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Geraud M, Cristini A, Salimbeni S, Bery N, Jouffret V, Russo M, Ajello AC, Fernandez Martinez L, Marinello J, Cordelier P, Trouche D, Favre G, Nicolas E, Capranico G, Sordet O. TDP1 mutation causing SCAN1 neurodegenerative syndrome hampers the repair of transcriptional DNA double-strand breaks. Cell Rep 2024; 43:114214. [PMID: 38761375 DOI: 10.1016/j.celrep.2024.114214] [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: 03/02/2023] [Revised: 03/05/2024] [Accepted: 04/24/2024] [Indexed: 05/20/2024] Open
Abstract
TDP1 removes transcription-blocking topoisomerase I cleavage complexes (TOP1ccs), and its inactivating H493R mutation causes the neurodegenerative syndrome SCAN1. However, the molecular mechanism underlying the SCAN1 phenotype is unclear. Here, we generate human SCAN1 cell models using CRISPR-Cas9 and show that they accumulate TOP1ccs along with changes in gene expression and genomic distribution of R-loops. SCAN1 cells also accumulate transcriptional DNA double-strand breaks (DSBs) specifically in the G1 cell population due to increased DSB formation and lack of repair, both resulting from abortive removal of transcription-blocking TOP1ccs. Deficient TDP1 activity causes increased DSB production, and the presence of mutated TDP1 protein hampers DSB repair by a TDP2-dependent backup pathway. This study provides powerful models to study TDP1 functions under physiological and pathological conditions and unravels that a gain of function of the mutated TDP1 protein, which prevents DSB repair, rather than a loss of TDP1 activity itself, could contribute to SCAN1 pathogenesis.
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Affiliation(s)
- Mathéa Geraud
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France
| | - Agnese Cristini
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France
| | - Simona Salimbeni
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France; Department of Pharmacy and Biotechnology, Alma Mater Studiorum, University of Bologna, 40126 Bologna, Italy
| | - Nicolas Bery
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France
| | - Virginie Jouffret
- MCD, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France; BigA Core Facility, Centre de Biologie Intégrative (CBI), Université de Toulouse, 31062 Toulouse, France
| | - Marco Russo
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum, University of Bologna, 40126 Bologna, Italy
| | - Andrea Carla Ajello
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France
| | - Lara Fernandez Martinez
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France
| | - Jessica Marinello
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum, University of Bologna, 40126 Bologna, Italy
| | - Pierre Cordelier
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France
| | - Didier Trouche
- MCD, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Gilles Favre
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France
| | - Estelle Nicolas
- MCD, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Giovanni Capranico
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum, University of Bologna, 40126 Bologna, Italy.
| | - Olivier Sordet
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France.
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2
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Valenzisi P, Marabitti V, Pichierri P, Franchitto A. WRNIP1 prevents transcription-associated genomic instability. eLife 2024; 12:RP89981. [PMID: 38488661 PMCID: PMC10942783 DOI: 10.7554/elife.89981] [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] [Indexed: 03/17/2024] Open
Abstract
R-loops are non-canonical DNA structures that form during transcription and play diverse roles in various physiological processes. Disruption of R-loop homeostasis can lead to genomic instability and replication impairment, contributing to several human diseases, including cancer. Although the molecular mechanisms that protect cells against such events are not fully understood, recent research has identified fork protection factors and DNA damage response proteins as regulators of R-loop dynamics. In this study, we identify the Werner helicase-interacting protein 1 (WRNIP1) as a novel factor that counteracts transcription-associated DNA damage upon replication perturbation. Loss of WRNIP1 leads to R-loop accumulation, resulting in collisions between the replisome and transcription machinery. We observe co-localization of WRNIP1 with transcription/replication complexes and R-loops after replication perturbation, suggesting its involvement in resolving transcription-replication conflicts. Moreover, WRNIP1-deficient cells show impaired replication restart from transcription-induced fork stalling. Notably, transcription inhibition and RNase H1 overexpression rescue all the defects caused by loss of WRNIP1. Importantly, our findings highlight the critical role of WRNIP1 ubiquitin-binding zinc finger (UBZ) domain in preventing pathological persistence of R-loops and limiting DNA damage, thereby safeguarding genome integrity.
