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Machitani M, Nomura A, Yamashita T, Yasukawa M, Ueki S, Fujita KI, Ueno T, Yamashita A, Tanzawa Y, Watanabe M, Taniguchi T, Saitoh N, Kaneko S, Kato Y, Mano H, Masutomi K. Maintenance of R-loop structures by phosphorylated hTERT preserves genome integrity. Nat Cell Biol 2024; 26:932-945. [PMID: 38806647 DOI: 10.1038/s41556-024-01427-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 04/23/2024] [Indexed: 05/30/2024]
Abstract
As aberrant accumulation of RNA-DNA hybrids (R-loops) causes DNA damage and genome instability, cells express regulators of R-loop structures. Here we report that RNA-dependent RNA polymerase (RdRP) activity of human telomerase reverse transcriptase (hTERT) regulates R-loop formation. We found that the phosphorylated form of hTERT (p-hTERT) exhibits RdRP activity in nuclear speckles both in telomerase-positive cells and telomerase-negative cells with alternative lengthening of telomeres (ALT) activity. The p-hTERT did not associate with telomerase RNA component in nuclear speckles but, instead, with TERRA RNAs to resolve R-loops. Targeting of the TERT gene in ALT cells ablated RdRP activity and impaired tumour growth. Using a genome-scale CRISPR loss-of-function screen, we identified Fanconi anaemia/BRCA genes as synthetic lethal partners of hTERT RdRP. Inactivation of RdRP and Fanconi anaemia/BRCA genes caused accumulation of R-loop structures and DNA damage. These findings indicate that RdRP activity of p-hTERT guards against genome instability by removing R-loop structures.
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Affiliation(s)
- Mitsuhiro Machitani
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Akira Nomura
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
- Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Isehara, Japan
| | - Taro Yamashita
- Department of Gastroenterology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Mami Yasukawa
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Saori Ueki
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Ken-Ichi Fujita
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Toshihide Ueno
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, Japan
| | - Akio Yamashita
- Department of Investigative Medicine, University of the Ryukyus Graduate School of Medicine, Nakagami, Japan
| | - Yoshikazu Tanzawa
- Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Isehara, Japan
| | - Masahiko Watanabe
- Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Isehara, Japan
| | - Toshiyasu Taniguchi
- Department of Molecular Life Science, Tokai University School of Medicine, Isehara, Japan
| | - Noriko Saitoh
- Division of Cancer Biology, The Cancer Institute of JFCR, Tokyo, Japan
| | - Shuichi Kaneko
- Department of Gastroenterology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Yukinari Kato
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Molecular Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroyuki Mano
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, Japan
| | - Kenkichi Masutomi
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan.
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R P, Rakshit S, Shanmugam G, George M, Sarkar K. Wiskott Aldrich syndrome protein (WASp)-deficient Th1 cells promote R-loop-driven transcriptional insufficiency and transcription-coupled nucleotide excision repair factor (TC-NER)-driven genome-instability in the pathogenesis of T cell acute lymphoblastic leukemia. Clin Immunol 2024; 263:110204. [PMID: 38582251 DOI: 10.1016/j.clim.2024.110204] [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: 01/25/2024] [Revised: 03/21/2024] [Accepted: 04/01/2024] [Indexed: 04/08/2024]
Abstract
BACKGROUND T-ALL is an aggressive hematological tumor that develops as the result of a multi-step oncogenic process which causes expansion of hematopoietic progenitors that are primed for T cell development to undergo malignant transformation and growth. Even though first-line therapy has a significant response rate, 40% of adult patients and 20% of pediatric patients will relapse. Therefore, there is an unmet need for treatment for relapsed/refractory T-ALL to develop potential targeted therapies. METHODS Pediatric T-ALL patient derived T cells were grown under either nonskewingTh0 or Th1-skewing conditions to further process for ChIP-qPCR, RDIP-qPCR and other RT-PCR assays. Endogenous WASp was knocked out using CRISPR-Cas9 and was confirmed using flow cytometry and western blotting. LC-MS/MS was performed to find out proteomic dataset of WASp-interactors generated from Th1-skewed, human primary Th-cells. DNA-damage was assessed by immunofluorescence confocal-imaging and single-cell gel electrophoresis (comet assay). Overexpression of RNaseH1 was also done to restore normal Th1-transcription in WASp-deficient Th1-skewed cells. RESULTS We discovered that nuclear-WASp is required for suppressing R-loop production (RNA/DNA-hybrids) at Th1-network genes by ribonucleaseH2 (RNH2) and topoisomerase1. Nuclear-WASp is associated with the factors involved in preventing and dissolving R-loops in Th1 cells. In nuclear- WASp-reduced malignant Th1-cells, R-loops accumulate in vivo and are processed into DNA-breaks by transcription-coupled-nucleotide-excision repair (TC-NER). Several epigenetic modifications were also found to be involved at Th1 gene locus which are responsible for active/repressive marks of particular genes. By demonstrating WASp as a physiologic regulator of programmed versus unprogrammed R-loops, we suggest that the transcriptional role of WASp in vivo extends also to prevent transcription-linked DNA damage during malignancy and through modification of epigenetic dysregulations. CONCLUSION Our findings present a provocative possibility of resetting R-loops as a therapeutic intervention to correct both immune deficiency and malignancy in T-cell acute lymphoblastic leukemia patients and a novel role of WASp in the epigenetic regulation of T helper cell differentiation in T-ALL patients, anticipating WASp's requirement for the suppression of T-ALL progression.
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Affiliation(s)
- Pradeep R
- Department of Biotechnology, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu 603203, India
| | - Sudeshna Rakshit
- Department of Biotechnology, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu 603203, India
| | - Geetha Shanmugam
- Department of Biotechnology, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu 603203, India
| | - Melvin George
- Department of Clinical Pharmacology, SRM Medical College Hospital and Research Centre, Kattankulathur, Tamil Nadu 603203, India
| | - Koustav Sarkar
- Department of Biotechnology, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu 603203, India.
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Liu Z, Ajit K, Wu Y, Zhu WG, Gullerova M. The GATAD2B-NuRD complex drives DNA:RNA hybrid-dependent chromatin boundary formation upon DNA damage. EMBO J 2024; 43:2453-2485. [PMID: 38719994 PMCID: PMC11183058 DOI: 10.1038/s44318-024-00111-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 04/17/2024] [Accepted: 04/18/2024] [Indexed: 06/19/2024] Open
Abstract
Double-strand breaks (DSBs) are the most lethal form of DNA damage. Transcriptional activity at DSBs, as well as transcriptional repression around DSBs, are both required for efficient DNA repair. The chromatin landscape defines and coordinates these two opposing events. However, how the open and condensed chromatin architecture is regulated remains unclear. Here, we show that the GATAD2B-NuRD complex associates with DSBs in a transcription- and DNA:RNA hybrid-dependent manner, to promote histone deacetylation and chromatin condensation. This activity establishes a spatio-temporal boundary between open and closed chromatin, which is necessary for the correct termination of DNA end resection. The lack of the GATAD2B-NuRD complex leads to chromatin hyperrelaxation and extended DNA end resection, resulting in homologous recombination (HR) repair failure. Our results suggest that the GATAD2B-NuRD complex is a key coordinator of the dynamic interplay between transcription and the chromatin landscape, underscoring its biological significance in the RNA-dependent DNA damage response.
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Affiliation(s)
- Zhichao Liu
- Sir William Dunn School of Pathology, South Parks Road, Oxford, OX1 3RE, United Kingdom
| | - Kamal Ajit
- Sir William Dunn School of Pathology, South Parks Road, Oxford, OX1 3RE, United Kingdom
| | - Yupei Wu
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Shenzhen University International Cancer Center, Marshall Laboratory of Biomedical Engineering, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, 518055, Shenzhen, China
| | - Wei-Guo Zhu
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Shenzhen University International Cancer Center, Marshall Laboratory of Biomedical Engineering, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, 518055, Shenzhen, China
| | - Monika Gullerova
- Sir William Dunn School of Pathology, South Parks Road, Oxford, OX1 3RE, United Kingdom.
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McShane A, Narayanan IV, Paulsen MT, Ashaka M, Blinkiewicz H, Yang NT, Magnuson B, Bedi K, Wilson TE, Ljungman M. Characterizing nascent transcription patterns of PROMPTs, eRNAs, and readthrough transcripts in the ENCODE4 deeply profiled cell lines. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.09.588612. [PMID: 38645116 PMCID: PMC11030308 DOI: 10.1101/2024.04.09.588612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Arising as co-products of canonical gene expression, transcription-associated lincRNAs, such as promoter upstream transcripts (PROMPTs), enhancer RNAs (eRNAs), and readthrough (RT) transcripts, are often regarded as byproducts of transcription, although they may be important for the expression of nearby genes. We identified regions of nascent expression of these lincRNA in 16 human cell lines using Bru-seq techniques, and found distinctly regulated patterns of PROMPT, eRNA, and RT transcription using the diverse biochemical approaches in the ENCODE4 deeply profiled cell lines collection. Transcription of these lincRNAs was influenced by sequence-specific features and the local or 3D chromatin landscape. However, these sequence and chromatin features do not describe the full spectrum of lincRNA expression variability we identify, highlighting the complexity of their regulation. This may suggest that transcription-associated lincRNAs are not merely byproducts, but rather that the transcript itself, or the act of its transcription, is important for genomic function.
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Mukhopadhyay P, Miller H, Stoja A, Bishop AJR. Approaches for Mapping and Analysis of R-loops. Curr Protoc 2024; 4:e1037. [PMID: 38666626 DOI: 10.1002/cpz1.1037] [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] [Indexed: 05/04/2024]
Abstract
R-loops are nucleic acid structures composed of a DNA:RNA hybrid with a displaced non-template single-stranded DNA. Current approaches to identify and map R-loop formation across the genome employ either an antibody targeted against R-loops (S9.6) or a catalytically inactivated form of RNase H1 (dRNH1), a nuclease that can bind and resolve DNA:RNA hybrids via RNA exonuclease activity. This overview article outlines several ways to map R-loops using either methodology, explaining the differences and similarities among the approaches. Bioinformatic analysis of R-loops involves several layers of quality control and processing before visualizing the data. This article provides resources and tools that can be used to accurately process R-loop mapping data and explains the advantages and disadvantages of the resources as compared to one another. © 2024 Wiley Periodicals LLC.
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Affiliation(s)
- Pramiti Mukhopadhyay
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, Texas
| | | | - Aiola Stoja
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, Texas
| | - Alexander J R Bishop
- Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, Texas
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6
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Piguet B, Houseley J. Transcription as source of genetic heterogeneity in budding yeast. Yeast 2024; 41:171-185. [PMID: 38196235 DOI: 10.1002/yea.3926] [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: 10/07/2023] [Revised: 12/10/2023] [Accepted: 12/20/2023] [Indexed: 01/11/2024] Open
Abstract
Transcription presents challenges to genome stability both directly, by altering genome topology and exposing single-stranded DNA to chemical insults and nucleases, and indirectly by introducing obstacles to the DNA replication machinery. Such obstacles include the RNA polymerase holoenzyme itself, DNA-bound regulatory factors, G-quadruplexes and RNA-DNA hybrid structures known as R-loops. Here, we review the detrimental impacts of transcription on genome stability in budding yeast, as well as the mitigating effects of transcription-coupled nucleotide excision repair and of systems that maintain DNA replication fork processivity and integrity. Interactions between DNA replication and transcription have particular potential to induce mutation and structural variation, but we conclude that such interactions must have only minor effects on DNA replication by the replisome with little if any direct mutagenic outcome. However, transcription can significantly impair the fidelity of replication fork rescue mechanisms, particularly Break Induced Replication, which is used to restart collapsed replication forks when other means fail. This leads to de novo mutations, structural variation and extrachromosomal circular DNA formation that contribute to genetic heterogeneity, but only under particular conditions and in particular genetic contexts, ensuring that the bulk of the genome remains extremely stable despite the seemingly frequent interactions between transcription and DNA replication.
