cusanelli E. TERRA beyond cancer: the biology of telomeric repeat-containing RNAs in somatic and germ cells. FRONTIERS IN AGING 2023; 4:1224225. [PMID: 37636218 PMCID: PMC10448526 DOI: 10.3389/fragi.2023.1224225] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/31/2023] [Indexed: 08/29/2023]
Abstract
The telomeric noncoding RNA TERRA is a key component of telomeres and it is widely expressed in normal as well as cancer cells. In the last 15 years, several publications have shed light on the role of TERRA in telomere homeostasis and cell survival in cancer cells. However, only few studies have investigated the regulation or the functions of TERRA in normal tissues. A better understanding of the biology of TERRA in non-cancer cells may provide unexpected insights into how these lncRNAs are transcribed and operate in cells, and their potential role in physiological processes, such as aging, age-related pathologies, inflammatory processes and human genetic diseases. In this review we aim to discuss the findings that have advanced our understanding of the biology of TERRA using non-cancer mammalian cells as a model system.
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Affiliation(s)
- Julieta Rivosecchi
- Laboratory of Cell Biology and Molecular Genetics, Department of Cellular, Computational and Integrative Biology—CIBIO, University of Trento, Trento, Italy
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17
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Biswas U, Deb Mallik T, Pschirer J, Lesche M, Sameith K, Jessberger R. Cohesin SMC1β promotes closed chromatin and controls TERRA expression at spermatocyte telomeres. Life Sci Alliance 2023; 6:e202201798. [PMID: 37160312 PMCID: PMC10172765 DOI: 10.26508/lsa.202201798] [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: 11/03/2022] [Revised: 04/26/2023] [Accepted: 04/26/2023] [Indexed: 05/11/2023] Open
Abstract
Previous data showed that meiotic cohesin SMC1β protects spermatocyte telomeres from damage. The underlying reason, however, remained unknown as the expressions of telomerase and shelterin components were normal in Smc1β -/- spermatocytes. Here. we report that SMC1β restricts expression of the long noncoding RNA TERRA (telomeric repeat containing RNA) in spermatocytes. In somatic cell lines increased TERRA was reported to cause telomere damage through altering telomere chromatin structure. In Smc1β -/- spermatocytes, we observed strongly increased levels of TERRA which accumulate on damaged chromosomal ends, where enhanced R-loop formation was found. This suggested a more open chromatin configuration near telomeres in Smc1β -/- spermatocytes, which was confirmed by ATAC-seq. Telomere-distal regions were not affected by the absence of SMC1β but RNA-seq revealed increased transcriptional activity in telomere-proximal regions. Thus, SMC1β promotes closed chromatin specifically near telomeres and limits TERRA expression in spermatocytes.
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Affiliation(s)
- Uddipta Biswas
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Tanaya Deb Mallik
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Johannes Pschirer
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Matthias Lesche
- Center for Molecular and Cellular Bioengineering, Genome Center Technology Platform, Dresden, Germany
| | - Katrin Sameith
- Center for Molecular and Cellular Bioengineering, Genome Center Technology Platform, Dresden, Germany
| | - Rolf Jessberger
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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18
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Clatterbuck Soper SF, Meltzer PS. ATRX/DAXX: Guarding the Genome against the Hazards of ALT. Genes (Basel) 2023; 14:genes14040790. [PMID: 37107548 PMCID: PMC10137841 DOI: 10.3390/genes14040790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/21/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023] Open
Abstract
Proliferating cells must enact a telomere maintenance mechanism to ensure genomic stability. In a subset of tumors, telomeres are maintained not by telomerase, but through a homologous recombination-based mechanism termed Alternative Lengthening of Telomeres or ALT. The ALT process is linked to mutations in the ATRX/DAXX/H3.3 histone chaperone complex. This complex is responsible for depositing non-replicative histone variant H3.3 at pericentric and telomeric heterochromatin but has also been found to have roles in ameliorating replication in repeat sequences and in promoting DNA repair. In this review, we will discuss ways in which ATRX/DAXX helps to protect the genome, and how loss of this complex allows ALT to take hold.
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19
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Chen L, Zhang C, Ma W, Huang J, Zhao Y, Liu H. METTL3-mediated m6A modification stabilizes TERRA and maintains telomere stability. Nucleic Acids Res 2022; 50:11619-11634. [PMID: 36399511 PMCID: PMC9723618 DOI: 10.1093/nar/gkac1027] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 09/23/2022] [Accepted: 10/21/2022] [Indexed: 11/19/2022] Open
Abstract
Telomeric repeat-containing RNA (TERRA) is a type of long non-coding RNA transcribed from telomeres, and it forms R-loops by invasion into telomeric DNA. Since either an excessive or inadequate number of R-loops leads to telomere instability, the TERRA levels need to be delicately modulated. In this study, we found that m6A modification presents on the subtelomeric regions of TERRA and stabilizes it, and the loss of METTL3 impacts telomere stability. Mechanically, the m6A modification on TERRA is catalyzed by METTL3, recognized and stabilized by the m6A reader YTHDC1. Knockdown of either METTL3 or YTHDC1 enhances TERRA degradation. The m6A-modified TERRA forms R-loops and promotes homologous recombination which is essential for the alternative lengthening of telomeres (ALT) pathway in cancer cells. METTL3 depletion leads to R-loop reduction, telomere shortening and instability. Altogether, these findings reveal that METTL3 protects telomeres by catalyzing m6A modification on TERRA, indicating that inhibition or deletion of METTL3 is potentially a new avenue for ALT cancer therapy.
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Affiliation(s)
| | | | - Wenbin Ma
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Junjiu Huang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
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20
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Takeuchi C, Yokoshi M, Kondo S, Shibuya A, Saito K, Fukaya T, Siomi H, Iwasaki Y. Mod(mdg4) variants repress telomeric retrotransposon HeT-A by blocking subtelomeric enhancers. Nucleic Acids Res 2022; 50:11580-11599. [PMID: 36373634 PMCID: PMC9723646 DOI: 10.1093/nar/gkac1034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/17/2022] [Accepted: 10/22/2022] [Indexed: 11/16/2022] Open
Abstract
Telomeres in Drosophila are composed of sequential non-LTR retrotransposons HeT-A, TART and TAHRE. Although they are repressed by the PIWI-piRNA pathway or heterochromatin in the germline, the regulation of these retrotransposons in somatic cells is poorly understood. In this study, we demonstrated that specific splice variants of Mod(mdg4) repress HeT-A by blocking subtelomeric enhancers in ovarian somatic cells. Among the variants, we found that the Mod(mdg4)-N variant represses HeT-A expression the most efficiently. Subtelomeric sequences bound by Mod(mdg4)-N block enhancer activity within subtelomeric TAS-R repeats. This enhancer-blocking activity is increased by the tandem association of Mod(mdg4)-N to repetitive subtelomeric sequences. In addition, the association of Mod(mdg4)-N couples with the recruitment of RNA polymerase II to the subtelomeres, which reinforces its enhancer-blocking function. Our findings provide novel insights into how telomeric retrotransposons are regulated by the specific variants of insulator proteins associated with subtelomeric sequences.
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Affiliation(s)
- Chikara Takeuchi
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Moe Yokoshi
- Laboratory of Transcription Dynamics, Research Center for Biological Visualization, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo 113-0032, Japan
| | - Shu Kondo
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Shizuoka 411-8540, Japan
| | - Aoi Shibuya
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kuniaki Saito
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Shizuoka 411-8540, Japan
| | - Takashi Fukaya
- Laboratory of Transcription Dynamics, Research Center for Biological Visualization, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 113-0032, Japan
| | | | - Yuka W Iwasaki
- To whom correspondence should be addressed. Tel: +81 3 5363 3529; Fax: +81 3 5363 3266;
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21
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Ectopic expression of meiotic cohesin generates chromosome instability in cancer cell line. Proc Natl Acad Sci U S A 2022; 119:e2204071119. [PMID: 36179046 PMCID: PMC9549395 DOI: 10.1073/pnas.2204071119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
This work originated from mining of cancer genome data and proceeded to analyze the effects of ectopic expression of meiotic cohesins in mitotic cells in culture. In the process, apart from conclusively answering the question on mechanisms for RAD21L toxicity and its underrepresentation in tumor transcriptomes, we found an association of meiotic cohesin binding with BORIS/CTCFL sites in the normal testis. We also elucidated the patterns and outcomes of meiotic cohesin binding to chromosomes in model cell lines. Furthermore, we uncovered that RAD21L-based meiotic cohesin possesses a self-contained chromosome restructuring activity able to trigger sustainable but imperfect mitotic arrest leading to chromosomal instability. The discovered epigenomic and genetic mechanisms can be relevant to chromosome instability in cancer. Many tumors express meiotic genes that could potentially drive somatic chromosome instability. While germline cohesin subunits SMC1B, STAG3, and REC8 are widely expressed in many cancers, messenger RNA and protein for RAD21L subunit are expressed at very low levels. To elucidate the potential of meiotic cohesins to contribute to genome instability, their expression was investigated in human cell lines, predominately in DLD-1. While the induction of the REC8 complex resulted in a mild mitotic phenotype, the expression of the RAD21L complex produced an arrested but viable cell pool, thus providing a source of DNA damage, mitotic chromosome missegregation, sporadic polyteny, and altered gene expression. We also found that genomic binding profiles of ectopically expressed meiotic cohesin complexes were reminiscent of their corresponding specific binding patterns in testis. Furthermore, meiotic cohesins were found to localize to the same sites as BORIS/CTCFL, rather than CTCF sites normally associated with the somatic cohesin complex. These findings highlight the existence of a germline epigenomic memory that is conserved in cells that normally do not express meiotic genes. Our results reveal a mechanism of action by unduly expressed meiotic cohesins that potentially links them to aneuploidy and chromosomal mutations in affected cells.
