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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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2
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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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3
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Gerber JP, Russ J, Chandrasekar V, Offermann N, Lee HM, Spear S, Guzzi N, Maida S, Pattabiraman S, Zhang R, Kayvanjoo AH, Datta P, Kasturiarachchi J, Sposito T, Izotova N, Händler K, Adams PD, Marafioti T, Enver T, Wenzel J, Beyer M, Mass E, Bellodi C, Schultze JL, Capasso M, Nimmo R, Salomoni P. Aberrant chromatin landscape following loss of the H3.3 chaperone Daxx in haematopoietic precursors leads to Pu.1-mediated neutrophilia and inflammation. Nat Cell Biol 2021; 23:1224-1239. [PMID: 34876685 PMCID: PMC8683376 DOI: 10.1038/s41556-021-00774-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 09/14/2021] [Indexed: 12/25/2022]
Abstract
Defective silencing of retrotransposable elements has been linked to inflammageing, cancer and autoimmune diseases. However, the underlying mechanisms are only partially understood. Here we implicate the histone H3.3 chaperone Daxx, a retrotransposable element repressor inactivated in myeloid leukaemia and other neoplasms, in protection from inflammatory disease. Loss of Daxx alters the chromatin landscape, H3.3 distribution and histone marks of haematopoietic progenitors, leading to engagement of a Pu.1-dependent transcriptional programme for myelopoiesis at the expense of B-cell differentiation. This causes neutrophilia and inflammation, predisposing mice to develop an autoinflammatory skin disease. While these molecular and phenotypic perturbations are in part reverted in animals lacking both Pu.1 and Daxx, haematopoietic progenitors in these mice show unique chromatin and transcriptome alterations, suggesting an interaction between these two pathways. Overall, our findings implicate retrotransposable element silencing in haematopoiesis and suggest a cross-talk between the H3.3 loading machinery and the pioneer transcription factor Pu.1.
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Grants
- P01 AG031862 NIA NIH HHS
- C416/A25145 Cancer Research UK
- C16420/A18066 Cancer Research UK
- MC_U132670601 Medical Research Council
- C33499/A20265 Cancer Research UK
- Deutsches Zentrum für Neurodegenerative Erkrankungen (German Center for Neurodegenerative Diseases)
- Worldwide Cancer Research
- Deutsche Forschungsgemeinschaft (German Research Foundation)
- EC | EC Seventh Framework Programm | FP7 People: Marie-Curie Actions (FP7-PEOPLE - Specific Programme People Implementing the Seventh Framework Programme of the European Community for Research, Technological Development and Demonstration Activities (2007 to 2013))
- Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC2151 – 390873048, Excellence Cluster Immunosensation2
- Aging and Metabolic Programming (AMPro) Consortium from Helmholtz
- Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC2151 – 390873048, Excellence Cluster Immunosensation2ImmunoSensation2
- Cancer Research UK (CRUK)
- Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC2151 – 390873048, Excellence Cluster ImmunoSensation2
- EC | EC Seventh Framework Programm | FP7 Ideas: European Research Council (FP7-IDEAS-ERC - Specific Programme: Ideas Implementing the Seventh Framework Programme of the European Community for Research, Technological Development and Demonstration Activities (2007 to 2013))
- Wilhelm Sander-Stiftung (Wilhelm Sander Foundation)
- Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC2151 – 390873048, Excellence Cluster ImmunoSensation2 Aging and Metabolic Programming (AMPro) Consortium from Helmholtz
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Affiliation(s)
- Julia P Gerber
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Department of Cancer Biology, UCL Cancer Institute, London, UK
| | - Jenny Russ
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | | | - Nina Offermann
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Hang-Mao Lee
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Sarah Spear
- Barts Cancer Institute, Queen Mary University of London, London, UK
| | - Nicola Guzzi
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medicine, Lund University, Lund, Sweden
| | - Simona Maida
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | | | - Ruoyu Zhang
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Amir H Kayvanjoo
- Life and Medical Sciences (LIMES) Institute, Developmental Biology of the Immune System, University of Bonn, Bonn, Germany
| | - Preeta Datta
- Department of Cancer Biology, UCL Cancer Institute, London, UK
| | | | - Teresa Sposito
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Natalia Izotova
- Department of Cancer Biology, UCL Cancer Institute, London, UK
| | - Kristian Händler
- Platform for Single Cell Genomics and Epigenomics (PRECISE) at the German Center for Neurodegenerative Diseases and the University of Bonn, Bonn, Germany
| | - Peter D Adams
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, USA
| | - Teresa Marafioti
- Department of Cancer Biology, UCL Cancer Institute, London, UK
- Department of Pathology, University College London, London, UK
| | - Tariq Enver
- Department of Cancer Biology, UCL Cancer Institute, London, UK
| | - Jörg Wenzel
- Department of Dermatology and Allergy, University Medical Center, Bonn, Germany
| | - Marc Beyer
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Platform for Single Cell Genomics and Epigenomics (PRECISE) at the German Center for Neurodegenerative Diseases and the University of Bonn, Bonn, Germany
| | - Elvira Mass
- Life and Medical Sciences (LIMES) Institute, Developmental Biology of the Immune System, University of Bonn, Bonn, Germany
| | - Cristian Bellodi
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medicine, Lund University, Lund, Sweden
| | - Joachim L Schultze
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Platform for Single Cell Genomics and Epigenomics (PRECISE) at the German Center for Neurodegenerative Diseases and the University of Bonn, Bonn, Germany
- Genomics and Immunoregulation, LIMES Institute, University of Bonn, Bonn, Germany
| | - Melania Capasso
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Barts Cancer Institute, Queen Mary University of London, London, UK
| | - Rachael Nimmo
- Department of Cancer Biology, UCL Cancer Institute, London, UK
| | - Paolo Salomoni
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
- Department of Cancer Biology, UCL Cancer Institute, London, UK.
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4
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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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5
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iDRiP for the systematic discovery of proteins bound directly to noncoding RNA. Nat Protoc 2021; 16:3672-3694. [PMID: 34108731 DOI: 10.1038/s41596-021-00555-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 04/13/2021] [Indexed: 11/09/2022]
Abstract
More than 90% of the human genome is transcribed into noncoding RNAs, but their functional characterization has lagged behind. A major bottleneck in the understanding of their functions and mechanisms has been a dearth of systematic methods for identifying interacting protein partners. There now exist several methods, including identification of direct RNA interacting proteins (iDRiP), chromatin isolation by RNA purification (ChIRP), and RNA antisense purification, each previously applied towards identifying a proteome for the prototype noncoding RNA, Xist. iDRiP has recently been modified to successfully identify proteomes for two additional noncoding RNAs of interest, TERRA and U1 RNA. Here we describe the modified protocol in detail, highlighting technical differences that facilitate capture of various noncoding RNAs. The protocol can be applied to short and long RNAs in both cultured cells and tissues, and requires ~1 week from start to finish. Here we also perform a comparative analysis between iDRiP and ChIRP. We obtain partially overlapping profiles, but find that iDRiP yields a greater number of specific proteins and fewer mitochondrial contaminants. With an increasing number of essential long noncoding RNAs being described, robust RNA-centric protein capture methods are critical for the probing of noncoding RNA function and mechanism.