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7
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Wang D, Tang M, Zhang P, Yang K, Huang L, Wu M, Shen Q, Yue J, Wang W, Gong Y, Warner M, Dai L, He H, Yang Z, Gustafsson JA, Zhou S. Activation of ERβ hijacks the splicing machinery to trigger R-loop formation in triple-negative breast cancer. Proc Natl Acad Sci U S A 2024; 121:e2306814121. [PMID: 38513102 PMCID: PMC10990146 DOI: 10.1073/pnas.2306814121] [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: 04/26/2023] [Accepted: 01/23/2024] [Indexed: 03/23/2024] Open
Abstract
Triple-negative breast cancer (TNBC) is a subtype of breast cancer with aggressive behavior and poor prognosis. Current therapeutic options available for TNBC patients are primarily chemotherapy. With our evolving understanding of this disease, novel targeted therapies, including poly ADP-ribose polymerase (PARP) inhibitors, antibody-drug conjugates, and immune-checkpoint inhibitors, have been developed for clinical use. Previous reports have demonstrated the essential role of estrogen receptor β (ERβ) in TNBC, but the detailed molecular mechanisms downstream ERβ activation in TNBC are still far from elucidated. In this study, we demonstrated that a specific ERβ agonist, LY500307, potently induces R-loop formation and DNA damage in TNBC cells. Subsequent interactome experiments indicated that the residues 151 to 165 of U2 small nuclear RNA auxiliary factor 1 (U2AF1) and the Trp439 and Lys443 of ERβ were critical for the binding between U2AF1 and ERβ. Combined RNA sequencing and ribosome sequencing analysis demonstrated that U2AF1-regulated downstream RNA splicing of 5-oxoprolinase (OPLAH) could affect its enzymatic activity and is essential for ERβ-induced R-loop formation and DNA damage. In clinical samples including 115 patients from The Cancer Genome Atlas (TCGA) and 32 patients from an in-house cohort, we found a close correlation in the expression of ESR2 and U2AF1 in TNBC patients. Collectively, our study has unraveled the molecular mechanisms that explain the therapeutic effects of ERβ activation in TNBC, which provides rationale for ERβ activation-based single or combined therapy for patients with TNBC.
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Affiliation(s)
- Dongfang Wang
- Department of Obstetrics and Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education and State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University and Collaborative Innovation Center, Chengdu610041, People’s Republic of China
| | - Muya Tang
- Department of Obstetrics and Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education and State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University and Collaborative Innovation Center, Chengdu610041, People’s Republic of China
| | - Peidong Zhang
- Department of Obstetrics and Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education and State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University and Collaborative Innovation Center, Chengdu610041, People’s Republic of China
| | - Kailin Yang
- Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, OH44106
| | - Liang Huang
- Department of Obstetrics and Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education and State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University and Collaborative Innovation Center, Chengdu610041, People’s Republic of China
| | - Mengrui Wu
- Department of Obstetrics and Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education and State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University and Collaborative Innovation Center, Chengdu610041, People’s Republic of China
| | - Qiuhong Shen
- Department of Obstetrics and Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education and State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University and Collaborative Innovation Center, Chengdu610041, People’s Republic of China
| | - Jing Yue
- Department of Obstetrics and Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education and State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University and Collaborative Innovation Center, Chengdu610041, People’s Republic of China
| | - Wei Wang
- Department of Gynecology, Biomedical Big Data Center, Huzhou Maternity and Child Health Care Hospital, Huzhou, Zhejiang313000, People’s Republic of China
| | - Yanqiu Gong
- National Clinical Research Center for Geriatrics and General Practice Medical Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu610041, People’s Republic of China
| | - Margaret Warner
- Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, TX77204
| | - Lunzhi Dai
- National Clinical Research Center for Geriatrics and General Practice Medical Center, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu610041, People’s Republic of China
| | - Haihuai He
- Department of Neurosurgery, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu610041, People’s Republic of China
| | - Zhengnan Yang
- Department of Obstetrics and Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education and State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University and Collaborative Innovation Center, Chengdu610041, People’s Republic of China
| | - Jan-Ake Gustafsson
- Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, TX77204
- Department of Biosciences and Nutrition, Karolinska Institute, Huddinge14157, Sweden
| | - Shengtao Zhou
- Department of Obstetrics and Gynecology, Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education and State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University and Collaborative Innovation Center, Chengdu610041, People’s Republic of China
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8
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Westover KR, Jin P, Yao B. Bridging the gap: R-loop mediated genomic instability and its implications in neurological diseases. Epigenomics 2024; 16:589-608. [PMID: 38530068 PMCID: PMC11160457 DOI: 10.2217/epi-2023-0379] [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: 10/27/2023] [Accepted: 03/12/2024] [Indexed: 03/27/2024] Open
Abstract
R-loops, intricate three-stranded structures formed by RNA-DNA hybrids and an exposed non-template DNA strand, are fundamental to various biological phenomena. They carry out essential and contrasting functions within cellular mechanisms, underlining their critical role in maintaining cellular homeostasis. The specific cellular context that dictates R-loop formation determines their function, particularly emphasizing the necessity for their meticulous genomic regulation. Notably, the aberrant formation or misregulation of R-loops is implicated in numerous neurological disorders. This review focuses on the complex interactions between R-loops and double-strand DNA breaks, exploring how R-loop dysregulation potentially contributes to the pathogenesis of various brain disorders, which could provide novel insights into the molecular mechanisms underpinning neurological disease progression and identify potential therapeutic targets by highlighting these aspects.
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Affiliation(s)
- Katherine R Westover
- Department of Human Genetics, Emory University, School of Medicine, Atlanta, GA 30322, USA
| | - Peng Jin
- Department of Human Genetics, Emory University, School of Medicine, Atlanta, GA 30322, USA
| | - Bing Yao
- Department of Human Genetics, Emory University, School of Medicine, Atlanta, GA 30322, USA
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9
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Hourvitz N, Awad A, Tzfati Y. The many faces of the helicase RTEL1 at telomeres and beyond. Trends Cell Biol 2024; 34:109-121. [PMID: 37532653 DOI: 10.1016/j.tcb.2023.07.002] [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: 04/13/2023] [Revised: 07/01/2023] [Accepted: 07/05/2023] [Indexed: 08/04/2023]
Abstract
Regulator of telomere elongation 1 (RTEL1) is known as a DNA helicase that is important for telomeres and genome integrity. However, the diverse phenotypes of RTEL1 dysfunction, the wide spectrum of symptoms caused by germline RTEL1 mutations, and the association of RTEL1 mutations with cancers suggest that RTEL1 is a complex machine that interacts with DNA, RNA, and proteins, and functions in diverse cellular pathways. We summarize the proposed functions of RTEL1 and discuss their implications for telomere maintenance. Studying RTEL1 is crucial for understanding the complex interplay between telomere maintenance and other nuclear pathways, and how compromising these pathways causes telomere biology diseases, various aging-associated pathologies, and cancer.
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Affiliation(s)
- Noa Hourvitz
- Department of Genetics, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Safra Campus, Jerusalem 91904, Israel
| | - Aya Awad
- Department of Genetics, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Safra Campus, Jerusalem 91904, Israel
| | - Yehuda Tzfati
- Department of Genetics, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Safra Campus, Jerusalem 91904, Israel.
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10
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Kumar C, Remus D. Looping out of control: R-loops in transcription-replication conflict. Chromosoma 2024; 133:37-56. [PMID: 37419963 PMCID: PMC10771546 DOI: 10.1007/s00412-023-00804-8] [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: 04/18/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/09/2023]
Abstract
Transcription-replication conflict is a major cause of replication stress that arises when replication forks collide with the transcription machinery. Replication fork stalling at sites of transcription compromises chromosome replication fidelity and can induce DNA damage with potentially deleterious consequences for genome stability and organismal health. The block to DNA replication by the transcription machinery is complex and can involve stalled or elongating RNA polymerases, promoter-bound transcription factor complexes, or DNA topology constraints. In addition, studies over the past two decades have identified co-transcriptional R-loops as a major source for impairment of DNA replication forks at active genes. However, how R-loops impede DNA replication at the molecular level is incompletely understood. Current evidence suggests that RNA:DNA hybrids, DNA secondary structures, stalled RNA polymerases, and condensed chromatin states associated with R-loops contribute to the of fork progression. Moreover, since both R-loops and replication forks are intrinsically asymmetric structures, the outcome of R-loop-replisome collisions is influenced by collision orientation. Collectively, the data suggest that the impact of R-loops on DNA replication is highly dependent on their specific structural composition. Here, we will summarize our current understanding of the molecular basis for R-loop-induced replication fork progression defects.
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Affiliation(s)
- Charanya Kumar
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA
| | - Dirk Remus
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA.
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11
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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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12
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Wu Y, Song T, Xu Q. R-LOOPs on Short Tandem Repeat Expansion Disorders in Neurodegenerative Diseases. Mol Neurobiol 2023; 60:7185-7195. [PMID: 37540313 DOI: 10.1007/s12035-023-03531-4] [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: 05/16/2023] [Accepted: 07/24/2023] [Indexed: 08/05/2023]
Abstract
Expansions of short tandem repeats (STRs) have been found to be present in more than 50 diseases and have a close connection with neurodegenerative diseases. Transcriptional silencing and R-LOOP formation, RNA-mediated sequestration of RNA-binding proteins (RBPs), gain-of-function (GOF) proteins containing expanded repeats, and repeat-associated non-AUG (RAN) translation of toxic repeat peptides are some potential molecular mechanisms underlying STR expansion disorders. R-LOOP, a byproduct of transcription, is a three-stranded nucleic acid structure with abnormal accumulation that participates in the pathogenesis of STR expansion disorders by inducing DNA damage and genome instability. R-LOOPs can engender a series of DNA damage, such as DNA double-strand breaks (DSBs), single-strand breaks (SSBs), DNA recombination, or mutations in the DNA replication, transcription, or repair processes. In this review, we provide an in-depth discussion of recent advancements in R-LOOP and systematically elaborate on its genetic destabilizing effects in several neurodegenerative diseases. These molecular mechanisms will provide novel targets for drug design and therapeutic upgrading of these devastating diseases.
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Affiliation(s)
- Yiting Wu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Tingwei Song
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Qian Xu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, China.
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China.
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Ma TS, Worth KR, Maher C, Ng N, Beghè C, Gromak N, Rose AM, Hammond EM. Hypoxia-induced transcriptional stress is mediated by ROS-induced R-loops. Nucleic Acids Res 2023; 51:11584-11599. [PMID: 37843099 PMCID: PMC10681727 DOI: 10.1093/nar/gkad858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 08/21/2023] [Accepted: 09/27/2023] [Indexed: 10/17/2023] Open
Abstract
Hypoxia is a common feature of solid tumors and is associated with poor patient prognosis, therapy resistance and metastasis. Radiobiological hypoxia (<0.1% O2) is one of the few physiologically relevant stresses that activates both the replication stress/DNA damage response and the unfolded protein response. Recently, we found that hypoxia also leads to the robust accumulation of R-loops, which led us to question here both the mechanism and consequence of hypoxia-induced R-loops. Interestingly, we found that the mechanism of R-loop accumulation in hypoxia is dependent on non-DNA damaging levels of reactive oxygen species. We show that hypoxia-induced R-loops play a critical role in the transcriptional stress response, evidenced by the repression of ribosomal RNA synthesis and the translocation of nucleolin from the nucleolus into the nucleoplasm. Upon depletion of R-loops, we observed a rescue of both rRNA transcription and nucleolin translocation in hypoxia. Mechanistically, R-loops accumulate on the rDNA in hypoxia and promote the deposition of heterochromatic H3K9me2 which leads to the inhibition of Pol I-mediated transcription of rRNA. These data highlight a novel mechanistic insight into the hypoxia-induced transcriptional stress response through the ROS-R-loop-H3K9me2 axis. Overall, this study highlights the contribution of transcriptional stress to hypoxia-mediated tumorigenesis.
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Affiliation(s)
- Tiffany S Ma
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Katja R Worth
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Conor Maher
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Natalie Ng
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Chiara Beghè
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Natalia Gromak
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Anna M Rose
- Department of Pediatrics, University of Oxford, Oxford OX3 9DU, UK
| | - Ester M Hammond
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
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14
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Abstract
Transcription and replication both require large macromolecular complexes to act on a DNA template, yet these machineries cannot simultaneously act on the same DNA sequence. Conflicts between the replication and transcription machineries (transcription-replication conflicts, or TRCs) are widespread in both prokaryotes and eukaryotes and have the capacity to both cause DNA damage and compromise complete, faithful replication of the genome. This review will highlight recent studies investigating the genomic locations of TRCs and the mechanisms by which they may be prevented, mitigated, or resolved. We address work from both model organisms and mammalian systems but predominantly focus on multicellular eukaryotes owing to the additional complexities inherent in the coordination of replication and transcription in the context of cell type-specific gene expression and higher-order chromatin organization.