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22
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Gershman A, Sauria MEG, Guitart X, Vollger MR, Hook PW, Hoyt SJ, Jain M, Shumate A, Razaghi R, Koren S, Altemose N, Caldas GV, Logsdon GA, Rhie A, Eichler EE, Schatz MC, O'Neill RJ, Phillippy AM, Miga KH, Timp W. Epigenetic patterns in a complete human genome. Science 2022; 376:eabj5089. [PMID: 35357915 PMCID: PMC9170183 DOI: 10.1126/science.abj5089] [Citation(s) in RCA: 116] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The completion of a telomere-to-telomere human reference genome, T2T-CHM13, has resolved complex regions of the genome, including repetitive and homologous regions. Here, we present a high-resolution epigenetic study of previously unresolved sequences, representing entire acrocentric chromosome short arms, gene family expansions, and a diverse collection of repeat classes. This resource precisely maps CpG methylation (32.28 million CpGs), DNA accessibility, and short-read datasets (166,058 previously unresolved chromatin immunoprecipitation sequencing peaks) to provide evidence of activity across previously unidentified or corrected genes and reveals clinically relevant paralog-specific regulation. Probing CpG methylation across human centromeres from six diverse individuals generated an estimate of variability in kinetochore localization. This analysis provides a framework with which to investigate the most elusive regions of the human genome, granting insights into epigenetic regulation.
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Affiliation(s)
- Ariel Gershman
- Department of Molecular Biology and Genetics, Johns Hopkins University, Baltimore, MD, USA
| | - Michael E G Sauria
- Department of Biology and Computer Science, Johns Hopkins University, Baltimore, MD, USA
| | - Xavi Guitart
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Mitchell R Vollger
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Paul W Hook
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Savannah J Hoyt
- Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Miten Jain
- UC Santa Cruz Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Alaina Shumate
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Roham Razaghi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Sergey Koren
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Nicolas Altemose
- Department of Bioengineering, University of California Berkeley, Berkeley, CA, USA
| | - Gina V Caldas
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley CA, USA
| | - Glennis A Logsdon
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Arang Rhie
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Evan E Eichler
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA
| | - Michael C Schatz
- Department of Biology and Computer Science, Johns Hopkins University, Baltimore, MD, USA
| | - Rachel J O'Neill
- Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Adam M Phillippy
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Karen H Miga
- UC Santa Cruz Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Winston Timp
- Department of Molecular Biology and Genetics, Johns Hopkins University, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
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23
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Vourc’h C, Dufour S, Timcheva K, Seigneurin-Berny D, Verdel A. HSF1-Activated Non-Coding Stress Response: Satellite lncRNAs and Beyond, an Emerging Story with a Complex Scenario. Genes (Basel) 2022; 13:genes13040597. [PMID: 35456403 PMCID: PMC9032817 DOI: 10.3390/genes13040597] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/18/2022] [Accepted: 03/19/2022] [Indexed: 12/21/2022] Open
Abstract
In eukaryotes, the heat shock response is orchestrated by a transcription factor named Heat Shock Factor 1 (HSF1). HSF1 is mostly characterized for its role in activating the expression of a repertoire of protein-coding genes, including the heat shock protein (HSP) genes. Remarkably, a growing set of reports indicate that, upon heat shock, HSF1 also targets various non-coding regions of the genome. Focusing primarily on mammals, this review aims at reporting the identity of the non-coding genomic sites directly bound by HSF1, and at describing the molecular function of the long non-coding RNAs (lncRNAs) produced in response to HSF1 binding. The described non-coding genomic targets of HSF1 are pericentric Satellite DNA repeats, (sub)telomeric DNA repeats, Short Interspersed Nuclear Element (SINE) repeats, transcriptionally active enhancers and the NEAT1 gene. This diverse set of non-coding genomic sites, which already appears to be an integral part of the cellular response to stress, may only represent the first of many. Thus, the study of the evolutionary conserved heat stress response has the potential to emerge as a powerful cellular context to study lncRNAs, produced from repeated or unique DNA regions, with a regulatory function that is often well-documented but a mode of action that remains largely unknown.
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Affiliation(s)
- Claire Vourc’h
- Université de Grenoble Alpes (UGA), 38700 La Tronche, France
- Correspondence: (C.V.); (A.V.)
| | - Solenne Dufour
- Institute for Advanced Biosciences (IAB), Centre de Recherche UGA/Inserm U 1209/CNRS UMR 5309, Site Santé-Allée des Alpes, 38700 La Tronche, France; (S.D.); (K.T.); (D.S.-B.)
| | - Kalina Timcheva
- Institute for Advanced Biosciences (IAB), Centre de Recherche UGA/Inserm U 1209/CNRS UMR 5309, Site Santé-Allée des Alpes, 38700 La Tronche, France; (S.D.); (K.T.); (D.S.-B.)
| | - Daphné Seigneurin-Berny
- Institute for Advanced Biosciences (IAB), Centre de Recherche UGA/Inserm U 1209/CNRS UMR 5309, Site Santé-Allée des Alpes, 38700 La Tronche, France; (S.D.); (K.T.); (D.S.-B.)
| | - André Verdel
- Institute for Advanced Biosciences (IAB), Centre de Recherche UGA/Inserm U 1209/CNRS UMR 5309, Site Santé-Allée des Alpes, 38700 La Tronche, France; (S.D.); (K.T.); (D.S.-B.)
- Correspondence: (C.V.); (A.V.)
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24
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Methylation of Subtelomeric Chromatin Modifies the Expression of the lncRNA TERRA, Disturbing Telomere Homeostasis. Int J Mol Sci 2022; 23:ijms23063271. [PMID: 35328692 PMCID: PMC8955364 DOI: 10.3390/ijms23063271] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/08/2022] [Accepted: 03/10/2022] [Indexed: 02/01/2023] Open
Abstract
The long noncoding RNA (lncRNA) telomeric repeat-containing RNA (TERRA) has been associated with telomeric homeostasis, telomerase recruitment, and the process of chromosome healing; nevertheless, the impact of this association has not been investigated during the carcinogenic process. Determining whether changes in TERRA expression are a cause or a consequence of cell transformation is a complex task because studies are usually carried out using either cancerous cells or tumor samples. To determine the role of this lncRNA in cellular aging and chromosome healing, we evaluated telomeric integrity and TERRA expression during the establishment of a clone of untransformed myeloid cells. We found that reduced expression of TERRA disturbed the telomeric homeostasis of certain loci, but the expression of the lncRNA was affected only when the methylation of subtelomeric bivalent chromatin domains was compromised. We conclude that the disruption in TERRA homeostasis is a consequence of cellular transformation and that changes in its expression profile can lead to telomeric and genomic instability.
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25
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Telomeric Repeat-Containing RNA (TERRA): A Review of the Literature and First Assessment in Cutaneous T-Cell Lymphomas. Genes (Basel) 2022; 13:genes13030539. [PMID: 35328092 PMCID: PMC8953746 DOI: 10.3390/genes13030539] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/14/2022] [Accepted: 03/16/2022] [Indexed: 01/11/2023] Open
Abstract
Telomeric Repeat-containing RNA (TERRA) are long non-coding RNAs transcribed from telomeric DNA sequences from multiple chromosome ends. Major research efforts have been made to understand TERRA roles and functions in several physiological and pathological processes. We summarize herein available data regarding TERRA’s roles in human cells and we report the first investigation in cutaneous T-cells lymphomas (CTCL) using real-time PCR. Among the TERRA analysed, our data suggest a particular role for TERRA 16p downregulation and TERRA 11q upregulation in CTCL lymphomagenesis.