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6
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Viceconte N, Loriot A, Lona Abreu P, Scheibe M, Fradera Sola A, Butter F, De Smet C, Azzalin CM, Arnoult N, Decottignies A. PAR-TERRA is the main contributor to telomeric repeat-containing RNA transcripts in normal and cancer mouse cells. RNA (NEW YORK, N.Y.) 2021; 27:106-121. [PMID: 33127860 PMCID: PMC7749631 DOI: 10.1261/rna.076281.120] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 10/28/2020] [Indexed: 05/12/2023]
Abstract
Telomeric repeat-containing RNA (TERRA) molecules play important roles at telomeres, from heterochromatin regulation to telomerase activity control. In human cells, TERRA is transcribed from subtelomeric promoters located on most chromosome ends and associates with telomeres. The origin of mouse TERRA molecules is, however, unclear, as transcription from the pseudoautosomal PAR locus was recently suggested to account for the vast majority of TERRA in embryonic stem cells (ESC). Here, we confirm the production of TERRA from both the chromosome 18q telomere and the PAR locus in mouse embryonic fibroblasts, ESC, and various mouse cancer and immortalized cell lines, and we identify two novel sources of TERRA on mouse chromosome 2 and X. Using various approaches, we show that PAR-TERRA molecules account for the majority of TERRA transcripts, displaying an increase of two to four orders of magnitude compared to the telomeric 18q transcript. Finally, we present a SILAC-based pull-down screen revealing a large overlap between TERRA-interacting proteins in human and mouse cells, including PRC2 complex subunits, chromatin remodeling factors, DNA replication proteins, Aurora kinases, shelterin complex subunits, Bloom helicase, Coilin, and paraspeckle proteins. Hence, despite originating from distinct genomic regions, mouse and human TERRA are likely to play similar functions in cells.
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Affiliation(s)
- Nikenza Viceconte
- Genetic and Epigenetic Alterations of Genomes, de Duve Institute, Université catholique de Louvain (UCLouvain), 1200 Brussels, Belgium
| | - Axelle Loriot
- Genetic and Epigenetic Alterations of Genomes, de Duve Institute, Université catholique de Louvain (UCLouvain), 1200 Brussels, Belgium
| | - Patrícia Lona Abreu
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Marion Scheibe
- Quantitative Proteomics, Institute of Molecular Biology (IMB), 55128 Mainz, Germany
| | - Albert Fradera Sola
- Quantitative Proteomics, Institute of Molecular Biology (IMB), 55128 Mainz, Germany
| | - Falk Butter
- Quantitative Proteomics, Institute of Molecular Biology (IMB), 55128 Mainz, Germany
| | - Charles De Smet
- Genetic and Epigenetic Alterations of Genomes, de Duve Institute, Université catholique de Louvain (UCLouvain), 1200 Brussels, Belgium
| | - Claus M Azzalin
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Nausica Arnoult
- MCBD-University of Colorado Boulder, Boulder, Colorado 80309-0347, USA
| | - Anabelle Decottignies
- Genetic and Epigenetic Alterations of Genomes, de Duve Institute, Université catholique de Louvain (UCLouvain), 1200 Brussels, Belgium
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7
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Kwapisz M, Morillon A. Subtelomeric Transcription and its Regulation. J Mol Biol 2020; 432:4199-4219. [PMID: 32035903 PMCID: PMC7374410 DOI: 10.1016/j.jmb.2020.01.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 01/14/2020] [Accepted: 01/14/2020] [Indexed: 12/13/2022]
Abstract
The subtelomeres, highly heterogeneous repeated sequences neighboring telomeres, are transcribed into coding and noncoding RNAs in a variety of organisms. Telomereproximal subtelomeric regions produce non-coding transcripts i.e., ARRET, αARRET, subTERRA, and TERRA, which function in telomere maintenance. The role and molecular mechanisms of the majority of subtelomeric transcripts remain unknown. This review depicts the current knowledge and puts into perspective the results obtained in different models from yeasts to humans.
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Affiliation(s)
- Marta Kwapisz
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, France
| | - Antonin Morillon
- ncRNA, Epigenetic and Genome Fluidity, CNRS UMR 3244, Sorbonne Université, PSL University, Institut Curie, Centre de Recherche, 26 rue d'Ulm, 75248, Paris, France.
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8
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Frenk S, Lister-Shimauchi EH, Ahmed S. Telomeric small RNAs in the genus Caenorhabditis. RNA (NEW YORK, N.Y.) 2019; 25:1061-1077. [PMID: 31239299 PMCID: PMC6800518 DOI: 10.1261/rna.071324.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 05/28/2019] [Indexed: 06/09/2023]
Abstract
Telomeric DNA is composed of simple tandem repeat sequences and has a G-rich strand that runs 5' to 3' toward the chromosome terminus. Small RNAs with homology to telomeres have been observed in several organisms and could originate from telomeres or from interstitial telomere sequences (ITSs), which are composites of degenerate and perfect telomere repeat sequences found on chromosome arms. We identified Caenorhabditis elegans small RNAs composed of the Caenorhabditis telomere sequence (TTAGGC)n with up to three mismatches, which might interact with telomeres. We rigorously defined ITSs for genomes of C. elegans and for two closely related nematodes, Caenorhabditis briggsae and Caenorhabditis remanei Most telomeric small RNAs with mismatches originated from ITSs, which were depleted from mRNAs but were enriched in introns whose genes often displayed hallmarks of genomic silencing. C. elegans small RNAs composed of perfect telomere repeats were very rare but their levels increased by several orders of magnitude in C. briggsae and C. remanei Major small RNA species in C. elegans begin with a 5' guanine nucleotide, which was strongly depleted from perfect telomeric small RNAs of all three Caenorhabditis species. Perfect G-rich or C-rich telomeric small RNAs commonly began with 5' UAGGCU and 5' UUAGGC or 5' CUAAGC, respectively. In contrast, telomeric small RNAs with mismatches had a mixture of all four 5' nucleotides. We suggest that perfect telomeric small RNAs have a mechanism of biogenesis that is distinct from known classes of small RNAs and that a dramatic change in their regulation occurred during recent Caenorhabditis evolution.
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Affiliation(s)
- Stephen Frenk
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
| | - Evan H Lister-Shimauchi
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
| | - Shawn Ahmed
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
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9
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Liu B, Maekawa T, Yoshida K, Ly NH, Inoue K, Hasegawa A, Chatton B, Ogura A, Ishii S. Telomere shortening by transgenerational transmission of TNF-α-induced TERRA via ATF7. Nucleic Acids Res 2019; 47:283-298. [PMID: 30407559 PMCID: PMC6326783 DOI: 10.1093/nar/gky1149] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 10/30/2018] [Indexed: 12/30/2022] Open
Abstract
Various stresses increase disease susceptibility and accelerate aging, and increasing evidence suggests that these effects can be transmitted over generation. Epidemiological studies suggest that stressors experienced by parents affect the longevity of their offspring, possibly by regulating telomere dynamics. Telomeres are elongated by telomerase and shortened by certain stresses as well as telomere repeat-containing RNA (TERRA), a telomere transcript. However, the mechanism underlying the transgenerational effects is poorly understood. Here, we show that TNF-α, which is induced by various psychological stresses, induces the p38-dependent phosphorylation of ATF7, a stress-responsive chromatin regulator, in mouse testicular germ cells. This caused a release of ATF7 from the TERRA gene promoter in the subtelomeric region, which disrupted heterochromatin and induced TERRA. TERRA was transgenerationally transmitted to zygotes via sperm and caused telomere shortening. These results suggest that ATF7 and TERRA play key roles in paternal stress-induced telomere shortening in the offspring.