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Affiliation(s)
- Pasquale Valenzisi
- Section of Mechanisms Biomarkers and Models, Department of Environment and Health, Istituto Superiore di SanitaRomeItaly
| | - Veronica Marabitti
- Section of Mechanisms Biomarkers and Models, Department of Environment and Health, Istituto Superiore di SanitaRomeItaly
| | - Pietro Pichierri
- Section of Mechanisms Biomarkers and Models, Department of Environment and Health, Istituto Superiore di SanitaRomeItaly
| | - Annapaola Franchitto
- Section of Mechanisms Biomarkers and Models, Department of Environment and Health, Istituto Superiore di SanitaRomeItaly
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3
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Bothra A, Perry ML, Wei E, Moayeri M, Ma Q, Biamonte MA, Siirin M, Leppla SH. S9.6-based hybrid capture immunoassay for pathogen detection. Sci Rep 2023; 13:22562. [PMID: 38110611 PMCID: PMC10728093 DOI: 10.1038/s41598-023-49881-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: 10/20/2023] [Accepted: 12/13/2023] [Indexed: 12/20/2023] Open
Abstract
The detection of pathogens is critical for clinical diagnosis and public health surveillance. Detection is usually done with nucleic acid-based tests (NATs) and rapid antigen tests (e.g., lateral flow assays [LFAs]). Although NATs are more sensitive and specific, their use is often limited in resource-poor settings due to specialized requirements. To address this limitation, we developed a rapid DNA-RNA Hybrid Capture immunoassay (HC) that specifically detects RNA from pathogens. This assay utilizes a unique monoclonal antibody, S9.6, which binds DNA-RNA hybrids. Biotinylated single-stranded DNA probes are hybridized to target RNAs, followed by hybrid capture on streptavidin and detection with S9.6. The HC-ELISA assay can detect as few as 104 RNA molecules that are 2.2 kb in length. We also adapted this assay into a LFA format, where captured Bacillus anthracis rpoB RNA of 3.5 kb length was detectable from a bacterial load equivalent to 107 CFU per 100 mg of mouse tissue using either HC-ELISA or HC-LFA. Importantly, we also demonstrated the versatility of HC by detecting other pathogens, including SARS-CoV-2 and Toxoplasma gondii, showing its potential for broad pathogen detection. Notably, HC does not require amplification of the target nucleic acid and utilizes economical formats like ELISA and LFA, making it suitable for use in sentinel labs for pathogen detection or as a molecular tool in basic research laboratories. Our study highlights the potential of HC as a sensitive and versatile method for RNA-based pathogen detection.
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Affiliation(s)
- Ankur Bothra
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA.
| | - Megan L Perry
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Elena Wei
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Mahtab Moayeri
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Qian Ma
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | | | - Marina Siirin
- Drugs and Diagnostics for Tropical Diseases, San Diego, CA, USA
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
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4
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Templeton CW, Laimins LA. p53-dependent R-loop formation and HPV pathogenesis. Proc Natl Acad Sci U S A 2023; 120:e2305907120. [PMID: 37611058 PMCID: PMC10467572 DOI: 10.1073/pnas.2305907120] [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: 04/12/2023] [Accepted: 06/30/2023] [Indexed: 08/25/2023] Open
Abstract
R-loops are trimeric RNA: DNA hybrids that are important physiological regulators of transcription; however, their aberrant formation or turnover leads to genomic instability and DNA breaks. High-risk human papillomaviruses (HPV) are the causative agents of genital as well as oropharyngeal cancers and exhibit enhanced amounts of DNA breaks. The levels of R-loops were found to be increased up to 50-fold in cells that maintain high-risk HPV genomes and were readily detected in squamous cell cervical carcinomas in vivo but not in normal cells. The high levels of R-loops in HPV-positive cells were present on both viral and cellular sites together with RNase H1, an enzyme that controls their resolution. Depletion of RNase H1 in HPV-positive cells further increased R-loop levels, resulting in impaired viral transcription and replication along with reduced expression of the DNA repair genes such as FANCD2 and ATR, both of which are necessary for viral functions. Overexpression of RNase H1 decreased total R-loop levels, resulting in a reduction of DNA breaks by over 50%. Furthermore, increased RNase H1 expression blocked viral transcription and replication while enhancing the expression of factors in the innate immune regulatory pathway. This suggests that maintaining elevated R-loop levels is important for the HPV life cycle. The E6 viral oncoprotein was found to be responsible for inducing high levels of R-loops by inhibiting p53's transcriptional activity. Our studies indicate that high R-loop levels are critical for HPV pathogenesis and that this depends on suppressing the p53 pathway.
