1
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Montano C, Flores-Arenas C, Carpenter S. LncRNAs, nuclear architecture and the immune response. Nucleus 2024; 15:2350182. [PMID: 38738760 PMCID: PMC11093052 DOI: 10.1080/19491034.2024.2350182] [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: 02/05/2024] [Accepted: 04/22/2024] [Indexed: 05/14/2024] Open
Abstract
Long noncoding RNAs (LncRNAs) are key regulators of gene expression and can mediate their effects in both the nucleus and cytoplasm. Some of the best-characterized lncRNAs are localized within the nucleus, where they modulate the nuclear architecture and influence gene expression. In this review, we discuss the role of lncRNAs in nuclear architecture in the context of their gene regulatory functions in innate immunity. Here, we discuss various approaches to functionally characterize nuclear-localized lncRNAs and the challenges faced in the field.
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Affiliation(s)
- Christy Montano
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
| | - Cristina Flores-Arenas
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
| | - Susan Carpenter
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
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2
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Nickerson JA, Momen-Heravi F. Long non-coding RNAs: roles in cellular stress responses and epigenetic mechanisms regulating chromatin. Nucleus 2024; 15:2350180. [PMID: 38773934 PMCID: PMC11123517 DOI: 10.1080/19491034.2024.2350180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/22/2024] [Indexed: 05/24/2024] Open
Abstract
Most of the genome is transcribed into RNA but only 2% of the sequence codes for proteins. Non-coding RNA transcripts include a very large number of long noncoding RNAs (lncRNAs). A growing number of identified lncRNAs operate in cellular stress responses, for example in response to hypoxia, genotoxic stress, and oxidative stress. Additionally, lncRNA plays important roles in epigenetic mechanisms operating at chromatin and in maintaining chromatin architecture. Here, we address three lncRNA topics that have had significant recent advances. The first is an emerging role for many lncRNAs in cellular stress responses. The second is the development of high throughput screening assays to develop causal relationships between lncRNAs across the genome with cellular functions. Finally, we turn to recent advances in understanding the role of lncRNAs in regulating chromatin architecture and epigenetics, advances that build on some of the earliest work linking RNA to chromatin architecture.
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Affiliation(s)
- Jeffrey A Nickerson
- Division of Genes & Development, Department of Pediatrics, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Fatemeh Momen-Heravi
- College of Dental Medicine, Columbia University Medical Center, New York, NY, USA
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, USA
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3
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Johnson K, Seidel JM, Cech TR. Small molecule telomerase inhibitors are also potent inhibitors of telomeric C-strand synthesis. RNA (NEW YORK, N.Y.) 2024; 30:1213-1226. [PMID: 38918043 DOI: 10.1261/rna.080043.124] [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: 04/01/2024] [Accepted: 06/10/2024] [Indexed: 06/27/2024]
Abstract
Telomere replication is essential for continued proliferation of human cells, such as stem cells and cancer cells. Telomerase lengthens the telomeric G-strand, while C-strand replication is accomplished by CST-polymerase α-primase (CST-PP). Replication of both strands is inhibited by formation of G-quadruplex (GQ) structures in the G-rich single-stranded DNA. TMPyP4 and pyridostatin (PDS), which stabilize GQ structures in both DNA and RNA, inhibit telomerase in vitro, and in human cells they cause telomere shortening that has been attributed to telomerase inhibition. Here, we show that TMPyP4 and PDS also inhibit C-strand synthesis by stabilizing DNA secondary structures and thereby preventing CST-PP from binding to telomeric DNA. We also show that these small molecules inhibit CST-PP binding to a DNA sequence containing no consecutive guanine residues, which is unlikely to form GQs. Thus, while these "telomerase inhibitors" indeed inhibit telomerase, they are also robust inhibitors of telomeric C-strand synthesis. Furthermore, given their binding to GQ RNA and their limited specificity for GQ structures, they may disrupt many other protein-nucleic acid interactions in human cells.
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Affiliation(s)
- Kaitlin Johnson
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Julia M Seidel
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Thomas R Cech
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
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4
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Dunn-Davies H, Dudnakova T, Nogara A, Rodor J, Thomas AC, Parish E, Gautier P, Meynert A, Ulitsky I, Madeddu P, Caporali A, Baker A, Tollervey D, Mitić T. Control of endothelial cell function and arteriogenesis by MEG3:EZH2 epigenetic regulation of integrin expression. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102173. [PMID: 38617973 PMCID: PMC11015509 DOI: 10.1016/j.omtn.2024.102173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/14/2024] [Indexed: 04/16/2024]
Abstract
Epigenetic processes involving long non-coding RNAs regulate endothelial gene expression. However, the underlying regulatory mechanisms causing endothelial dysfunction remain to be elucidated. Enhancer of zeste homolog 2 (EZH2) is an important rheostat of histone H3K27 trimethylation (H3K27me3) that represses endothelial targets, but EZH2 RNA binding capacity and EZH2:RNA functional interactions have not been explored in post-ischemic angiogenesis. We used formaldehyde/UV-assisted crosslinking ligation and sequencing of hybrids and identified a new role for maternally expressed gene 3 (MEG3). MEG3 formed the predominant RNA:RNA hybrid structures in endothelial cells. Moreover, MEG3:EZH2 assists recruitment onto chromatin. By EZH2-chromatin immunoprecipitation, following MEG3 depletion, we demonstrated that MEG3 controls recruitment of EZH2/H3K27me3 onto integrin subunit alpha4 (ITGA4) promoter. Both MEG3 knockdown or EZH2 inhibition (A-395) promoted ITGA4 expression and improved endothelial cell migration and adhesion to fibronectin in vitro. The A-395 inhibitor re-directed MEG3-assisted chromatin remodeling, offering a direct therapeutic benefit by increasing endothelial function and resilience. This approach subsequently increased the expression of ITGA4 in arterioles following ischemic injury in mice, thus promoting arteriogenesis. Our findings show a context-specific role for MEG3 in guiding EZH2 to repress ITGA4. Novel therapeutic strategies could antagonize MEG3:EZH2 interaction for pre-clinical studies.
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Affiliation(s)
- Hywel Dunn-Davies
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building Max Born Crescent, King’s Buildings, Edinburgh EH9 3BF, UK
| | - Tatiana Dudnakova
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute (QMRI), The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Antonella Nogara
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute (QMRI), The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Julie Rodor
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute (QMRI), The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Anita C. Thomas
- Bristol Medical School, Translational Health Sciences, University of Bristol, Research and Teaching Floor Level 7, Queens Building, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Elisa Parish
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute (QMRI), The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Philippe Gautier
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Alison Meynert
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, The University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK
| | - Igor Ulitsky
- Department of Immunology and Regenerative Biology and Department of Molecular Neuroscience, Weizmann-UK Building rm. 007, Weizmann Institute of Science Rehovot 76100, Israel
| | - Paolo Madeddu
- Bristol Medical School, Translational Health Sciences, University of Bristol, Research and Teaching Floor Level 7, Queens Building, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Andrea Caporali
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute (QMRI), The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Andrew Baker
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute (QMRI), The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - David Tollervey
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building Max Born Crescent, King’s Buildings, Edinburgh EH9 3BF, UK
| | - Tijana Mitić
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute (QMRI), The University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
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5
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Gail EH, Healy E, Flanigan SF, Jones N, Ng XH, Uckelmann M, Levina V, Zhang Q, Davidovich C. Inseparable RNA binding and chromatin modification activities of a nucleosome-interacting surface in EZH2. Nat Genet 2024; 56:1193-1202. [PMID: 38744974 PMCID: PMC11176075 DOI: 10.1038/s41588-024-01740-8] [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: 06/12/2022] [Accepted: 04/02/2024] [Indexed: 05/16/2024]
Abstract
Polycomb repressive complex 2 (PRC2) interacts with RNA in cells, but there is no consensus on how RNA regulates PRC2 canonical functions, including chromatin modification and the maintenance of transcription programs in lineage-committed cells. We assayed two separation-of-function mutants of the PRC2 catalytic subunit EZH2, defective in RNA binding but functional in methyltransferase activity. We find that part of the RNA-binding surface of EZH2 is required for chromatin modification, yet this activity is independent of RNA. Mechanistically, the RNA-binding surface within EZH2 is required for chromatin modification in vitro and in cells, through interactions with nucleosomal DNA. Contrarily, an RNA-binding-defective mutant exhibited normal chromatin modification activity in vitro and in lineage-committed cells, accompanied by normal gene repression activity. Collectively, we show that part of the RNA-binding surface of EZH2, rather than the RNA-binding activity per se, is required for the histone methylation in vitro and in cells, through interactions with the substrate nucleosome.
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Affiliation(s)
- Emma H Gail
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Evan Healy
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Sarena F Flanigan
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Natasha Jones
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Xiao Han Ng
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Michael Uckelmann
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Vitalina Levina
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Qi Zhang
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia.
- South Australian immunoGENomics Cancer Institute (SAiGENCI), Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia.
- EMBL-Australia at SAiGENCI, Adelaide, South Australia, Australia.
| | - Chen Davidovich
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia.
- EMBL-Australia, Clayton, Victoria, Australia.
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6
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Alammari F, Al-Hujaily EM, Alshareeda A, Albarakati N, Al-Sowayan BS. Hidden regulators: the emerging roles of lncRNAs in brain development and disease. Front Neurosci 2024; 18:1392688. [PMID: 38841098 PMCID: PMC11150811 DOI: 10.3389/fnins.2024.1392688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 04/22/2024] [Indexed: 06/07/2024] Open
Abstract
Long non-coding RNAs (lncRNAs) have emerged as critical players in brain development and disease. These non-coding transcripts, which once considered as "transcriptional junk," are now known for their regulatory roles in gene expression. In brain development, lncRNAs participate in many processes, including neurogenesis, neuronal differentiation, and synaptogenesis. They employ their effect through a wide variety of transcriptional and post-transcriptional regulatory mechanisms through interactions with chromatin modifiers, transcription factors, and other regulatory molecules. Dysregulation of lncRNAs has been associated with certain brain diseases, including Alzheimer's disease, Parkinson's disease, cancer, and neurodevelopmental disorders. Altered expression and function of specific lncRNAs have been implicated with disrupted neuronal connectivity, impaired synaptic plasticity, and aberrant gene expression pattern, highlighting the functional importance of this subclass of brain-enriched RNAs. Moreover, lncRNAs have been identified as potential biomarkers and therapeutic targets for neurological diseases. Here, we give a comprehensive review of the existing knowledge of lncRNAs. Our aim is to provide a better understanding of the diversity of lncRNA structure and functions in brain development and disease. This holds promise for unravelling the complexity of neurodevelopmental and neurodegenerative disorders, paving the way for the development of novel biomarkers and therapeutic targets for improved diagnosis and treatment.
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Affiliation(s)
- Farah Alammari
- Department of Blood and Cancer Research, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
- Clinical Laboratory Sciences Department, College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Ensaf M. Al-Hujaily
- Department of Blood and Cancer Research, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Alaa Alshareeda
- Department of Blood and Cancer Research, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
- Saudi Biobank Department, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
| | - Nada Albarakati
- Department of Blood and Cancer Research, King Abdullah International Medical Research Center, Jeddah, Saudi Arabia
- King Saud Bin Abdulaziz University for Health Sciences, Ministry of the National Guard-Health Affairs, Jeddah, Saudi Arabia
| | - Batla S. Al-Sowayan
- Department of Blood and Cancer Research, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
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7
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Lee YW, Weissbein U, Blum R, Lee JT. G-quadruplex folding in Xist RNA antagonizes PRC2 activity for stepwise regulation of X chromosome inactivation. Mol Cell 2024; 84:1870-1885.e9. [PMID: 38759625 DOI: 10.1016/j.molcel.2024.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 11/25/2023] [Accepted: 04/19/2024] [Indexed: 05/19/2024]
Abstract
How Polycomb repressive complex 2 (PRC2) is regulated by RNA remains an unsolved problem. Although PRC2 binds G-tracts with the potential to form RNA G-quadruplexes (rG4s), whether rG4s fold extensively in vivo and whether PRC2 binds folded or unfolded rG4 are unknown. Using the X-inactivation model in mouse embryonic stem cells, here we identify multiple folded rG4s in Xist RNA and demonstrate that PRC2 preferentially binds folded rG4s. High-affinity rG4 binding inhibits PRC2's histone methyltransferase activity, and stabilizing rG4 in vivo antagonizes H3 at lysine 27 (H3K27me3) enrichment on the inactive X chromosome. Surprisingly, mutagenizing the rG4 does not affect PRC2 recruitment but promotes its release and catalytic activation on chromatin. H3K27me3 marks are misplaced, however, and gene silencing is compromised. Xist-PRC2 complexes become entrapped in the S1 chromosome compartment, precluding the required translocation into the S2 compartment. Thus, Xist rG4 folding controls PRC2 activity, H3K27me3 enrichment, and the stepwise regulation of chromosome-wide gene silencing.