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26
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Dinami R, Petti E, Porru M, Rizzo A, Ganci F, Sacconi A, Ostano P, Chiorino G, Trusolino L, Blandino G, Ciliberto G, Zizza P, Biroccio A. TRF2 cooperates with CTCF for controlling the oncomiR-193b-3p in colorectal cancer. Cancer Lett 2022; 533:215607. [PMID: 35240232 DOI: 10.1016/j.canlet.2022.215607] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 02/11/2022] [Accepted: 02/24/2022] [Indexed: 12/14/2022]
Abstract
The Telomeric Repeat binding Factor 2 (TRF2), a key protein involved in telomere integrity, is over-expressed in several human cancers and promotes tumor formation and progression. Recently, TRF2 has been also found outside telomeres where it can affect gene expression. Here we provide evidence that TRF2 is able to modulate the expression of microRNAs (miRNAs), small non-coding RNAs altered in human tumors. Among the miRNAs regulated by TRF2, we focused on miR-193b-3p, an oncomiRNA that positively correlates with TRF2 expression in human colorectal cancer patients from The Cancer Genome Atlas dataset. At the mechanistic level, the control of miR-193b-3p expression requires the cooperative activity between TRF2 and the chromatin organization factor CTCF. We found that CTCF physically interacts with TRF2, thus driving the proper positioning of TRF2 on a binding site located upstream the miR-193b-3p host-gene. The binding of TRF2 on the identified region is necessary for promoting the expression of miR-193b3p which, in turn, inhibits the translation of the onco-suppressive methyltransferase SUV39H1 and promotes tumor cell proliferation. The translational relevance of the oncogenic properties of miR-193b-3p was confirmed in patients, in whom the association between TRF2 and miR-193b-3p has a prognostic value.
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Affiliation(s)
- Roberto Dinami
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, via Elio Chianesi 53, Rome, 00144, Italy
| | - Eleonora Petti
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, via Elio Chianesi 53, Rome, 00144, Italy
| | - Manuela Porru
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, via Elio Chianesi 53, Rome, 00144, Italy
| | - Angela Rizzo
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, via Elio Chianesi 53, Rome, 00144, Italy
| | - Federica Ganci
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, via Elio Chianesi 53, Rome, 00144, Italy
| | - Andrea Sacconi
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, via Elio Chianesi 53, Rome, 00144, Italy
| | - Paola Ostano
- Cancer Genomics Lab, Fondazione Edo ed Elvo Tempia, via Malta 3, Biella, 13900, Italy
| | - Giovanna Chiorino
- Cancer Genomics Lab, Fondazione Edo ed Elvo Tempia, via Malta 3, Biella, 13900, Italy
| | - Livio Trusolino
- Department of Oncology, University of Torino, Strada Provinciale 142, Candiolo, TO, 10060, Italy; Laboratory of Translational Cancer Medicine, Candiolo Cancer Institute, FPO - IRCCS, Strada Provinciale 142, Candiolo, TO, 10060, Italy
| | - Giovanni Blandino
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, via Elio Chianesi 53, Rome, 00144, Italy
| | - Gennaro Ciliberto
- Scientific Direction, IRCCS - Regina Elena National Cancer Institute, via Elio Chianesi 53, Rome, 00144, Italy
| | - Pasquale Zizza
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, via Elio Chianesi 53, Rome, 00144, Italy.
| | - Annamaria Biroccio
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, via Elio Chianesi 53, Rome, 00144, Italy.
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27
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Sharaf R, Montesion M, Hopkins JF, Song J, Frampton GM, Albacker LA. A pan-cancer landscape of telomeric content shows that RAD21 and HGF alterations are associated with longer telomeres. Genome Med 2022; 14:25. [PMID: 35227290 PMCID: PMC8883689 DOI: 10.1186/s13073-022-01029-7] [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: 08/04/2021] [Accepted: 02/11/2022] [Indexed: 01/02/2023] Open
Abstract
Background Cancer cells can proliferate indefinitely through telomere maintenance mechanisms. These mechanisms include telomerase-dependent elongation, mediated by TERT activation, and alternative lengthening of telomeres (ALT), linked to loss of ATRX or DAXX. Methods We analyzed the telomeric content of 89,959 tumor samples within the Foundation Medicine dataset and investigated the genomic determinants of high telomeric content, linking them to clinical outcomes, when available. Results Telomeric content varied widely by disease type with leiomyosarcoma having the highest and Merkel cell carcinoma having the lowest telomeric content. In agreement with previous studies, telomeric content was significantly higher in samples with alterations in TERC, ATRX, and DAXX. We further identified that amplifications in two genes, RAD21 and HGF, were enriched in samples with high telomeric content, which was confirmed using the PCAWG/ICGC dataset. We identified the minimal amplified region associated with high telomeric content for RAD21 (8q23.1–8q24.12), which excludes MYC, and for HGF (7q21.11). Our results demonstrated that RAD21 and HGF exerted an additive telomere lengthening effect on samples with existing alterations in canonical genes previously associated with telomere elongation. Furthermore, patients with breast cancer who harbor RAD21 alterations had poor median overall survival and trended towards higher levels of Ki-67 staining. Conclusions This study highlights the importance of the role played by RAD21 (8q23.1–8q24.12) and HGF (7q21.11) in the lengthening of telomeres, supporting unlimited replication in tumors. These findings open avenues for work aimed at targeting this crucial pathway in tumorigenesis. Supplementary Information The online version contains supplementary material available at 10.1186/s13073-022-01029-7.
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Affiliation(s)
- Radwa Sharaf
- Foundation Medicine Inc, 150 Second Street, Cambridge, MA, 02141, USA
| | - Meagan Montesion
- Foundation Medicine Inc, 150 Second Street, Cambridge, MA, 02141, USA
| | - Julia F Hopkins
- Foundation Medicine Inc, 150 Second Street, Cambridge, MA, 02141, USA
| | - Jiarong Song
- Foundation Medicine Inc, 150 Second Street, Cambridge, MA, 02141, USA
| | | | - Lee A Albacker
- Foundation Medicine Inc, 150 Second Street, Cambridge, MA, 02141, USA.
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28
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Tarazón E, Pérez-Carrillo L, Giménez-Escamilla I, Ramos-Castellanos P, Martínez-Dolz L, Portolés M, Roselló-Lletí E. Relationships of Telomere Homeostasis with Oxidative Stress and Cardiac Dysfunction in Human Ischaemic Hearts. Antioxidants (Basel) 2021; 10:antiox10111750. [PMID: 34829621 PMCID: PMC8615212 DOI: 10.3390/antiox10111750] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/28/2021] [Accepted: 10/29/2021] [Indexed: 12/24/2022] Open
Abstract
Although the roles of telomeres and oxidative stress in ischaemic cardiomyopathy (ICM) are known, mechanisms of telomere homeostasis and their relationship with oxidative stress are incompletely understood. We performed two RNA-seq analyses (mRNA n = 23; ncRNA n = 30) and protein validation on left ventricles of explanted hearts from ICM and control subjects. We observed dysregulation of the shelterin and cohesin complexes, which was related to an increase in the response to cellular oxidative stress. Moreover, we found alterations at mRNA level in the mechanisms of telomeric DNA repair. Specifically, increased RAD51D mRNA levels were correlated with left ventricular diameters. RAD51D protein levels were unaltered, however, and were inversely corelated with the miR-103a-3p upregulation. We also observed the overexpression of lncRNAs (TERRA and GUARDIN) involved in telomere protection in response to stress and alterations in their regulatory molecules. Expression of the TERRA transcription factor ATF7 was correlated with superoxide dismutase 1 expression and left ventricular diameters. The levels of GUARDIN and its transcription factor FOSL2 were correlated with those of catalase. Therefore, we showed specific alterations in the mechanisms of telomeric DNA repair and protection, and these alterations are related to an increase in the response mechanisms to oxidative stress and cardiac dysfunction in ICM.
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Affiliation(s)
- Estefanía Tarazón
- Myocardial Dysfunction and Cardiac Transplantation Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain; (L.P.-C.); (I.G.-E.); (P.R.-C.); (L.M.-D.); (M.P.)
- CIBERCV, Institute of Health Carlos III, C/Monforte de Lemos 3–5, Pabellón 11, Planta 0, 28029 Madrid, Spain
- Correspondence: (E.T.); (E.R.-L.); Tel.: +34-96-124-66-44 (E.T. & E.R.-L.)
| | - Lorena Pérez-Carrillo
- Myocardial Dysfunction and Cardiac Transplantation Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain; (L.P.-C.); (I.G.-E.); (P.R.-C.); (L.M.-D.); (M.P.)
| | - Isaac Giménez-Escamilla
- Myocardial Dysfunction and Cardiac Transplantation Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain; (L.P.-C.); (I.G.-E.); (P.R.-C.); (L.M.-D.); (M.P.)
| | - Pablo Ramos-Castellanos
- Myocardial Dysfunction and Cardiac Transplantation Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain; (L.P.-C.); (I.G.-E.); (P.R.-C.); (L.M.-D.); (M.P.)
| | - Luis Martínez-Dolz
- Myocardial Dysfunction and Cardiac Transplantation Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain; (L.P.-C.); (I.G.-E.); (P.R.-C.); (L.M.-D.); (M.P.)
- CIBERCV, Institute of Health Carlos III, C/Monforte de Lemos 3–5, Pabellón 11, Planta 0, 28029 Madrid, Spain
- Heart Failure and Transplantation Unit, Cardiology Department, University and Polytechnic La Fe Hospital, 46026 Valencia, Spain
| | - Manuel Portolés
- Myocardial Dysfunction and Cardiac Transplantation Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain; (L.P.-C.); (I.G.-E.); (P.R.-C.); (L.M.-D.); (M.P.)