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Affiliation(s)
- Binbin Liu
- RIKEN Cluster for Pioneering Research, Tsukuba, Ibaraki 305-0074, Japan
| | - Toshio Maekawa
- RIKEN Cluster for Pioneering Research, Tsukuba, Ibaraki 305-0074, Japan
| | - Keisuke Yoshida
- RIKEN Cluster for Pioneering Research, Tsukuba, Ibaraki 305-0074, Japan
| | - Nhung Hong Ly
- RIKEN Cluster for Pioneering Research, Tsukuba, Ibaraki 305-0074, Japan.,Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Kimiko Inoue
- RIKEN BioResource Center, Tsukuba, Ibaraki 305-0074, Japan
| | - Ayumi Hasegawa
- RIKEN BioResource Center, Tsukuba, Ibaraki 305-0074, Japan
| | - Bruno Chatton
- Université de Strasbourg, UMR7242 Biotechnologie et Signalisation Cellulaire, Ecole Supérieure de Biotechnologie de Strasbourg, BP10413, Illkirch, France
| | - Atsuo Ogura
- RIKEN BioResource Center, Tsukuba, Ibaraki 305-0074, Japan
| | - Shunsuke Ishii
- RIKEN Cluster for Pioneering Research, Tsukuba, Ibaraki 305-0074, Japan.,Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
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10
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The Emerging Roles of TERRA in Telomere Maintenance and Genome Stability. Cells 2019; 8:cells8030246. [PMID: 30875900 PMCID: PMC6468625 DOI: 10.3390/cells8030246] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/08/2019] [Accepted: 03/12/2019] [Indexed: 12/20/2022] Open
Abstract
The finding that transcription occurs at chromosome ends has opened new fields of study on the roles of telomeric transcripts in chromosome end maintenance and genome stability. Indeed, the ends of chromosomes are required to be protected from activation of DNA damage response and DNA repair pathways. Chromosome end protection is achieved by the activity of specific proteins that associate with chromosome ends, forming telomeres. Telomeres need to be constantly maintained as they are in a heterochromatic state and fold into specific structures (T-loops), which may hamper DNA replication. In addition, in the absence of maintenance mechanisms, chromosome ends shorten at every cell division due to limitations in the DNA replication machinery, which is unable to fully replicate the extremities of chromosomes. Altered telomere structure or critically short chromosome ends generate dysfunctional telomeres, ultimately leading to replicative senescence or chromosome instability. Telomere biology is thus implicated in multiple human diseases, including cancer. Emerging evidence indicates that a class of long noncoding RNAs transcribed at telomeres, known as TERRA for “TElomeric Repeat-containing RNA,” actively participates in the mechanisms regulating telomere maintenance and chromosome end protection. However, the molecular details of TERRA activities remain to be elucidated. In this review, we discuss recent findings on the emerging roles of TERRA in telomere maintenance and genome stability and their implications in human diseases.
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11
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Li W, Hong R, Lai LT, Dong Q, Ni P, Chelliah R, Huq M, Ismail SNB, Chandola U, Ang Z, Lin B, Chen X, Chen L, Zhang LF. Genome-Wide RNAi Screen Identify Melanoma-Associated Antigen Mageb3 Involved in X Chromosome Inactivation. J Mol Biol 2018; 430:2734-2746. [DOI: 10.1016/j.jmb.2018.05.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 05/17/2018] [Accepted: 05/17/2018] [Indexed: 10/16/2022]
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12
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Long Non-Coding RNAs in Neuronal Aging. Noncoding RNA 2018; 4:ncrna4020012. [PMID: 29670042 PMCID: PMC6027360 DOI: 10.3390/ncrna4020012] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/06/2018] [Accepted: 04/10/2018] [Indexed: 02/07/2023] Open
Abstract
The expansion of long non-coding RNAs (lncRNAs) in organismal genomes has been associated with the emergence of sophisticated regulatory networks that may have contributed to more complex neuronal processes, such as higher-order cognition. In line with the important roles of lncRNAs in the normal functioning of the human brain, dysregulation of lncRNA expression has been implicated in aging and age-related neurodegenerative disorders. In this paper, we discuss the function and expression of known neuronal-associated lncRNAs, their impact on epigenetic changes, the contribution of transposable elements to lncRNA expression, and the implication of lncRNAs in maintaining the 3D nuclear architecture in neurons. Moreover, we discuss how the complex molecular processes that are orchestrated by lncRNAs in the aged brain may contribute to neuronal pathogenesis by promoting protein aggregation and neurodegeneration. Finally, this review explores the possibility that age-related disturbances of lncRNA expression change the genomic and epigenetic regulatory landscape of neurons, which may affect neuronal processes such as neurogenesis and synaptic plasticity.
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13
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Xu X, Guo M, Zhang N, Ye S. Telomeric noncoding RNA promotes mouse embryonic stem cell self-renewal through inhibition of TCF3 activity. Am J Physiol Cell Physiol 2018. [PMID: 29513567 DOI: 10.1152/ajpcell.00292.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although long noncoding RNAs (lncRNAs) are emerging as new modulators in the fate decision of pluripotent stem cells, the functions of specific lncRNAs remain unclear. Here, we found that telomeric RNA (TERRA or TelRNA), one type of lncRNAs, is highly expressed in mouse embryonic stem cells (mESCs) but declines significantly upon differentiation. TERRA is induced by the Wnt/β-catenin signaling pathway and can reproduce its self-renewal-promoting effect when overexpressed. Further studies revealed that T cell factor 3 ( TCF3) is a potential downstream target of TERRA and mediates the effect of TERRA in mESC maintenance. TERRA inhibits TCF3 transcription, while enforced TCF3 expression abrogates the undifferentiated state of mESCs supported by TERRA. Accordingly, the transcripts of the pluripotency genes Esrrb, Tfcp2l1, and Klf2, repressed by TCF3 in mESCs, are increased in TERRA-overexpressing cells. Our study therefore highlights the important role of TERRA in mESC maintenance and also uncovers a mechanism by which TERRA promotes self-renewal. These data will expand our understanding of the pluripotent regulatory network of ESCs.
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Affiliation(s)
- Xiaojuan Xu
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei , People's Republic of China.,University of Science and Technology of China , Hefei , People's Republic of China
| | - Mengmeng Guo
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University , Hefei , People's Republic of China
| | - Na Zhang
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences , Hefei , People's Republic of China
| | - Shoudong Ye
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University , Hefei , People's Republic of China
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14
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Diman A, Decottignies A. Genomic origin and nuclear localization of TERRA telomeric repeat-containing RNA: from Darkness to Dawn. FEBS J 2017; 285:1389-1398. [PMID: 29240300 DOI: 10.1111/febs.14363] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/10/2017] [Accepted: 12/08/2017] [Indexed: 01/03/2023]
Abstract
Long noncoding RNAs, produced from distinct regions of the chromosomes, are emerging as new key players in several important biological processes. The long noncoding RNAs add a new layer of complexity to cellular regulatory pathways, from transcription to cellular trafficking or chromatin remodeling. More than 25 years ago, the discovery of a transcriptional activity at telomeres of protozoa ended the long-lasting belief that telomeres were transcriptionally silent. Since then, progressively accumulating evidences established that production of TElomeric Repeat-containing RNA (TERRA) was a general feature of eukaryotic cells. Whether TERRA molecules always originate from the telomeres or whether they can be transcribed from internal telomeric repeats as well is however still a matter of debate. Whether TERRA transcripts always localize to telomeres and play similar roles in all eukaryotic cells is also unclear. We review the studies on TERRA localization in the cell, its composition and some aspects of its transcriptional regulation to summarize the current knowledge and controversies about the genomic origin of TERRA, with a focus on human and mouse TERRA.