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Affiliation(s)
- Conor Winslow Templeton
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL60611
| | - Laimonis A. Laimins
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL60611
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5
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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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6
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Rabany O, Nachmani D. Small Nucleolar (Sno)RNA: Therapy Lays in Translation. Noncoding RNA 2023; 9:35. [PMID: 37368335 DOI: 10.3390/ncrna9030035] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/28/2023] Open
Abstract
The ribosome is one of the largest complexes in the cell. Adding to its complexity are more than 200 RNA modification sites present on ribosomal RNAs (rRNAs) in a single human ribosome. These modifications occur in functionally important regions of the rRNA molecule, and they are vital for ribosome function and proper gene expression. Until recent technological advancements, the study of rRNA modifications and their profiles has been extremely laborious, leaving many questions unanswered. Small nucleolar RNAs (snoRNAs) are non-coding RNAs that facilitate and dictate the specificity of rRNA modification deposition, making them an attractive target for ribosome modulation. Here, we propose that through the mapping of rRNA modification profiles, we can identify cell-specific modifications with high therapeutic potential. We also describe the challenges of achieving the targeting specificity needed to implement snoRNAs as therapeutic targets in cancers.
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Affiliation(s)
- Ofri Rabany
- Department of Genetics, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 9190401, Israel
| | - Daphna Nachmani
- Department of Genetics, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 9190401, Israel
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7
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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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8
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Gritti I, Basso V, Rinchai D, Corigliano F, Pivetti S, Gaviraghi M, Rosano D, Mazza D, Barozzi S, Roncador M, Parmigiani G, Legube G, Parazzoli D, Cittaro D, Bedognetti D, Mondino A, Segalla S, Tonon G. Loss of ribonuclease DIS3 hampers genome integrity in myeloma by disrupting DNA:RNA hybrid metabolism. EMBO J 2022; 41:e108040. [PMID: 36215697 PMCID: PMC9670201 DOI: 10.15252/embj.2021108040] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 07/25/2022] [Accepted: 09/23/2022] [Indexed: 01/13/2023] Open
Abstract
The ribonuclease DIS3 is one of the most frequently mutated genes in the hematological cancer multiple myeloma, yet the basis of its tumor suppressor function in this disease remains unclear. Herein, exploiting the TCGA dataset, we found that DIS3 plays a prominent role in the DNA damage response. DIS3 inactivation causes genomic instability by increasing mutational load, and a pervasive accumulation of DNA:RNA hybrids that induces genomic DNA double-strand breaks (DSBs). DNA:RNA hybrid accumulation also prevents binding of the homologous recombination (HR) machinery to double-strand breaks, hampering DSB repair. DIS3-inactivated cells become sensitive to PARP inhibitors, suggestive of a defect in homologous recombination repair. Accordingly, multiple myeloma patient cells mutated for DIS3 harbor an increased mutational burden and a pervasive overexpression of pro-inflammatory interferon, correlating with the accumulation of DNA:RNA hybrids. We propose DIS3 loss in myeloma to be a driving force for tumorigenesis via DNA:RNA hybrid-dependent enhanced genome instability and increased mutational rate. At the same time, DIS3 loss represents a liability that might be therapeutically exploited in patients whose cancer cells harbor DIS3 mutations.