- CIBERCV, Institute of Health Carlos III, C/Monforte de Lemos 3–5, Pabellón 11, Planta 0, 28029 Madrid, Spain
| | - Esther Roselló-Lletí
- Myocardial Dysfunction and Cardiac Transplantation Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain; (L.P.-C.); (I.G.-E.); (P.R.-C.); (L.M.-D.); (M.P.)
- CIBERCV, Institute of Health Carlos III, C/Monforte de Lemos 3–5, Pabellón 11, Planta 0, 28029 Madrid, Spain
- Correspondence: (E.T.); (E.R.-L.); Tel.: +34-96-124-66-44 (E.T. & E.R.-L.)
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29
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Targeting of Telomeric Repeat-Containing RNA G-Quadruplexes: From Screening to Biophysical and Biological Characterization of a New Hit Compound. Int J Mol Sci 2021; 22:ijms221910315. [PMID: 34638655 PMCID: PMC8508872 DOI: 10.3390/ijms221910315] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/10/2021] [Accepted: 09/22/2021] [Indexed: 12/19/2022] Open
Abstract
DNA G-quadruplex (G4) structures, either within gene promoter sequences or at telomeres, have been extensively investigated as potential small-molecule therapeutic targets. However, although G4s forming at the telomeric DNA have been extensively investigated as anticancer targets, few studies focus on the telomeric repeat-containing RNA (TERRA), transcribed from telomeres, as potential pharmacological targets. Here, a virtual screening approach to identify a library of drug-like putative TERRA G4 binders, in tandem with circular dichroism melting assay to study their TERRA G4-stabilizing properties, led to the identification of a new hit compound. The affinity of this compound for TERRA RNA and some DNA G4s was analyzed through several biophysical techniques and its biological activity investigated in terms of antiproliferative effect, DNA damage response (DDR) activation, and TERRA RNA expression in high vs. low TERRA-expressing human cancer cells. The selected hit showed good affinity for TERRA G4 and no binding to double-stranded DNA. In addition, biological assays showed that this compound is endowed with a preferential cytotoxic effect on high TERRA-expressing cells, where it induces a DDR at telomeres, probably by displacing TERRA from telomeres. Our studies demonstrate that the identification of TERRA G4-targeting drugs with potential pharmacological effects is achievable, shedding light on new perspectives aimed at discovering new anticancer agents targeting these G4 structures.
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30
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Li B, Zhao Y. Regulation of Antigenic Variation by Trypanosoma brucei Telomere Proteins Depends on Their Unique DNA Binding Activities. Pathogens 2021; 10:pathogens10080967. [PMID: 34451431 PMCID: PMC8402208 DOI: 10.3390/pathogens10080967] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 07/22/2021] [Accepted: 07/27/2021] [Indexed: 01/17/2023] Open
Abstract
Trypanosoma brucei causes human African trypanosomiasis and regularly switches its major surface antigen, Variant Surface Glycoprotein (VSG), to evade the host immune response. Such antigenic variation is a key pathogenesis mechanism that enables T. brucei to establish long-term infections. VSG is expressed exclusively from subtelomere loci in a strictly monoallelic manner, and DNA recombination is an important VSG switching pathway. The integrity of telomere and subtelomere structure, maintained by multiple telomere proteins, is essential for T. brucei viability and for regulating the monoallelic VSG expression and VSG switching. Here we will focus on T. brucei TRF and RAP1, two telomere proteins with unique nucleic acid binding activities, and summarize their functions in telomere integrity and stability, VSG switching, and monoallelic VSG expression. Targeting the unique features of TbTRF and TbRAP1′s nucleic acid binding activities to perturb the integrity of telomere structure and disrupt VSG monoallelic expression may serve as potential therapeutic strategy against T. brucei.
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Affiliation(s)
- Bibo Li
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
- Case Comprehensive Cancer Center, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
- Center for RNA Science and Therapeutics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
- Correspondence: (B.L.); (Y.Z.)
| | - Yanxiang Zhao
- Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, China
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
- Correspondence: (B.L.); (Y.Z.)
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31
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Novo CL. A Tale of Two States: Pluripotency Regulation of Telomeres. Front Cell Dev Biol 2021; 9:703466. [PMID: 34307383 PMCID: PMC8300013 DOI: 10.3389/fcell.2021.703466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/08/2021] [Indexed: 01/01/2023] Open
Abstract
Inside the nucleus, chromatin is functionally organized and maintained as a complex three-dimensional network of structures with different accessibility such as compartments, lamina associated domains, and membraneless bodies. Chromatin is epigenetically and transcriptionally regulated by an intricate and dynamic interplay of molecular processes to ensure genome stability. Phase separation, a process that involves the spontaneous organization of a solution into separate phases, has been proposed as a mechanism for the timely coordination of several cellular processes, including replication, transcription and DNA repair. Telomeres, the repetitive structures at the end of chromosomes, are epigenetically maintained in a repressed heterochromatic state that prevents their recognition as double-strand breaks (DSB), avoiding DNA damage repair and ensuring cell proliferation. In pluripotent embryonic stem cells, telomeres adopt a non-canonical, relaxed epigenetic state, which is characterized by a low density of histone methylation and expression of telomere non-coding transcripts (TERRA). Intriguingly, this telomere non-canonical conformation is usually associated with chromosome instability and aneuploidy in somatic cells, raising the question of how genome stability is maintained in a pluripotent background. In this review, we will explore how emerging technological and conceptual developments in 3D genome architecture can provide novel mechanistic perspectives for the pluripotent epigenetic paradox at telomeres. In particular, as RNA drives the formation of LLPS, we will consider how pluripotency-associated high levels of TERRA could drive and coordinate phase separation of several nuclear processes to ensure genome stability. These conceptual advances will provide a better understanding of telomere regulation and genome stability within the highly dynamic pluripotent background.
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Affiliation(s)
- Clara Lopes Novo
- The Francis Crick Institute, London, United Kingdom
- Imperial College London, London, United Kingdom
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32
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Saha A, Gaurav AK, Pandya UM, Afrin M, Sandhu R, Nanavaty V, Schnur B, Li B. TbTRF suppresses the TERRA level and regulates the cell cycle-dependent TERRA foci number with a TERRA binding activity in its C-terminal Myb domain. Nucleic Acids Res 2021; 49:5637-5653. [PMID: 34048580 PMCID: PMC8191777 DOI: 10.1093/nar/gkab401] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/05/2021] [Accepted: 04/29/2021] [Indexed: 02/07/2023] Open
Abstract
Telomere repeat-containing RNA (TERRA) has been identified in multiple organisms including Trypanosoma brucei, a protozoan parasite that causes human African trypanosomiasis. T. brucei regularly switches its major surface antigen, VSG, to evade the host immune response. VSG is expressed exclusively from subtelomeric expression sites, and we have shown that telomere proteins play important roles in the regulation of VSG silencing and switching. In this study, we identify several unique features of TERRA and telomere biology in T. brucei. First, the number of TERRA foci is cell cycle-regulated and influenced by TbTRF, the duplex telomere DNA binding factor in T. brucei. Second, TERRA is transcribed by RNA polymerase I mainly from a single telomere downstream of the active VSG. Third, TbTRF binds TERRA through its C-terminal Myb domain, which also has the duplex DNA binding activity, in a sequence-specific manner and suppresses the TERRA level without affecting its half-life. Finally, levels of the telomeric R-loop and telomere DNA damage were increased upon TbTRF depletion. Overexpression of an ectopic allele of RNase H1 that resolves the R-loop structure in TbTRF RNAi cells can partially suppress these phenotypes, revealing an underlying mechanism of how TbTRF helps maintain telomere integrity.
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Affiliation(s)
- Arpita Saha
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
| | - Amit Kumar Gaurav
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
| | - Unnati M Pandya
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
| | - Marjia Afrin
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
| | - Ranjodh Sandhu
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
| | - Vishal Nanavaty
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
| | - Brittny Schnur
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
| | - Bibo Li
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA.,Case Comprehensive Cancer Center, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.,Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA.,Center for RNA Science and Therapeutics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
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Li B. Keeping Balance Between Genetic Stability and Plasticity at the Telomere and Subtelomere of Trypanosoma brucei. Front Cell Dev Biol 2021; 9:699639. [PMID: 34291053 PMCID: PMC8287324 DOI: 10.3389/fcell.2021.699639] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
Telomeres, the nucleoprotein complexes at chromosome ends, are well-known for their essential roles in genome integrity and chromosome stability. Yet, telomeres and subtelomeres are frequently less stable than chromosome internal regions. Many subtelomeric genes are important for responding to environmental cues, and subtelomeric instability can facilitate organismal adaptation to extracellular changes, which is a common theme in a number of microbial pathogens. In this review, I will focus on the delicate and important balance between stability and plasticity at telomeres and subtelomeres of a kinetoplastid parasite, Trypanosoma brucei, which causes human African trypanosomiasis and undergoes antigenic variation to evade the host immune response. I will summarize the current understanding about T. brucei telomere protein complex, the telomeric transcript, and telomeric R-loops, focusing on their roles in maintaining telomere and subtelomere stability and integrity. The similarities and differences in functions and underlying mechanisms of T. brucei telomere factors will be compared with those in human and yeast cells.