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Affiliation(s)
- Aurélie Diman
- Genetic & Epigenetic Alterations of Genomes, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Anabelle Decottignies
- Genetic & Epigenetic Alterations of Genomes, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
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15
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Tian X, Zhang Z. miR-191/DAB2 axis regulates the tumorigenicity of estrogen receptor-positive breast cancer. IUBMB Life 2017; 70:71-80. [DOI: 10.1002/iub.1705] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 12/02/2017] [Indexed: 12/28/2022]
Affiliation(s)
- Xinxin Tian
- Tianjin International Joint Academy of Biomedicine (TJAB); Tianjin People's Republic of China
- Department of Biochemistry and Biophysics; Texas A&M University and Texas AgriLife Research; College Station TX USA
| | - Zhiqian Zhang
- Tianjin International Joint Academy of Biomedicine (TJAB); Tianjin People's Republic of China
- State Key Laboratory of Medicinal Chemical Biology; Nankai University; Tianjin People's Republic of China
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16
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Krivega I, Dean A. A tetrad of chromatin interactions for chromosome pairing in X inactivation. Nat Struct Mol Biol 2017; 24:607-608. [PMID: 28771462 PMCID: PMC6247907 DOI: 10.1038/nsmb.3447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
An unusual pairing of homologous X chromosomes occurs during X inactivation. A new study in mouse embryonic stem cells shows that telomeres and the telomeric RNA PAR-TERRA are responsible for additional pairwise interactions that guide Xic–Xic pairing.
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Affiliation(s)
- Ivan Krivega
- Laboratory of Cellular and Developmental Biology at the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
| | - Ann Dean
- Laboratory of Cellular and Developmental Biology at the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
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17
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TERRA RNA Antagonizes ATRX and Protects Telomeres. Cell 2017; 170:86-101.e16. [PMID: 28666128 DOI: 10.1016/j.cell.2017.06.017] [Citation(s) in RCA: 166] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 05/26/2017] [Accepted: 06/09/2017] [Indexed: 12/20/2022]
Abstract
Through an integration of genomic and proteomic approaches to advance understanding of long noncoding RNAs, we investigate the function of the telomeric transcript, TERRA. By identifying thousands of TERRA target sites in the mouse genome, we demonstrate that TERRA can bind both in cis to telomeres and in trans to genic targets. We then define a large network of interacting proteins, including epigenetic factors, telomeric proteins, and the RNA helicase, ATRX. TERRA and ATRX share hundreds of target genes and are functionally antagonistic at these loci: whereas TERRA activates, ATRX represses gene expression. At telomeres, TERRA competes with telomeric DNA for ATRX binding, suppresses ATRX localization, and ensures telomeric stability. Depleting TERRA increases telomerase activity and induces telomeric pathologies, including formation of telomere-induced DNA damage foci and loss or duplication of telomeric sequences. We conclude that TERRA functions as an epigenomic modulator in trans and as an essential regulator of telomeres in cis.
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18
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Zeng S, Liu L, Sun Y, Lu G, Lin G. Role of telomeric repeat-containing RNA in telomeric chromatin remodeling during the early expansion of human embryonic stem cells. FASEB J 2017; 31:4783-4795. [PMID: 28765174 DOI: 10.1096/fj.201600939rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 07/05/2017] [Indexed: 01/05/2023]
Abstract
This study aimed to explore the role of telomeric repeat-containing RNA (TERRA) in telomeric chromatin remodeling during the early expansion of human embryonic stem cells (hESCs). During the derivation of hESCs, histone demethylation in the telomeric region facilitates telomerase-mediated telomere elongation. An adequate telomere repeat is essential for hESCs to acquire and/or maintain the unlimited symmetric division, which suggests that there is a link between pluripotency and telomere maintenance. The present study found that the gradual decrease in TERRA levels and related TERRA foci were correlated with telomeric length elongation in the early expansion of hESCs. In addition, TERRA participated in telomeric chromatin remodeling by cooperating with SUV39H1 (suppressor of variegation 3-9 homolog 1/2) to propagate telomeric heterochromatin marker, histone H3 trimethylation of lysine 9. Moreover, the fibroblast growth factor signaling pathway, which is activated in hESCs, could suppress TERRA levels via telomeric repeat factor 1, which results in reduced SUV39H1 recruitment by TERRA at the telomere. Taken together, these results highlight the role of TERRA in hESC telomere elongation and homeostasis in the acquisition and/or maintenance of stem cell pluripotency.-Zeng, S., Liu, L., Sun, Y., Lu, G., Lin, G. Role of telomeric repeat-containing RNA in telomeric chromatin remodeling during the early expansion of human embryonic stem cells.
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Affiliation(s)
- Sicong Zeng
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, China.,National Engineering and Research Center of Human Stem Cell, Changsha, China
| | - Lvjun Liu
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, China.,National Engineering and Research Center of Human Stem Cell, Changsha, China
| | - Yi Sun
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, China.,National Engineering and Research Center of Human Stem Cell, Changsha, China
| | - Guangxiu Lu
- National Engineering and Research Center of Human Stem Cell, Changsha, China
| | - Ge Lin
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, China; .,National Engineering and Research Center of Human Stem Cell, Changsha, China
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19
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Chu HP, Froberg JE, Kesner B, Oh HJ, Ji F, Sadreyev R, Pinter SF, Lee JT. PAR-TERRA directs homologous sex chromosome pairing. Nat Struct Mol Biol 2017; 24:620-631. [PMID: 28692038 PMCID: PMC5553554 DOI: 10.1038/nsmb.3432] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 06/09/2017] [Indexed: 12/25/2022]
Abstract
In mammals, homologous chromosomes rarely pair outside of meiosis. An exception is the X-chromosome, which transiently pairs during X-chromosome inactivation (XCI). How two chromosomes find each other in 3D space is not known. Here, we reveal a required interaction between the X-inactivation center (Xic) and the telomere in mouse embryonic stem cells. The sub-telomeric, pseudoautosomal region (PAR) of both sex chromosomes (X,Y) also undergoes pairing. PAR transcribes a class of telomeric RNA, dubbed “PAR-TERRA”, which accounts for a vast majority of all TERRA transcripts. PAR-TERRA binds throughout the genome, including PAR and Xic. PAR-TERRA anchors the Xic to PAR, creating a “tetrad” of pairwise homologous interactions (Xic:Xic, PAR:PAR, Xic:PAR). Xic pairing occurs within the tetrad. Depleting PAR-TERRA abrogates pairing and blocks initiation of XCI, whereas autosomal PAR-TERRA induces ectopic pairing. We proposed a Constrained Diffusion Model in which PAR-TERRA creates an interaction hub to guide Xic homology searching during XCI.