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Affiliation(s)
- Ilaria Gritti
- Functional Genomics of Cancer Unit, Division of Experimental OncologyIstituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly
| | - Veronica Basso
- Division of Immunology, Transplantation and Infectious DiseaseIstituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly
| | | | - Federica Corigliano
- Functional Genomics of Cancer Unit, Division of Experimental OncologyIstituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly
| | - Silvia Pivetti
- Functional Genomics of Cancer Unit, Division of Experimental OncologyIstituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly
| | - Marco Gaviraghi
- Functional Genomics of Cancer Unit, Division of Experimental OncologyIstituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly
| | - Dalia Rosano
- Functional Genomics of Cancer Unit, Division of Experimental OncologyIstituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly
| | - Davide Mazza
- Experimental Imaging CenterIstituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly
| | - Sara Barozzi
- IFOM, The FIRC Institute of Molecular OncologyMilanoItaly
| | - Marco Roncador
- Department of Data SciencesDana Farber Cancer InstituteBostonMAUSA,Department of BiostatisticsHarvard T.H. Chan School of Public HealthBostonMAUSA
| | - Giovanni Parmigiani
- Department of Data SciencesDana Farber Cancer InstituteBostonMAUSA,Department of BiostatisticsHarvard T.H. Chan School of Public HealthBostonMAUSA
| | - Gaelle Legube
- MCD, Centre de Biologie Intégrative (CBI), CNRSUniversity of ToulouseToulouseFrance
| | | | - Davide Cittaro
- Center for Omics Sciences @OSR (COSR)Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly
| | - Davide Bedognetti
- Cancer Research DepartmentSidra MedicineDohaQatar,Dipartimento di Medicina Interna e Specialità MedicheUniversità degli Studi di GenovaGenoaItaly
| | - Anna Mondino
- Division of Immunology, Transplantation and Infectious DiseaseIstituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly
| | - Simona Segalla
- Functional Genomics of Cancer Unit, Division of Experimental OncologyIstituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly
| | - Giovanni Tonon
- Functional Genomics of Cancer Unit, Division of Experimental OncologyIstituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly,Center for Omics Sciences @OSR (COSR)Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Scientific InstituteMilanoItaly,Università Vita‐Salute San RaffaeleMilanItaly
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9
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Misic J, Milenkovic D, Al-Behadili A, Xie X, Jiang M, Jiang S, Filograna R, Koolmeister C, Siira S, Jenninger L, Filipovska A, Clausen A, Caporali L, Valentino M, La Morgia C, Carelli V, Nicholls T, Wredenberg A, Falkenberg M, Larsson NG. Mammalian RNase H1 directs RNA primer formation for mtDNA replication initiation and is also necessary for mtDNA replication completion. Nucleic Acids Res 2022; 50:8749-8766. [PMID: 35947649 PMCID: PMC9410905 DOI: 10.1093/nar/gkac661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/08/2022] [Accepted: 08/04/2022] [Indexed: 12/24/2022] Open
Abstract
The in vivo role for RNase H1 in mammalian mitochondria has been much debated. Loss of RNase H1 is embryonic lethal and to further study its role in mtDNA expression we characterized a conditional knockout of Rnaseh1 in mouse heart. We report that RNase H1 is essential for processing of RNA primers to allow site-specific initiation of mtDNA replication. Without RNase H1, the RNA:DNA hybrids at the replication origins are not processed and mtDNA replication is initiated at non-canonical sites and becomes impaired. Importantly, RNase H1 is also needed for replication completion and in its absence linear deleted mtDNA molecules extending between the two origins of mtDNA replication are formed accompanied by mtDNA depletion. The steady-state levels of mitochondrial transcripts follow the levels of mtDNA, and RNA processing is not altered in the absence of RNase H1. Finally, we report the first patient with a homozygous pathogenic mutation in the hybrid-binding domain of RNase H1 causing impaired mtDNA replication. In contrast to catalytically inactive variants of RNase H1, this mutant version has enhanced enzyme activity but shows impaired primer formation. This finding shows that the RNase H1 activity must be strictly controlled to allow proper regulation of mtDNA replication.
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Affiliation(s)
- Jelena Misic
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | | | - Ali Al-Behadili
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
| | - Xie Xie
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
| | - Min Jiang
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China
| | - Shan Jiang
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | - Roberta Filograna
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | - Camilla Koolmeister
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | - Stefan J Siira
- Harry Perkins Institute of Medical Research and ARC Centre of Excellence in Synthetic Biology, Nedlands, WA 6009, Australia
| | - Louise Jenninger
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
| | - Aleksandra Filipovska
- Harry Perkins Institute of Medical Research and ARC Centre of Excellence in Synthetic Biology, Nedlands, WA 6009, Australia,Telethon Kids Institute, Northern Entrance, Perth Children's Hospital, 15 Hospital Avenue, Nedlands, WA, Australia
| | - Anders R Clausen
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
| | - Leonardo Caporali
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Maria Lucia Valentino
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy,Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Chiara La Morgia
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy,Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Thomas J Nicholls
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Anna Wredenberg
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Maria Falkenberg
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
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10
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Karyka E, Berrueta Ramirez N, Webster CP, Marchi PM, Graves EJ, Godena VK, Marrone L, Bhargava A, Ray S, Ning K, Crane H, Hautbergue GM, El-Khamisy SF, Azzouz M. SMN-deficient cells exhibit increased ribosomal DNA damage. Life Sci Alliance 2022; 5:e202101145. [PMID: 35440492 PMCID: PMC9018017 DOI: 10.26508/lsa.202101145] [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: 06/28/2021] [Revised: 04/04/2022] [Accepted: 04/04/2022] [Indexed: 12/26/2022] Open
Abstract
Spinal muscular atrophy, the leading genetic cause of infant mortality, is a motor neuron disease caused by low levels of survival motor neuron (SMN) protein. SMN is a multifunctional protein that is implicated in numerous cytoplasmic and nuclear processes. Recently, increasing attention is being paid to the role of SMN in the maintenance of DNA integrity. DNA damage and genome instability have been linked to a range of neurodegenerative diseases. The ribosomal DNA (rDNA) represents a particularly unstable locus undergoing frequent breakage. Instability in rDNA has been associated with cancer, premature ageing syndromes, and a number of neurodegenerative disorders. Here, we report that SMN-deficient cells exhibit increased rDNA damage leading to impaired ribosomal RNA synthesis and translation. We also unravel an interaction between SMN and RNA polymerase I. Moreover, we uncover an spinal muscular atrophy motor neuron-specific deficiency of DDX21 protein, which is required for resolving R-loops in the nucleolus. Taken together, our findings suggest a new role of SMN in rDNA integrity.