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Affiliation(s)
- Bibo Li
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, Cleveland, OH, United States.,Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, United States.,Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.,Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, OH, United States
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34
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Oh BK, Choi Y, Choi JS. Telomere shortening and expression of TRF1 and TRF2 in uterine leiomyoma. Mol Med Rep 2021; 24:606. [PMID: 34184077 DOI: 10.3892/mmr.2021.12243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/05/2020] [Indexed: 11/06/2022] Open
Abstract
Uterine leiomyoma is a benign smooth muscle tumor of the uterus that can exhibit histopathological traits that mimic malignancy. Telomere shortening is an early event in tumorigenesis and telomerase activation facilitates tumor progression later in the course of carcinogenesis. Telomeric repeat‑binding factor (TRF)1 and TRF2 protect telomeres, and their gene expression levels are dysregulated in various cancer types. However, the roles of telomeres and telomere protection proteins in uterine leiomyoma remain largely unknown. In this study, telomere length and the mRNA levels of various telomere‑related genes in normal tissues and leiomyoma were determined, and their relationships were evaluated. Uterine leiomyoma and normal myometrium were surgically obtained from 18 and 13 patients, respectively. Telomere length and gene expression were determined by Southern blot analysis and reverse transcription‑quantitative PCR, respectively. In matched samples, telomeres were consistently shorter in leiomyoma tissue than in adjacent normal tissue. TRF1, TRF2, PIN2‑interacting telomerase inhibitor 1 (PINX1), and telomerase RNA component were expressed at comparable levels in both leiomyoma and normal tissues. None of these genes were associated with telomere length in leiomyoma. All tested tissues were negative for telomerase reverse transcriptase, which encodes the catalytic component of telomerase, indicating that cells in uterine leiomyoma were not immortalized. In summary, telomere erosion, which reflects active proliferation during tumor evolution, was evident in uterine leiomyoma. Steady‑state expression of TRF1, TRF2 and PINX1 may be important for maintenance of telomere integrity in leiomyoma, where telomere length is shortened.
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Affiliation(s)
- Bong-Kyeong Oh
- Institute for the Integration of Medicine and Innovative Technology, Hanyang University College of Medicine, Seoul 04763, Republic of Korea
| | - Yoojung Choi
- Department of Obstetrics and Gynecology, Hanyang University College of Medicine, Seoul 04763, Republic of Korea
| | - Joong Sub Choi
- Institute for the Integration of Medicine and Innovative Technology, Hanyang University College of Medicine, Seoul 04763, Republic of Korea
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35
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TERRA transcription destabilizes telomere integrity to initiate break-induced replication in human ALT cells. Nat Commun 2021; 12:3760. [PMID: 34145295 PMCID: PMC8213692 DOI: 10.1038/s41467-021-24097-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 05/31/2021] [Indexed: 01/22/2023] Open
Abstract
Alternative Lengthening of Telomeres (ALT) is a Break-Induced Replication (BIR)-based mechanism elongating telomeres in a subset of human cancer cells. While the notion that spontaneous DNA damage at telomeres is required to initiate ALT, the molecular triggers of this physiological telomere instability are largely unknown. We previously proposed that the telomeric long noncoding RNA TERRA may represent one such trigger; however, given the lack of tools to suppress TERRA transcription in cells, our hypothesis remained speculative. We have developed Transcription Activator-Like Effectors able to rapidly inhibit TERRA transcription from multiple chromosome ends in an ALT cell line. TERRA transcription inhibition decreases marks of DNA replication stress and DNA damage at telomeres and impairs ALT activity and telomere length maintenance. We conclude that TERRA transcription actively destabilizes telomere integrity in ALT cells, thereby triggering BIR and promoting telomere elongation. Our data point to TERRA transcription manipulation as a potentially useful target for therapy. TERRA RNA has previously been linked to Alternative lengthening of telomeres (ALT). Here the authors developed a tool to rapidly inhibit TERRA transcription from different chromosome ends in an ALT cell line to show that TERRA transcription actively promotes break induced replication (BIR) and destabilizes telomere integrity in ALT cells.
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36
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Vohhodina J, Goehring LJ, Liu B, Kong Q, Botchkarev VV, Huynh M, Liu Z, Abderazzaq FO, Clark AP, Ficarro SB, Marto JA, Hatchi E, Livingston DM. BRCA1 binds TERRA RNA and suppresses R-Loop-based telomeric DNA damage. Nat Commun 2021; 12:3542. [PMID: 34112789 PMCID: PMC8192922 DOI: 10.1038/s41467-021-23716-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 05/11/2021] [Indexed: 12/13/2022] Open
Abstract
R-loop structures act as modulators of physiological processes such as transcription termination, gene regulation, and DNA repair. However, they can cause transcription-replication conflicts and give rise to genomic instability, particularly at telomeres, which are prone to forming DNA secondary structures. Here, we demonstrate that BRCA1 binds TERRA RNA, directly and physically via its N-terminal nuclear localization sequence, as well as telomere-specific shelterin proteins in an R-loop-, and a cell cycle-dependent manner. R-loop-driven BRCA1 binding to CpG-rich TERRA promoters represses TERRA transcription, prevents TERRA R-loop-associated damage, and promotes its repair, likely in association with SETX and XRN2. BRCA1 depletion upregulates TERRA expression, leading to overly abundant TERRA R-loops, telomeric replication stress, and signs of telomeric aberrancy. Moreover, BRCA1 mutations within the TERRA-binding region lead to an excess of TERRA-associated R-loops and telomeric abnormalities. Thus, normal BRCA1/TERRA binding suppresses telomere-centered genome instability. BRCA1-mediated resolution of R-loops has previously been described. Here the authors reveal a functional association of BRCA1 with TERRA RNA at telomeres, which develops in an R-loop-, and a cell cycle-dependent manner.
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Affiliation(s)
- Jekaterina Vohhodina
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Department of Genetics, Harvard Medical School, Boston, MA, USA.
| | - Liana J Goehring
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Ben Liu
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Qing Kong
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Vladimir V Botchkarev
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Mai Huynh
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Zhiqi Liu
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Fieda O Abderazzaq
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Allison P Clark
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Scott B Ficarro
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jarrod A Marto
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Elodie Hatchi
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - David M Livingston
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Department of Genetics, Harvard Medical School, Boston, MA, USA.
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37
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Cheng X, Joseph A, Castro V, Chen-Liaw A, Skidmore Z, Ueno T, Fujisawa JI, Rauch DA, Challen GA, Martinez MP, Green P, Griffith M, Payton JE, Edwards JR, Ratner L. Epigenomic regulation of human T-cell leukemia virus by chromatin-insulator CTCF. PLoS Pathog 2021; 17:e1009577. [PMID: 34019588 PMCID: PMC8174705 DOI: 10.1371/journal.ppat.1009577] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 06/03/2021] [Accepted: 04/22/2021] [Indexed: 11/30/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus that causes an aggressive T-cell malignancy and a variety of inflammatory conditions. The integrated provirus includes a single binding site for the epigenomic insulator, CCCTC-binding protein (CTCF), but its function remains unclear. In the current study, a mutant virus was examined that eliminates the CTCF-binding site. The mutation did not disrupt the kinetics and levels of virus gene expression, or establishment of or reactivation from latency. However, the mutation disrupted the epigenetic barrier function, resulting in enhanced DNA CpG methylation downstream of the CTCF binding site on both strands of the integrated provirus and H3K4Me3, H3K36Me3, and H3K27Me3 chromatin modifications both up- and downstream of the site. A majority of clonal cell lines infected with wild type HTLV-1 exhibited increased plus strand gene expression with CTCF knockdown, while expression in mutant HTLV-1 clonal lines was unaffected. These findings indicate that CTCF binding regulates HTLV-1 gene expression, DNA and histone methylation in an integration site dependent fashion. Human T-cell leukemia virus type 1 (HTLV-1) is a cause of leukemia and lymphoma as well as several inflammatory medical disorders. The virus integrates in the host cell DNA, and it has a single binding site for a protein designated CTCF. This protein is important in the regulation of many DNA viruses, as well as many properties of normal and malignant cells. In order to define the role of CTCF binding to HTLV, we analyzed a mutant virus lacking the binding site. We found that this mutation variably affected gene expression, DNA and histone modification, suggesting a key role in regulation of virus replication in infected cells.