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Affiliation(s)
- Hsueh-Ping Chu
- Howard Hughes Medical Institute, Boston, Massachusetts, USA.,Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - John E Froberg
- Howard Hughes Medical Institute, Boston, Massachusetts, USA.,Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Barry Kesner
- Howard Hughes Medical Institute, Boston, Massachusetts, USA.,Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Hyun Jung Oh
- Howard Hughes Medical Institute, Boston, Massachusetts, USA.,Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Fei Ji
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Ruslan Sadreyev
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Stefan F Pinter
- Howard Hughes Medical Institute, Boston, Massachusetts, USA.,Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Jeannie T Lee
- Howard Hughes Medical Institute, Boston, Massachusetts, USA.,Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
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20
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Wang Z, Deng Z, Dahmane N, Tsai K, Wang P, Williams DR, Kossenkov AV, Showe LC, Zhang R, Huang Q, Conejo-Garcia JR, Lieberman PM. Telomeric repeat-containing RNA (TERRA) constitutes a nucleoprotein component of extracellular inflammatory exosomes. Proc Natl Acad Sci U S A 2015; 112:E6293-300. [PMID: 26578789 PMCID: PMC4655533 DOI: 10.1073/pnas.1505962112] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Telomeric repeat-containing RNA (TERRA) has been identified as a telomere-associated regulator of chromosome end protection. Here, we report that TERRA can also be found in extracellular fractions that stimulate innate immune signaling. We identified extracellular forms of TERRA in mouse tumor and embryonic brain tissue, as well as in human tissue culture cell lines using RNA in situ hybridization. RNA-seq analyses revealed TERRA to be among the most highly represented transcripts in extracellular fractions derived from both normal and cancer patient blood plasma. Cell-free TERRA (cfTERRA) could be isolated from the exosome fractions derived from human lymphoblastoid cell line (LCL) culture media. cfTERRA is a shorter form (∼200 nt) of cellular TERRA and copurifies with CD63- and CD83-positive exosome vesicles that could be visualized by cyro-electron microscopy. These fractions were also enriched for histone proteins that physically associate with TERRA in extracellular ChIP assays. Incubation of cfTERRA-containing exosomes with peripheral blood mononuclear cells stimulated transcription of several inflammatory cytokine genes, including TNFα, IL6, and C-X-C chemokine 10 (CXCL10) Exosomes engineered with elevated TERRA or liposomes with synthetic TERRA further stimulated inflammatory cytokines, suggesting that exosome-associated TERRA augments innate immune signaling. These findings imply a previously unidentified extrinsic function for TERRA and a mechanism of communication between telomeres and innate immune signals in tissue and tumor microenvironments.
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Affiliation(s)
- Zhuo Wang
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104; Cancer Biology Program, University of the Sciences in Philadelphia, Philadelphia, PA 19104
| | - Zhong Deng
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104
| | - Nadia Dahmane
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104
| | - Kevin Tsai
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104
| | - Pu Wang
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104
| | - Dewight R Williams
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104
| | - Andrew V Kossenkov
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104
| | - Louise C Showe
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104
| | - Rugang Zhang
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104
| | - Qihong Huang
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104
| | - José R Conejo-Garcia
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104
| | - Paul M Lieberman
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104;
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21
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Wang C, Zhao L, Lu S. Role of TERRA in the regulation of telomere length. Int J Biol Sci 2015; 11:316-23. [PMID: 25678850 PMCID: PMC4323371 DOI: 10.7150/ijbs.10528] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/25/2014] [Indexed: 01/08/2023] Open
Abstract
Telomere dysfunction is closely associated with human diseases such as cancer and ageing. Inappropriate changes in telomere length and/or structure result in telomere dysfunction. Telomeres have been considered to be transcriptionally silent, but it was recently demonstrated that mammalian telomeres are transcribed into telomeric repeat-containing RNA (TERRA). TERRA, a long non-coding RNA, participates in the regulation of telomere length, telomerase activity and heterochromatinization. The correct regulation of telomere length may be crucial to telomeric homeostasis and functions. Here, we summarize recent advances in our understanding of the crucial role of TERRA in the maintenance of telomere length, with focus on the variety of mechanisms by which TERRA is involved in the regulation of telomere length. This review aims to enable further understanding of how TERRA-targeted drugs can target telomere-related diseases.
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Affiliation(s)
- Caiqin Wang
- Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, China, Women's Hospital, School of Medicine, Zhejiang University, Xueshi Road 1#, Hangzhou 310006, China
| | - Li Zhao
- Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, China, Women's Hospital, School of Medicine, Zhejiang University, Xueshi Road 1#, Hangzhou 310006, China
| | - Shiming Lu
- Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, China, Women's Hospital, School of Medicine, Zhejiang University, Xueshi Road 1#, Hangzhou 310006, China
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22
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Levy MA, Kernohan KD, Jiang Y, Bérubé NG. ATRX promotes gene expression by facilitating transcriptional elongation through guanine-rich coding regions. Hum Mol Genet 2014; 24:1824-35. [PMID: 25452430 DOI: 10.1093/hmg/ddu596] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
ATRX is a chromatin remodeling protein involved in deposition of the histone variant H3.3 at telomeres and pericentromeric heterochromatin. It also influences the expression level of specific genes; however, deposition of H3.3 at transcribed genes is currently thought to occur independently of ATRX. We focused on a set of genes, including the autism susceptibility gene Neuroligin 4 (Nlgn4), that exhibit decreased expression in ATRX-null cells to investigate the mechanisms used by ATRX to promote gene transcription. Overall TERRA levels, as well as DNA methylation and histone modifications at ATRX target genes are not altered and thus cannot explain transcriptional dysregulation. We found that ATRX does not associate with the promoter of these genes, but rather binds within regions of the gene body corresponding to high H3.3 occupancy. These intragenic regions consist of guanine-rich DNA sequences predicted to form non-B DNA structures called G-quadruplexes during transcriptional elongation. We demonstrate that ATRX deficiency corresponds to reduced H3.3 incorporation and stalling of RNA polymerase II at these G-rich intragenic sites. These findings suggest that ATRX promotes the incorporation of histone H3.3 at particular transcribed genes and facilitates transcriptional elongation through G-rich sequences. The inability to transcribe genes such as Nlgn4 could cause deficits in neuronal connectivity and cognition associated with ATRX mutations in humans.
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Affiliation(s)
- Michael A Levy
- Department of Paediatrics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada N6A 5C1, Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada N6A 5C1 Children's Health Research Institute, London, Ontario, Canada N6C 2V5
| | - Kristin D Kernohan
- Department of Paediatrics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada N6A 5C1, Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada N6A 5C1 Children's Health Research Institute, London, Ontario, Canada N6C 2V5
| | - Yan Jiang
- Department of Paediatrics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada N6A 5C1, Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada N6A 5C1 Children's Health Research Institute, London, Ontario, Canada N6C 2V5
| | - Nathalie G Bérubé
- Department of Paediatrics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada N6A 5C1, Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada N6A 5C1 Children's Health Research Institute, London, Ontario, Canada N6C 2V5
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23
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Yue M, Charles Richard JL, Yamada N, Ogawa A, Ogawa Y. Quick fluorescent in situ hybridization protocol for Xist RNA combined with immunofluorescence of histone modification in X-chromosome inactivation. J Vis Exp 2014:e52053. [PMID: 25489864 DOI: 10.3791/52053] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Combining RNA fluorescent in situ hybridization (FISH) with immunofluorescence (immuno-FISH) creates a technique that can be employed at the single cell level to detect the spatial dynamics of RNA localization with simultaneous insight into the localization of proteins, epigenetic modifications and other details which can be highlighted by immunofluorescence. X-chromosome inactivation is a paradigm for long non-coding RNA (lncRNA)-mediated gene silencing. X-inactive specific transcript (Xist) lncRNA accumulation (called an Xist cloud) on one of the two X-chromosomes in mammalian females is a critical step to initiate X-chromosome inactivation. Xist RNA directly or indirectly interacts with various chromatin-modifying enzymes and introduces distinct epigenetic landscapes to the inactive X-chromosome (Xi). One known epigenetic hallmark of the Xi is the Histone H3 trimethyl-lysine 27 (H3K27me3) modification. Here, we describe a simple and quick immuno-FISH protocol for detecting Xist RNA using RNA FISH with multiple oligonucleotide probes coupled with immunofluorescence of H3K27me3 to examine the localization of Xist RNA and associated epigenetic modifications. Using oligonucleotide probes results in a shorter incubation time and more sensitive detection of Xist RNA compared to in vitro transcribed RNA probes (riboprobes). This protocol provides a powerful tool for understanding the dynamics of lncRNAs and its associated epigenetic modification, chromatin structure, nuclear organization and transcriptional regulation.