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Affiliation(s)
- Yong Woo Lee
- Department of Molecular Biology, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA 02114, USA
| | - Uri Weissbein
- Department of Molecular Biology, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA 02114, USA
| | - Roy Blum
- Department of Molecular Biology, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA 02114, USA
| | - Jeannie T Lee
- Department of Molecular Biology, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA 02114, USA.
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8
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Guo JK, Blanco MR, Walkup WG, Bonesteele G, Urbinati CR, Banerjee AK, Chow A, Ettlin O, Strehle M, Peyda P, Amaya E, Trinh V, Guttman M. Denaturing purifications demonstrate that PRC2 and other widely reported chromatin proteins do not appear to bind directly to RNA in vivo. Mol Cell 2024; 84:1271-1289.e12. [PMID: 38387462 PMCID: PMC10997485 DOI: 10.1016/j.molcel.2024.01.026] [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: 10/06/2023] [Revised: 12/01/2023] [Accepted: 01/30/2024] [Indexed: 02/24/2024]
Abstract
Polycomb repressive complex 2 (PRC2) is reported to bind to many RNAs and has become a central player in reports of how long non-coding RNAs (lncRNAs) regulate gene expression. Yet, there is a growing discrepancy between the biochemical evidence supporting specific lncRNA-PRC2 interactions and functional evidence demonstrating that PRC2 is often dispensable for lncRNA function. Here, we revisit the evidence supporting RNA binding by PRC2 and show that many reported interactions may not occur in vivo. Using denaturing purification of in vivo crosslinked RNA-protein complexes in human and mouse cell lines, we observe a loss of detectable RNA binding to PRC2 and chromatin-associated proteins previously reported to bind RNA (CTCF, YY1, and others), despite accurately mapping bona fide RNA-binding sites across others (SPEN, TET2, and others). Taken together, these results argue for a critical re-evaluation of the broad role of RNA binding to orchestrate various chromatin regulatory mechanisms.
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Affiliation(s)
- Jimmy K Guo
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Mario R Blanco
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
| | - Ward G Walkup
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Grant Bonesteele
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Carl R Urbinati
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Department of Biology, Loyola Marymount University, Los Angeles, CA 90045, USA
| | - Abhik K Banerjee
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Amy Chow
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Olivia Ettlin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Mackenzie Strehle
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Parham Peyda
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Enrique Amaya
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Vickie Trinh
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Mitchell Guttman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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9
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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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10
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Valyaeva AA, Sheval EV. Nonspecific Interactions in Transcription Regulation and Organization of Transcriptional Condensates. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:688-700. [PMID: 38831505 DOI: 10.1134/s0006297924040084] [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: 10/10/2023] [Revised: 11/19/2023] [Accepted: 11/20/2023] [Indexed: 06/05/2024]
Abstract
Eukaryotic cells are characterized by a high degree of compartmentalization of their internal contents, which ensures precise and controlled regulation of intracellular processes. During many processes, including different stages of transcription, dynamic membraneless compartments termed biomolecular condensates are formed. Transcription condensates contain various transcription factors and RNA polymerase and are formed by high- and low-specificity interactions between the proteins, DNA, and nearby RNA. This review discusses recent data demonstrating important role of nonspecific multivalent protein-protein and RNA-protein interactions in organization and regulation of transcription.
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Affiliation(s)
- Anna A Valyaeva
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia.
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
- Department of Cell Biology and Histology, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Eugene V Sheval
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
- Department of Cell Biology and Histology, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
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11
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Healy E, Zhang Q, Gail EH, Agius SC, Sun G, Bullen M, Pandey V, Das PP, Polo JM, Davidovich C. The apparent loss of PRC2 chromatin occupancy as an artifact of RNA depletion. Cell Rep 2024; 43:113858. [PMID: 38416645 DOI: 10.1016/j.celrep.2024.113858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/08/2023] [Accepted: 02/08/2024] [Indexed: 03/01/2024] Open
Abstract
RNA has been implicated in the recruitment of chromatin modifiers, and previous studies have provided evidence in favor and against this idea. RNase treatment of chromatin is commonly used to study RNA-mediated regulation of chromatin modifiers, but the limitations of this approach remain unclear. RNase A treatment during chromatin immunoprecipitation (ChIP) reduces chromatin occupancy of the H3K27me3 methyltransferase Polycomb repressive complex 2 (PRC2). This led to suggestions of an "RNA bridge" between PRC2 and chromatin. Here, we show that RNase A treatment during ChIP causes the apparent loss of all facultative heterochromatin, including both PRC2 and H3K27me3 genome-wide. We track this observation to a gain of DNA from non-targeted chromatin, sequenced at the expense of DNA from facultative heterochromatin, which reduces ChIP signals. Our results emphasize substantial limitations in using RNase A treatment for mapping RNA-dependent chromatin occupancy and invalidate conclusions that were previously established for PRC2 based on this assay.
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Affiliation(s)
- Evan Healy
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
| | - Qi Zhang
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia; South Australian immunoGENomics Cancer Institute (SAiGENCI), Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia; EMBL-Australia at SAiGENCI, Adelaide, SA, Australia
| | - Emma H Gail
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
| | - Samuel C Agius
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
| | - Guizhi Sun
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Wellington Road, Clayton, VIC 3800, Australia
| | - Michael Bullen
- Department of Anatomy and Developmental Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Varun Pandey
- Department of Anatomy and Developmental Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Partha Pratim Das
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Wellington Road, Clayton, VIC 3800, Australia; Department of Anatomy and Developmental Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Jose M Polo
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Wellington Road, Clayton, VIC 3800, Australia; Department of Anatomy and Developmental Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia; Adelaide Centre for Epigenetics and South Australian immunoGENomics Cancer Institute, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - Chen Davidovich
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia; EMBL-Australia, Clayton, VIC, Australia.
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12
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Hall Hickman A, Jenner RG. Apparent RNA bridging between PRC2 and chromatin is an artifact of non-specific chromatin precipitation upon RNA degradation. Cell Rep 2024; 43:113856. [PMID: 38416641 DOI: 10.1016/j.celrep.2024.113856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 01/26/2024] [Accepted: 02/08/2024] [Indexed: 03/01/2024] Open
Abstract
Polycomb repressive complex 2 (PRC2) modifies chromatin to maintain repression of genes specific for other cell lineages. In vitro, RNA inhibits PRC2 activity, but the effect of RNA on PRC2 in cells is less clear, with studies concluding that RNA either antagonizes or promotes PRC2 chromatin association. The addition of RNase A to chromatin immunoprecipitation reactions has been reported to reduce detection of PRC2 target sites, suggesting the existence of RNA bridges connecting PRC2 to chromatin. Here, we show that the apparent loss of PRC2 chromatin association after RNase A treatment is due to non-specific chromatin precipitation. RNA degradation precipitates chromatin out of solution, thereby masking enrichment of specific DNA sequences in chromatin immunoprecipitation reactions. Maintaining chromatin solubility by the addition of poly-L-glutamic acid rescues detection of PRC2 chromatin occupancy upon RNA degradation. These findings undermine support for the model that RNA bridges PRC2 and chromatin in cells.
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Affiliation(s)
- Alexander Hall Hickman
- UCL Cancer Institute, University College London, London WC1E 6BT, UK; CRUK City of London Centre, University College London, London WC1E 6BT, UK
| | - Richard G Jenner
- UCL Cancer Institute, University College London, London WC1E 6BT, UK; CRUK City of London Centre, University College London, London WC1E 6BT, UK.
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13
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Ajit K, Alagia A, Burger K, Gullerova M. Tyrosine 1-phosphorylated RNA polymerase II transcribes PROMPTs to facilitate proximal promoter pausing and induce global transcriptional repression in response to DNA damage. Genome Res 2024; 34:201-216. [PMID: 38467418 PMCID: PMC10984383 DOI: 10.1101/gr.278644.123] [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: 10/18/2023] [Accepted: 02/15/2024] [Indexed: 03/13/2024]
Abstract
DNA damage triggers a complex transcriptional response that involves both activation and repression of gene expression. In this study, we investigated global changes in transcription in response to ionizing irradiation (IR), which induces double-strand breaks in DNA. We used mNET-seq to profile nascent transcripts bound to different phosphorylated forms of the RNA polymerase II (RNA Pol II) C-terminal domain (CTD). We found that IR leads to global transcriptional repression of protein-coding genes, accompanied by an increase in antisense transcripts near promoters, called PROMPTs, transcribed by RNA Pol II phosphorylated on tyrosine 1 (Y1P) residue of the CTD. These Y1P-transcribed PROMPTs are enriched for PRC2 binding sites and associated with RNA Pol II proximal promoter pausing. We show the interaction between Y1P RNA Pol II and PRC2, as well as PRC2 binding to PROMPTs. Inhibition of PROMPTs or depletion of PRC2 leads to loss of transcriptional repression. Our results reveal a novel function of Y1P-dependent PROMPTs in mediating PRC2 recruitment to chromatin and RNA Pol II promoter pausing in response to DNA damage.
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Affiliation(s)
- Kamal Ajit
- Sir William Dunn School of Pathology, Oxford, OX1 3RE, United Kingdom
| | - Adele Alagia
- Sir William Dunn School of Pathology, Oxford, OX1 3RE, United Kingdom
| | - Kaspar Burger
- Mildred Scheel Early Career Center for Cancer Research, University Hospital Würzburg, 97080 Würzburg, Germany
- Department of Biochemistry and Molecular Biology, Biocenter of the University of Würzburg, 97074 Würzburg, Germany
| | - Monika Gullerova
- Sir William Dunn School of Pathology, Oxford, OX1 3RE, United Kingdom;
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14
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Pavesi A, Romerio F. Creation of the HIV-1 antisense gene asp coincided with the emergence of the pandemic group M and is associated with faster disease progression. Microbiol Spectr 2024; 12:e0380223. [PMID: 38230940 PMCID: PMC10846101 DOI: 10.1128/spectrum.03802-23] [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: 10/31/2023] [Accepted: 12/19/2023] [Indexed: 01/18/2024] Open
Abstract
Despite being first identified more than three decades ago, the antisense gene asp of HIV-1 remains an enigma. asp is present uniquely in pandemic (group M) HIV-1 strains, and it is absent in all non-pandemic (out-of-M) HIV-1 strains and virtually all non-human primate lentiviruses. This suggests that the creation of asp may have contributed to HIV-1 fitness or worldwide spread. It also raises the question of which evolutionary processes were at play in the creation of asp. Here, we show that HIV-1 genomes containing an intact asp gene are associated with faster HIV-1 disease progression. Furthermore, we demonstrate that the creation of a full-length asp gene occurred via the evolution of codon usage in env overlapping asp on the opposite strand. This involved differential use of synonymous codons or conservative amino acid substitution in env that eliminated internal stop codons in asp, and redistribution of synonymous codons in env that minimized the likelihood of new premature stops arising in asp. Nevertheless, the creation of a full-length asp gene reduced the genetic diversity of env. The Luria-Delbruck fluctuation test suggests that the interrupted asp open reading frame (ORF) is the progenitor of the intact ORF, rather than a descendant under random genetic drift. Therefore, the existence of group-M isolates with a truncated asp ORF indicates an incomplete transition process. For the first time, our study links the presence of a full-length asp ORF to faster disease progression, thus warranting further investigation into the cellular processes and molecular mechanisms through which the ASP protein impacts HIV-1 replication, transmission, and pathogenesis.IMPORTANCEOverlapping genes engage in a tug-of-war, constraining each other's evolution. The creation of a new gene overlapping an existing one comes at an evolutionary cost. Thus, its conservation must be advantageous, or it will be lost, especially if the pre-existing gene is essential for the viability of the virus or cell. We found that the creation and conservation of the HIV-1 antisense gene asp occurred through differential use of synonymous codons or conservative amino acid substitutions within the overlapping gene, env. This process did not involve amino acid changes in ENV that benefited its function, but rather it constrained the evolution of ENV. Nonetheless, the creation of asp brought a net selective advantage to HIV-1 because asp is conserved especially among high-prevalence strains. The association between the presence of an intact asp gene and faster HIV-1 disease progression supports that conclusion and warrants further investigation.