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Affiliation(s)
- Liana Goehring
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, USA;
| | - Tony T Huang
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, USA;
| | - Duncan J Smith
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, USA;
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15
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Banerjee D, Tateishi-Karimata H, Toplishek M, Ohyama T, Ghosh S, Takahashi S, Trajkovski M, Plavec J, Sugimoto N. In-Cell Stability Prediction of RNA/DNA Hybrid Duplexes for Designing Oligonucleotides Aimed at Therapeutics. J Am Chem Soc 2023; 145:23503-23518. [PMID: 37873979 DOI: 10.1021/jacs.3c06706] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
In cells, the formation of RNA/DNA hybrid duplexes regulates gene expression and modification. The environment inside cellular organelles is heterogeneously crowded with high concentrations of biomolecules that affect the structure and stability of RNA/DNA hybrid duplexes. However, the detailed environmental effects remain unclear. Therefore, the mechanistic details of the effect of such molecular crowding were investigated at the molecular level by using thermodynamic and nuclear magnetic resonance analyses, revealing structure-dependent destabilization of the duplexes under crowded conditions. The transition from B- to A-like hybrid duplexes due to a change in conformation of the DNA strand guided by purine-pyrimidine asymmetry significantly increased the hydration number, which resulted in greater destabilization by the addition of cosolutes. By quantifying the individual contributions of environmental factors and the bulk structure of the duplex, we developed a set of parameters that predict the stability of hybrid duplexes with conformational dissimilarities under diverse crowding conditions. A comparison of the effects of environmental conditions in living cells and in vitro crowded solutions on hybrid duplex formation using the Förster resonance energy transfer technique established the applicability of our parameters to living cells. Moreover, our derived parameters can be used to estimate the efficiency of transcriptional inhibition, genome editing, and silencing techniques in cells. This supports the usefulness of our parameters for the visualization of cellular mechanisms of gene expression and the development of nucleic acid-based therapeutics targeting different cells.
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Affiliation(s)
- Dipanwita Banerjee
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Hisae Tateishi-Karimata
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Maria Toplishek
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
| | - Tatsuya Ohyama
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Saptarshi Ghosh
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Shuntaro Takahashi
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Marko Trajkovski
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
| | - Janez Plavec
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
- EN → FIST Centre of Excellence, Trg Osvobodilne fronte 13, SI-1001 Ljubljana, Slovenia
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
- Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
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16
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Bayona-Feliu A, Herrera-Moyano E, Badra-Fajardo N, Galván-Femenía I, Soler-Oliva ME, Aguilera A. The chromatin network helps prevent cancer-associated mutagenesis at transcription-replication conflicts. Nat Commun 2023; 14:6890. [PMID: 37898641 PMCID: PMC10613258 DOI: 10.1038/s41467-023-42653-0] [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: 02/07/2023] [Accepted: 10/09/2023] [Indexed: 10/30/2023] Open
Abstract
Genome instability is a feature of cancer cells, transcription being an important source of DNA damage. This is in large part associated with R-loops, which hamper replication, especially at head-on transcription-replication conflicts (TRCs). Here we show that TRCs trigger a DNA Damage Response (DDR) involving the chromatin network to prevent genome instability. Depletion of the key chromatin factors INO80, SMARCA5 and MTA2 results in TRCs, fork stalling and R-loop-mediated DNA damage which mostly accumulates at S/G2, while histone H3 Ser10 phosphorylation, a mark of chromatin compaction, is enriched at TRCs. Strikingly, TRC regions show increased mutagenesis in cancer cells with signatures of homologous recombination deficiency, transcription-coupled nucleotide excision repair (TC-NER) and of the AID/APOBEC cytidine deaminases, being predominant at head-on collisions. Thus, our results support that the chromatin network prevents R-loops and TRCs from genomic instability and mutagenic signatures frequently associated with cancer.
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Affiliation(s)
- Aleix Bayona-Feliu
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092, Seville, Spain.
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012, Seville, Spain.
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
| | - Emilia Herrera-Moyano
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092, Seville, Spain
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012, Seville, Spain
| | - Nibal Badra-Fajardo
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092, Seville, Spain
| | - Iván Galván-Femenía
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - María Eugenia Soler-Oliva
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092, Seville, Spain
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012, Seville, Spain
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092, Seville, Spain.
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012, Seville, Spain.
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17
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Camino LP, Dutta A, Barroso S, Pérez-Calero C, Katz JN, García-Rubio M, Sung P, Gómez-González B, Aguilera A. DICER ribonuclease removes harmful R-loops. Mol Cell 2023; 83:3707-3719.e5. [PMID: 37827159 PMCID: PMC11034902 DOI: 10.1016/j.molcel.2023.09.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 07/08/2023] [Accepted: 09/19/2023] [Indexed: 10/14/2023]
Abstract
R-loops, which consist of a DNA-RNA hybrid and a displaced DNA strand, are known to threaten genome integrity. To counteract this, different mechanisms suppress R-loop accumulation by either preventing the hybridization of RNA with the DNA template (RNA biogenesis factors), unwinding the hybrid (DNA-RNA helicases), or degrading the RNA moiety of the R-loop (type H ribonucleases [RNases H]). Thus far, RNases H are the only nucleases known to cleave DNA-RNA hybrids. Now, we show that the RNase DICER also resolves R-loops. Biochemical analysis reveals that DICER acts by specifically cleaving the RNA within R-loops. Importantly, a DICER RNase mutant impaired in R-loop processing causes a strong accumulation of R-loops in cells. Our results thus not only reveal a function of DICER as an R-loop resolvase independent of DROSHA but also provide evidence for the role of multi-functional RNA processing factors in the maintenance of genome integrity in higher eukaryotes.
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Affiliation(s)
- Lola P Camino
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - Arijit Dutta
- Greehey Children's Cancer Research Institute, Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Sonia Barroso
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - Carmen Pérez-Calero
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - Jeffrey N Katz
- Greehey Children's Cancer Research Institute, Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - María García-Rubio
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - Patrick Sung
- Greehey Children's Cancer Research Institute, Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
| | - Belén Gómez-González
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain.
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, CSIC, 41092 Seville, Spain; Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain.
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18
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Li F, Zafar A, Luo L, Denning AM, Gu J, Bennett A, Yuan F, Zhang Y. R-Loops in Genome Instability and Cancer. Cancers (Basel) 2023; 15:4986. [PMID: 37894353 PMCID: PMC10605827 DOI: 10.3390/cancers15204986] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/04/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
R-loops are unique, three-stranded nucleic acid structures that primarily form when an RNA molecule displaces one DNA strand and anneals to the complementary DNA strand in a double-stranded DNA molecule. R-loop formation can occur during natural processes, such as transcription, in which the nascent RNA molecule remains hybridized with the template DNA strand, while the non-template DNA strand is displaced. However, R-loops can also arise due to many non-natural processes, including DNA damage, dysregulation of RNA degradation pathways, and defects in RNA processing. Despite their prevalence throughout the whole genome, R-loops are predominantly found in actively transcribed gene regions, enabling R-loops to serve seemingly controversial roles. On one hand, the pathological accumulation of R-loops contributes to genome instability, a hallmark of cancer development that plays a role in tumorigenesis, cancer progression, and therapeutic resistance. On the other hand, R-loops play critical roles in regulating essential processes, such as gene expression, chromatin organization, class-switch recombination, mitochondrial DNA replication, and DNA repair. In this review, we summarize discoveries related to the formation, suppression, and removal of R-loops and their influence on genome instability, DNA repair, and oncogenic events. We have also discussed therapeutical opportunities by targeting pathological R-loops.
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Affiliation(s)
- Fang Li
- Department of Biochemistry & Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Alyan Zafar
- Department of Biochemistry & Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Liang Luo
- Department of Biochemistry & Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Ariana Maria Denning
- Department of Biochemistry & Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Jun Gu
- Department of Molecular and Cellular Pharmacology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Ansley Bennett
- Department of Biochemistry & Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Fenghua Yuan
- Department of Biochemistry & Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Yanbin Zhang
- Department of Biochemistry & Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
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19
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Zukher I, Dujardin G, Sousa-Luís R, Proudfoot NJ. Elongation roadblocks mediated by dCas9 across human genes modulate transcription and nascent RNA processing. Nat Struct Mol Biol 2023; 30:1536-1548. [PMID: 37783853 PMCID: PMC10584677 DOI: 10.1038/s41594-023-01090-9] [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: 06/14/2022] [Accepted: 08/04/2023] [Indexed: 10/04/2023]
Abstract
Non-cleaving Cas9 (dCas9) is widely employed to manipulate specific gene loci, often with scant regard for unintended transcriptional effects. We demonstrate here that dCas9 mediates precise RNA polymerase II transcriptional pausing followed by transcription termination and potential alternative polyadenylation. By contrast, alternative splicing is unaffected, likely requiring more sustained alteration to elongation speed. The effect on transcription is orientation specific, with pausing only being induced when dCas9-associated guide RNA anneals to the non-template strand. Targeting the template strand induces minimal effects on transcription elongation and thus provides a neutral approach to recruit dCas9-linked effector domains to specific gene regions. In essence, we evaluate molecular effects of targeting dCas9 to mammalian transcription units. In so doing, we also provide new information on elongation by RNA polymerase II and coupled pre-mRNA processing.
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Affiliation(s)
- Inna Zukher
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
| | - Gwendal Dujardin
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Rui Sousa-Luís
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Nick J Proudfoot
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
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20
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McCann JL, Cristini A, Law EK, Lee SY, Tellier M, Carpenter MA, Beghè C, Kim JJ, Sanchez A, Jarvis MC, Stefanovska B, Temiz NA, Bergstrom EN, Salamango DJ, Brown MR, Murphy S, Alexandrov LB, Miller KM, Gromak N, Harris RS. APOBEC3B regulates R-loops and promotes transcription-associated mutagenesis in cancer. Nat Genet 2023; 55:1721-1734. [PMID: 37735199 PMCID: PMC10562255 DOI: 10.1038/s41588-023-01504-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 08/17/2023] [Indexed: 09/23/2023]
Abstract
The single-stranded DNA cytosine-to-uracil deaminase APOBEC3B is an antiviral protein implicated in cancer. However, its substrates in cells are not fully delineated. Here APOBEC3B proteomics reveal interactions with a surprising number of R-loop factors. Biochemical experiments show APOBEC3B binding to R-loops in cells and in vitro. Genetic experiments demonstrate R-loop increases in cells lacking APOBEC3B and decreases in cells overexpressing APOBEC3B. Genome-wide analyses show major changes in the overall landscape of physiological and stimulus-induced R-loops with thousands of differentially altered regions, as well as binding of APOBEC3B to many of these sites. APOBEC3 mutagenesis impacts genes overexpressed in tumors and splice factor mutant tumors preferentially, and APOBEC3-attributed kataegis are enriched in RTCW motifs consistent with APOBEC3B deamination. Taken together with the fact that APOBEC3B binds single-stranded DNA and RNA and preferentially deaminates DNA, these results support a mechanism in which APOBEC3B regulates R-loops and contributes to R-loop mutagenesis in cancer.
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Affiliation(s)
- Jennifer L McCann
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Agnese Cristini
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Emily K Law
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Seo Yun Lee
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
- Department of Life Science and Multidisciplinary Genome Institute, Hallym University, Chuncheon, Republic of Korea
| | - Michael Tellier
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Michael A Carpenter
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
- Biochemistry and Structural Biology Department, University of Texas Health San Antonio, San Antonio, TX, USA
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Chiara Beghè
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Jae Jin Kim
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
- Department of Life Science and Multidisciplinary Genome Institute, Hallym University, Chuncheon, Republic of Korea
| | - Anthony Sanchez
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Matthew C Jarvis
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Bojana Stefanovska
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
- Biochemistry and Structural Biology Department, University of Texas Health San Antonio, San Antonio, TX, USA
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Nuri A Temiz
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Institute for Health Informatics, University of Minnesota, Minneapolis, MN, USA
| | - Erik N Bergstrom
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA, USA
- Department of Bioengineering, UC San Diego, La Jolla, CA, USA
- Moores Cancer Center, UC San Diego, La Jolla, CA, USA
| | - Daniel J Salamango
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Margaret R Brown
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Shona Murphy
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Ludmil B Alexandrov
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA, USA
- Department of Bioengineering, UC San Diego, La Jolla, CA, USA
- Moores Cancer Center, UC San Diego, La Jolla, CA, USA
| | - Kyle M Miller
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA.
- Livestrong Cancer Institutes, Dell Medical School, University of Texas at Austin, Austin, TX, USA.
| | - Natalia Gromak
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
| | - Reuben S Harris
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN, USA.
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.
- Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA.