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Affiliation(s)
- Minghui Yue
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center; Department of Pediatrics, University of Cincinnati College of Medicine
| | - John Lalith Charles Richard
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center; Department of Pediatrics, University of Cincinnati College of Medicine
| | - Norishige Yamada
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center; Department of Pediatrics, University of Cincinnati College of Medicine
| | - Akiyo Ogawa
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center
| | - Yuya Ogawa
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center; Department of Pediatrics, University of Cincinnati College of Medicine;
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24
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Basu R, Lai LT, Meng Z, Wu J, Shao F, Zhang LF. Using amino-labeled nucleotide probes for simultaneous single molecule RNA-DNA FISH. PLoS One 2014; 9:e107425. [PMID: 25226542 PMCID: PMC4167323 DOI: 10.1371/journal.pone.0107425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 08/07/2014] [Indexed: 01/17/2023] Open
Abstract
Using amino-labeled oligonucleotide probes, we established a simple, robust and low-noise method for simultaneous detection of RNA and DNA by fluorescence in situ hybridization, a highly useful tool to study the large pool of long non-coding RNAs being identified in the current research. With probes either chemically or biologically synthesized, we demonstrate that the method can be applied to study a wide range of RNA and DNA targets at the single-cell and single-molecule level in cellular contexts.
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Affiliation(s)
- Reelina Basu
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Lan-Tian Lai
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Zhenyu Meng
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Jun Wu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Fangwei Shao
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail: (FS); (L-FZ)
| | - Li-Feng Zhang
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail: (FS); (L-FZ)
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25
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Abstract
Telomeres protect chromosome ends from degradation and inappropriate DNA damage response activation through their association with specific factors. Interestingly, these telomeric factors are able to localize outside telomeric regions, where they can regulate the transcription of genes involved in metabolism, immunity and differentiation. These findings delineate a signalling pathway by which telomeric changes control the ability of their associated factors to regulate transcription. This mechanism is expected to enable a greater diversity of cellular responses that are adapted to specific cell types and telomeric changes, and may therefore represent a pivotal aspect of development, ageing and telomere-mediated diseases.
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26
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Reig-Viader R, Vila-Cejudo M, Vitelli V, Buscà R, Sabaté M, Giulotto E, Caldés MG, Ruiz-Herrera A. Telomeric Repeat-Containing RNA (TERRA) and Telomerase Are Components of Telomeres During Mammalian Gametogenesis1. Biol Reprod 2014; 90:103. [DOI: 10.1095/biolreprod.113.116954] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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27
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Cusanelli E, Chartrand P. Telomeric noncoding RNA: telomeric repeat-containing RNA in telomere biology. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 5:407-19. [PMID: 24523222 DOI: 10.1002/wrna.1220] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Telomeres are nucleoprotein structures that cap the ends of eukaryotic chromosomes, protecting them from degradation and activation of DNA damage response. For this reason, functional telomeres are vital to genome stability. For years, telomeres were assumed to be transcriptionally silent, because of their heterochromatic state. It was only recently shown that, in several organisms, telomeres are transcribed, giving rise to a long noncoding RNA (lncRNA) called telomeric repeat-containing RNA (TERRA). Several lines of evidence now indicate that TERRA molecules play crucial roles in telomere homeostasis and telomere functions. Recent studies have shown that the expression and regulation of TERRA are dynamically controlled by each chromosome end. TERRA has been involved in the regulation of telomere length, telomerase activity, and heterochromatin formation at telomeres. The correct regulation of the telomeric transcripts may be essential to genome stability, and altered TERRA levels associate with tumorigenesis and cellular senescence. Thus, the study of the molecular mechanisms of TERRA biogenesis and function may advance the understanding of telomere-related diseases, including cancer and aging.
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Affiliation(s)
- Emilio Cusanelli
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Canada
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28
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Watson LA, Solomon LA, Li JR, Jiang Y, Edwards M, Shin-ya K, Beier F, Bérubé NG. Atrx deficiency induces telomere dysfunction, endocrine defects, and reduced life span. J Clin Invest 2013; 123:2049-63. [PMID: 23563309 DOI: 10.1172/jci65634] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 02/14/2013] [Indexed: 01/02/2023] Open
Abstract
Human ATRX mutations are associated with cognitive deficits, developmental abnormalities, and cancer. We show that the Atrx-null embryonic mouse brain accumulates replicative damage at telomeres and pericentromeric heterochromatin, which is exacerbated by loss of p53 and linked to ATM activation. ATRX-deficient neuroprogenitors exhibited higher incidence of telomere fusions and increased sensitivity to replication stress-inducing drugs. Treatment of Atrx-null neuroprogenitors with the G-quadruplex (G4) ligand telomestatin increased DNA damage, indicating that ATRX likely aids in the replication of telomeric G4-DNA structures. Unexpectedly, mutant mice displayed reduced growth, shortened life span, lordokyphosis, cataracts, heart enlargement, and hypoglycemia, as well as reduction of mineral bone density, trabecular bone content, and subcutaneous fat. We show that a subset of these defects can be attributed to loss of ATRX in the embryonic anterior pituitary that resulted in low circulating levels of thyroxine and IGF-1. Our findings suggest that loss of ATRX increases DNA damage locally in the forebrain and anterior pituitary and causes tissue attrition and other systemic defects similar to those seen in aging.
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Affiliation(s)
- L Ashley Watson
- Children’s Health Research Institute, London, Ontario, Canada
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Giraud-Panis MJ, Pisano S, Benarroch-Popivker D, Pei B, Le Du MH, Gilson E. One identity or more for telomeres? Front Oncol 2013; 3:48. [PMID: 23509004 PMCID: PMC3598436 DOI: 10.3389/fonc.2013.00048] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Accepted: 02/23/2013] [Indexed: 12/19/2022] Open
Abstract
A major issue in telomere research is to understand how the integrity of chromosome ends is controlled. The fact that different types of nucleoprotein complexes have been described at the telomeres of different organisms raises the question of whether they have in common a structural identity that explains their role in chromosome protection. We will review here how telomeric nucleoprotein complexes are structured, comparing different organisms and trying to link these structures to telomere biology. It emerges that telomeres are formed by a complex and specific network of interactions between DNA, RNA, and proteins. The fact that these interactions and associated activities are reinforcing each other might help to guarantee the robustness of telomeric functions across the cell cycle and in the event of cellular perturbations. We will also discuss the recent notion that telomeres have evolved specific systems to overcome the DNA topological stress generated during their replication and transcription. This will lead to revisit the way we envisage the functioning of telomeric complexes since the regulation of topology is central to DNA stability, replication, recombination, and transcription as well as to chromosome higher-order organization.