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Affiliation(s)
- Angelo Pavesi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Fabio Romerio
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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15
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Shiekh S, Kodikara SG, Balci H. Structure, Topology, and Stability of Multiple G-quadruplexes in Long Telomeric Overhangs. J Mol Biol 2024; 436:168205. [PMID: 37481156 PMCID: PMC10799177 DOI: 10.1016/j.jmb.2023.168205] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/05/2023] [Accepted: 07/12/2023] [Indexed: 07/24/2023]
Abstract
Telomeres and their single stranded overhangs gradually shorten with successive cell divisions, as part of the natural aging process, but can be elongated by telomerase, a nucleoprotein complex which is activated in the majority of cancers. This prominent implication in cancer and aging has made the repetitive telomeric sequences (TTAGGG repeats) and the G-quadruplex structures that form in their overhangs the focus of intense research in the past several decades. However, until recently most in vitro efforts to understand the structure, stability, dynamics, and interactions of telomeric overhangs had been focused on short sequences that are not representative of longer sequences encountered in a physiological setting. In this review, we will provide a broad perspective about telomeres and associated factors, and introduce the agents and structural characteristics involved in organizing, maintaining, and protecting telomeric DNA. We will also present a summary of recent research performed on long telomeric sequences, nominally defined as those that can form two or more tandem G-quadruplexes, i.e., which contain eight or more TTAGGG repeats. Results of experimental studies using a broad array of experimental tools, in addition to recent computational efforts will be discussed, particularly in terms of their implications for the stability, folding topology, and compactness of the tandem G-quadruplexes that form in long telomeric overhangs.
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Affiliation(s)
- Sajad Shiekh
- Department of Physics, Kent State University, Kent, OH 44242, USA
| | | | - Hamza Balci
- Department of Physics, Kent State University, Kent, OH 44242, USA.
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16
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Qu X, Lin Z, Jayawickramarajah J, Alsager JS, Schmidt E, Nephew KP, Fang F, Balasubramanian S, Shan B. G-quadruplex is critical to epigenetic activation of the lncRNA HOTAIR in cancer cells. iScience 2023; 26:108559. [PMID: 38144452 PMCID: PMC10746524 DOI: 10.1016/j.isci.2023.108559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/29/2023] [Accepted: 11/20/2023] [Indexed: 12/26/2023] Open
Abstract
The cancer-promoting lncRNA HOTAIR has multiple isoforms. Which isoform of HOTAIR accounts for its expression and functions in cancer is unknown. Unlike HOTAIR's canonical intergenic isoform NR_003716 (HOTAIR-C), the novel isoform NR_047517 (HOTAIR-N) forms an overlapping antisense transcription locus with HOXC11. We identified HOTAIR-N as the dominant isoform that regulates the gene expression programs and networks for cell proliferation, survival, and death in cancer cells. The CpG island in the HOTAIR-N promoter was marked with epigenetic markers for active transcription. We identified a G-quadruplex (G4) motif rich region in the HOTAIR-N CpG island. Our findings indicate that G4s in HOTAIR-N CpG island is critical for expression of HOTAIR-N in cancer cells. Disruption of G4 may represent a novel therapeutic approach for cancer. The transcriptomes regulated by HOTAIR-N and Bloom in cancer cells as provided herein are important resources for the exploration of lncRNA, DNA helicases, and G4 in cancer.
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Affiliation(s)
- Xiaohan Qu
- Department of Thoracic Surgery, The First Hospital of China Medical University, Shenyang, Liaoning 110001, China
| | - Zhen Lin
- Deparmtent of Pathology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | | | - John S. Alsager
- Department of Biomedical Sciences, Elson S Floyd College of Medicine, Washington State University, Spokane, WA 99202, USA
| | - Emily Schmidt
- Department of Chemistry, Tulane University, New Orleans, LA 70118, USA
| | - Kenneth P. Nephew
- Medical Sciences, Cell and Molecular Cancer Biology Program, Indiana University School of Medicine, Bloomington, IN 47405, USA
| | - Fang Fang
- Medical Sciences, Cell and Molecular Cancer Biology Program, Indiana University School of Medicine, Bloomington, IN 47405, USA
| | - Shankar Balasubramanian
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
- Cancer Research UK, Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, UK
| | - Bin Shan
- Department of Biomedical Sciences, Elson S Floyd College of Medicine, Washington State University, Spokane, WA 99202, USA
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17
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Neupane A, Chariker JH, Rouchka EC. Analysis of Nucleotide Variations in Human G-Quadruplex Forming Regions Associated with Disease States. Genes (Basel) 2023; 14:2125. [PMID: 38136947 PMCID: PMC10742762 DOI: 10.3390/genes14122125] [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: 10/31/2023] [Revised: 11/20/2023] [Accepted: 11/23/2023] [Indexed: 12/24/2023] Open
Abstract
While the role of G quadruplex (G4) structures has been identified in cancers and metabolic disorders, single nucleotide variations (SNVs) and their effect on G4s in disease contexts have not been extensively studied. The COSMIC and CLINVAR databases were used to detect SNVs present in G4s to identify sequence level changes and their effect on the alteration of the G4 secondary structure. A total of 37,515 G4 SNVs in the COSMIC database and 2378 in CLINVAR were identified. Of those, 7236 COSMIC (19.3%) and 457 (19%) of the CLINVAR variants result in G4 loss, while 2728 (COSMIC) and 129 (CLINVAR) SNVs gain a G4 structure. The remaining variants potentially affect the folding energy without affecting the presence of a G4. Analysis of mutational patterns in the G4 structure shows a higher selective pressure (3-fold) in the coding region on the template strand compared to the reverse strand. At the same time, an equal proportion of SNVs were observed among intronic, promoter, and enhancer regions across strands.
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Affiliation(s)
- Aryan Neupane
- School of Graduate and Interdisciplinary Studies, University of Louisville, Louisville, KY 40292, USA;
| | - Julia H. Chariker
- Department of Neuroscience Training, University of Louisville, Louisville, KY 40292, USA;
- Kentucky IDeA Network of Biomedical Research Excellence (KY INBRE) Bioinformatics Core, University of Louisville, Louisville, KY 40292, USA
| | - Eric C. Rouchka
- Kentucky IDeA Network of Biomedical Research Excellence (KY INBRE) Bioinformatics Core, University of Louisville, Louisville, KY 40292, USA
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, KY 40292, USA
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18
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Song J, Gooding AR, Hemphill WO, Love BD, Robertson A, Yao L, Zon LI, North TE, Kasinath V, Cech TR. Structural basis for inactivation of PRC2 by G-quadruplex RNA. Science 2023; 381:1331-1337. [PMID: 37733873 PMCID: PMC11191771 DOI: 10.1126/science.adh0059] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 08/22/2023] [Indexed: 09/23/2023]
Abstract
Polycomb repressive complex 2 (PRC2) silences genes through trimethylation of histone H3K27. PRC2 associates with numerous precursor messenger RNAs (pre-mRNAs) and long noncoding RNAs (lncRNAs) with a binding preference for G-quadruplex RNA. In this work, we present a 3.3-Å-resolution cryo-electron microscopy structure of PRC2 bound to a G-quadruplex RNA. Notably, RNA mediates the dimerization of PRC2 by binding both protomers and inducing a protein interface composed of two copies of the catalytic subunit EZH2, thereby blocking nucleosome DNA interaction and histone H3 tail accessibility. Furthermore, an RNA-binding loop of EZH2 facilitates the handoff between RNA and DNA, another activity implicated in PRC2 regulation by RNA. We identified a gain-of-function mutation in this loop that activates PRC2 in zebrafish. Our results reveal mechanisms for RNA-mediated regulation of a chromatin-modifying enzyme.
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Affiliation(s)
- Jiarui Song
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Anne R. Gooding
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Wayne O. Hemphill
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Brittney D. Love
- Stem Cell and Regenerative Biology Department, Harvard University, Cambridge, MA 02138, USA
- Stem Cell Program, Division of Hematology/Oncology, Boston Children’s Hospital and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Anne Robertson
- Stem Cell and Regenerative Biology Department, Harvard University, Cambridge, MA 02138, USA
- Stem Cell Program, Division of Hematology/Oncology, Boston Children’s Hospital and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Liqi Yao
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Leonard I. Zon
- Stem Cell and Regenerative Biology Department, Harvard University, Cambridge, MA 02138, USA
- Stem Cell Program, Division of Hematology/Oncology, Boston Children’s Hospital and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Trista E. North
- Stem Cell and Regenerative Biology Department, Harvard University, Cambridge, MA 02138, USA
- Stem Cell Program, Division of Hematology/Oncology, Boston Children’s Hospital and Dana-Farber Cancer Institute, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
| | - Vignesh Kasinath
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Thomas R. Cech
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80303, USA
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19
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Ghobashi AH, Vuong TT, Kimani JW, Ladaika CA, Hollenhorst PC, O’Hagan HM. Activation of AKT induces EZH2-mediated β-catenin trimethylation in colorectal cancer. iScience 2023; 26:107630. [PMID: 37670785 PMCID: PMC10475482 DOI: 10.1016/j.isci.2023.107630] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 08/09/2023] [Accepted: 08/11/2023] [Indexed: 09/07/2023] Open
Abstract
Colorectal cancer (CRC) develops in part through the deregulation of different signaling pathways, including activation of the WNT/β-catenin and PI3K/AKT pathways. Additionally, the lysine methyltransferase enhancer of zeste homologue 2 (EZH2) is commonly overexpressed in CRC. EZH2 canonically represses gene transcription by trimethylating lysine 27 of histone H3, but also has non-histone substrates. Here, we demonstrated that in CRC, active AKT phosphorylated EZH2 on serine 21. Phosphorylation of EZH2 by AKT induced EZH2 to interact with and methylate β-catenin at lysine 49, which increased β-catenin's binding to the chromatin. Additionally, EZH2-mediated β-catenin trimethylation induced β-catenin to interact with TCF1 and RNA polymerase II and resulted in dramatic gains in genomic regions with β-catenin occupancy. EZH2 catalytic inhibition decreased stemness but increased migratory phenotypes of CRC cells with active AKT. Overall, we demonstrated that EZH2 modulates AKT-induced changes in gene expression through the AKT/EZH2/β-catenin axis in CRC.
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Affiliation(s)
- Ahmed H. Ghobashi
- Genome, Cell, and Developmental Biology Graduate Program, Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
- Medical Sciences Program, Indiana University School of Medicine, Bloomington, IN 47405, USA
| | - Truc T. Vuong
- Medical Sciences Program, Indiana University School of Medicine, Bloomington, IN 47405, USA
- Cell, Molecular and Cancer Biology Graduate Program, Indiana University School of Medicine, Bloomington, IN 47405, USA
| | - Jane W. Kimani
- Medical Sciences Program, Indiana University School of Medicine, Bloomington, IN 47405, USA
| | - Christopher A. Ladaika
- Genome, Cell, and Developmental Biology Graduate Program, Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
- Medical Sciences Program, Indiana University School of Medicine, Bloomington, IN 47405, USA
| | - Peter C. Hollenhorst
- Medical Sciences Program, Indiana University School of Medicine, Bloomington, IN 47405, USA
- Cell, Molecular and Cancer Biology Graduate Program, Indiana University School of Medicine, Bloomington, IN 47405, USA
- Tumor Microenvironment & Metastasis Program, Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, IN 46202, USA
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Heather M. O’Hagan
- Medical Sciences Program, Indiana University School of Medicine, Bloomington, IN 47405, USA
- Cell, Molecular and Cancer Biology Graduate Program, Indiana University School of Medicine, Bloomington, IN 47405, USA
- Tumor Microenvironment & Metastasis Program, Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, IN 46202, USA
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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20
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Herbert A. Flipons and small RNAs accentuate the asymmetries of pervasive transcription by the reset and sequence-specific microcoding of promoter conformation. J Biol Chem 2023; 299:105140. [PMID: 37544644 PMCID: PMC10474125 DOI: 10.1016/j.jbc.2023.105140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/25/2023] [Accepted: 07/31/2023] [Indexed: 08/08/2023] Open
Abstract
The role of alternate DNA conformations such as Z-DNA in the regulation of transcription is currently underappreciated. These structures are encoded by sequences called flipons, many of which are enriched in promoter and enhancer regions. Through a change in their conformation, flipons provide a tunable mechanism to mechanically reset promoters for the next round of transcription. They act as actuators that capture and release energy to ensure that the turnover of the proteins at promoters is optimized to cell state. Likewise, the single-stranded DNA formed as flipons cycle facilitates the docking of RNAs that are able to microcode promoter conformations and canalize the pervasive transcription commonly observed in metazoan genomes. The strand-specific nature of the interaction between RNA and DNA likely accounts for the known asymmetry of epigenetic marks present on the histone tetramers that pair to form nucleosomes. The role of these supercoil-dependent processes in promoter choice and transcriptional interference is reviewed. The evolutionary implications are examined: the resilience and canalization of flipon-dependent gene regulation is contrasted with the rapid adaptation enabled by the spread of flipon repeats throughout the genome. Overall, the current findings underscore the important role of flipons in modulating the readout of genetic information and how little we know about their biology.