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
- Biochemistry and Structural Biology Department, University of Texas Health San Antonio, San Antonio, TX, USA.
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, TX, USA.
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21
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Yang H, Lachtara EM, Ran X, Hopkins J, Patel PS, Zhu X, Xiao Y, Phoon L, Gao B, Zou L, Lawrence MS, Lan L. The RNA m5C modification in R-loops as an off switch of Alt-NHEJ. Nat Commun 2023; 14:6114. [PMID: 37777505 PMCID: PMC10542358 DOI: 10.1038/s41467-023-41790-w] [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: 02/01/2023] [Accepted: 09/19/2023] [Indexed: 10/02/2023] Open
Abstract
The roles of R-loops and RNA modifications in homologous recombination (HR) and other DNA double-stranded break (DSB) repair pathways remain poorly understood. Here, we find that DNA damage-induced RNA methyl-5-cytosine (m5C) modification in R-loops plays a crucial role to regulate PARP1-mediated poly ADP-ribosylation (PARylation) and the choice of DSB repair pathways at sites of R-loops. Through bisulfite sequencing, we discover that the methyltransferase TRDMT1 preferentially generates m5C after DNA damage in R-loops across the genome. In the absence of m5C, R-loops activate PARP1-mediated PARylation both in vitro and in cells. Concurrently, m5C promotes transcription-coupled HR (TC-HR) while suppressing PARP1-dependent alternative non-homologous end joining (Alt-NHEJ), favoring TC-HR over Alt-NHEJ in transcribed regions as the preferred repair pathway. Importantly, simultaneous disruption of both TC-HR and Alt-NHEJ with TRDMT1 and PARP or Polymerase θ inhibitors prevents alternative DSB repair and exhibits synergistic cytotoxic effects on cancer cells, suggesting an effective strategy to exploit genomic instability in cancer therapy.
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Affiliation(s)
- Haibo Yang
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Emily M Lachtara
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Xiaojuan Ran
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Jessica Hopkins
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Parasvi S Patel
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Xueping Zhu
- Center for Immunology and Inflammatory Diseases, Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Yao Xiao
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Laiyee Phoon
- Departments of Molecular Genetics and Microbiology, School of Medicine, Duke University, Durham, NC, USA
| | - Boya Gao
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Lee Zou
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Michael S Lawrence
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Li Lan
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA.
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
- Departments of Molecular Genetics and Microbiology, School of Medicine, Duke University, Durham, NC, USA.
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22
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Suzuki M, Sakai S, Ota K, Bando Y, Uchida C, Niida H, Kitagawa M, Ohhata T. CCIVR2 facilitates comprehensive identification of both overlapping and non-overlapping antisense transcripts within specified regions. Sci Rep 2023; 13:14807. [PMID: 37684517 PMCID: PMC10491648 DOI: 10.1038/s41598-023-42044-x] [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: 04/13/2023] [Accepted: 09/04/2023] [Indexed: 09/10/2023] Open
Abstract
Pairs of sense and antisense transcriptions that are adjacent at their 5' and 3' regions are called divergent and convergent transcription, respectively. However, the structural properties of divergent/convergent transcription in different species or RNA biotypes are poorly characterized. Here, we developed CCIVR2, a program that facilitates identification of both overlapping and non-overlapping antisense transcripts produced from divergent/convergent transcription whose transcription start sites (TSS) or transcript end sites (TES) are located within a specified region. We used CCIVR2 to analyze antisense transcripts starting around the sense TSS (from divergent transcription) or ending around the sense TES (from convergent transcription) in 11 different species and found species- and RNA biotype-specific features of divergent/convergent transcription. Furthermore, we confirmed that CCIVR2 enables the identification of multiple sense/antisense transcript pairs from divergent transcription, including those with known functions in processes such as embryonic stem cell differentiation and TGFβ stimulation. CCIVR2 is therefore a valuable bioinformatics tool that facilitates the characterization of divergent/convergent transcription in different species and aids the identification of functional sense/antisense transcript pairs from divergent transcription in specified biological processes.
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Affiliation(s)
- Maya Suzuki
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, 431-3192, Japan
| | - Satoshi Sakai
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, 431-3192, Japan
| | - Kosuke Ota
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, 431-3192, Japan
| | - Yuki Bando
- Department of Organ and Tissue Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, 431-3192, Japan
| | - Chiharu Uchida
- Advanced Research Facilities and Services, Preeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, 431-3192, Japan
| | - Hiroyuki Niida
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, 431-3192, Japan
| | - Masatoshi Kitagawa
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, 431-3192, Japan
| | - Tatsuya Ohhata
- Department of Molecular Biology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, 431-3192, Japan.
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23
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Zhou J, Lei X, Shafiq S, Zhang W, Li Q, Li K, Zhu J, Dong Z, He XJ, Sun Q. DDM1-mediated R-loop resolution and H2A.Z exclusion facilitates heterochromatin formation in Arabidopsis. SCIENCE ADVANCES 2023; 9:eadg2699. [PMID: 37566662 PMCID: PMC10421056 DOI: 10.1126/sciadv.adg2699] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 07/13/2023] [Indexed: 08/13/2023]
Abstract
Programmed constitutive heterochromatin silencing is essential for eukaryotic genome regulation, yet the initial step of this process is ambiguous. A large proportion of R-loops (RNA:DNA hybrids) had been unexpectedly identified within Arabidopsis pericentromeric heterochromatin with unknown functions. Through a genome-wide R-loop profiling screen, we find that DDM1 (decrease in DNA methylation 1) is the primary restrictor of pericentromeric R-loops via its RNA:DNA helicase activity. Low levels of pericentromeric R-loops resolved by DDM1 cotranscriptionally can facilitate constitutive heterochromatin silencing. Furthermore, we demonstrate that DDM1 physically excludes histone H2A variant H2A.Z and promotes H2A.W deposition for faithful heterochromatin initiation soon after R-loop clearance. The dual functions of DDM1 in R-loop resolution and H2A.Z eviction are essential for sperm nuclei structure maintenance in mature pollen. Our work unravels the cotranscriptional R-loop resolution coupled with accurate H2A variants deposition is the primary step of constitutive heterochromatin silencing in Arabidopsis, which might be conserved across eukaryotes.
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Affiliation(s)
- Jincong Zhou
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Xue Lei
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Sarfraz Shafiq
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Weifeng Zhang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Qin Li
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Kuan Li
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Jiafu Zhu
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Zhicheng Dong
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Xin-jian He
- National Institute of Biological Sciences, Beijing, China
| | - Qianwen Sun
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
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24
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Li L, Wu Y, Dai K, Wang Q, Ye S, Shi Q, Chen Z, Huang YC, Zhao W, Li L. The CHCHD2/Sirt1 corepressors involve in G9a-mediated regulation of RNase H1 expression to control R-loop. CELL INSIGHT 2023; 2:100112. [PMID: 37388553 PMCID: PMC10300302 DOI: 10.1016/j.cellin.2023.100112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/25/2023] [Accepted: 05/28/2023] [Indexed: 07/01/2023]
Abstract
R-loops are regulators of many cellular processes and are threats to genome integrity. Therefore, understanding the mechanisms underlying the regulation of R-loops is important. Inspired by the findings on RNase H1-mediated R-loop degradation or accumulation, we focused our interest on the regulation of RNase H1 expression. In the present study, we report that G9a positively regulates RNase H1 expression to boost R-loop degradation. CHCHD2 acts as a repressive transcription factor that inhibits the expression of RNase H1 to promote R-loop accumulation. Sirt1 interacts with CHCHD2 and deacetylates it, which functions as a corepressor that suppresses the expression of downstream target gene RNase H1. We also found that G9a methylated the promoter of RNase H1, inhibiting the binding of CHCHD2 and Sirt1. In contrast, when G9a was knocked down, recruitment of CHCHD2 and Sirt1 to the RNase H1 promoter increased, which co-inhibited RNase H1 transcription. Furthermore, knockdown of Sirt1 led to binding of G9a to the RNase H1 promoter. In summary, we demonstrated that G9a regulates RNase H1 expression to maintain the steady-state balance of R-loops by suppressing the recruitment of CHCHD2/Sirt1 corepressors to the target gene promoter.
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25
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Conn VM, Gabryelska M, Toubia J, Kirk K, Gantley L, Powell JA, Cildir G, Marri S, Liu R, Stringer BW, Townley S, Webb ST, Lin H, Samaraweera SE, Bailey S, Moore AS, Maybury M, Liu D, Colella AD, Chataway T, Wallington-Gates CT, Walters L, Sibbons J, Selth LA, Tergaonkar V, D'Andrea RJ, Pitson SM, Goodall GJ, Conn SJ. Circular RNAs drive oncogenic chromosomal translocations within the MLL recombinome in leukemia. Cancer Cell 2023; 41:1309-1326.e10. [PMID: 37295428 DOI: 10.1016/j.ccell.2023.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/03/2023] [Accepted: 05/03/2023] [Indexed: 06/12/2023]
Abstract
The first step of oncogenesis is the acquisition of a repertoire of genetic mutations to initiate and sustain the malignancy. An important example of this initiation phase in acute leukemias is the formation of a potent oncogene by chromosomal translocations between the mixed lineage leukemia (MLL) gene and one of 100 translocation partners, known as the MLL recombinome. Here, we show that circular RNAs (circRNAs)-a family of covalently closed, alternatively spliced RNA molecules-are enriched within the MLL recombinome and can bind DNA, forming circRNA:DNA hybrids (circR loops) at their cognate loci. These circR loops promote transcriptional pausing, proteasome inhibition, chromatin re-organization, and DNA breakage. Importantly, overexpressing circRNAs in mouse leukemia xenograft models results in co-localization of genomic loci, de novo generation of clinically relevant chromosomal translocations mimicking the MLL recombinome, and hastening of disease onset. Our findings provide fundamental insight into the acquisition of chromosomal translocations by endogenous RNA carcinogens in leukemia.
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Affiliation(s)
- Vanessa M Conn
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia; Centre for Cancer Biology, SA Pathology & University of South Australia, Adelaide, SA 5000, Australia
| | - Marta Gabryelska
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - John Toubia
- Centre for Cancer Biology, SA Pathology & University of South Australia, Adelaide, SA 5000, Australia; ACRF Cancer Genomics Facility, SA Pathology, Adelaide, SA 5000, Australia
| | - Kirsty Kirk
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Laura Gantley
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Jason A Powell
- Centre for Cancer Biology, SA Pathology & University of South Australia, Adelaide, SA 5000, Australia; Adelaide Medical School, Faculty of Health and Medical Sciences, the University of Adelaide, Adelaide, SA 5000, Australia
| | - Gökhan Cildir
- Centre for Cancer Biology, SA Pathology & University of South Australia, Adelaide, SA 5000, Australia
| | - Shashikanth Marri
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Ryan Liu
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Brett W Stringer
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Scott Townley
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Stuart T Webb
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - He Lin
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Saumya E Samaraweera
- Centre for Cancer Biology, SA Pathology & University of South Australia, Adelaide, SA 5000, Australia
| | - Sheree Bailey
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA 5000, Australia
| | - Andrew S Moore
- Child Health Research Centre, the University of Queensland, Brisbane, QLD 4101, Australia; Oncology Service, Children's Health Queensland Hospital and Health Service, Brisbane, QLD 4101, Australia
| | - Mellissa Maybury
- Child Health Research Centre, the University of Queensland, Brisbane, QLD 4101, Australia
| | - Dawei Liu
- Centre for Cancer Biology, SA Pathology & University of South Australia, Adelaide, SA 5000, Australia
| | - Alex D Colella
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia; Flinders Omics Facility, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Timothy Chataway
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia; Flinders Omics Facility, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Craig T Wallington-Gates
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia; Centre for Cancer Biology, SA Pathology & University of South Australia, Adelaide, SA 5000, Australia; Adelaide Medical School, Faculty of Health and Medical Sciences, the University of Adelaide, Adelaide, SA 5000, Australia; Flinders Medical Centre, Bedford Park, SA 5042, Australia
| | - Lucie Walters
- Adelaide Rural Clinical School, Faculty of Health and Medical Sciences, the University of Adelaide, Adelaide, SA 5000, Australia
| | - Jane Sibbons
- Adelaide Microscopy, Division of Research and Innovation, University of Adelaide, Adelaide, SA 5000, Australia
| | - Luke A Selth
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia; Freemasons Centre for Male Health and Wellbeing, Flinders University, Bedford Park, SA 5042, Australia
| | - Vinay Tergaonkar
- Laboratory of NFκB Signalling, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A(∗)STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Republic of Singapore
| | - Richard J D'Andrea
- Centre for Cancer Biology, SA Pathology & University of South Australia, Adelaide, SA 5000, Australia
| | - Stuart M Pitson
- Centre for Cancer Biology, SA Pathology & University of South Australia, Adelaide, SA 5000, Australia; Adelaide Medical School, Faculty of Health and Medical Sciences, the University of Adelaide, Adelaide, SA 5000, Australia
| | - Gregory J Goodall
- Centre for Cancer Biology, SA Pathology & University of South Australia, Adelaide, SA 5000, Australia; Adelaide Medical School, Faculty of Health and Medical Sciences, the University of Adelaide, Adelaide, SA 5000, Australia
| | - Simon J Conn
- Flinders Health and Medical Research Institute, College of Medicine & Public Health, Flinders University, Bedford Park, SA 5042, Australia; Centre for Cancer Biology, SA Pathology & University of South Australia, Adelaide, SA 5000, Australia.