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Affiliation(s)
- Xiaogang Cheng
- Department of Medicine, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Ancy Joseph
- Department of Medicine, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Victor Castro
- Department of Medicine, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Alice Chen-Liaw
- Department of Medicine, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Zachary Skidmore
- Department of Medicine, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Takaharu Ueno
- Department of Microbiology, Kansai Medical University, Osaka, Japan
| | | | - Daniel A. Rauch
- Department of Medicine, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Grant A. Challen
- Department of Medicine, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Michael P. Martinez
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, United States of America
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, United States of America
| | - Patrick Green
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, United States of America
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, United States of America
| | - Malachi Griffith
- Department of Medicine, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Jacqueline E. Payton
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - John R. Edwards
- Department of Medicine, Washington University School of Medicine, St Louis, Missouri, United States of America
- Department of Phamacogenomics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Lee Ratner
- Department of Medicine, Washington University School of Medicine, St Louis, Missouri, United States of America
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri, United States of America
- * E-mail:
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38
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RTEL1 influences the abundance and localization of TERRA RNA. Nat Commun 2021; 12:3016. [PMID: 34021146 PMCID: PMC8140157 DOI: 10.1038/s41467-021-23299-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 04/22/2021] [Indexed: 12/13/2022] Open
Abstract
Telomere repeat containing RNAs (TERRAs) are a family of long non-coding RNAs transcribed from the subtelomeric regions of eukaryotic chromosomes. TERRA transcripts can form R-loops at chromosome ends; however the importance of these structures or the regulation of TERRA expression and retention in telomeric R-loops remain unclear. Here, we show that the RTEL1 (Regulator of Telomere Length 1) helicase influences the abundance and localization of TERRA in human cells. Depletion of RTEL1 leads to increased levels of TERRA RNA while reducing TERRA-containing R loops at telomeres. In vitro, RTEL1 shows a strong preference for binding G-quadruplex structures which form in TERRA. This binding is mediated by the C-terminal region of RTEL1, and is independent of the RTEL1 helicase domain. RTEL1 binding to TERRA appears to be essential for cell viability, underscoring the importance of this function. Degradation of TERRA-containing R-loops by overexpression of RNAse H1 partially recapitulates the increased TERRA levels and telomeric instability associated with RTEL1 deficiency. Collectively, these data suggest that regulation of TERRA is a key function of the RTEL1 helicase, and that loss of that function may contribute to the disease phenotypes of patients with RTEL1 mutations. Long non coding RNA TERRA transcripts can form R-loops at chromosome ends. Here, the authors reveal a role for the helicase RTEL in affecting TERRA levels and localization.
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39
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Rocca MS, Dusi L, Di Nisio A, Alviggi E, Iussig B, Bertelle S, De Toni L, Garolla A, Foresta C, Ferlin A. TERRA: A Novel Biomarker of Embryo Quality and Art Outcome. Genes (Basel) 2021; 12:genes12040475. [PMID: 33806168 PMCID: PMC8066328 DOI: 10.3390/genes12040475] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 12/30/2022] Open
Abstract
Telomeres are considered to be an internal biological clock, and their progressive shortening has been associated with the risk of age-related diseases and reproductive alterations. Over recent years, an increasing number of studies have focused on the association between telomere length and fertility, identifying sperm telomere length (STL) as a novel biomarker of male fertility. Although typically considered to be repeated DNA sequences, telomeres have recently been shown to also include a long non-coding RNA (lncRNA) known as TERRA (telomeric repeat-containing RNAs). Interestingly, males with idiopathic infertility show reduced testicular TERRA expression, suggesting a link between TERRA and male fertility. The aim of this study was to investigate the role of seminal TERRA expression in embryo quality. To this end, STL and TERRA expression were quantified by Real Time qPCR in the semen of 35 men who underwent assisted reproductive technologies (ART) and 30 fertile men. We found that TERRA expression in semen and STL was reduced in patients that underwent ART (both p < 0.001). Interestingly, TERRA and STL expressions were positively correlated (p = 0.010), and TERRA expression was positively associated with embryo quality (p < 0.001). These preliminary findings suggest a role for TERRA in the maintenance of sperm telomere integrity during gametogenesis, and for the first time, TERRA expression was found as a predictive factor for embryo quality in the setting of assisted reproduction.
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Affiliation(s)
- Maria Santa Rocca
- Department of Medicine, University Hospital of Padova, 35128 Padova, Italy; (M.S.R.); (A.D.N.).; (L.D.T.); (A.G.)
| | - Ludovica Dusi
- GENERA Veneto, GENERA Center for Reproductive Medicine, 36063 Marostica, Italy; (L.D.); (B.I.); (S.B.)
| | - Andrea Di Nisio
- Department of Medicine, University Hospital of Padova, 35128 Padova, Italy; (M.S.R.); (A.D.N.).; (L.D.T.); (A.G.)
| | - Erminia Alviggi
- Clinica Ruesch, GENERA Center for Reproductive Medicine, 80122 Napoli, Italy;
| | - Benedetta Iussig
- GENERA Veneto, GENERA Center for Reproductive Medicine, 36063 Marostica, Italy; (L.D.); (B.I.); (S.B.)
| | - Sara Bertelle
- GENERA Veneto, GENERA Center for Reproductive Medicine, 36063 Marostica, Italy; (L.D.); (B.I.); (S.B.)
| | - Luca De Toni
- Department of Medicine, University Hospital of Padova, 35128 Padova, Italy; (M.S.R.); (A.D.N.).; (L.D.T.); (A.G.)
| | - Andrea Garolla
- Department of Medicine, University Hospital of Padova, 35128 Padova, Italy; (M.S.R.); (A.D.N.).; (L.D.T.); (A.G.)
| | - Carlo Foresta
- Department of Medicine, University Hospital of Padova, 35128 Padova, Italy; (M.S.R.); (A.D.N.).; (L.D.T.); (A.G.)
- Correspondence: ; Tel.: +39-0498218517
| | - Alberto Ferlin
- Department of Clinical and Experimental Sciences, Unit of Endocrinology and Metabolism, University of Brescia and ASST Spedali Civili Brescia, 25121 Brescia, Italy;
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40
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Libertini G, Corbi G, Nicola F. Importance and Meaning of TERRA Sequences for Aging Mechanisms. BIOCHEMISTRY (MOSCOW) 2021; 85:1505-1517. [PMID: 33705290 DOI: 10.1134/s0006297920120044] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Any theory suggesting an adaptive meaning for aging implicitly postulates the existence of specific mechanisms, genetically determined and modulated, causing progressive decline of an organism. According to the subtelomere-telomere theory, each telomere is covered by a hood formed in the first cell of an organism having a size preserved at each subsequent duplication. Telomere shortening, which is quantitatively different for each cell type according to the telomerase regulation, causes the hood to slide on the subtelomere repressing it by the telomeric position effect. At this point, the theory postulates existence of subtelomeric regulatory sequences, whose progressive transcriptional repression by the hood should cause cellular alterations that would be the likely determinant of aging manifestations. However, sequences with characteristics of these hypothetical sequences have already been described and documented. They are the [sub]TElomeric Repeat-containing RNA (TERRA) sequences. The repression of TERRA sequences causes progressively: (i) down- or up-regulation of many other regulatory sequences; (ii) increase in the probability of activation of cell senescence program (blockage of the ability to replicate and very significant alterations of the cellular functions). When cell senescence program has not been triggered and the repression is partial, there is a partial alteration of the cellular functions that is easily reversible by telomerase activation. Location of the extremely important sequences in chromosomal parts that are most vulnerable to repression by the telomeric hood is evolutionarily unjustifiable if aging is not considered adaptive: this location must be necessarily adaptive with the specific function of determining aging of the cell and consequently of the whole organism.
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Affiliation(s)
- G Libertini
- Independent researcher, member of the Italian Society for Evolutionary Biology, Asti, 14100, Italy.
| | - G Corbi
- Department of Medicine and Health Sciences, University of Molise, Campobasso, 86100, Italy.,Italian Society of Gerontology and Geriatrics (SIGG), Firenze, 50129, Italy
| | - F Nicola
- Department of Translational Medical Sciences, Federico II University of Naples, Naples, 80131, Italy.,Istituti Clinici Scientifici Maugeri SPA - Società Benefit, IRCCS, Telese Terme, BN, 82037, Italy
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41
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Vladimirova O, De Leo A, Deng Z, Wiedmer A, Hayden J, Lieberman PM. Phase separation and DAXX redistribution contribute to LANA nuclear body and KSHV genome dynamics during latency and reactivation. PLoS Pathog 2021; 17:e1009231. [PMID: 33471863 PMCID: PMC7943007 DOI: 10.1371/journal.ppat.1009231] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 03/09/2021] [Accepted: 12/08/2020] [Indexed: 12/14/2022] Open
Abstract
Liquid-liquid phase separation (LLPS) can drive formation of diverse and essential macromolecular structures, including those specified by viruses. Kaposi’s Sarcoma-Associated Herpesvirus (KSHV) genomes associate with the viral encoded Latency-Associated Nuclear Antigen (LANA) to form stable nuclear bodies (NBs) during latent infection. Here, we show that LANA-NB formation and KSHV genome conformation involves LLPS. Using LLPS disrupting solvents, we show that LANA-NBs are partially disrupted, while DAXX and PML foci are highly resistant. LLPS disruption altered the LANA-dependent KSHV chromosome conformation but did not stimulate lytic reactivation. We found that LANA-NBs undergo major morphological transformation during KSHV lytic reactivation to form LANA-associated replication compartments encompassing KSHV DNA. DAXX colocalizes with the LANA-NBs during latency but is evicted from the LANA-associated lytic replication compartments. These findings indicate the LANA-NBs are dynamic super-molecular nuclear structures that partly depend on LLPS and undergo morphological transitions corresponding to the different modes of viral replication. During latent infection, gamma-herpesvirus genomes are maintained as extrachromosomal circular DNA, referred to as episomes, by dedicated viral-encoded episome maintenance proteins. KSHV-encoded LANA maintains viral episomes through binding as an oligomeric protein to repetitive DNA elements in the viral terminal repeats (TRs). Viral episomes can be visualized as LANA-associated nuclear bodies (LANA-NBs). Here, we show that LANA-NBs utilize mechanisms of self-assembly through liquid-liquid phase separation (LLPS) to build dynamic structures that change during cell cycle and viral life cycle. We find that DAXX is a component of the latent phase LANA-NBs, but is evicted during the transition to lytic replication where LANA remains associated with KSHV DNA to form a ring-like replication compartment.