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Affiliation(s)
- Alan Herbert
- Discovery Division, InsideOutBio, Charlestown, Massachusetts, USA.
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21
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Mangoni D, Simi A, Lau P, Armaos A, Ansaloni F, Codino A, Damiani D, Floreani L, Di Carlo V, Vozzi D, Persichetti F, Santoro C, Pandolfini L, Tartaglia GG, Sanges R, Gustincich S. LINE-1 regulates cortical development by acting as long non-coding RNAs. Nat Commun 2023; 14:4974. [PMID: 37591988 PMCID: PMC10435495 DOI: 10.1038/s41467-023-40743-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 08/07/2023] [Indexed: 08/19/2023] Open
Abstract
Long Interspersed Nuclear Elements-1s (L1s) are transposable elements that constitute most of the genome's transcriptional output yet have still largely unknown functions. Here we show that L1s are required for proper mouse brain corticogenesis operating as regulatory long non-coding RNAs. They contribute to the regulation of the balance between neuronal progenitors and differentiation, the migration of post-mitotic neurons and the proportions of different cell types. In cortical cultured neurons, L1 RNAs are mainly associated to chromatin and interact with the Polycomb Repressive Complex 2 (PRC2) protein subunits enhancer of Zeste homolog 2 (Ezh2) and suppressor of zeste 12 (Suz12). L1 RNA silencing influences PRC2's ability to bind a portion of its targets and the deposition of tri-methylated histone H3 (H3K27me3) marks. Our results position L1 RNAs as crucial signalling hubs for genome-wide chromatin remodelling, enabling the fine-tuning of gene expression during brain development and evolution.
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Affiliation(s)
- Damiano Mangoni
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Alessandro Simi
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Pierre Lau
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Alexandros Armaos
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Federico Ansaloni
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Azzurra Codino
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Devid Damiani
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Lavinia Floreani
- Area of Neuroscience, International School for Advanced Studies (SISSA), Trieste, Italy
| | - Valerio Di Carlo
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Diego Vozzi
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Francesca Persichetti
- Department of Health Sciences and Research Center on Autoimmune and Allergic Diseases (CAAD), University of Piemonte Orientale (UPO), Novara, Italy
| | - Claudio Santoro
- Department of Health Sciences and Research Center on Autoimmune and Allergic Diseases (CAAD), University of Piemonte Orientale (UPO), Novara, Italy
| | - Luca Pandolfini
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | | | - Remo Sanges
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy.
- Area of Neuroscience, International School for Advanced Studies (SISSA), Trieste, Italy.
| | - Stefano Gustincich
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy.
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22
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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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23
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Deforzh E, Kharel P, Karelin A, Ivanov P, Krichevsky AM. HOXDeRNA activates a cancerous transcription program and super-enhancers genome-wide. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.30.547275. [PMID: 37425921 PMCID: PMC10327164 DOI: 10.1101/2023.06.30.547275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Background The origin and genesis of highly malignant and heterogenous glioblastoma brain tumors remain unknown. We previously identified an enhancer-associated long non-coding RNA, LINC01116 (named HOXDeRNA here), that is absent in the normal brain but is commonly expressed in malignant glioma. HOXDeRNA has a unique capacity to transform human astrocytes into glioma-like cells. This work aimed to investigate molecular events underlying the genome-wide function of this lncRNA in glial cell fate and transformation. Results Using a combination of RNA-Seq, ChIRP-Seq, and ChIP-Seq, we now demonstrate that HOXDeRNA binds in trans to the promoters of genes encoding 44 glioma-specific transcription factors distributed throughout the genome and derepresses them by removing the Polycomb repressive complex 2 (PRC2). Among the activated transcription factors are the core neurodevelopmental regulators SOX2, OLIG2, POU3F2, and SALL2. This process requires an RNA quadruplex structure of HOXDeRNA that interacts with EZH2. Moreover, HOXDeRNA-induced astrocyte transformation is accompanied by the activation of multiple oncogenes such as EGFR, PDGFR, BRAF, and miR-21, and glioma-specific super-enhancers enriched for binding sites of glioma master transcription factors SOX2 and OLIG2. Conclusions Our results demonstrate that HOXDeRNA overrides PRC2 repression of glioma core regulatory circuitry with RNA quadruplex structure. These findings help reconstruct the sequence of events underlying the process of astrocyte transformation and suggest a driving role for HOXDeRNA and a unifying RNA-dependent mechanism of gliomagenesis.
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Affiliation(s)
- Evgeny Deforzh
- Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Prakash Kharel
- Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Anton Karelin
- Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Pavel Ivanov
- Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Anna M. Krichevsky
- Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
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24
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Dar MS, Mensah IK, He M, McGovern S, Sohal IS, Whitlock HC, Bippus NE, Ceminsky M, Emerson ML, Tan HJ, Hall MC, Gowher H. Dnmt3bas coordinates transcriptional induction and alternative exon inclusion to promote catalytically active Dnmt3b expression. Cell Rep 2023; 42:112587. [PMID: 37294637 PMCID: PMC10592478 DOI: 10.1016/j.celrep.2023.112587] [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: 06/03/2022] [Revised: 03/16/2023] [Accepted: 05/16/2023] [Indexed: 06/11/2023] Open
Abstract
Embryonic expression of DNMT3B is critical for establishing de novo DNA methylation. This study uncovers the mechanism through which the promoter-associated long non-coding RNA (lncRNA) Dnmt3bas controls the induction and alternative splicing of Dnmt3b during embryonic stem cell (ESC) differentiation. Dnmt3bas recruits the PRC2 (polycomb repressive complex 2) at cis-regulatory elements of the Dnmt3b gene expressed at a basal level. Correspondingly, Dnmt3bas knockdown enhances Dnmt3b transcriptional induction, whereas overexpression of Dnmt3bas dampens it. Dnmt3b induction coincides with exon inclusion, switching the predominant isoform from the inactive Dnmt3b6 to the active Dnmt3b1. Intriguingly, overexpressing Dnmt3bas further enhances the Dnmt3b1:Dnmt3b6 ratio, attributed to its interaction with hnRNPL (heterogeneous nuclear ribonucleoprotein L), a splicing factor that promotes exon inclusion. Our data suggest that Dnmt3bas coordinates alternative splicing and transcriptional induction of Dnmt3b by facilitating the hnRNPL and RNA polymerase II (RNA Pol II) interaction at the Dnmt3b promoter. This dual mechanism precisely regulates the expression of catalytically active DNMT3B, ensuring fidelity and specificity of de novo DNA methylation.
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Affiliation(s)
- Mohd Saleem Dar
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Isaiah K Mensah
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Ming He
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Sarah McGovern
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Ikjot Singh Sohal
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA; Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | | | - Nina Elise Bippus
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Madison Ceminsky
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Martin L Emerson
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Hern J Tan
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Mark C Hall
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA; Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Humaira Gowher
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA; Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
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25
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Gil N, Perry RBT, Mukamel Z, Tuck A, Bühler M, Ulitsky I. Complex regulation of Eomes levels mediated through distinct functional features of the Meteor long non-coding RNA locus. Cell Rep 2023; 42:112569. [PMID: 37256750 PMCID: PMC10320833 DOI: 10.1016/j.celrep.2023.112569] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/07/2023] [Accepted: 05/12/2023] [Indexed: 06/02/2023] Open
Abstract
Long non-coding RNAs (lncRNAs) are implicated in a plethora of cellular processes, but an in-depth understanding of their functional features or their mechanisms of action is currently lacking. Here we study Meteor, a lncRNA transcribed near the gene encoding EOMES, a pleiotropic transcription factor implicated in various processes throughout development and in adult tissues. Using a wide array of perturbation techniques, we show that transcription elongation through the Meteor locus is required for Eomes activation in mouse embryonic stem cells, with Meteor repression linked to a change in the subpopulation primed to differentiate to the mesoderm lineage. We further demonstrate that a distinct functional feature of the locus-namely, the underlying DNA element-is required for suppressing Eomes expression following neuronal differentiation. Our results demonstrate the complex regulation that can be conferred by a single locus and emphasize the importance of careful selection of perturbation techniques when studying lncRNA loci.
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Affiliation(s)
- Noa Gil
- Department of Immunology and Regenerative Biology and Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Rotem Ben-Tov Perry
- Department of Immunology and Regenerative Biology and Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Zohar Mukamel
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alex Tuck
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Marc Bühler
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland; University of Basel, Basel, Switzerland
| | - Igor Ulitsky
- Department of Immunology and Regenerative Biology and Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 76100, Israel.
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26
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Hemphill W, Fenske R, Gooding A, Cech T. PRC2 direct transfer from G-quadruplex RNA to dsDNA has implications for RNA-binding chromatin modifiers. Proc Natl Acad Sci U S A 2023; 120:e2220528120. [PMID: 37252986 PMCID: PMC10266057 DOI: 10.1073/pnas.2220528120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 05/01/2023] [Indexed: 06/01/2023] Open
Abstract
The chromatin-modifying enzyme, Polycomb Repressive Complex 2 (PRC2), deposits the H3K27me3 epigenetic mark to negatively regulate expression at numerous target genes, and this activity has been implicated in embryonic development, cell differentiation, and various cancers. A biological role for RNA binding in regulating PRC2 histone methyltransferase activity is generally accepted, but the nature and mechanism of this relationship remains an area of active investigation. Notably, many in vitro studies demonstrate that RNA inhibits PRC2 activity on nucleosomes through mutually antagonistic binding, while some in vivo studies indicate that PRC2's RNA-binding activity is critical for facilitating its biological function(s). Here we use biochemical, biophysical, and computational approaches to interrogate PRC2's RNA and DNA-binding kinetics. Our findings demonstrate that PRC2-polynucleotide dissociation rates are dependent on the concentration of free ligand, indicating the potential for direct transfer between nucleic acid ligands without a free-enzyme intermediate. Direct transfer explains the variation in previously reported dissociation kinetics, allows reconciliation of prior in vitro and in vivo studies, and expands the potential mechanisms of RNA-mediated PRC2 regulation. Moreover, simulations indicate that such a direct transfer mechanism could be obligatory for RNA to recruit proteins to chromatin.
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Affiliation(s)
- Wayne O. Hemphill
- Department of Biochemistry, BioFrontiers Institute, University of Colorado Boulder, Boulder, CO80309
- HHMI, University of Colorado Boulder, Boulder, CO80309
| | - Regan Fenske
- Department of Biochemistry, BioFrontiers Institute, University of Colorado Boulder, Boulder, CO80309
- HHMI, University of Colorado Boulder, Boulder, CO80309
| | - Anne R. Gooding
- Department of Biochemistry, BioFrontiers Institute, University of Colorado Boulder, Boulder, CO80309
- HHMI, University of Colorado Boulder, Boulder, CO80309
| | - Thomas R. Cech
- Department of Biochemistry, BioFrontiers Institute, University of Colorado Boulder, Boulder, CO80309
- HHMI, University of Colorado Boulder, Boulder, CO80309
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27
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Mattick JS, Amaral PP, Carninci P, Carpenter S, Chang HY, Chen LL, Chen R, Dean C, Dinger ME, Fitzgerald KA, Gingeras TR, Guttman M, Hirose T, Huarte M, Johnson R, Kanduri C, Kapranov P, Lawrence JB, Lee JT, Mendell JT, Mercer TR, Moore KJ, Nakagawa S, Rinn JL, Spector DL, Ulitsky I, Wan Y, Wilusz JE, Wu M. Long non-coding RNAs: definitions, functions, challenges and recommendations. Nat Rev Mol Cell Biol 2023; 24:430-447. [PMID: 36596869 PMCID: PMC10213152 DOI: 10.1038/s41580-022-00566-8] [Citation(s) in RCA: 426] [Impact Index Per Article: 426.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2022] [Indexed: 01/05/2023]
Abstract
Genes specifying long non-coding RNAs (lncRNAs) occupy a large fraction of the genomes of complex organisms. The term 'lncRNAs' encompasses RNA polymerase I (Pol I), Pol II and Pol III transcribed RNAs, and RNAs from processed introns. The various functions of lncRNAs and their many isoforms and interleaved relationships with other genes make lncRNA classification and annotation difficult. Most lncRNAs evolve more rapidly than protein-coding sequences, are cell type specific and regulate many aspects of cell differentiation and development and other physiological processes. Many lncRNAs associate with chromatin-modifying complexes, are transcribed from enhancers and nucleate phase separation of nuclear condensates and domains, indicating an intimate link between lncRNA expression and the spatial control of gene expression during development. lncRNAs also have important roles in the cytoplasm and beyond, including in the regulation of translation, metabolism and signalling. lncRNAs often have a modular structure and are rich in repeats, which are increasingly being shown to be relevant to their function. In this Consensus Statement, we address the definition and nomenclature of lncRNAs and their conservation, expression, phenotypic visibility, structure and functions. We also discuss research challenges and provide recommendations to advance the understanding of the roles of lncRNAs in development, cell biology and disease.