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26
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Gatti V, De Domenico S, Melino G, Peschiaroli A. Senataxin and R-loops homeostasis: multifaced implications in carcinogenesis. Cell Death Discov 2023; 9:145. [PMID: 37147318 PMCID: PMC10163015 DOI: 10.1038/s41420-023-01441-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/06/2023] [Accepted: 04/20/2023] [Indexed: 05/07/2023] Open
Abstract
R-loops are inherent byproducts of transcription consisting of an RNA:DNA hybrid and a displaced single-stranded DNA. These structures are of key importance in controlling numerous physiological processes and their homeostasis is tightly controlled by the activities of several enzymes deputed to process R-loops and prevent their unproper accumulation. Senataxin (SETX) is an RNA/DNA helicase which catalyzes the unwinding of RNA:DNA hybrid portion of the R-loops, promoting thus their resolution. The key importance of SETX in R-loops homeostasis and its relevance with pathophysiological events is highlighted by the evidence that gain or loss of function SETX mutations underlie the pathogenesis of two distinct neurological disorders. Here, we aim to describe the potential impact of SETX on tumor onset and progression, trying to emphasize how dysregulation of this enzyme observed in human tumors might impact tumorigenesis. To this aim, we will describe the functional relevance of SETX in regulating gene expression, genome integrity, and inflammation response and discuss how cancer-associated SETX mutations might affect these pathways, contributing thus to tumor development.
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Affiliation(s)
- Veronica Gatti
- National Research Council of Italy, Institute of Translational Pharmacology, Rome, Italy
| | - Sara De Domenico
- Department of Experimental Medicine, TOR, University of Rome Tor Vergata, Rome, Italy
| | - Gerry Melino
- Department of Experimental Medicine, TOR, University of Rome Tor Vergata, Rome, Italy
| | - Angelo Peschiaroli
- National Research Council of Italy, Institute of Translational Pharmacology, Rome, Italy.
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27
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Gong D, Wang L, Zhou H, Gao J, Zhang W, Zheng P. Long noncoding RNA Lnc530 localizes on R-loops and regulates R-loop formation and genomic stability in mouse embryonic stem cells. Stem Cell Reports 2023; 18:952-968. [PMID: 36931280 PMCID: PMC10147553 DOI: 10.1016/j.stemcr.2023.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 02/13/2023] [Accepted: 02/13/2023] [Indexed: 03/18/2023] Open
Abstract
Embryonic stem cells (ESCs) are superior to differentiated cells to maintain genome stability, but the underlying mechanisms remain largely elusive. R-loops are constantly formed during transcription and are inducers of DNA damage if not resolved. Here we report that mouse ESCs (mESCs) can efficiently prevent unscheduled R-loop formation, and a long noncoding RNA Lnc530 plays regulatory role. Lnc530 is expressed in mESCs and localizes on R-loops. Depletion of Lnc530 in mESCs causes R-loop accumulation and DNA damage, whereas forced expression of Lnc530 in differentiated cells suppresses the R-loop formation. Mechanistically, Lnc530 associates with DDX5 and TDP-43 in an inter-dependent manner on R-loops. Formation of Lnc530-DDX5-TDP-43 complex substantially increases the local protein levels of DDX5 and TDP-43, both of which play critical roles in R-loop regulation. This study uncovers an efficient strategy to prevent R-loop accumulation and preserve genomic stability in mESCs and possibly other stem cell types.
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Affiliation(s)
- Daohua Gong
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650203, China; University of Chinese Academy of Sciences, Beijing 101408, China; Key Laboratory of Animal Models and Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650203, China
| | - Lin Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650203, China; Key Laboratory of Animal Models and Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650203, China
| | - Hu Zhou
- Department of Analytical Chemistry and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Jing Gao
- Department of Analytical Chemistry and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Weidao Zhang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650203, China; Key Laboratory of Animal Models and Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650203, China
| | - Ping Zheng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650203, China; KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650203, China; Key Laboratory of Animal Models and Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650203, China.
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28
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Porter H, Li Y, Neguembor MV, Beltran M, Varsally W, Martin L, Cornejo MT, Pezić D, Bhamra A, Surinova S, Jenner RG, Cosma MP, Hadjur S. Cohesin-independent STAG proteins interact with RNA and R-loops and promote complex loading. eLife 2023; 12:e79386. [PMID: 37010886 PMCID: PMC10238091 DOI: 10.7554/elife.79386] [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: 04/10/2022] [Accepted: 04/02/2023] [Indexed: 04/04/2023] Open
Abstract
Most studies of cohesin function consider the Stromalin Antigen (STAG/SA) proteins as core complex members given their ubiquitous interaction with the cohesin ring. Here, we provide functional data to support the notion that the SA subunit is not a mere passenger in this structure, but instead plays a key role in the localization of cohesin to diverse biological processes and promotes loading of the complex at these sites. We show that in cells acutely depleted for RAD21, SA proteins remain bound to chromatin, cluster in 3D and interact with CTCF, as well as with a wide range of RNA binding proteins involved in multiple RNA processing mechanisms. Accordingly, SA proteins interact with RNA, and R-loops, even in the absence of cohesin. Our results place SA1 on chromatin upstream of the cohesin ring and reveal a role for SA1 in cohesin loading which is independent of NIPBL, the canonical cohesin loader. We propose that SA1 takes advantage of structural R-loop platforms to link cohesin loading and chromatin structure with diverse functions. Since SA proteins are pan-cancer targets, and R-loops play an increasingly prevalent role in cancer biology, our results have important implications for the mechanistic understanding of SA proteins in cancer and disease.
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Affiliation(s)
- Hayley Porter
- Research Department of Cancer Biology, Cancer Institute, University College LondonLondonUnited Kingdom
| | - Yang Li
- Research Department of Cancer Biology, Cancer Institute, University College LondonLondonUnited Kingdom
| | - Maria Victoria Neguembor
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Manuel Beltran
- Regulatory Genomics Group, Cancer Institute, University College LondonLondonUnited Kingdom
| | - Wazeer Varsally
- Research Department of Cancer Biology, Cancer Institute, University College LondonLondonUnited Kingdom
| | - Laura Martin
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Manuel Tavares Cornejo
- Regulatory Genomics Group, Cancer Institute, University College LondonLondonUnited Kingdom
| | - Dubravka Pezić
- Research Department of Cancer Biology, Cancer Institute, University College LondonLondonUnited Kingdom
| | - Amandeep Bhamra
- Proteomics Research Translational Technology Platform, Cancer Institute, University College LondonLondonUnited Kingdom
| | - Silvia Surinova
- Proteomics Research Translational Technology Platform, Cancer Institute, University College LondonLondonUnited Kingdom
| | - Richard G Jenner
- Regulatory Genomics Group, Cancer Institute, University College LondonLondonUnited Kingdom
| | - Maria Pia Cosma
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
- Institució Catalana de Recerca i Estudis Avançats (ICREA)BarcelonaSpain
| | - Suzana Hadjur
- Research Department of Cancer Biology, Cancer Institute, University College LondonLondonUnited Kingdom
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29
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Marchena-Cruz E, Camino LP, Bhandari J, Silva S, Marqueta-Gracia JJ, Amdeen SA, Guillén-Mendoza C, García-Rubio ML, Calderón-Montaño JM, Xue X, Luna R, Aguilera A. DDX47, MeCP2, and other functionally heterogeneous factors protect cells from harmful R loops. Cell Rep 2023; 42:112148. [PMID: 36827184 PMCID: PMC10066596 DOI: 10.1016/j.celrep.2023.112148] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 12/20/2022] [Accepted: 02/06/2023] [Indexed: 02/25/2023] Open
Abstract
Unscheduled R loops can be a source of genome instability, a hallmark of cancer cells. Although targeted proteomic approaches and cellular analysis of specific mutants have uncovered factors potentially involved in R-loop homeostasis, we report a more open screening of factors whose depletion causes R loops based on the ability of activation-induced cytidine deaminase (AID) to target R loops. Immunofluorescence analysis of γH2AX caused by small interfering RNAs (siRNAs) covering 3,205 protein-coding genes identifies 59 potential candidates, from which 13 are analyzed further and show a significant increase of R loops. Such candidates are enriched in factors involved in chromatin, transcription, and RNA biogenesis and other processes. A more focused study shows that the DDX47 helicase is an R-loop resolvase, whereas the MeCP2 methyl-CpG-binding protein uncovers a link between DNA methylation and R loops. Thus, our results suggest that a plethora of gene dysfunctions can alter cell physiology via affecting R-loop homeostasis by different mechanisms.
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Affiliation(s)
- Esther Marchena-Cruz
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
| | - Lola P Camino
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
| | - Jay Bhandari
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Sónia Silva
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
| | - José Javier Marqueta-Gracia
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain; Departmento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - Shahad A Amdeen
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Cristina Guillén-Mendoza
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain; Departmento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - María L García-Rubio
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain; Departmento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
| | - José M Calderón-Montaño
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain
| | - Xiaoyu Xue
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Rosa Luna
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain; Departmento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain.
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092 Seville, Spain; Departmento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain.
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30
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Kumar C, Remus D. A transcription-based approach to purify R-loop-containing plasmid DNA templates in vitro. STAR Protoc 2023; 4:101937. [PMID: 36520635 PMCID: PMC9758483 DOI: 10.1016/j.xpro.2022.101937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/14/2022] [Accepted: 11/22/2022] [Indexed: 12/15/2022] Open
Abstract
To study the direct effects of R-loops on DNA replication and other DNA-templated processes in vitro, R-loop-containing DNA templates need to be prepared efficiently and to near homogeneity. Here, we describe a simple transcription-based approach to form R-loops on plasmid DNA templates in vitro. We detail steps to transcribe a DNA sequence element with a high propensity to form co-transcriptional R-loops using T7 RNA polymerase. We describe nucleolytic digestion of free RNA, deproteinization, and repurification of R-loop-containing templates via gel filtration. For complete details on the use and execution of this protocol, please refer to Kumar et al.1.
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Affiliation(s)
- Charanya Kumar
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065, USA
| | - Dirk Remus
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065, USA.
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31
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Yeo SJ, Ying C, Fullwood MJ, Tergaonkar V. Emerging regulatory mechanisms of noncoding RNAs in topologically associating domains. Trends Genet 2023; 39:217-232. [PMID: 36642680 DOI: 10.1016/j.tig.2022.12.003] [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: 08/15/2022] [Revised: 12/17/2022] [Accepted: 12/20/2022] [Indexed: 01/15/2023]
Abstract
Topologically associating domains (TADs) are integral to spatial genome organization, instructing gene expression, and cell fate. Recently, several advances have uncovered roles for noncoding RNAs (ncRNAs) in the regulation of the form and function of mammalian TADs. Phase separation has also emerged as a potential arbiter of ncRNAs in the regulation of TADs. In this review we discuss the implications of these novel findings in relation to how ncRNAs might structurally and functionally regulate TADs from two perspectives: moderating loop extrusion through interactions with architectural proteins, and facilitating TAD phase separation. Additionally, we propose future studies and directions to investigate these phenomena.
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Affiliation(s)
- Samuel Jianjie Yeo
- Laboratory of NFκB Signaling, Institute of Molecular Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University (NTU), Singapore 308232, Singapore
| | - Chen Ying
- Laboratory of NFκB Signaling, Institute of Molecular Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore
| | - Melissa Jane Fullwood
- Cancer Science Institute of Singapore, Centre for Translational Medicine, National University of Singapore, Singapore 117599, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore.
| | - Vinay Tergaonkar
- Laboratory of NFκB Signaling, Institute of Molecular Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore; Department of Pathology and the Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore 117597, Singapore.