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Affiliation(s)
- Marie-Josèphe Giraud-Panis
- Faculté de Médecine de Nice, Université de Nice-Sophia Antipolis, Institute for Research on Cancer and Aging Nice, UMR 7284 CNRS, U1081 INSERM Nice, France
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30
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Lai LT, Lee PJ, Zhang LF. Immunofluorescence protects RNA signals in simultaneous RNA–DNA FISH. Exp Cell Res 2013; 319:46-55. [DOI: 10.1016/j.yexcr.2012.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 10/24/2012] [Accepted: 11/11/2012] [Indexed: 01/19/2023]
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31
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Reig-Viader R, Brieno-Enriquez MA, Khouriauli L, Toran N, Cabero L, Giulotto E, Garcia-Caldes M, Ruiz-Herrera A. Telomeric repeat-containing RNA and telomerase in human fetal oocytes. Hum Reprod 2012; 28:414-22. [DOI: 10.1093/humrep/des363] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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32
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Arnoult N, Van Beneden A, Decottignies A. Telomere length regulates TERRA levels through increased trimethylation of telomeric H3K9 and HP1α. Nat Struct Mol Biol 2012; 19:948-56. [PMID: 22922742 DOI: 10.1038/nsmb.2364] [Citation(s) in RCA: 178] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 07/19/2012] [Indexed: 01/07/2023]
Abstract
Gene silencing by the repressive telomeric chromatin environment, referred to as telomere position effect (TPE), has been well characterized in yeast and depends on telomere length. However, proof of its existence at native human chromosome ends has remained elusive, mainly owing to the paucity of genes near telomeres. The discovery of TERRAs, the telomeric noncoding RNAs transcribed from subtelomeric promoters, paved the way to probing for telomere-length impact on physiological TPE. Using cell lines of various origins, we show that telomere elongation consistently represses TERRA expression. Repression is mediated by increased trimethylated H3K9 density at telomeres and by heterochromatin protein HP1α, with no detectable spreading of the marks beyond the telomeric tract, restricting human TPE to telomere transcription. Our data further support the existence of a negative-feedback mechanism in which longer TERRA molecules repress their own transcription upon telomere elongation.
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Affiliation(s)
- Nausica Arnoult
- Genetic and Epigenetic Alterations of Genomes, de Duve Institute, Faculty of Pharmacy and Biomedical Sciences, Catholic University of Louvain, Brussels, Belgium
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33
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Deng Z, Wang Z, Xiang C, Molczan A, Baubet V, Conejo-Garcia J, Xu X, Lieberman PM, Dahmane N. Formation of telomeric repeat-containing RNA (TERRA) foci in highly proliferating mouse cerebellar neuronal progenitors and medulloblastoma. J Cell Sci 2012; 125:4383-94. [PMID: 22641694 DOI: 10.1242/jcs.108118] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Telomeres play crucial roles in the maintenance of genome integrity and control of cellular senescence. Most eukaryotic telomeres can be transcribed to generate a telomeric repeat-containing RNA (TERRA) that persists as a heterogeneous nuclear RNA and can be developmentally regulated. However, the precise function and regulation of TERRA in normal and cancer cell development remains poorly understood. Here, we show that TERRA accumulates in highly proliferating normal and cancer cells, and forms large nuclear foci, which are distinct from previously characterized markers of DNA damage or replication stress. Using a mouse model for medulloblastoma driven by chronic Sonic hedgehog (SHH) signaling, TERRA RNA was detected in tumor, but not adjacent normal cells using both RNA fluorescence in situ hybridization (FISH) and northern blotting. RNA FISH revealed the formation of TERRA foci (TERFs) in the nuclear regions of rapidly proliferating tumor cells. In the normal developing cerebellum, TERRA aggregates could also be detected in highly proliferating zones of progenitor neurons. SHH could enhance TERRA expression in purified granule progenitor cells in vitro, suggesting that proliferation signals contribute to TERRA expression in responsive tissue. TERRA foci did not colocalize with γH2AX foci, promyelocytic leukemia (PML) or Cajal bodies in mouse tumor tissue. We also provide evidence that TERRA is elevated in a variety of human cancers. These findings suggest that elevated TERRA levels reflect a novel early form of telomere regulation during replication stress and cancer cell evolution, and the TERRA RNA aggregates may form a novel nuclear body in highly proliferating mammalian cells.
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Affiliation(s)
- Zhong Deng
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA 19104, USA
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34
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Basu R, Zhang LF. X chromosome inactivation: a silence that needs to be broken. Genesis 2011; 49:821-34. [PMID: 21898762 DOI: 10.1002/dvg.20792] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 08/04/2011] [Accepted: 08/06/2011] [Indexed: 11/08/2022]
Abstract
Each mammalian female cell transcriptionally inactivates one X chromosome to balance X-linked gene dosage between males and females. This phenomenon, called X chromosome inactivation, is a perfect epigenetic event, in which two chromosomes with identical DNA sequences are solely distinguished by epigenetic modifications. In this case, epigenetic marks, such as histone modifications, histone variants, DNA methylation, and ncRNAs, are all enriched on one chromosome, the inactive X chromosome (Xi), to establish its chromosome-wide gene silencing. At face value, it seems that the gene silencing mechanism of Xi is well understood. However, the "silence" of Xi in somatic cells is so tightly maintained that it remains largely intact even after almost all known epigenetic modifications are artificially depleted. To understand how the gene silence of Xi is maintained in soma is a major challenge in current research. We summarize the current knowledge related with this issue and discuss future research directions.
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Affiliation(s)
- Reelina Basu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore
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35
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Subtelomeric repetitive elements determine TERRA regulation by Rap1/Rif and Rap1/Sir complexes in yeast. EMBO Rep 2011; 12:587-93. [PMID: 21525956 DOI: 10.1038/embor.2011.73] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Revised: 03/23/2011] [Accepted: 03/30/2011] [Indexed: 01/28/2023] Open
Abstract
Telomeric repeat-containing RNA (TERRA) has been implicated in the control of heterochromatin and telomerase. We demonstrate that yeast TERRA is regulated by telomere-binding proteins in a chromosome-end-specific manner that is dependent on subtelomeric repetitive DNA elements. At telomeres that contain only X-elements, the Rap1 carboxy-terminal domain recruits the Sir2/3/4 and Rif1/2 complexes to repress transcription in addition to promoting Rat1-nuclease-dependent TERRA degradation. At telomeres that contain Y' elements, however, Rap1 represses TERRA through recruitment of Rif1 and Rif2. Our work emphasizes the importance of subtelomeric DNA in the control of telomeric protein composition and telomere transcription.