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Affiliation(s)
- John S Mattick
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, Australia.
- UNSW RNA Institute, UNSW, Sydney, NSW, Australia.
| | - Paulo P Amaral
- INSPER Institute of Education and Research, São Paulo, Brazil
| | - Piero Carninci
- RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
- Human Technopole, Milan, Italy
| | - Susan Carpenter
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Howard Y Chang
- Center for Personal Dynamics Regulomes, Stanford University School of Medicine, Stanford, CA, USA
- Department of Dermatology, Stanford, CA, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Ling-Ling Chen
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Runsheng Chen
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Caroline Dean
- John Innes Centre, Norwich Research Park, Norwich, UK
| | - Marcel E Dinger
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, Australia
- UNSW RNA Institute, UNSW, Sydney, NSW, Australia
| | - Katherine A Fitzgerald
- Division of Innate Immunity, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | | | - Mitchell Guttman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Tetsuro Hirose
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Maite Huarte
- Department of Gene Therapy and Regulation of Gene Expression, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
- Institute of Health Research of Navarra, Pamplona, Spain
| | - Rory Johnson
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
- Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Chandrasekhar Kanduri
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Philipp Kapranov
- Institute of Genomics, School of Medicine, Huaqiao University, Xiamen, China
| | - Jeanne B Lawrence
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jeannie T Lee
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Joshua T Mendell
- Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX, USA
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Timothy R Mercer
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, QLD, Australia
| | - Kathryn J Moore
- Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA
| | - Shinichi Nakagawa
- RNA Biology Laboratory, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - John L Rinn
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO, USA
| | - David L Spector
- Cold Spring Harbour Laboratory, Cold Spring Harbour, NY, USA
| | - Igor Ulitsky
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Yue Wan
- Laboratory of RNA Genomics and Structure, Genome Institute of Singapore, A*STAR, Singapore, Singapore
- Department of Biochemistry, National University of Singapore, Singapore, Singapore
| | - Jeremy E Wilusz
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Therapeutic Innovation Center, Baylor College of Medicine, Houston, TX, USA
| | - Mian Wu
- Translational Research Institute, Henan Provincial People's Hospital, Academy of Medical Science, Zhengzhou University, Zhengzhou, China
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28
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Arratia F, Fierro C, Blanco A, Fuentes S, Nahuelquen D, Montecino M, Rojas A, Aguilar R. Selective Concurrence of the Long Non-Coding RNA MALAT1 and the Polycomb Repressive Complex 2 to Promoter Regions of Active Genes in MCF7 Breast Cancer Cells. Curr Issues Mol Biol 2023; 45:4735-4748. [PMID: 37367050 DOI: 10.3390/cimb45060301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/23/2023] [Accepted: 05/28/2023] [Indexed: 06/28/2023] Open
Abstract
In cancer cells, the long non-coding RNA (lncRNA) MALAT1 has arisen as a key partner for the Polycomb Repressive Complex 2 (PRC2), an epigenetic modifier. However, it is unknown whether this partnership occurs genome-wide at the chromatin level, as most of the studies focus on single genes that are usually repressed. Due to the genomic binding properties of both macromolecules, we wondered whether there are binding sites shared by PRC2 and MALAT1. Using public genome-binding datasets for PRC2 and MALAT1 derived from independent ChIP- and CHART-seq experiments performed with the breast cancer cell line MCF7, we searched for regions containing PRC2 and MALAT1 overlapping peaks. Peak calls for each molecule were performed using MACS2 and then overlapping peaks were identified by bedtools intersect. Using this approach, we identified 1293 genomic sites where PRC2 and MALAT1 concur. Interestingly, 54.75% of those sites are within gene promoter regions (<3000 bases from the TSS). These analyses were also linked with the transcription profiles of MCF7 cells, obtained from public RNA-seq data. Hence, it is suggested that MALAT1 and PRC2 can concomitantly bind to promoters of actively-transcribed genes in MCF7 cells. Gene ontology analyses revealed an enrichment of genes related to categories including cancer malignancy and epigenetic regulation. Thus, by re-visiting occupancy and transcriptomic data, we identified a key gene subset controlled by the collaboration of MALAT1 and PRC2.
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Affiliation(s)
- Felipe Arratia
- Institute of Biomedical Sciences (ICB), Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370071, Chile
| | - Cristopher Fierro
- Institute of Biomedical Sciences (ICB), Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370071, Chile
| | - Alejandro Blanco
- Institute of Biomedical Sciences (ICB), Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370071, Chile
| | - Sebastian Fuentes
- Institute of Biomedical Sciences (ICB), Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370071, Chile
| | - Daniela Nahuelquen
- Institute of Biomedical Sciences (ICB), Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370071, Chile
| | - Martin Montecino
- Institute of Biomedical Sciences (ICB), Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370071, Chile
| | - Adriana Rojas
- Institute of Human Genetics, Faculty of Medicine, Pontificia Universidad Javeriana, Bogotá 110211, Colombia
| | - Rodrigo Aguilar
- Institute of Biomedical Sciences (ICB), Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370071, Chile
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29
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Prorok P, Forouzanfar F, Murugarren N, Peiffer I, Charton R, Akerman I, Méchali M. Loss of Ezh2 function remodels the DNA replication initiation landscape. Cell Rep 2023; 42:112280. [PMID: 36995935 DOI: 10.1016/j.celrep.2023.112280] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 12/13/2022] [Accepted: 03/03/2023] [Indexed: 03/31/2023] Open
Abstract
In metazoan cells, DNA replication initiates from thousands of genomic loci scattered throughout the genome called DNA replication origins. Origins are strongly associated with euchromatin, particularly open genomic regions such as promoters and enhancers. However, over a third of transcriptionally silent genes are associated with DNA replication initiation. Most of these genes are bound and repressed by the Polycomb repressive complex-2 (PRC2) through the repressive H3K27me3 mark. This is the strongest overlap observed for a chromatin regulator with replication origin activity. Here, we asked whether Polycomb-mediated gene repression is functionally involved in recruiting DNA replication origins to transcriptionally silent genes. We show that the absence of EZH2, the catalytic subunit of PRC2, results in increased DNA replication initiation, specifically in the vicinity of EZH2 binding sites. The increase in DNA replication initiation does not correlate with transcriptional de-repression or the acquisition of activating histone marks but does correlate with loss of H3K27me3 from bivalent promoters.
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Affiliation(s)
- Paulina Prorok
- Institute of Human Genetics, CNRS-University of Montpellier, Montpellier 34090, France.
| | - Faezeh Forouzanfar
- Institute of Human Genetics, CNRS-University of Montpellier, Montpellier 34090, France
| | - Nerea Murugarren
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham B152TT, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham B152TT, UK
| | - Isabelle Peiffer
- Institute of Human Genetics, CNRS-University of Montpellier, Montpellier 34090, France
| | - Romain Charton
- Institute of Human Genetics, CNRS-University of Montpellier, Montpellier 34090, France
| | - Ildem Akerman
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham B152TT, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham B152TT, UK.
| | - Marcel Méchali
- Institute of Human Genetics, CNRS-University of Montpellier, Montpellier 34090, France.
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30
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Di Giorgio E, Benetti R, Kerschbamer E, Xodo L, Brancolini C. Super-enhancer landscape rewiring in cancer: The epigenetic control at distal sites. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2023; 380:97-148. [PMID: 37657861 DOI: 10.1016/bs.ircmb.2023.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/03/2023]
Abstract
Super-enhancers evolve as elements at the top of the hierarchical control of gene expression. They are important end-gatherers of signaling pathways that control stemness, differentiation or adaptive responses. Many epigenetic regulations focus on these regions, and not surprisingly, during the process of tumorigenesis, various alterations can account for their dysfunction. Super-enhancers are emerging as key drivers of the aberrant gene expression landscape that sustain the aggressiveness of cancer cells. In this review, we will describe and discuss about the structure of super-enhancers, their epigenetic regulation, and the major changes affecting their functionality in cancer.
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Affiliation(s)
- Eros Di Giorgio
- Laboratory of Biochemistry, Department of Medicine, Università degli Studi di Udine, Udine, Italy
| | - Roberta Benetti
- Laboratory of Epigenomics, Department of Medicine, Università degli Studi di Udine, Udine, Italy
| | - Emanuela Kerschbamer
- Laboratory of Epigenomics, Department of Medicine, Università degli Studi di Udine, Udine, Italy
| | - Luigi Xodo
- Laboratory of Biochemistry, Department of Medicine, Università degli Studi di Udine, Udine, Italy
| | - Claudio Brancolini
- Laboratory of Epigenomics, Department of Medicine, Università degli Studi di Udine, Udine, Italy.
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31
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Nakamura R, Nakayama JI. Regulation of the SUV39H Family Methyltransferases: Insights from Fission Yeast. Biomolecules 2023; 13:biom13040593. [PMID: 37189341 DOI: 10.3390/biom13040593] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/22/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023] Open
Abstract
Histones, which make up nucleosomes, undergo various post-translational modifications, such as acetylation, methylation, phosphorylation, and ubiquitylation. In particular, histone methylation serves different cellular functions depending on the location of the amino acid residue undergoing modification, and is tightly regulated by the antagonistic action of histone methyltransferases and demethylases. The SUV39H family of histone methyltransferases (HMTases) are evolutionarily conserved from fission yeast to humans and play an important role in the formation of higher-order chromatin structures called heterochromatin. The SUV39H family HMTases catalyzes the methylation of histone H3 lysine 9 (H3K9), and this modification serves as a binding site for heterochromatin protein 1 (HP1) to form a higher-order chromatin structure. While the regulatory mechanism of this family of enzymes has been extensively studied in various model organisms, Clr4, a fission yeast homologue, has made an important contribution. In this review, we focus on the regulatory mechanisms of the SUV39H family of proteins, in particular, the molecular mechanisms revealed by the studies of the fission yeast Clr4, and discuss their generality in comparison to other HMTases.
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32
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McGregor LA, Zhu B, Goetz AM, Sczepanski JT. Thymine DNA Glycosylase is an RNA-Binding Protein with High Selectivity for G-Rich Sequences. J Biol Chem 2023; 299:104590. [PMID: 36889585 PMCID: PMC10124917 DOI: 10.1016/j.jbc.2023.104590] [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: 12/28/2022] [Revised: 02/17/2023] [Accepted: 02/27/2023] [Indexed: 03/08/2023] Open
Abstract
Thymine DNA glycosylase (TDG) is a multifaceted enzyme involved in several critical biological pathways, including transcriptional activation, DNA demethylation, and DNA repair. Recent studies have established regulatory relationships between TDG and RNA, but the molecular interactions underlying these relationships is poorly understood. Herein, we now demonstrate that TDG binds directly to RNA with nanomolar affinity. Using synthetic oligonucleotides of defined length and sequence, we show that TDG has a strong preference for binding G-rich sequences in single-stranded RNA but binds weakly to single-stranded DNA and duplex RNA. TDG also binds tightly to endogenous RNA sequences. Studies with truncated proteins indicate that TDG binds RNA primarily through its structured catalytic domain and that its disordered C-terminal domain plays a key role in regulating TDG's affinity and selectivity for RNA. Finally, we show that RNA competes with DNA for binding to TDG, resulting in inhibition of TDG-mediated excision in the presence of RNA. Together, this work provides support for and insights into a mechanism wherein TDG-mediated processes (e.g., DNA demethylation) are regulated through the direct interactions of TDG with RNA.