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Affiliation(s)
- Evangelia Karyka
- The Healthy Lifespan Institute and Neuroscience Institute, Neurodegeneration and Genome Stability Group, University of Sheffield, Sheffield, UK
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Nelly Berrueta Ramirez
- The Healthy Lifespan Institute and Neuroscience Institute, Neurodegeneration and Genome Stability Group, University of Sheffield, Sheffield, UK
- Department of Molecular Biology and Biotechnology, The Institute of Neuroscience and the Healthy Lifespan Institute, School of Bioscience, Firth Court, University of Sheffield, Sheffield, UK
| | - Christopher P Webster
- The Healthy Lifespan Institute and Neuroscience Institute, Neurodegeneration and Genome Stability Group, University of Sheffield, Sheffield, UK
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Paolo M Marchi
- The Healthy Lifespan Institute and Neuroscience Institute, Neurodegeneration and Genome Stability Group, University of Sheffield, Sheffield, UK
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Emily J Graves
- The Healthy Lifespan Institute and Neuroscience Institute, Neurodegeneration and Genome Stability Group, University of Sheffield, Sheffield, UK
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Vinay K Godena
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Lara Marrone
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Anushka Bhargava
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Swagat Ray
- Department of Molecular Biology and Biotechnology, The Institute of Neuroscience and the Healthy Lifespan Institute, School of Bioscience, Firth Court, University of Sheffield, Sheffield, UK
- Department of Life Sciences, School of Life and Environmental Sciences, University of Lincoln, Lincoln, UK
| | - Ke Ning
- The Healthy Lifespan Institute and Neuroscience Institute, Neurodegeneration and Genome Stability Group, University of Sheffield, Sheffield, UK
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Hannah Crane
- Department of Molecular Biology and Biotechnology, The Institute of Neuroscience and the Healthy Lifespan Institute, School of Bioscience, Firth Court, University of Sheffield, Sheffield, UK
| | - Guillaume M Hautbergue
- The Healthy Lifespan Institute and Neuroscience Institute, Neurodegeneration and Genome Stability Group, University of Sheffield, Sheffield, UK
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Sherif F El-Khamisy
- The Healthy Lifespan Institute and Neuroscience Institute, Neurodegeneration and Genome Stability Group, University of Sheffield, Sheffield, UK
- Department of Molecular Biology and Biotechnology, The Institute of Neuroscience and the Healthy Lifespan Institute, School of Bioscience, Firth Court, University of Sheffield, Sheffield, UK
- The Institute of Cancer Therapeutics, University of Bradford, Bradford, UK
| | - Mimoun Azzouz
- The Healthy Lifespan Institute and Neuroscience Institute, Neurodegeneration and Genome Stability Group, University of Sheffield, Sheffield, UK
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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11
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Zhang L, Bernardo KD, Vickers TA, Tian J, Liang XH, Crooke ST. NAT10 and DDX21 Proteins Interact with RNase H1 and Affect the Performance of Phosphorothioate Oligonucleotides. Nucleic Acid Ther 2022; 32:280-299. [PMID: 35852833 PMCID: PMC9416547 DOI: 10.1089/nat.2021.0107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
RNase H1-dependent phosphorothioate oligonucleotides (PS-ASOs) have been developed to treat various diseases through specific degradation of target RNAs. Although many factors or features of RNA and PS-ASOs have been demonstrated to affect antisense activity of PS-ASOs, little is known regarding the roles of RNase H1-associated proteins in PS-ASO performance. In this study, we report that two nucleolar proteins, NAT10 and DDX21, interact with RNase H1 and affect the potency and safety of PS-ASOs. The interactions of these two proteins with RNase H1 were determined using BioID proximity labeling in cells and confirmed biochemically. Reduction of NAT10 and DDX21 decreased PS-ASO activity in cells, and purified NAT10 and DDX21 proteins enhanced RNase H1 cleavage rates, indicating that these two proteins facilitate RNase H1 endoribonuclease activity. Consistently, reduction of these proteins increased the levels of R-loops, and impaired pre-rRNA processing. In addition, reduction of the two proteins increased the cytotoxicity of toxic PS-ASOs, and treatment of toxic PS-ASOs also altered the localization of these proteins. Together, this study shows for the first time that NAT10 and DDX21 interact with RNase H1 protein and enhance its enzymatic activity, contributing to the potency and safety of PS-ASOs.