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Affiliation(s)
| | - Alessandra De Leo
- Department of Immunology, H. Lee Moffit Cancer and Research Center, Tampa Florida, United States of America
| | - Zhong Deng
- The Wistar Institute, Philadelphia, United States of America
| | - Andreas Wiedmer
- The Wistar Institute, Philadelphia, United States of America
| | - James Hayden
- The Wistar Institute, Philadelphia, United States of America
| | - Paul M. Lieberman
- The Wistar Institute, Philadelphia, United States of America
- * E-mail:
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42
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Idilli AI, Pazzi C, dal Pozzolo F, Roccuzzo M, Mione MC. Rad21 Haploinsufficiency Prevents ALT-Associated Phenotypes in Zebrafish Brain Tumors. Genes (Basel) 2020; 11:E1442. [PMID: 33266037 PMCID: PMC7760354 DOI: 10.3390/genes11121442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 01/17/2023] Open
Abstract
Cohesin is a protein complex consisting of four core subunits responsible for sister chromatid cohesion in mitosis and meiosis, and for 3D genome organization and gene expression through the establishment of long distance interactions regulating transcriptional activity in the interphase. Both roles are important for telomere integrity, but the role of cohesin in telomere maintenance mechanisms in highly replicating cancer cells in vivo is poorly studied. Here we used a zebrafish model of brain tumor, which uses alternative lengthening of telomeres (ALT) as primary telomere maintenance mechanism to test whether haploinsufficiency for Rad21, a member of the cohesin ring, affects ALT development. We found that a reduction in Rad21 levels prevents ALT-associated phenotypes in zebrafish brain tumors and triggers an increase in tert expression. Despite the rescue of ALT phenotypes, tumor cells in rad21+/- fish exhibit an increase in DNA damage foci, probably due to a reduction in double-strand breaks repair efficiency.
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Affiliation(s)
- Aurora Irene Idilli
- Experimental Cancer Biology, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy; (A.I.I.); (C.P.); (F.d.P.)
| | - Cecilia Pazzi
- Experimental Cancer Biology, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy; (A.I.I.); (C.P.); (F.d.P.)
| | - Francesca dal Pozzolo
- Experimental Cancer Biology, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy; (A.I.I.); (C.P.); (F.d.P.)
| | - Michela Roccuzzo
- Advanced Imaging Facility, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy;
| | - Maria Caterina Mione
- Experimental Cancer Biology, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy; (A.I.I.); (C.P.); (F.d.P.)
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43
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Drosopoulos WC, Deng Z, Twayana S, Kosiyatrakul ST, Vladimirova O, Lieberman PM, Schildkraut CL. TRF2 Mediates Replication Initiation within Human Telomeres to Prevent Telomere Dysfunction. Cell Rep 2020; 33:108379. [PMID: 33176153 PMCID: PMC7790361 DOI: 10.1016/j.celrep.2020.108379] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/15/2020] [Accepted: 10/20/2020] [Indexed: 02/06/2023] Open
Abstract
The telomeric shelterin protein telomeric repeat-binding factor 2 (TRF2) recruits origin recognition complex (ORC) proteins, the foundational building blocks of DNA replication origins, to telomeres. We seek to determine whether TRF2-recruited ORC proteins give rise to functional origins in telomere repeat tracts. We find that reduction of telomeric recruitment of ORC2 by expression of an ORC interaction-defective TRF2 mutant significantly reduces telomeric initiation events in human cells. This reduction in initiation events is accompanied by telomere repeat loss, telomere aberrations and dysfunction. We demonstrate that telomeric origins are activated by induced replication stress to provide a key rescue mechanism for completing compromised telomere replication. Importantly, our studies also indicate that the chromatin remodeler SNF2H promotes telomeric initiation events by providing access for ORC2. Collectively, our findings reveal that active recruitment of ORC by TRF2 leads to formation of functional origins, providing an important mechanism for avoiding telomere dysfunction and rescuing challenged telomere replication.
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Affiliation(s)
- William C Drosopoulos
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
| | - Zhong Deng
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104, USA
| | - Shyam Twayana
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Settapong T Kosiyatrakul
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Olga Vladimirova
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104, USA
| | - Paul M Lieberman
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104, USA
| | - Carl L Schildkraut
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
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44
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Barral A, Déjardin J. Telomeric Chromatin and TERRA. J Mol Biol 2020; 432:4244-4256. [DOI: 10.1016/j.jmb.2020.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 03/03/2020] [Accepted: 03/03/2020] [Indexed: 01/01/2023]
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Mir SM, Samavarchi Tehrani S, Goodarzi G, Jamalpoor Z, Asadi J, Khelghati N, Qujeq D, Maniati M. Shelterin Complex at Telomeres: Implications in Ageing. Clin Interv Aging 2020; 15:827-839. [PMID: 32581523 PMCID: PMC7276337 DOI: 10.2147/cia.s256425] [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: 04/01/2020] [Accepted: 05/18/2020] [Indexed: 12/16/2022] Open
Abstract
Different factors influence the development and control of ageing. It is well known that progressive telomere shorting is one of the molecular mechanisms underlying ageing. The shelterin complex consists of six telomere-specific proteins which are involved in the protection of chromosome ends. More particularly, this vital complex protects the telomeres from degradation, prevents from activation of unwanted repair systems, regulates the activity of telomerase, and has a crucial role in cellular senescent and ageing-related pathologies. This review explores the organization and function of telomeric DNA along with the mechanism of telomeres during ageing, followed by a discussion of the critical role of shelterin components and their changes during ageing.
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Affiliation(s)
- Seyed Mostafa Mir
- Trauma Research Center, AJA University of Medical Sciences, Tehran, Iran.,Student Research Committee, Babol University of Medical Sciences, Babol, Iran.,Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Sadra Samavarchi Tehrani
- Department of Clinical Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Student Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Golnaz Goodarzi
- Department of Clinical Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Student Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Jamalpoor
- Trauma Research Center, AJA University of Medical Sciences, Tehran, Iran
| | - Jahanbakhsh Asadi
- Metabolic Disorders Research Center, Golestan University of Medical Sciences, Gorgan, Iran
| | - Nafiseh Khelghati
- Department of Clinical Biochemistry, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Durdi Qujeq
- Student Research Committee, Babol University of Medical Sciences, Babol, Iran.,Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Mahmood Maniati
- School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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46
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Idilli AI, Pagani F, Kerschbamer E, Berardinelli F, Bernabé M, Cayuela ML, Piazza S, Poliani PL, Cusanelli E, Mione MC. Changes in the Expression of Pre-Replicative Complex Genes in hTERT and ALT Pediatric Brain Tumors. Cancers (Basel) 2020; 12:cancers12041028. [PMID: 32331249 PMCID: PMC7226177 DOI: 10.3390/cancers12041028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/16/2020] [Accepted: 04/20/2020] [Indexed: 12/17/2022] Open
Abstract
Background: The up-regulation of a telomere maintenance mechanism (TMM) is a common feature of cancer cells and a hallmark of cancer. Routine methods for detecting TMMs in tumor samples are still missing, whereas telomerase targeting treatments are becoming available. In paediatric cancers, alternative lengthening of telomeres (ALT) is found in a subset of sarcomas and malignant brain tumors. ALT is a non-canonical mechanism of telomere maintenance developed by cancer cells with no-functional telomerase. Methods: To identify drivers and/or markers of ALT, we performed a differential gene expression analysis between two zebrafish models of juvenile brain tumors, that differ only for the telomere maintenance mechanism adopted by tumor cells: one is ALT while the other is telomerase-dependent. Results: Comparative analysis of gene expression identified five genes of the pre-replicative complex, ORC4, ORC6, MCM2, CDC45 and RPA3 as upregulated in ALT. We searched for a correlation between telomerase levels and expression of the pre-replicative complex genes in a cohort of paediatric brain cancers and identified a counter-correlation between telomerase expression and the genes of the pre-replicative complex. Moreover, the analysis of ALT markers in a group of 20 patients confirmed the association between ALT and increased RPA and decreased H3K9me3 localization at telomeres. Conclusions: Our study suggests that telomere maintenance mechanisms may act as a driver of telomeric DNA replication and chromatin status in brain cancers and identifies markers of ALT that could be exploited for precise prognostic and therapeutic purposes.