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Affiliation(s)
- Lauren A McGregor
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, USA
| | - Baiyu Zhu
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, USA
| | - Allison M Goetz
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, USA
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33
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Jansson-Fritzberg LI, Sousa CI, Smallegan MJ, Song JJ, Gooding AR, Kasinath V, Rinn JL, Cech TR. DNMT1 inhibition by pUG-fold quadruplex RNA. RNA (NEW YORK, N.Y.) 2023; 29:346-360. [PMID: 36574982 PMCID: PMC9945446 DOI: 10.1261/rna.079479.122] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Aberrant DNA methylation is one of the earliest hallmarks of cancer. DNMT1 is responsible for methylating newly replicated DNA, but the precise regulation of DNMT1 to ensure faithful DNA methylation remains poorly understood. A link between RNA and chromatin-associated proteins has recently emerged, and several studies have shown that DNMT1 can be regulated by a variety of RNAs. In this study, we have confirmed that human DNMT1 indeed interacts with multiple RNAs, including its own nuclear mRNA. Unexpectedly, we found that DNMT1 exhibits a strong and specific affinity for GU-rich RNAs that form a pUG-fold, a noncanonical G-quadruplex. We find that pUG-fold-capable RNAs inhibit DNMT1 activity by inhibiting binding of hemimethylated DNA, and we additionally provide evidence for multiple RNA binding modes with DNMT1. Together, our data indicate that a human chromatin-associated protein binds to and is regulated by pUG-fold RNA.
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Affiliation(s)
- Linnea I Jansson-Fritzberg
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Camila I Sousa
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Michael J Smallegan
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Jessica J Song
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Anne R Gooding
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Vignesh Kasinath
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - John L Rinn
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Thomas R Cech
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado 80303, USA
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
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34
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Song J, Gooding AR, Hemphill WO, Kasinath V, Cech TR. Structural basis for inactivation of PRC2 by G-quadruplex RNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.06.527314. [PMID: 36798278 PMCID: PMC9934548 DOI: 10.1101/2023.02.06.527314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The histone methyltransferase PRC2 (Polycomb Repressive Complex 2) silences genes via successively attaching three methyl groups to lysine 27 of histone H3. PRC2 associates with numerous pre-mRNA and lncRNA transcripts with a binding preference for G-quadruplex RNA. Here, we present a 3.3Ã…-resolution cryo-EM structure of PRC2 bound to a G-quadruplex RNA. Notably, RNA mediates the dimerization of PRC2 by binding both protomers and inducing a protein interface comprised of two copies of the catalytic subunit EZH2, which limits nucleosome DNA interaction and occludes H3 tail accessibility to the active site. Our results reveal an unexpected mechanism for RNA-mediated inactivation of a chromatin-modifying enzyme. Furthermore, the flexible loop of EZH2 that helps stabilize RNA binding also facilitates the handoff between RNA and DNA, an activity implicated in PRC2 regulation by RNA. One-Sentence Summary Cryo-EM structure of RNA-bound PRC2 dimer elucidates an unexpected mechanism of PRC2 inhibition by RNA.
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35
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Ghobashi AH, Vuong TT, Kimani JW, O'Hagan HM. Activation of AKT induces EZH2-mediated β-catenin trimethylation in colorectal cancer. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.31.526429. [PMID: 36778289 PMCID: PMC9915619 DOI: 10.1101/2023.01.31.526429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Colorectal cancer (CRC) develops in part through the deregulation of different signaling pathways, including activation of the WNT/β-catenin and PI3K/AKT pathways. Enhancer of zeste homolog 2 (EZH2) is a lysine methyltransferase that is involved in regulating stem cell development and differentiation and is overexpressed in CRC. However, depending on the study EZH2 has been found to be both positively and negatively correlated with the survival of CRC patients suggesting that EZH2's role in CRC may be context specific. In this study, we explored how PI3K/AKT activation alters EZH2's role in CRC. We found that activation of AKT by PTEN knockdown or by hydrogen peroxide treatment induced EZH2 phosphorylation at serine 21. Phosphorylation of EZH2 resulted in EZH2-mediated methylation of β-catenin and an associated increased interaction between β-catenin, TCF1, and RNA polymerase II. AKT activation increased β-catenin's enrichment across the genome and EZH2 inhibition reduced this enrichment by reducing the methylation of β-catenin. Furthermore, PTEN knockdown increased the expression of epithelial-mesenchymal transition (EMT)-related genes, and somewhat unexpectedly EZH2 inhibition further increased the expression of these genes. Consistent with these findings, EZH2 inhibition enhanced the migratory phenotype of PTEN knockdown cells. Overall, we demonstrated that EZH2 modulates AKT-induced changes in gene expression through the AKT/EZH2/ β-catenin axis in CRC with active PI3K/AKT signaling. Therefore, it is important to consider the use of EZH2 inhibitors in CRC with caution as these inhibitors will inhibit EZH2-mediated methylation of histone and non-histone targets such as β-catenin, which can have tumor-promoting effects.
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36
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Wen Z, He K, Zhan M, Li Y, Liu F, He X, Wei Y, Zhao W, Zhang Y, Xue Y, Xia Y, Wang F, Xia Z, Xin Y, Wu Y, Duan X, Xiao J, Shen F, Feng Y, Xiang G, Lu L. Distinct binding pattern of EZH2 and JARID2 on RNAs and DNAs in hepatocellular carcinoma development. Front Oncol 2022; 12:904633. [PMID: 36578923 PMCID: PMC9792092 DOI: 10.3389/fonc.2022.904633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 09/14/2022] [Indexed: 12/14/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is one of the most malignant cancers worldwide, with high mortality. However, the molecular regulatory mechanisms of liver cancer, especially transcriptional and post-transcriptional mechanisms, should be further studied. Here we used chromatin and cross-linking immunoprecipitation with high throughput sequencing methods (ChIP-seq and CLIP-seq) to capture the global binding profiles on RNAs and DNAs of Enhancer of zeste homolog 2 (EZH2) and its partner Jumonji And AT-Rich Interaction Domain Containing 2 (JARID2) in liver carcinoma cell lines (HepG2) and normal liver cell line (THLE-2), respectively. We also integrated HCC transcriptome data from the TCGA to analyze the expression pattern of bound genes. We found that EZH2 and JARID2 both showed distinct binding profiles between HepG2 and THLE-2 cells. By binding to the primary RNAs, bound transcripts of EZH2 and JARID2 in HepG2 showed significantly increased transcriptional levels in HCC patients. By performing gene set enrichment analysis (GSEA), the bound transcripts were also highly related to HCC development. We also found EZH2 and JARID2 could specifically bind to several long noncoding RNAs (lncRNAs), including H19. By exploring the DNA binding profile, we detected a dramatically repressed DNA binding ability of EZH2 in HepG2 cells. We also found that the EZH2-bound genes showed slightly increased transcriptional levels in HepG2 cells. Integrating analysis of the RNA and DNA binding profiles suggests EZH2 and JARID2 shift their binding ability from DNA to RNA in HepG2 cells to promote cancer development in HCC. Our study provided a comprehensive and distinct binding profile on RNAs and DNAs of EZH2 and JARID2 in liver cancer cell lines, suggesting their potential novel functional manners to promote HCC development.
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Affiliation(s)
- Zhili Wen
- Department of Gastroenterology, Second Affiliated Hospital, Nanchang University, Nanchang, China
- Infectious Hospital, Nanchang University, Nanchang, China
| | - Ke He
- Department of General Surgery, Guangdong Second Provincial General Hospital, Guangzhou, China
- Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory of Ministry of Education, Sun Yat-sen University, Guangzhou, China
| | - Meixiao Zhan
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
| | - Yong Li
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
| | - Fei Liu
- Department of General Surgery, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Xu He
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
| | - Yanli Wei
- Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory of Ministry of Education, Sun Yat-sen University, Guangzhou, China
| | - Wei Zhao
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
| | - Yu Zhang
- Center for Genome Analysis, ABLife Inc., Wuhan, China
| | - Yaqiang Xue
- Center for Genome Analysis, ABLife Inc., Wuhan, China
- Laboratory of Human Health and Genome Regulation, ABLife Inc., Wuhan, China
| | - Yong Xia
- Department of Hepatic Surgery, The Eastern Hepatobiliary Surgery Hospital, Navy Medical University, Shanghai, China
| | - Fenfen Wang
- Department of Gastroenterology, Second Affiliated Hospital, Nanchang University, Nanchang, China
| | - Zhenglin Xia
- Department of General Surgery, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Yongjie Xin
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
| | - Yeye Wu
- Department of Hepatic Surgery, The Eastern Hepatobiliary Surgery Hospital, Navy Medical University, Shanghai, China
| | - Xiaopeng Duan
- Department of General Surgery, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Jing Xiao
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
| | - Feng Shen
- Department of Hepatic Surgery, The Eastern Hepatobiliary Surgery Hospital, Navy Medical University, Shanghai, China
| | - Yuliang Feng
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
| | - Guoan Xiang
- Department of General Surgery, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Ligong Lu
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, China
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Genome-wide chromatin accessibility analysis unveils open chromatin convergent evolution during polyploidization in cotton. Proc Natl Acad Sci U S A 2022; 119:e2209743119. [PMID: 36279429 PMCID: PMC9636936 DOI: 10.1073/pnas.2209743119] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Allopolyploidization, resulting in divergent genomes in the same cell, is believed to trigger a “genome shock”, leading to broad genetic and epigenetic changes. However, little is understood about chromatin and gene-expression dynamics as underlying driving forces during allopolyploidization. Here, we examined the genome-wide DNase I-hypersensitive site (DHS) and its variations in domesticated allotetraploid cotton (
Gossypium hirsutum
and
Gossypium barbadense
, AADD) and its extant AA (
Gossypium arboreum
) and DD (
Gossypium raimondii
) progenitors. We observed distinct DHS distributions between
G. arboreum
and
G. raimondii
. In contrast, the DHSs of the two subgenomes of
G. hirsutum
and
G. barbadense
showed a convergent distribution. This convergent distribution of DHS was also present in the wild allotetraploids
Gossypium darwinii
and
G. hirsutum
var.
yucatanense
, but absent from a resynthesized hybrid of
G. arboreum
and
G. raimondii
, suggesting that it may be a common feature in polyploids, and not a consequence of domestication after polyploidization. We revealed that putative
cis
-regulatory elements (CREs) derived from polyploidization-related DHSs were dominated by several families, including Dof, ERF48, and BPC1. Strikingly, 56.6% of polyploidization-related DHSs were derived from transposable elements (TEs). Moreover, we observed positive correlations between DHS accessibility and the histone marks H3K4me3, H3K27me3, H3K36me3, H3K27ac, and H3K9ac, indicating that coordinated interplay among histone modifications, TEs, and CREs drives the DHS landscape dynamics under polyploidization. Collectively, these findings advance our understanding of the regulatory architecture in plants and underscore the complexity of regulome evolution during polyploidization.
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Wang G, Ye H, Wang X, Liu B. Polycomb repressive complex 2 controls cardiac cell fate decision via interacting with RNA: Promiscuously or well-ordered. Front Genet 2022; 13:1011228. [PMID: 36313464 PMCID: PMC9614146 DOI: 10.3389/fgene.2022.1011228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 09/29/2022] [Indexed: 11/13/2022] Open
Abstract
The epigenetic landscape determines cell fate during heart development. Polycomb repressive complex 2 (PRC2) mediates histone methyltransferase activity during cardiac cell differentiation. The PRC2 complex contains the proteins embryonic ectoderm development (EED), suppressor of zeste (SUZ12), the chromatin assembly factor 1 (CAF1) histone-binding proteins RBBP4 and RBBP7, and the histone methyltransferase called enhancer of zeste (EZH2 or EZH1), which incorporates the Su(var)3-9, Enhancer-of-zeste, Trithorax (SET) domain. Cardiac PRC2-deficient mice display lethal congenital heart malformations. The dynamic process of cardiac cell fate decisions is controlled by PRC2 and the PRC2-mediated epigenetic landscape. Although specific individual long noncoding RNAs (lncRNAs) including Braveheart were widely reported to regulate the recruitments of PRC2 to their specific targets, a promiscuous RNA binding profile by PRC2 was also identified to play an essential role in cardiac cell fate decision. In this review, we focus on RNA-mediated PRC2 recruitment machinery in the process of cardiac cell fate decisions. The roles of individual lncRNAs which recruit PRC2, as well as promiscuous RNA binding by PRC2 in heart development are summarized. Since the binding priority of RNAs with different primary and secondary structures differs in its affinity to PRC2, the competitive relationship between individual lncRNAs binding and promiscuous RNA binding by PRC2 may be important for understanding the machinery by which biding of individual lncRNA and promiscuous RNA by PRC2 coordinately control the well-ordered dynamic cardiac cell lineage differentiation process.