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36
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Pinpointing the expression of piRNAs and function of the PIWI protein subfamily during spermatogenesis in the mouse. Dev Biol 2011; 355:215-26. [PMID: 21539824 DOI: 10.1016/j.ydbio.2011.04.021] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 04/17/2011] [Indexed: 01/20/2023]
Abstract
PIWI proteins and piRNAs have been linked to transposon silencing in the primordial mouse testis, but their function in the adult testis remains elusive. Here we report the cytological characterization of piRNAs in the adult mouse testis and the phenotypic analysis of Miwi(-/-); Mili(-/-) mice. We show that piRNAs are specifically present in germ cells, especially abundant in spermatocytes and early round spermatids, regardless of the type of the genomic sequences to which they correspond. piRNAs and PIWI proteins are present in both the cytoplasm and nucleus. In the cytoplasm, they are enriched in the chromatoid body; whereas in the nucleus they are enriched in the dense body, a male-specific organelle associated with synapsis and the formation of the XY body during meiosis. Moreover, by generating Miwi(-/-); Mili(-/-) mice, which lack all PIWI proteins in the adult, we show that PIWI proteins and presumably piRNAs in the adult are required only for spermatogenesis. Spermatocytes without PIWI proteins are arrested at the pachytene stage, when the sex chromosomes undergo transcriptional silencing to form the XY body. These results pinpoint a function of the PIWI protein subfamily to meiosis during spermatogenesis.
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Arora R, Brun CMC, Azzalin CM. TERRA: Long Noncoding RNA at Eukaryotic Telomeres. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2011; 51:65-94. [PMID: 21287134 DOI: 10.1007/978-3-642-16502-3_4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Telomeres protect the ends of linear eukaryotic chromosomes from being recognized as DNA double-stranded breaks, thereby maintaining the stability of our genome. The highly heterochromatic nature of telomeres had, for a long time, reinforced the idea that telomeres were transcriptionally silent. Since a few years, however, we know that DNA-dependent RNA polymerase II transcribes telomeric DNA into TElomeric Repeat-containing RNA (TERRA) molecules in a large variety of eukaryotes. In this chapter, we summarize the current knowledge of telomere structure and function and extensively review data accumulated on TERRA biogenesis and regulation. We also discuss putative functions of TERRA in preserving telomere stability and propose future directions for research encompassing this novel and exciting aspect of telomere biology.
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Affiliation(s)
- Rajika Arora
- Institute of Biochemistry, ETHZ-Eidgenössische Technische Hochschule Zürich, CH-8093, Zürich, Switzerland
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38
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Probst AV, Okamoto I, Casanova M, El Marjou F, Le Baccon P, Almouzni G. A strand-specific burst in transcription of pericentric satellites is required for chromocenter formation and early mouse development. Dev Cell 2010; 19:625-38. [PMID: 20951352 DOI: 10.1016/j.devcel.2010.09.002] [Citation(s) in RCA: 242] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 07/01/2010] [Accepted: 08/18/2010] [Indexed: 01/21/2023]
Abstract
At the time of fertilization, the paternal genome lacks the typical configuration and marks characteristic of pericentric heterochromatin. It is thus essential to understand the dynamics of this region during early development, its importance during that time period and how a somatic configuration is attained. Here, we show that pericentric satellites undergo a transient peak in expression precisely at the time of chromocenter formation. This transcription is regulated in a strand-specific manner in time and space and is strongly biased by the parental asymmetry. The transcriptional upregulation follows a developmental clock, yet when replication is blocked chromocenter formation is impeded. Furthermore, interference with major satellite transcripts using locked nucleic acid (LNA)-DNA gapmers results in developmental arrest before completion of chromocenter formation. We conclude that the exquisite strand-specific expression dynamics at major satellites during the 2-cell stage, with both up and downregulation, are necessary events for proper chromocenter organization and developmental progression.
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Affiliation(s)
- Aline V Probst
- Laboratory of Nuclear Dynamics and Genome Plasticity, Unité Mixte de Recherche, 218 Centre National de la Recherche Scientifique/Institut Curie, 26, rue d'Ulm, 75248 Paris Cedex 05, France
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39
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Chromatin plasticity and genome organization in pluripotent embryonic stem cells. Curr Opin Cell Biol 2010; 22:334-41. [PMID: 20226651 DOI: 10.1016/j.ceb.2010.02.001] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 02/04/2010] [Accepted: 02/10/2010] [Indexed: 12/23/2022]
Abstract
In search of the mechanisms that govern pluripotency and embryonic stem cell (ESC) self-renewal, a growing list of evidence highlights chromatin as a leading factor, controlling ESC maintenance and differentiation. In-depth investigation of chromatin in ESCs revealed distinct features, including DNA methylation, histone modifications, chromatin protein composition and nuclear architecture. Here we review recent literature describing different aspects of chromatin and genome organization in ESCs. The emerging theme seems to support a mechanism maintaining chromatin plasticity in ESCs but without any dramatic changes in the organization and nuclear positioning of chromosomes and gene loci themselves. Plasticity thus seems to be supported more by different mechanisms maintaining an open chromatin state and less by regulating the location of genomic regions.
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40
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Deng Z, Campbell AE, Lieberman PM. TERRA, CpG methylation and telomere heterochromatin: lessons from ICF syndrome cells. Cell Cycle 2010; 9:69-74. [PMID: 20016274 DOI: 10.4161/cc.9.1.10358] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Self-reinforcing negative feedback loops are commonly observed in biological systems. RNA-mediated negative feedback loops have been described in the formation of heterochromatin at centromeres in fission yeast and the inactive X chromosome in mammalian cells. The telomere repeat-containing RNA (TERRA) has also been implicated in the formation of telomeric heterochromatin through a self-reinforcing negative feedback loop. In cells derived from human ICF syndrome, TERRA levels are abnormally elevated and telomeres are abnormally shortened. We now show that telomere heterochromatin is also abnormal in ICF cells. We propose that ICF cells fail to reinforce the TERRA-dependent negative feedback loop as a result of the inability to establish heterochromatin at subtelomeres. This failure is likely due to the lack of DNMT3b and DNA methylation, which is a genetic lesion associated with ICF syndrome. Failure of this feedback mechanism leads to catastrophic telomere dysfunction and chromosome instability.
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Affiliation(s)
- Zhong Deng
- The Wistar Institute, Philadelphia, PA, USA
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41
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Luke B, Lingner J. TERRA: telomeric repeat-containing RNA. EMBO J 2009; 28:2503-10. [PMID: 19629047 PMCID: PMC2722245 DOI: 10.1038/emboj.2009.166] [Citation(s) in RCA: 192] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Accepted: 05/25/2009] [Indexed: 02/06/2023] Open
Abstract
Telomeres, the physical ends of eukaryotic chromosomes, consist of tandem arrays of short DNA repeats and a large set of specialized proteins. A recent analysis has identified telomeric repeat-containing RNA (TERRA), a large non-coding RNA in animals and fungi, which forms an integral component of telomeric heterochromatin. TERRA transcription occurs at most or all chromosome ends and it is regulated by RNA surveillance factors and in response to changes in telomere length. TERRA functions that are emerging suggest important roles in the regulation of telomerase and in orchestrating chromatin remodelling throughout development and cellular differentiation. The accumulation of TERRA at telomeres can also interfere with telomere replication, leading to a sudden loss of telomere tracts. Such a phenotype can be observed upon impairment of the RNA surveillance machinery or in cells from ICF (Immunodeficiency, Centromeric region instability, Facial anomalies) patients, in which TERRA is upregulated because of DNA methylation defects in the subtelomeric region. Thus, TERRA may mediate several crucial functions at the telomeres, a region of the genome that had been considered to be transcriptionally silent.
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Affiliation(s)
- Brian Luke
- EPFL-Ecole Polytechnique Fédérale de Lausanne, ISREC-Swiss Institute for Experimental Cancer Research, Lausanne, Switzerland
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