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32
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Ma S, Yang Q, Chen N, Zheng A, Abbasi N, Wang G, Patel PR, Cho BS, Yee BA, Zhang L, Chu H, Evans SM, Yeo GW, Zheng Y, Huang WJM. RNA binding protein DDX5 restricts RORγt + T reg suppressor function to promote intestine inflammation. SCIENCE ADVANCES 2023; 9:eadd6165. [PMID: 36724232 PMCID: PMC9891705 DOI: 10.1126/sciadv.add6165] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 01/05/2023] [Indexed: 06/18/2023]
Abstract
Retinoid-related orphan receptor (RAR) gamma (RORγt)-expressing regulatory T cells (RORγt+ Tregs) play pivotal roles in preventing T cell hyperactivation and maintaining tissue homeostasis, in part by secreting the anti-inflammation cytokine interleukin-10 (IL-10). Here, we report that hypoxia-induced factor 1α (HIF1α) is the master transcription factor for Il10 in RORγt+ Tregs. This critical anti-inflammatory pathway is negatively regulated by an RNA binding protein DEAD box helicase 5 (DDX5). As a transcriptional corepressor, DDX5 restricts the expression of HIF1α and its downstream target gene Il10 in RORγt+ Tregs. T cell-specific Ddx5 knockout (DDX5ΔT) mice have augmented RORγt+ Treg suppressor activities and are better protected from intestinal inflammation. Genetic ablation or pharmacologic inhibition of HIF1α restores enteropathy susceptibility in DDX5ΔT mice. The DDX5-HIF1α-IL-10 pathway is conserved in mice and humans. These findings reveal potential therapeutic targets for intestinal inflammatory diseases.
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Affiliation(s)
- Shengyun Ma
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Qiyuan Yang
- NOMIS Center for Immunobiology and Microbial Pathogenesis, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Nicholas Chen
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Anna Zheng
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Nazia Abbasi
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Gaowei Wang
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Parth R. Patel
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Benjamin S. Cho
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Brian A. Yee
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Lunfeng Zhang
- Department of Pediatrics, Pediatric Diabetes Research Center, University of California San Diego, La Jolla, CA, USA
| | - Hiutung Chu
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
- Chiba University–UC San Diego Center for Mucosal Immunology, Allergy, and Vaccines (cMAV), University of California San Diego, La Jolla, CA, USA
| | - Sylvia M. Evans
- Department of Pediatrics, Pediatric Diabetes Research Center, University of California San Diego, La Jolla, CA, USA
- Department of Pharmacology, University of California San Diego, La Jolla, CA, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Gene W. Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Ye Zheng
- NOMIS Center for Immunobiology and Microbial Pathogenesis, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Wendy Jia Men Huang
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
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Wu T, Lyu R, He C. spKAS-seq reveals R-loop dynamics using low-input materials by detecting single-stranded DNA with strand specificity. SCIENCE ADVANCES 2022; 8:eabq2166. [PMID: 36449625 PMCID: PMC9710868 DOI: 10.1126/sciadv.abq2166] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 10/13/2022] [Indexed: 05/26/2023]
Abstract
R-loops affect transcription and genome stability. Dysregulation of R-loops is related to human diseases. Genome-wide R-loop mapping typically uses the S9.6 antibody or inactive ribonuclease H, both requiring a large number of cells with varying results observed depending on the approach applied. Here, we present strand-specific kethoxal-assisted single-stranded DNA (ssDNA) sequencing (spKAS-seq) to map R-loops by taking advantage of the presence of a ssDNA in the triplex structure. We show that spKAS-seq detects R-loops and their dynamics at coding sequences, enhancers, and other intergenic regions with as few as 50,000 cells. A joint analysis of R-loops and chromatin-bound RNA binding proteins (RBPs) suggested that R-loops can be RBP binding hotspots on the chromatin.
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Affiliation(s)
- Tong Wu
- Department of Chemistry, University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, University of Chicago, Chicago, IL, USA
| | - Ruitu Lyu
- Department of Chemistry, University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, University of Chicago, Chicago, IL, USA
| | - Chuan He
- Department of Chemistry, University of Chicago, Chicago, IL, USA
- Howard Hughes Medical Institute, University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
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Zhou J, Zhang W, Sun Q. R-loop: The new genome regulatory element in plants. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:2275-2289. [PMID: 36223078 DOI: 10.1111/jipb.13383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
An R-loop is a three-stranded chromatin structure that consists of a displaced single strand of DNA and an RNA:DNA hybrid duplex, which was thought to be a rare by-product of transcription. However, recent genome-wide data have shown that R-loops are widespread and pervasive in a variety of genomes, and a growing body of experimental evidence indicates that R-loops have both beneficial and harmful effects on an organism. To maximize benefit and avoid harm, organisms have evolved several means by which they tightly regulate R-loop levels. Here, we summarize our current understanding of the biogenesis and effects of R-loops, the mechanisms that regulate them, and methods of R-loop profiling, reviewing recent research advances on R-loops in plants. Furthermore, we provide perspectives on future research directions for R-loop biology in plants, which might lead to a more comprehensive understanding of R-loop functions in plant genome regulation and contribute to future agricultural improvements.
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Affiliation(s)
- Jincong Zhou
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Weifeng Zhang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Qianwen Sun
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
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35
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Khan ES, Danckwardt S. Pathophysiological Role and Diagnostic Potential of R-Loops in Cancer and Beyond. Genes (Basel) 2022; 13:genes13122181. [PMID: 36553448 PMCID: PMC9777984 DOI: 10.3390/genes13122181] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/07/2022] [Accepted: 11/14/2022] [Indexed: 11/24/2022] Open
Abstract
R-loops are DNA-RNA hybrids that play multifunctional roles in gene regulation, including replication, transcription, transcription-replication collision, epigenetics, and preserving the integrity of the genome. The aberrant formation and accumulation of unscheduled R-loops can disrupt gene expression and damage DNA, thereby causing genome instability. Recent links between unscheduled R-loop accumulation and the abundance of proteins that modulate R-loop biogenesis have been associated with numerous human diseases, including various cancers. Although R-loops are not necessarily causative for all disease entities described to date, they can perpetuate and even exacerbate the initially disease-eliciting pathophysiology, making them structures of interest for molecular diagnostics. In this review, we discuss the (patho) physiological role of R-loops in health and disease, their surprising diagnostic potential, and state-of-the-art techniques for their detection.
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Affiliation(s)
- Essak S. Khan
- Posttranscriptional Gene Regulation, Cancer Research and Experimental Hemostasis, University Medical Center Mainz, 55131 Mainz, Germany
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany
- German Consortium for Translational Cancer Research (DKTK), DKFZ Frankfurt-Mainz, 60590 Frankfurt am Main, Germany
| | - Sven Danckwardt
- Posttranscriptional Gene Regulation, Cancer Research and Experimental Hemostasis, University Medical Center Mainz, 55131 Mainz, Germany
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany
- German Center for Cardiovascular Research (DZHK), Rhine-Main, 55131 Mainz, Germany
- Correspondence:
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36
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Kaminski N, Wondisford AR, Kwon Y, Lynskey ML, Bhargava R, Barroso-González J, García-Expósito L, He B, Xu M, Mellacheruvu D, Watkins SC, Modesti M, Miller KM, Nesvizhskii AI, Zhang H, Sung P, O'Sullivan RJ. RAD51AP1 regulates ALT-HDR through chromatin-directed homeostasis of TERRA. Mol Cell 2022; 82:4001-4017.e7. [PMID: 36265488 PMCID: PMC9713952 DOI: 10.1016/j.molcel.2022.09.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 08/10/2022] [Accepted: 09/23/2022] [Indexed: 11/05/2022]
Abstract
Alternative lengthening of telomeres (ALT) is a homology-directed repair (HDR) mechanism of telomere elongation that controls proliferation in subsets of aggressive cancer. Recent studies have revealed that telomere repeat-containing RNA (TERRA) promotes ALT-associated HDR (ALT-HDR). Here, we report that RAD51AP1, a crucial ALT factor, interacts with TERRA and utilizes it to generate D- and R-loop HR intermediates. We also show that RAD51AP1 binds to and might stabilize TERRA-containing R-loops as RAD51AP1 depletion reduces R-loop formation at telomere DNA breaks. Proteomic analyses uncover a role for RAD51AP1-mediated TERRA R-loop homeostasis in a mechanism of chromatin-directed suppression of TERRA and prevention of transcription-replication collisions (TRCs) during ALT-HDR. Intriguingly, we find that both TERRA binding and this non-canonical function of RAD51AP1 require its intrinsic SUMO-SIM regulatory axis. These findings provide insights into the multi-contextual functions of RAD51AP1 within the ALT mechanism and regulation of TERRA.
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Affiliation(s)
- Nicole Kaminski
- Department of Pharmacology and Chemical Biology, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Anne R Wondisford
- Department of Pharmacology and Chemical Biology, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Youngho Kwon
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Michelle Lee Lynskey
- Department of Pharmacology and Chemical Biology, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ragini Bhargava
- Department of Pharmacology and Chemical Biology, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jonathan Barroso-González
- Department of Pharmacology and Chemical Biology, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Laura García-Expósito
- Department of Pharmacology and Chemical Biology, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Boxue He
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA; Department of Thoracic Surgery, Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Meng Xu
- Department of Biological Sciences, Mellon College of Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Dattatreya Mellacheruvu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Simon C Watkins
- Department of Cell Biology, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mauro Modesti
- Cancer Research Center of Marseille, CNRS UMR7258, Inserm UMR1068, Aix Marseille Université U105, Institut Paoli Calmettes, 27 Boulevard Lei Roure CS30059, 13273 Marseille Cedex 09, France
| | - Kyle M Miller
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, 2506 Speedway, Austin, TX 78712, USA
| | - Alexey I Nesvizhskii
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Huaiying Zhang
- Department of Biological Sciences, Mellon College of Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Roderick J O'Sullivan
- Department of Pharmacology and Chemical Biology, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, USA.
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37
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Khosraviani N, Abraham KJ, Chan JN, Mekhail K. Protocol to use RNaseH1-based CRISPR to modulate locus-associated R-loops. STAR Protoc 2022; 3:101734. [PMID: 36178790 PMCID: PMC9525952 DOI: 10.1016/j.xpro.2022.101734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/11/2022] [Accepted: 09/02/2022] [Indexed: 01/26/2023] Open
Abstract
Modulating R-loop triplex nucleic acid structures reveals their roles across the genome. However, common approaches cannot ascribe functions to R-loops in a locus-associated manner. This protocol presents the use of a locus-associated R-loop-modulating system (dubbed LasR), which employs an inducible RNaseH1-EGFP-dCas9 chimaera. We detail the in silico design of sgRNAs and their transfection with the chimaera, and outline steps confirming RNaseH1-EGFP-dCas9 expression, localization, locus-targeted association, and R-loop modulation in cis or trans using immunoblotting, microscopy, and chromatin and DNA-RNA immunoprecipitation. For complete details on the use and execution of this protocol, please refer to Abraham et al. (2020).
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Affiliation(s)
- Negin Khosraviani
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, 661 University Avenue, Toronto, ON, Canada
| | - Karan J. Abraham
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, 661 University Avenue, Toronto, ON, Canada
| | - Janet N.Y. Chan
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, 661 University Avenue, Toronto, ON, Canada,Corresponding author
| | - Karim Mekhail
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, 661 University Avenue, Toronto, ON, Canada,Canada Research Chairs Program, Faculty of Medicine, University of Toronto, 1 King’s College Circle, Toronto, ON, Canada,Corresponding author
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38
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Petermann E, Lan L, Zou L. Sources, resolution and physiological relevance of R-loops and RNA-DNA hybrids. Nat Rev Mol Cell Biol 2022; 23:521-540. [PMID: 35459910 DOI: 10.1038/s41580-022-00474-x] [Citation(s) in RCA: 102] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2022] [Indexed: 12/12/2022]
Abstract
RNA-DNA hybrids are generated during transcription, DNA replication and DNA repair and are crucial intermediates in these processes. When RNA-DNA hybrids are stably formed in double-stranded DNA, they displace one of the DNA strands and give rise to a three-stranded structure called an R-loop. R-loops are widespread in the genome and are enriched at active genes. R-loops have important roles in regulating gene expression and chromatin structure, but they also pose a threat to genomic stability, especially during DNA replication. To keep the genome stable, cells have evolved a slew of mechanisms to prevent aberrant R-loop accumulation. Although R-loops can cause DNA damage, they are also induced by DNA damage and act as key intermediates in DNA repair such as in transcription-coupled repair and RNA-templated DNA break repair. When the regulation of R-loops goes awry, pathological R-loops accumulate, which contributes to diseases such as neurodegeneration and cancer. In this Review, we discuss the current understanding of the sources of R-loops and RNA-DNA hybrids, mechanisms that suppress and resolve these structures, the impact of these structures on DNA repair and genome stability, and opportunities to therapeutically target pathological R-loops.