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Affiliation(s)
- Aurora Irene Idilli
- Department of Cellular, Computational and Integrative Biology–CIBIO, University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | - Francesca Pagani
- Pathology, Department of Molecular and Translational Medicine, University of Brescia, 25123 Brescia, Italy
| | - Emanuela Kerschbamer
- Department of Cellular, Computational and Integrative Biology–CIBIO, University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | | | - Manuel Bernabé
- Telomerase, Cancer and Aging, Department of Surgery, Instituto Murciano de Investigación Biosanitaria-Arrixaca, 30005 Murcia, Spain
| | - María Luisa Cayuela
- Telomerase, Cancer and Aging, Department of Surgery, Instituto Murciano de Investigación Biosanitaria-Arrixaca, 30005 Murcia, Spain
| | - Silvano Piazza
- Department of Cellular, Computational and Integrative Biology–CIBIO, University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | - Pietro Luigi Poliani
- Pathology, Department of Molecular and Translational Medicine, University of Brescia, 25123 Brescia, Italy
| | - Emilio Cusanelli
- Department of Cellular, Computational and Integrative Biology–CIBIO, University of Trento, Via Sommarive 9, 38123 Trento, Italy
- Correspondence: (E.C.); (M.C.M.); Tel.: +39-0461283312 (M.C.M.)
| | - Maria Caterina Mione
- Department of Cellular, Computational and Integrative Biology–CIBIO, University of Trento, Via Sommarive 9, 38123 Trento, Italy
- Correspondence: (E.C.); (M.C.M.); Tel.: +39-0461283312 (M.C.M.)
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Casa V, Moronta Gines M, Gade Gusmao E, Slotman JA, Zirkel A, Josipovic N, Oole E, van IJcken WFJ, Houtsmuller AB, Papantonis A, Wendt KS. Redundant and specific roles of cohesin STAG subunits in chromatin looping and transcriptional control. Genome Res 2020; 30:515-527. [PMID: 32253279 PMCID: PMC7197483 DOI: 10.1101/gr.253211.119] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 04/01/2020] [Indexed: 12/28/2022]
Abstract
Cohesin is a ring-shaped multiprotein complex that is crucial for 3D genome organization and transcriptional regulation during differentiation and development. It also confers sister chromatid cohesion and facilitates DNA damage repair. Besides its core subunits SMC3, SMC1A, and RAD21, cohesin in somatic cells contains one of two orthologous STAG subunits, STAG1 or STAG2. How these variable subunits affect the function of the cohesin complex is still unclear. STAG1- and STAG2-cohesin were initially proposed to organize cohesion at telomeres and centromeres, respectively. Here, we uncover redundant and specific roles of STAG1 and STAG2 in gene regulation and chromatin looping using HCT116 cells with an auxin-inducible degron (AID) tag fused to either STAG1 or STAG2. Following rapid depletion of either subunit, we perform high-resolution Hi-C, gene expression, and sequential ChIP studies to show that STAG1 and STAG2 do not co-occupy individual binding sites and have distinct ways by which they affect looping and gene expression. These findings are further supported by single-molecule localizations via direct stochastic optical reconstruction microscopy (dSTORM) super-resolution imaging. Since somatic and congenital mutations of the STAG subunits are associated with cancer (STAG2) and intellectual disability syndromes with congenital abnormalities (STAG1 and STAG2), we verified STAG1-/STAG2-dependencies using human neural stem cells, hence highlighting their importance in particular disease contexts.
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Affiliation(s)
- Valentina Casa
- Department of Cell Biology, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | | | - Eduardo Gade Gusmao
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany
- Institute of Pathology, University Medical Center, Georg-August University of Göttingen, 37075 Göttingen, Germany
| | - Johan A Slotman
- Optical Imaging Centre, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Anne Zirkel
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany
| | - Natasa Josipovic
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany
- Institute of Pathology, University Medical Center, Georg-August University of Göttingen, 37075 Göttingen, Germany
| | - Edwin Oole
- Center for Biomics, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Wilfred F J van IJcken
- Department of Cell Biology, Erasmus MC, 3015 GD Rotterdam, The Netherlands
- Center for Biomics, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | | | - Argyris Papantonis
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany
- Institute of Pathology, University Medical Center, Georg-August University of Göttingen, 37075 Göttingen, Germany
| | - Kerstin S Wendt
- Department of Cell Biology, Erasmus MC, 3015 GD Rotterdam, The Netherlands
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48
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Galigniana NM, Charó NL, Uranga R, Cabanillas AM, Piwien-Pilipuk G. Oxidative stress induces transcription of telomeric repeat-containing RNA (TERRA) by engaging PKA signaling and cytoskeleton dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118643. [DOI: 10.1016/j.bbamcr.2020.118643] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 12/27/2019] [Accepted: 01/02/2020] [Indexed: 12/11/2022]
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B Cell-Specific Transcription Activator PAX5 Recruits p300 To Support EBNA1-Driven Transcription. J Virol 2020; 94:JVI.02028-19. [PMID: 31941781 DOI: 10.1128/jvi.02028-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 12/23/2019] [Indexed: 01/09/2023] Open
Abstract
The binding of Epstein-Barr Virus (EBV) nuclear antigen 1 (EBNA1) to the latent replication origin (oriP) triggers multiple downstream events to support virus-induced pathogenesis and tumorigenesis. Although EBV is widely recognized as a B-lymphotropic infectious agent, little is known about how tissue-specific factors are involved in the establishment of latency. Here, we showed that EBNA1 binds B cell activator PAX5 to promote EBNA1/oriP-dependent binding and transcription. In addition to showing that short hairpin RNA (shRNA)-mediated PAX5 knockdown substantially abrogated the above EBNA1-dependent functions, two mini-EBV reporter plasmids were used to perform nonlytic nano-luciferase (nLuc) activity and chromatin immunoprecipitation (ChIP) assays to show how EBNA1 cooperates with PAX5 to activate the transcription at the oriP site. The expression plasmids of two PAX5 mutants, V26G (EBNA1 binding mutant) and P80R (which remained EBNA1 associated), were used to assess their capability to restore the defects caused by PAX5 depletion in EBNA1/oriP-mediated binding, transcription, and maintenance of the genome copy number of the mini-EBV episome reporter in BJAB cells stably expressing EBNA1 or that of the EBV genome in EBV-infected BJAB cells. Since p300 is known to be associated with PAX5, we showed that the loss of function of the P80R mutant in support of EBNA1/oriP-mediated transcription under PAX5 depletion conditions was linked to its defective binding to p300. ChIP-quantitative PCR (qPCR) confirmed that P80R indeed failed to recruit p300 to the oriP DNA. Our discovery suggests that EBV has evolved an exquisite strategy to take advantage of tissue-specific factors to enable the establishment of viral latency.IMPORTANCE Although B cells are known to be the primary target for EBV infection, there is limited knowledge regarding the mechanism that determines this preferable tissue tropism. An in-depth understanding of the potential link of tissue-specific factors with the viral genes and their functioning is key to deciphering how EBV induces persistent infection in the distinct types of host cells. In this study, a substantial protein-protein interaction mediated by the B cell-specific activator PAX5 and EBNA1 was identified as the general requirement for the binding of EBNA1 to the latent replication origin and for downstream events. Of importance, the EBNA1-PAX5-p300 network is directly linked to EBNA1-dependent transcription. These findings suggest that targeting the viral gene-associated tissue-specific factors may lead to new therapeutic strategies for EBV-associated malignancies.
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50
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Katahira J, Senokuchi K, Hieda M. Human THO maintains the stability of repetitive DNA. Genes Cells 2020; 25:334-342. [PMID: 32065701 DOI: 10.1111/gtc.12760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 01/31/2023]
Abstract
The evolutionarily conserved multiprotein complex THO/TREX is required for pre-mRNA processing, mRNA export and the maintenance of genome stability. In this study, we analyzed the genome-wide distribution of human THOC7, a component of human THO, by chromatin immunoprecipitation sequencing. The analysis revealed that human THOC7 occupies repetitive sequences, which include microsatellite repeats in genic and intergenic regions and telomeric repeats. The majority of the THOC7 ChIP peaks overlapped with those of the elongating form of RNA polymerase II and R-loops, indicating that THOC7 accumulates in transcriptionally active repeat regions. Knocking down THOC5, an RNA-binding component of human THO, by siRNA induced the accumulation of γH2AX in the repeat regions. We also observed an aberration in the telomeres in the THOC5-depleted condition. These results suggest that human THO restrains the transcription-associated instability of repeat regions in the human genome.
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Affiliation(s)
- Jun Katahira
- Laboratory of Cellular and Molecular Biology, Department of Veterinary Sciences, Osaka Prefecture University, Izumisano, Japan
| | - Kohei Senokuchi
- Laboratory of Cellular and Molecular Biology, Department of Veterinary Sciences, Osaka Prefecture University, Izumisano, Japan
| | - Miki Hieda
- Graduate School of Health Sciences, Ehime Prefectural University of Health Sciences, Iyo-gun, Japan
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