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Affiliation(s)
- Gang Wang
- Xiamen Cardiovascular Hospital, School of Medicine, Xiamen University, Xiamen, China
| | - Heng Ye
- Xiamen Cardiovascular Hospital, School of Medicine, Xiamen University, Xiamen, China
- School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang, Liaoning, China
| | - Xuchao Wang
- Xiamen Cardiovascular Hospital, School of Medicine, Xiamen University, Xiamen, China
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning, China
| | - Binbin Liu
- Xiamen Cardiovascular Hospital, School of Medicine, Xiamen University, Xiamen, China
- *Correspondence: Binbin Liu,
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p300/CBP sustains Polycomb silencing by non-enzymatic functions. Mol Cell 2022; 82:3580-3597.e9. [DOI: 10.1016/j.molcel.2022.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 06/16/2022] [Accepted: 09/06/2022] [Indexed: 12/29/2022]
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40
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Functions and underlying mechanisms of lncRNA HOTAIR in cancer chemotherapy resistance. Cell Death Dis 2022; 8:383. [PMID: 36100611 PMCID: PMC9470550 DOI: 10.1038/s41420-022-01174-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/25/2022] [Accepted: 08/31/2022] [Indexed: 11/30/2022]
Abstract
Chemotherapy has been one of the most important treatments for advanced cancer in recent decades. Although the sensitivity rate of initial chemotherapy is high, patients with chemotherapy resistant tumors, experience tumor recurrence. In recent years, many studies have shown that homeobox transcript antisense intergenic RNA (HOTAIR) is involved in many pathological processes including carcinogenesis. The abnormal regulation of a variety of cell functions by HOTAIR, such as apoptosis, the cell cycle, epithelial-mesenchymal transition, autophagy, self-renewal, and metabolism, is associated with chemotherapy resistance. Therefore, there is an urgent need to understand the biology and mechanism underlying the role of HOTAIR in tumor behavior and its potential as a biomarker for predicting the effect of chemotherapy. In this manuscript, we review the mechanisms underlying HOTAIR-related drug resistance and discuss the limitations of current knowledge and propose potential future directions.
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41
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Sommerauer C, Kutter C. Noncoding RNAs in liver physiology and metabolic diseases. Am J Physiol Cell Physiol 2022; 323:C1003-C1017. [PMID: 35968891 DOI: 10.1152/ajpcell.00232.2022] [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] [Indexed: 12/14/2022]
Abstract
The liver holds central roles in detoxification, energy metabolism and whole-body homeostasis but can develop malignant phenotypes when being chronically overwhelmed with fatty acids and glucose. The global rise of metabolic-associated fatty liver disease (MAFLD) is already affecting a quarter of the global population. Pharmaceutical treatment options against different stages of MAFLD do not yet exist and several clinical trials against hepatic transcription factors and other proteins have failed. However, emerging roles of noncoding RNAs, including long (lncRNA) and short noncoding RNAs (sRNA), in various cellular processes pose exciting new avenues for treatment interventions. Actions of noncoding RNAs mostly rely on interactions with proteins, whereby the noncoding RNA fine-tunes protein function in a process termed riboregulation. The developmental stage-, disease stage- and cell type-specific nature of noncoding RNAs harbors enormous potential to precisely target certain cellular pathways in a spatio-temporally defined manner. Proteins interacting with RNAs can be categorized into canonical or non-canonical RNA binding proteins (RBPs) depending on the existence of classical RNA binding domains. Both, RNA- and RBP-centric methods have generated new knowledge of the RNA-RBP interface and added an additional regulatory layer. In this review, we summarize recent advances of how of RBP-lncRNA interactions and various sRNAs shape cellular physiology and the development of liver diseases such as MAFLD and hepatocellular carcinoma.
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Affiliation(s)
- Christian Sommerauer
- Science for Life Laboratory, Department of Microbiology, Tumor and Cell Biology, grid.4714.6Karolinska Institute, Stockholm, Sweden
| | - Claudia Kutter
- Science for Life Laboratory, Department of Microbiology, Tumor and Cell Biology, grid.4714.6Karolinska Institute, Stockholm, Sweden
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Abstract
Enhancers confer precise spatiotemporal patterns of gene expression in response to developmental and environmental stimuli. Over the last decade, the transcription of enhancer RNAs (eRNAs) – nascent RNAs transcribed from active enhancers – has emerged as a key factor regulating enhancer activity. eRNAs are relatively short-lived RNA species that are transcribed at very high rates but also quickly degraded. Nevertheless, eRNAs are deeply intertwined within enhancer regulatory networks and are implicated in a number of transcriptional control mechanisms. Enhancers show changes in function and sequence over evolutionary time, raising questions about the relationship between enhancer sequences and eRNA function. Moreover, the vast majority of single nucleotide polymorphisms associated with human complex diseases map to the non-coding genome, with causal disease variants enriched within enhancers. In this Primer, we survey the diverse roles played by eRNAs in enhancer-dependent gene expression, evaluating different models for eRNA function. We also explore questions surrounding the genetic conservation of enhancers and how this relates to eRNA function and dysfunction. Summary: This Primer evaluates the ideas that underpin developing models for eRNA function, exploring cases in which perturbed eRNA function contributes to disease.
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Affiliation(s)
- Laura J. Harrison
- Molecular and Cellular Biology, School of Biosciences, Sheffield Institute For Nucleic Acids, The University of Sheffield, Firth Court, Western Bank , Sheffield S10 2TN , UK
| | - Daniel Bose
- Molecular and Cellular Biology, School of Biosciences, Sheffield Institute For Nucleic Acids, The University of Sheffield, Firth Court, Western Bank , Sheffield S10 2TN , UK
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Ilieva M, Uchida S. Long Non-Coding RNAs in Cardiac and Pulmonary Fibroblasts and Fibrosis. Noncoding RNA 2022; 8:ncrna8040053. [PMID: 35893236 PMCID: PMC9326574 DOI: 10.3390/ncrna8040053] [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: 06/22/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 11/16/2022] Open
Abstract
The cardiopulmonary system delivers oxygen throughout the body via blood circulation. It is an essential part of the body to sustain the lives of organisms. The integral parts of the cardiopulmonary system—the heart and lungs—are constantly exposed to damaging agents (e.g., dust, viruses), and can be greatly affected by injuries caused by dysfunction in tissues (e.g., myocardial infarction). When damaged, mesenchymal cells, such as fibroblasts, are activated to become myofibroblasts to initiate fibrosis as part of a regenerative mechanism. In diseased states, the excess accumulation of extracellular matrices secreted by myofibroblasts results in further dysfunction in the damaged organs. These fibrotic tissues cannot easily be removed. Thus, there is a growing interest in understanding the fibrotic process, as well as finding biomolecules that can be targets for slowing down or potentially stopping fibrosis. Among these biomolecules, the interest in studying long non-coding RNAs (lncRNAs; any non-protein-coding RNAs longer than 200 nucleotides) has intensified in recent years. In this commentary, we summarize the current status of lncRNA research in the cardiopulmonary system by focusing on cardiac and pulmonary fibrosis.
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44
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Liu X, Liu X. PRC2, Chromatin Regulation, and Human Disease: Insights From Molecular Structure and Function. Front Oncol 2022; 12:894585. [PMID: 35800061 PMCID: PMC9255955 DOI: 10.3389/fonc.2022.894585] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/17/2022] [Indexed: 01/25/2023] Open
Abstract
Polycomb repressive complex 2 (PRC2) is a multisubunit histone-modifying enzyme complex that mediates methylation of histone H3 lysine 27 (H3K27). Trimethylated H3K27 (H3K27me3) is an epigenetic hallmark of gene silencing. PRC2 plays a crucial role in a plethora of fundamental biological processes, and PRC2 dysregulation has been repeatedly implicated in cancers and developmental disorders. Here, we review the current knowledge on mechanisms of cellular regulation of PRC2 function, particularly regarding H3K27 methylation and chromatin targeting. PRC2-related disease mechanisms are also discussed. The mode of action of PRC2 in gene regulation is summarized, which includes competition between H3K27 methylation and acetylation, crosstalk with transcription machinery, and formation of high-order chromatin structure. Recent progress in the structural biology of PRC2 is highlighted from the aspects of complex assembly, enzyme catalysis, and chromatin recruitment, which together provide valuable insights into PRC2 function in close-to-atomic detail. Future studies on the molecular function and structure of PRC2 in the context of native chromatin and in the presence of other regulators like RNAs will continue to deepen our understanding of the stability and plasticity of developmental transcriptional programs broadly impacted by PRC2.
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45
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Huang X, Bashkenova N, Hong Y, Lyu C, Guallar D, Hu Z, Malik V, Li D, Wang H, Shen X, Zhou H, Wang J. A TET1-PSPC1-Neat1 molecular axis modulates PRC2 functions in controlling stem cell bivalency. Cell Rep 2022; 39:110928. [PMID: 35675764 PMCID: PMC9214724 DOI: 10.1016/j.celrep.2022.110928] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 03/29/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
TET1 maintains hypomethylation at bivalent promoters through its catalytic activity in embryonic stem cells (ESCs). However, TET1 catalytic activity-independent function in regulating bivalent genes is not well understood. Using a proteomics approach, we map the TET1 interactome in ESCs and identify PSPC1 as a TET1 partner. Genome-wide location analysis reveals that PSPC1 functionally associates with TET1 and Polycomb repressive complex-2 (PRC2). We establish that PSPC1 and TET1 repress, and the lncRNA Neat1 activates, bivalent gene expression. In ESCs, Neat1 is preferentially bound to PSPC1 alongside its PRC2 association at bivalent promoters. During the ESC-to-epiblast-like stem cell (EpiLC) transition, PSPC1 and TET1 maintain PRC2 chromatin occupancy at bivalent gene promoters, while Neat1 facilitates the activation of certain bivalent genes by promoting PRC2 binding to their mRNAs. Our study demonstrates a TET1-PSPC1-Neat1 molecular axis that modulates PRC2-binding affinity to chromatin and bivalent gene transcripts in controlling stem cell bivalency.
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Affiliation(s)
- Xin Huang
- Department of Medicine, Columbia Center for Human Development, Columbia Stem Cell Initiative, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Nazym Bashkenova
- Department of Medicine, Columbia Center for Human Development, Columbia Stem Cell Initiative, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Yantao Hong
- Tsinghua Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Cong Lyu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Diana Guallar
- Center for Research in Molecular Medicine and Chronic Diseases (CiMUS), Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Zhe Hu
- Department of Medicine, Columbia Center for Human Development, Columbia Stem Cell Initiative, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Vikas Malik
- Department of Medicine, Columbia Center for Human Development, Columbia Stem Cell Initiative, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Dan Li
- Department of Medicine, Columbia Center for Human Development, Columbia Stem Cell Initiative, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Hailin Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xiaohua Shen
- Tsinghua Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Hongwei Zhou
- Department of Medicine, Columbia Center for Human Development, Columbia Stem Cell Initiative, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jianlong Wang
- Department of Medicine, Columbia Center for Human Development, Columbia Stem Cell Initiative, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA.
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Kraft K, Yost KE, Murphy SE, Magg A, Long Y, Corces MR, Granja JM, Wittler L, Mundlos S, Cech TR, Boettiger AN, Chang HY. Polycomb-mediated genome architecture enables long-range spreading of H3K27 methylation. Proc Natl Acad Sci U S A 2022; 119:e2201883119. [PMID: 35617427 PMCID: PMC9295753 DOI: 10.1073/pnas.2201883119] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 03/31/2022] [Indexed: 02/07/2023] Open
Abstract
Polycomb-group proteins play critical roles in gene silencing through the deposition of histone H3 lysine 27 trimethylation (H3K27me3) and chromatin compaction. This process is essential for embryonic stem cell (ESC) pluripotency, differentiation, and development. Polycomb repressive complex 2 (PRC2) can both read and write H3K27me3, enabling progressive spreading of H3K27me3 on the linear genome. Long-range Polycomb-associated DNA contacts have also been described, but their regulation and role in gene silencing remain unclear. Here, we apply H3K27me3 HiChIP, a protein-directed chromosome conformation method, and optical reconstruction of chromatin architecture to profile long-range Polycomb-associated DNA loops that span tens to hundreds of megabases across multiple topological associated domains in mouse ESCs and human induced pluripotent stem cells. We find that H3K27me3 loop anchors are enriched for Polycomb nucleation points and coincide with key developmental genes. Genetic deletion of H3K27me3 loop anchors results in disruption of spatial contact between distant loci and altered H3K27me3 in cis, both locally and megabases away on the same chromosome. In mouse embryos, loop anchor deletion leads to ectopic activation of the partner gene, suggesting that Polycomb-associated loops control gene silencing during development. Further, we find that alterations in PRC2 occupancy resulting from an RNA binding–deficient EZH2 mutant are accompanied by loss of Polycomb-associated DNA looping. Together, these results suggest PRC2 uses RNA binding to enhance long-range chromosome folding and H3K27me3 spreading. Developmental gene loci have unique roles in Polycomb spreading, emerging as important architectural elements of the epigenome.