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Affiliation(s)
- Eva Petermann
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
- Birmingham Centre for Genome Biology, University of Birmingham, Birmingham, UK
| | - Li Lan
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Lee Zou
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA.
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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High-throughput techniques enable advances in the roles of DNA and RNA secondary structures in transcriptional and post-transcriptional gene regulation. Genome Biol 2022; 23:159. [PMID: 35851062 PMCID: PMC9290270 DOI: 10.1186/s13059-022-02727-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 07/07/2022] [Indexed: 12/27/2022] Open
Abstract
The most stable structure of DNA is the canonical right-handed double helix termed B DNA. However, certain environments and sequence motifs favor alternative conformations, termed non-canonical secondary structures. The roles of DNA and RNA secondary structures in transcriptional regulation remain incompletely understood. However, advances in high-throughput assays have enabled genome wide characterization of some secondary structures. Here, we describe their regulatory functions in promoters and 3’UTRs, providing insights into key mechanisms through which they regulate gene expression. We discuss their implication in human disease, and how advances in molecular technologies and emerging high-throughput experimental methods could provide additional insights.
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40
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Torri A, Jaeger J, Pradeu T, Saleh MC. The origin of RNA interference: Adaptive or neutral evolution? PLoS Biol 2022; 20:e3001715. [PMID: 35767561 PMCID: PMC9275709 DOI: 10.1371/journal.pbio.3001715] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/12/2022] [Indexed: 11/30/2022] Open
Abstract
The origin of RNA interference (RNAi) is usually explained by a defense-based hypothesis, in which RNAi evolved as a defense against transposable elements (TEs) and RNA viruses and was already present in the last eukaryotic common ancestor (LECA). However, since RNA antisense regulation and double-stranded RNAs (dsRNAs) are ancient and widespread phenomena, the origin of defensive RNAi should have occurred in parallel with its regulative functions to avoid imbalances in gene regulation. Thus, we propose a neutral evolutionary hypothesis for the origin of RNAi in which qualitative system drift from a prokaryotic antisense RNA gene regulation mechanism leads to the formation of RNAi through constructive neutral evolution (CNE). We argue that RNAi was already present in the ancestor of LECA before the need for a new defense system arose and that its presence helped to shape eukaryotic genomic architecture and stability. Where does RNA interference come from? This Essay describes a new step-by-step evolutionary model of how RNA interference might have originated in early eukaryotes through neutral events from the molecular machinery present in prokaryotes.
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Affiliation(s)
- Alessandro Torri
- Virus & RNA interference Unit, Department of Virology, Institut Pasteur, CNRS UMR 3569, Université Paris Cité, Paris, France
- * E-mail: (AT); (M-CS)
| | | | - Thomas Pradeu
- ImmunoConcEpT, CNRS UMR 5164, University of Bordeaux, Bordeaux, France
- Institut d’histoire et de philosophie des sciences et des techniques, CNRS UMR 8590, Pantheon-Sorbonne University, Paris, France
| | - Maria-Carla Saleh
- Virus & RNA interference Unit, Department of Virology, Institut Pasteur, CNRS UMR 3569, Université Paris Cité, Paris, France
- * E-mail: (AT); (M-CS)
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41
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Shirai M, Nara T, Takahashi H, Takayama K, Chen Y, Hirose Y, Fujii M, Awazu A, Shimoda N, Kikuchi Y. Identification of aberrant transcription termination at specific gene loci with DNA hypomethylated transcription termination sites caused by DNA methyltransferase deficiency. Gene 2022; 97:139-152. [PMID: 35718462 DOI: 10.1266/ggs.21-00092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
CpG methylation of genomic DNA is a well-known repressive epigenetic marker in eukaryotic transcription, and DNA methylation of promoter regions is correlated with gene silencing. In contrast to the promoter regions, the function of DNA methylation during transcription termination remains to be elucidated. A recent study revealed that mouse DNA methyltransferase 3a (Dnmt3a) mainly functions in de novo methylation in the promoter and gene body regions, including transcription termination sites (TTSs), during development. To investigate the relationship between DNA methylation overlapping the TTSs and transcription termination, we performed bioinformatics analysis using six pre-existing Dnmt-/- mouse cell datasets: four types of neurons (three Dnmt3a-/- and one Dnmt1-/- mutants) and two types of embryonic fibroblasts (MEFs) (Dnmt3a-/- and Dnmt3b-/- mutants). Combined analyses using methylome and transcriptome data revealed that read counts downstream of hypomethylated TTSs were increased in three types of neurons (two Dnmt3a-/- and one Dnmt1-/- mutants). Among these, an increase in chimeric transcripts downstream of the TTSs was observed in Dnmt3a-/- mature olfactory sensory neurons and Dnmt3a-/- agouti-related peptide (protein)-producing neurons, thereby indicating that read-through occurs in hypomethylated TTSs at specific gene loci in these two mutants. Conversely, in Dnmt3a-/- MEFs, we detected reductions in read counts downstream of hypomethylated TTSs. These results indicate that the hypomethylation of TTSs can both positively and negatively regulate transcription termination, dependent on Dnmt and cell types. This study is the first to identify the aberrant termination of transcription at specific gene loci with DNA hypomethylated TTSs attributable to Dnmt deficiency.
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Affiliation(s)
- Masaki Shirai
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima
| | - Takuya Nara
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima
| | - Haruko Takahashi
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima.,Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima
| | - Kazuya Takayama
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima
| | - Yuan Chen
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima
| | - Yudai Hirose
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima
| | - Masashi Fujii
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima
| | - Akinori Awazu
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima
| | - Nobuyoshi Shimoda
- Laboratory of Molecular Analysis, Core Facilities, National Center for Geriatrics and Gerontology
| | - Yutaka Kikuchi
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima.,Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima
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42
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Wang Y, Ma B, Liu X, Gao G, Che Z, Fan M, Meng S, Zhao X, Sugimura R, Cao H, Zhou Z, Xie J, Lin C, Luo Z. ZFP281-BRCA2 prevents R-loop accumulation during DNA replication. Nat Commun 2022; 13:3493. [PMID: 35715464 PMCID: PMC9205938 DOI: 10.1038/s41467-022-31211-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/08/2022] [Indexed: 11/16/2022] Open
Abstract
R-loops are prevalent in mammalian genomes and involved in many fundamental cellular processes. Depletion of BRCA2 leads to aberrant R-loop accumulation, contributing to genome instability. Here, we show that ZFP281 cooperates with BRCA2 in preventing R-loop accumulation to facilitate DNA replication in embryonic stem cells. ZFP281 depletion reduces PCNA levels on chromatin and impairs DNA replication. Mechanistically, we demonstrate that ZFP281 can interact with BRCA2, and that BRCA2 is enriched at G/C-rich promoters and requires both ZFP281 and PRC2 for its proper recruitment to the bivalent chromatin at the genome-wide scale. Furthermore, depletion of ZFP281 or BRCA2 leads to accumulation of R-loops over the bivalent regions, and compromises activation of the developmental genes by retinoic acid during stem cell differentiation. In summary, our results reveal that ZFP281 recruits BRCA2 to the bivalent chromatin regions to ensure proper progression of DNA replication through preventing persistent R-loops. R-loops are prevalent in mammalian genomes and involved in many fundamental cellular processes. Here, Wang et al. report that ZFP281 cooperates with BRCA2 in preventing R-loop accumulation to facilitate DNA replication in embryonic stem cells.
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Affiliation(s)
- Yan Wang
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China
| | - Binbin Ma
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Xiaoxu Liu
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China
| | - Ge Gao
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong, 999077, China
| | - Zhuanzhuan Che
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China
| | - Menghan Fan
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China
| | - Siyan Meng
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China
| | - Xiru Zhao
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China
| | - Rio Sugimura
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong, 999077, China
| | - Hua Cao
- Key Laboratory of Technical Evaluation of Fertility Regulation of Non-human primate, Fujian Provincial Maternity and Children's Hospital, Affiliated Hospital of Fujian Medical University, Fuzhou, 350005, China
| | - Zhongjun Zhou
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong, 999077, China
| | - Jing Xie
- Institute for Regenerative Medicine, Shanghai East Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Chengqi Lin
- Key Laboratory of Technical Evaluation of Fertility Regulation of Non-human primate, Fujian Provincial Maternity and Children's Hospital, Affiliated Hospital of Fujian Medical University, Fuzhou, 350005, China. .,Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research, Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China. .,Shenzhen Research Institute, Southeast University, 19 Gaoxin South 4th Road, Nanshan District, Shenzhen, 518063, China.
| | - Zhuojuan Luo
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China. .,Shenzhen Research Institute, Southeast University, 19 Gaoxin South 4th Road, Nanshan District, Shenzhen, 518063, China.
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43
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Stanek TJ, Cao W, Mehra RM, Ellison CE. Sex-specific variation in R-loop formation in Drosophila melanogaster. PLoS Genet 2022; 18:e1010268. [PMID: 35687614 PMCID: PMC9223372 DOI: 10.1371/journal.pgen.1010268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 06/23/2022] [Accepted: 05/22/2022] [Indexed: 11/18/2022] Open
Abstract
R-loops are three-stranded nucleotide structures consisting of a DNA:RNA hybrid and a displaced ssDNA non-template strand. Previous work suggests that R-loop formation is primarily determined by the thermodynamics of DNA:RNA binding, which are governed by base composition (e.g., GC skew) and transcription-induced DNA superhelicity. However, R-loops have been described at genomic locations that lack these properties, suggesting that they may serve other context-specific roles. To better understand the genetic determinants of R-loop formation, we have characterized the Drosophila melanogaster R-loop landscape across strains and between sexes using DNA:RNA immunoprecipitation followed by high-throughput sequencing (DRIP-seq). We find that R-loops are associated with sequence motifs that are G-rich or exhibit G/C skew, as well as highly expressed genes, tRNAs, and small nuclear RNAs, consistent with a role for DNA sequence and torsion in R-loop specification. However, we also find motifs associated with R-loops that are A/T-rich and lack G/C skew as well as a subset of R-loops that are enriched in polycomb-repressed chromatin. Differential enrichment analysis reveals a small number of sex-biased R-loops: while non-differentially enriched and male-enriched R-loops form at similar genetic features and chromatin states and contain similar sequence motifs, female-enriched R-loops form at unique genetic features, chromatin states, and sequence motifs and are associated with genes that show ovary-biased expression. Male-enriched R-loops are most abundant on the dosage-compensated X chromosome, where R-loops appear stronger compared to autosomal R-loops. R-loop-containing genes on the X chromosome are dosage-compensated yet show lower MOF binding and reduced H4K16ac compared to R-loop-absent genes, suggesting that H4K16ac or MOF may attenuate R-loop formation. Collectively, these results suggest that R-loop formation in vivo is not fully explained by DNA sequence and topology and raise the possibility that a distinct subset of these hybrid structures plays an important role in the establishment and maintenance of epigenetic differences between sexes.
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Affiliation(s)
- Timothy J. Stanek
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
- Department of Pathology, Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Weihuan Cao
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Rohan M Mehra
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Christopher E. Ellison
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
- * E-mail:
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44
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Munden A, Benton ML, Capra JA, Nordman JT. R-loop mapping and characterization during Drosophila embryogenesis reveals developmental plasticity in R-loop signatures. J Mol Biol 2022; 434:167645. [PMID: 35609632 PMCID: PMC9254486 DOI: 10.1016/j.jmb.2022.167645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/16/2022] [Accepted: 05/18/2022] [Indexed: 11/26/2022]
Abstract
R-loops are involved in transcriptional regulation, DNA and histone post-translational modifications, genome replication and genome stability. To what extent R-loop abundance and genome-wide localization is actively regulated during metazoan embryogenesis is unknown. Drosophila embryogenesis provides a powerful system to address these questions due to its well-characterized developmental program, the sudden onset of zygotic transcription and available genome-wide data sets. Here, we measure the overall abundance and genome localization of R-loops in early and late-stage embryos relative to Drosophila cultured cells. We demonstrate that absolute R-loop levels change during embryogenesis and that RNaseH1 catalytic activity is critical for embryonic development. R-loop mapping by strand-specific DRIP-seq reveals that R-loop localization is plastic across development, both in the genes which form R-loops and where they localize relative to gene bodies. Importantly, these changes are not driven by changes in the transcriptional program. Negative GC skew and absolute changes in AT skew are associated with R-loop formation in Drosophila. Furthermore, we demonstrate that while some chromatin binding proteins and histone modifications such as H3K27me3 are associated with R-loops throughout development, other chromatin factors associated with R-loops in a developmental specific manner. Our findings highlight the importance and developmental plasticity of R-loops during Drosophila embryogenesis.
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Affiliation(s)
- Alexander Munden
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37212, USA
| | | | - John A Capra
- Bakar Computational Health Sciences Institute and Department of Epidemiology and Biostatistics, University of California, San Francisco, CA 94103, USA
| | - Jared T Nordman
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37212, USA.
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45
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Muralimanoharan S, Shamby R, Stansbury N, Schenken R, de la Pena Avalos B, Javanmardi S, Dray E, Sung P, Boyer TG. Aberrant R-loop-induced replication stress in MED12-mutant uterine fibroids. Sci Rep 2022; 12:6169. [PMID: 35418189 PMCID: PMC9008039 DOI: 10.1038/s41598-022-10188-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 03/31/2022] [Indexed: 11/09/2022] Open
Abstract
Uterine fibroid (UF) driver mutations in Mediator complex subunit 12 (MED12) trigger genomic instability and tumor development through unknown mechanisms. Herein, we show that MED12 mutations trigger aberrant R-loop-induced replication stress, suggesting a possible route to genomic instability and a novel therapeutic vulnerability in this dominant UF subclass. Immunohistochemical analyses of patient-matched tissue samples revealed that MED12 mutation-positive UFs, compared to MED12 mutation-negative UFs and myometrium, exhibited significantly higher levels of R-loops and activated markers of Ataxia Telangiectasia and Rad3-related (ATR) kinase-dependent replication stress signaling in situ. Single molecule DNA fiber analysis revealed that primary cells from MED12 mutation-positive UFs, compared to those from patient-matched MED12 mutation-negative UFs and myometrium, exhibited defects in replication fork dynamics, including reduced fork speeds, increased and decreased numbers of stalled and restarted forks, respectively, and increased asymmetrical bidirectional forks. Notably, these phenotypes were recapitulated and functionally linked in cultured uterine smooth muscle cells following chemical inhibition of Mediator-associated CDK8/19 kinase activity that is known to be disrupted by UF driver mutations in MED12. Thus, Mediator kinase inhibition triggered enhanced R-loop formation and replication stress leading to an S-phase cell cycle delay, phenotypes that were rescued by overexpression of the R-loop resolving enzyme RNaseH. Altogether, these findings reveal MED12-mutant UFs to be uniquely characterized by aberrant R-loop induced replication stress, suggesting a possible basis for genomic instability and new avenues for therapeutic intervention that involve the replication stress phenotype in this dominant UF subtype.
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Affiliation(s)
- Sribalasubashini Muralimanoharan
- Department of Molecular Medicine, UT Health San Antonio, STRF, 8210 Floyd Curl Drive, Mail Code 8257, San Antonio, TX, 78229-3900, USA
| | - Ross Shamby
- Department of Molecular Medicine, UT Health San Antonio, STRF, 8210 Floyd Curl Drive, Mail Code 8257, San Antonio, TX, 78229-3900, USA
| | - Nicholas Stansbury
- Department of Obstetrics and Gynecology, UT Health San Antonio, San Antonio, TX, USA
| | - Robert Schenken
- Department of Obstetrics and Gynecology, UT Health San Antonio, San Antonio, TX, USA
| | | | - Samin Javanmardi
- Department of Molecular Medicine, UT Health San Antonio, STRF, 8210 Floyd Curl Drive, Mail Code 8257, San Antonio, TX, 78229-3900, USA
| | - Eloise Dray
- Department of Biochemistry and Structural Biology, UT Health San Antonio, San Antonio, TX, USA
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, UT Health San Antonio, San Antonio, TX, USA
| | - Thomas G Boyer
- Department of Molecular Medicine, UT Health San Antonio, STRF, 8210 Floyd Curl Drive, Mail Code 8257, San Antonio, TX, 78229-3900, USA.
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46
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Nissani N, Ulitsky I. Unique features of transcription termination and initiation at closely spaced tandem human genes. Mol Syst Biol 2022; 18:e10682. [PMID: 35362230 PMCID: PMC8972054 DOI: 10.15252/msb.202110682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 11/09/2022] Open
Abstract
The synthesis of RNA polymerase II (Pol2) products, which include messenger RNAs or long noncoding RNAs, culminates in transcription termination. How the transcriptional termination of a gene impacts the activity of promoters found immediately downstream of it, and which can be subject to potential transcriptional interference, remains largely unknown. We examined in an unbiased manner the features of the intergenic regions between pairs of 'tandem genes'-closely spaced (< 2 kb) human genes found on the same strand. Intergenic regions separating tandem genes are enriched with guanines and are characterized by binding of several proteins, including AGO1 and AGO2 of the RNA interference pathway. Additionally, we found that Pol2 is particularly enriched in this region, and it is lost upon perturbations affecting splicing or transcriptional elongation. Perturbations of genes involved in Pol2 pausing and R loop biology preferentially affect expression of downstream genes in tandem gene pairs. Overall, we find that features associated with Pol2 pausing and accumulation rather than those associated with avoidance of transcriptional interference are the predominant driving force shaping short tandem intergenic regions.
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Affiliation(s)
- Noa Nissani
- Departments of Biological Regulation and Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
| | - Igor Ulitsky
- Departments of Biological Regulation and Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
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47
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Telomeric Repeat-Containing RNA (TERRA): A Review of the Literature and First Assessment in Cutaneous T-Cell Lymphomas. Genes (Basel) 2022; 13:genes13030539. [PMID: 35328092 PMCID: PMC8953746 DOI: 10.3390/genes13030539] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/14/2022] [Accepted: 03/16/2022] [Indexed: 01/11/2023] Open
Abstract
Telomeric Repeat-containing RNA (TERRA) are long non-coding RNAs transcribed from telomeric DNA sequences from multiple chromosome ends. Major research efforts have been made to understand TERRA roles and functions in several physiological and pathological processes. We summarize herein available data regarding TERRA’s roles in human cells and we report the first investigation in cutaneous T-cells lymphomas (CTCL) using real-time PCR. Among the TERRA analysed, our data suggest a particular role for TERRA 16p downregulation and TERRA 11q upregulation in CTCL lymphomagenesis.
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48
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Seredinski S, Boos F, Günther S, Oo JA, Warwick T, Izquierdo Ponce J, Lillich FF, Proschak E, Knapp S, Gilsbach R, Pflüger-Müller B, Brandes RP, Leisegang MS. DNA topoisomerase inhibition with the HIF inhibitor acriflavine promotes transcription of lncRNAs in endothelial cells. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 27:1023-1035. [PMID: 35228897 PMCID: PMC8844413 DOI: 10.1016/j.omtn.2022.01.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 01/21/2022] [Indexed: 02/08/2023]
Abstract
The transcription factor hypoxia-inducible factor 1 (HIF1) is an important driver of cancer and is therefore an attractive drug target. Acriflavine (ACF) has been suggested to inhibit HIF1, but its mechanism of action is unknown. Here we investigated the interaction of ACF with DNA and long non-coding RNAs (lncRNAs) and its function in human endothelial cells. ACF promoted apoptosis and reduced proliferation, network formation, and angiogenic capacity. It also induced changes in gene expression, as determined by RNA sequencing (RNA-seq), which could not be attributed to specific inhibition of HIF1. A similar response was observed in murine lung endothelial cells. Although ACF increased and decreased a similar number of protein-coding genes, lncRNAs were preferentially upregulated under normoxic and hypoxic conditions. An assay for transposase accessibility with subsequent DNA sequencing (ATAC-seq) demonstrated that ACF induced strong changes in chromatin accessibility at lncRNA promoters. Immunofluorescence showed displacement of DNA:RNA hybrids. Such effects might be due to ACF-mediated topoisomerase inhibition, which was indeed the case, as reflected by DNA unwinding assays. Comparison with other acridine derivatives and topoisomerase inhibitors suggested that the specific function of ACF is an effect of acridinium-class compounds. This study demonstrates that ACF inhibits topoisomerases rather than HIF specifically and that it elicits a unique expression response of lncRNAs.
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Affiliation(s)
- Sandra Seredinski
- Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.,German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt, Germany
| | - Frederike Boos
- Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.,German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt, Germany
| | - Stefan Günther
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - James A Oo
- Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.,German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt, Germany
| | - Timothy Warwick
- Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.,German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt, Germany
| | - Judit Izquierdo Ponce
- Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | - Felix F Lillich
- Institute of Pharmaceutical Chemistry, Goethe University, 60438 Frankfurt, Germany
| | - Ewgenij Proschak
- Institute of Pharmaceutical Chemistry, Goethe University, 60438 Frankfurt, Germany
| | - Stefan Knapp
- Institute of Pharmaceutical Chemistry, Goethe University, 60438 Frankfurt, Germany
| | - Ralf Gilsbach
- Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.,German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt, Germany
| | - Beatrice Pflüger-Müller
- Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.,German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt, Germany
| | - Ralf P Brandes
- Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.,German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt, Germany
| | - Matthias S Leisegang
- Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.,German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt, Germany
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49
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La Rocca G, Cavalieri V. Roles of the Core Components of the Mammalian miRISC in Chromatin Biology. Genes (Basel) 2022; 13:genes13030414. [PMID: 35327968 PMCID: PMC8954937 DOI: 10.3390/genes13030414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/20/2022] [Accepted: 02/23/2022] [Indexed: 12/16/2022] Open
Abstract
The Argonaute (AGO) and the Trinucleotide Repeat Containing 6 (TNRC6) family proteins are the core components of the mammalian microRNA-induced silencing complex (miRISC), the machinery that mediates microRNA function in the cytoplasm. The cytoplasmic miRISC-mediated post-transcriptional gene repression has been established as the canonical mechanism through which AGO and TNRC6 proteins operate. However, growing evidence points towards an additional mechanism through which AGO and TNRC6 regulate gene expression in the nucleus. While several mechanisms through which miRISC components function in the nucleus have been described, in this review we aim to summarize the major findings that have shed light on the role of AGO and TNRC6 in mammalian chromatin biology and on the implications these novel mechanisms may have in our understanding of regulating gene expression.
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Affiliation(s)
- Gaspare La Rocca
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
- Correspondence: (G.L.R.); (V.C.)
| | - Vincenzo Cavalieri
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90128 Palermo, Italy
- Correspondence: (G.L.R.); (V.C.)
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50
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Sabino JC, de Almeida MR, Abreu PL, Ferreira AM, Caldas P, Domingues MM, Santos NC, Azzalin CM, Grosso AR, de Almeida SF. Epigenetic reprogramming by TET enzymes impacts co-transcriptional R-loops. eLife 2022; 11:69476. [PMID: 35191837 PMCID: PMC8896830 DOI: 10.7554/elife.69476] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
DNA oxidation by ten-eleven translocation (TET) family enzymes is essential for epigenetic reprogramming. The conversion of 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) initiates developmental and cell-type-specific transcriptional programs through mechanisms that include changes in the chromatin structure. Here, we show that the presence of 5hmC in the transcribed gene promotes the annealing of the nascent RNA to the template DNA strand, leading to the formation of an R-loop. Depletion of TET enzymes reduced global R-loops in absence of gene expression changes, whereas CRISPR-mediated tethering of TET to an active gene promoted the formation of R-loops. The genome-wide distribution of 5hmC and R-loops show a positive correlation in mouse and human stem cells and overlap in half of all active genes. Moreover, R-loop resolution leads to differential expression of a subset of genes that are involved in crucial events during stem cell proliferation. Altogether, our data reveal that epigenetic reprogramming via TET activity promotes co-transcriptional R-loop formation, disclosing new mechanisms of gene expression regulation.
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Affiliation(s)
- João C Sabino
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Madalena R de Almeida
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Patrícia L Abreu
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Ana M Ferreira
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Paulo Caldas
- Institute for Health and Bioeconomy, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Marco M Domingues
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Nuno C Santos
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Claus M Azzalin
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Ana Rita Grosso
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Sérgio Fernandes de Almeida
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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