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Affiliation(s)
- Katerina Kraft
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA 94305
| | - Kathryn E. Yost
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA 94305
| | | | - Andreas Magg
- Research Group of Development and Disease, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
- Institute for Medical and Human Genetics, Charité Universitätsmedizin, 10117 Berlin, Germany
| | - Yicheng Long
- HHMI, University of Colorado, Boulder, CO 80309
- Department of Biochemistry, University of Colorado, Boulder, CO 80309
- BioFrontiers Institute, University of Colorado, Boulder, CO 80309
| | - M. Ryan Corces
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA 94305
| | - Jeffrey M. Granja
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA 94305
- Department of Genetics, Stanford University, Stanford, CA 94305
| | - Lars Wittler
- Department of Developmental Genetics, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Stefan Mundlos
- Research Group of Development and Disease, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
- Institute for Medical and Human Genetics, Charité Universitätsmedizin, 10117 Berlin, Germany
| | - Thomas R. Cech
- HHMI, University of Colorado, Boulder, CO 80309
- Department of Biochemistry, University of Colorado, Boulder, CO 80309
- BioFrontiers Institute, University of Colorado, Boulder, CO 80309
| | | | - Howard Y. Chang
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA 94305
- HHMI, Stanford University School of Medicine, Stanford, CA 94305
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47
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Ullah I, Thölken C, Zhong Y, John M, Rossbach O, Lenz J, Gößringer M, Nist A, Albert L, Stiewe T, Hartmann R, Vázquez O, Chung HR, Mackay JP, Brehm A. RNA inhibits dMi-2/CHD4 chromatin binding and nucleosome remodeling. Cell Rep 2022; 39:110895. [PMID: 35649367 DOI: 10.1016/j.celrep.2022.110895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 03/30/2022] [Accepted: 05/09/2022] [Indexed: 11/03/2022] Open
Abstract
The ATP-dependent nucleosome remodeler Mi-2/CHD4 broadly modulates chromatin landscapes to repress transcription and to maintain genome integrity. Here we use individual nucleotide resolution crosslinking and immunoprecipitation (iCLIP) to show that Drosophila Mi-2 associates with thousands of mRNA molecules in vivo. Biochemical data reveal that recombinant dMi-2 preferentially binds to G-rich RNA molecules using two intrinsically disordered regions of unclear function. Pharmacological inhibition of transcription and RNase digestion approaches establish that RNA inhibits the association of dMi-2 with chromatin. We also show that RNA inhibits dMi-2-mediated nucleosome mobilization by competing with the nucleosome substrate. Importantly, this activity is shared by CHD4, the human homolog of dMi-2, strongly suggesting that RNA-mediated regulation of remodeler activity is an evolutionary conserved mechanism. Our data support a model in which RNA serves to protect actively transcribed regions of the genome from dMi-2/CHD4-mediated establishment of repressive chromatin structures.
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Affiliation(s)
- Ikram Ullah
- Institute of Molecular Biology and Tumor Research, Biomedical Research Center, Philipps-University, Marburg, Germany
| | - Clemens Thölken
- Institute for Medical Bioinformatics and Biostatistic, Philipps-University, Marburg, Germany
| | - Yichen Zhong
- School of Life and Environmental Sciences, University of Sydney, NSW 2006, Australia
| | - Mara John
- Institute of Molecular Biology and Tumor Research, Biomedical Research Center, Philipps-University, Marburg, Germany
| | - Oliver Rossbach
- Institute of Biochemistry, Department of Biology and Chemistry, Justus Liebig University Giessen, Giessen, Germany
| | - Jonathan Lenz
- Institute of Molecular Biology and Tumor Research, Biomedical Research Center, Philipps-University, Marburg, Germany
| | - Markus Gößringer
- Institute of Pharmaceutical Chemistry, Philipps-University, Marburg, Germany
| | - Andrea Nist
- Genomics Core Facility, Institute of Molecular Oncology, Member of the German Center for Lung Research (DZL), Philipps-University, Marburg, Germany
| | - Lea Albert
- Faculty of Chemistry, Philipps-University, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
| | - Thorsten Stiewe
- Genomics Core Facility, Institute of Molecular Oncology, Member of the German Center for Lung Research (DZL), Philipps-University, Marburg, Germany
| | - Roland Hartmann
- Institute of Pharmaceutical Chemistry, Philipps-University, Marburg, Germany
| | - Olalla Vázquez
- Faculty of Chemistry, Philipps-University, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
| | - Ho-Ryung Chung
- Institute for Medical Bioinformatics and Biostatistic, Philipps-University, Marburg, Germany
| | - Joel P Mackay
- School of Life and Environmental Sciences, University of Sydney, NSW 2006, Australia
| | - Alexander Brehm
- Institute of Molecular Biology and Tumor Research, Biomedical Research Center, Philipps-University, Marburg, Germany.
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48
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The Disordered EZH2 Loop: Atomic Level Characterization by 1H N- and 1H α-Detected NMR Approaches, Interaction with the Long Noncoding HOTAIR RNA. Int J Mol Sci 2022; 23:ijms23116150. [PMID: 35682829 PMCID: PMC9181245 DOI: 10.3390/ijms23116150] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 02/06/2023] Open
Abstract
The 96-residue-long loop of EZH2 is proposed to play a role in the interaction with long non-coding RNAs (lncRNAs) and to contribute to EZH2 recruitment to the chromatin. However, molecular details of RNA recognition have not been described so far. Cellular studies have suggested that phosphorylation of the Thr345 residue localized in this loop influences RNA binding; however, no mechanistic explanation has been offered. To address these issues, a systematic NMR study was performed. As the 1HN-detected NMR approach presents many challenges under physiological conditions, our earlier developed, as well as improved, 1Hα-detected experiments were used. As a result of the successful resonance assignment, the obtained chemical shift values indicate the highly disordered nature of the EZH2 loop, with some nascent helical tendency in the Ser407–Ser412 region. Further investigations conducted on the phosphomimetic mutant EZH2T345D showed that the mutation has only a local effect, and that the loop remains disordered. On the other hand, the mutation influences the cis/trans Pro346 equilibrium. Interactions of both the wild-type and the phosphomimetic mutant with the lncRNA HOTAIR140 (1–140 nt) highlight that the Thr367–Ser375 region is affected. This segment does not resemble any of the previously reported RNA-binding motifs, therefore the identified binding region is unique. As no structural changes occur in the EZH2 loop upon RNA binding, we can consider the protein–RNA interaction as a “fuzzy” complex.
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49
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Gorbovytska V, Kim SK, Kuybu F, Götze M, Um D, Kang K, Pittroff A, Brennecke T, Schneider LM, Leitner A, Kim TK, Kuhn CD. Enhancer RNAs stimulate Pol II pause release by harnessing multivalent interactions to NELF. Nat Commun 2022; 13:2429. [PMID: 35508485 PMCID: PMC9068813 DOI: 10.1038/s41467-022-29934-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 03/24/2022] [Indexed: 12/12/2022] Open
Abstract
Enhancer RNAs (eRNAs) are long non-coding RNAs that originate from enhancers. Although eRNA transcription is a canonical feature of activated enhancers, the molecular features required for eRNA function and the mechanism of how eRNAs impinge on target gene transcription have not been established. Thus, using eRNA-dependent RNA polymerase II (Pol II) pause release as a model, we here investigate the requirement of sequence, structure and length of eRNAs for their ability to stimulate Pol II pause release by detaching NELF from paused Pol II. We find eRNAs not to exert their function through common structural or sequence motifs. Instead, eRNAs that exhibit a length >200 nucleotides and that contain unpaired guanosines make multiple, allosteric contacts with NELF subunits -A and -E to trigger efficient NELF release. By revealing the molecular determinants of eRNA function, our study establishes eRNAs as an important player in Pol II pause release, and it provides new insight into the regulation of metazoan transcription.
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Affiliation(s)
- Vladyslava Gorbovytska
- RNA Biochemistry, University of Bayreuth, Universitätsstrasse 30, 95447, Bayreuth, Germany
| | - Seung-Kyoon Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 37673, Republic of Korea.,Department of Convergent Bioscience and Informatics, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Filiz Kuybu
- RNA Biochemistry, University of Bayreuth, Universitätsstrasse 30, 95447, Bayreuth, Germany
| | - Michael Götze
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, 8093, Zurich, Switzerland
| | - Dahun Um
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Keunsoo Kang
- Department of Microbiology, Dankook University, Cheonan, 31116, Republic of Korea
| | - Andreas Pittroff
- RNA Biochemistry, University of Bayreuth, Universitätsstrasse 30, 95447, Bayreuth, Germany
| | - Theresia Brennecke
- RNA Biochemistry, University of Bayreuth, Universitätsstrasse 30, 95447, Bayreuth, Germany
| | - Lisa-Marie Schneider
- RNA Biochemistry, University of Bayreuth, Universitätsstrasse 30, 95447, Bayreuth, Germany
| | - Alexander Leitner
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, 8093, Zurich, Switzerland
| | - Tae-Kyung Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 37673, Republic of Korea. .,Institute of Convergence Science, Yonsei University, Seoul, 03722, Republic of Korea.
| | - Claus-D Kuhn
- RNA Biochemistry, University of Bayreuth, Universitätsstrasse 30, 95447, Bayreuth, Germany.
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50
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Teo WW, Cao X, Wu CS, Tan HK, Zhou Q, Gao C, Vanuytsel K, Kumar SS, Murphy GJ, Yang H, Chai L, Tenen DG. Non-coding RNA LEVER sequestration of PRC2 can mediate long range gene regulation. Commun Biol 2022; 5:343. [PMID: 35411071 PMCID: PMC9001699 DOI: 10.1038/s42003-022-03250-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 03/09/2022] [Indexed: 11/20/2022] Open
Abstract
Polycomb Repressive Complex 2 (PRC2) is an epigenetic regulator required for gene silencing during development. Although PRC2 is a well-established RNA-binding complex, the biological function of PRC2-RNA interaction has been controversial. Here, we study the gene-regulatory role of the inhibitory PRC2-RNA interactions. We report a nuclear long non-coding RNA, LEVER, which mapped 236 kb upstream of the β-globin cluster as confirmed by Nanopore sequencing. LEVER RNA interacts with PRC2 in its nascent form, and this prevents the accumulation of the H3K27 repressive histone marks within LEVER locus. Interestingly, the accessible LEVER chromatin, in turn, suppresses the chromatin interactions between the ε-globin locus and β-globin locus control region (LCR), resulting in a repressive effect on ε-globin gene expression. Our findings validate that the nascent RNA-PRC2 interaction inhibits local PRC2 function in situ. More importantly, we demonstrate that such a local process can in turn regulate the expression of neighboring genes. Identification of a long non-coding RNA LEVER, that inhibits the Polycomb Repressive Complex 2 (PRC2) and controls nearby embryonic form of beta-globin gene, provides additional evidence for PRC2-RNA functional interaction.
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Affiliation(s)
- Wei Wen Teo
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Xinang Cao
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore.,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Chan-Shuo Wu
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Hong Kee Tan
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore.,National University of Singapore, Graduate School for Integrative Sciences and Engineering, Singapore, Singapore
| | - Qiling Zhou
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Chong Gao
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Kim Vanuytsel
- Section of Hematology and Medical Oncology, School of Medicine, Boston University, Boston, MA, USA.,Center for Regenerative Medicine, Boston University and Boston Medical Center, Boston, MA, USA
| | - Sara S Kumar
- Section of Hematology and Medical Oncology, School of Medicine, Boston University, Boston, MA, USA.,Center for Regenerative Medicine, Boston University and Boston Medical Center, Boston, MA, USA
| | - George J Murphy
- Section of Hematology and Medical Oncology, School of Medicine, Boston University, Boston, MA, USA.,Center for Regenerative Medicine, Boston University and Boston Medical Center, Boston, MA, USA
| | - Henry Yang
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Li Chai
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.
| | - Daniel G Tenen
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore. .,Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA. .,Harvard Initiative for RNA Medicine, Harvard Medical School, Boston, MA, USA.
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