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Affiliation(s)
- Lingdi Zhang
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Karla D. Bernardo
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Timothy A. Vickers
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Jun Tian
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Xue-hai Liang
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Stanley T. Crooke
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
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12
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Fleurier S, Dapa T, Tenaillon O, Condon C, Matic I. rRNA operon multiplicity as a bacterial genome stability insurance policy. Nucleic Acids Res 2022; 50:12601-12620. [PMID: 35552441 PMCID: PMC9825170 DOI: 10.1093/nar/gkac332] [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: 10/05/2021] [Revised: 04/12/2022] [Accepted: 04/21/2022] [Indexed: 01/29/2023] Open
Abstract
Quick growth restart after upon encountering favourable environmental conditions is a major fitness contributor in natural environment. It is widely assumed that the time required to restart growth after nutritional upshift is determined by how long it takes for cells to synthesize enough ribosomes to produce the proteins required to reinitiate growth. Here we show that a reduction in the capacity to synthesize ribosomes by reducing number of ribosomal RNA (rRNA) operons (rrn) causes a longer transition from stationary phase to growth of Escherichia coli primarily due to high mortality rates. Cell death results from DNA replication blockage and massive DNA breakage at the sites of the remaining rrn operons that become overloaded with RNA polymerases (RNAPs). Mortality rates and growth restart duration can be reduced by preventing R-loop formation and improving DNA repair capacity. The same molecular mechanisms determine the duration of the recovery phase after ribosome-damaging stresses, such as antibiotics, exposure to bile salts or high temperature. Our study therefore suggests that a major function of rrn operon multiplicity is to ensure that individual rrn operons are not saturated by RNAPs, which can result in catastrophic chromosome replication failure and cell death during adaptation to environmental fluctuations.
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Affiliation(s)
- Sebastien Fleurier
- Department of Infection, Immunity and Inflammation, Institut Cochin, Inserm U1016, CNRS UMR8104, Université de Paris, 75014 Paris, France
| | - Tanja Dapa
- Department of Infection, Immunity and Inflammation, Institut Cochin, Inserm U1016, CNRS UMR8104, Université de Paris, 75014 Paris, France
| | | | - Ciarán Condon
- Institut de Biologie Physico-Chimique, CNRS UMR8261, Université de Paris, 75005 Paris, France
| | - Ivan Matic
- To whom correspondence should be addressed.
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13
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Wu W, He JN, Lan M, Zhang P, Chu WK. Transcription-Replication Collisions and Chromosome Fragility. Front Genet 2021; 12:804547. [PMID: 34956339 PMCID: PMC8703014 DOI: 10.3389/fgene.2021.804547] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/29/2021] [Indexed: 11/13/2022] Open
Abstract
Accurate replication of the entire genome is critical for cell division and propagation. Certain regions in the genome, such as fragile sites (common fragile sites, rare fragile sites, early replicating fragile sites), rDNA and telomeres, are intrinsically difficult to replicate, especially in the presence of replication stress caused by, for example, oncogene activation during tumor development. Therefore, these regions are particularly prone to deletions and chromosome rearrangements during tumorigenesis, rendering chromosome fragility. Although, the mechanism underlying their “difficult-to-replicate” nature and genomic instability is still not fully understood, accumulating evidence suggests transcription might be a major source of endogenous replication stress (RS) leading to chromosome fragility. Here, we provide an updated overview of how transcription affects chromosome fragility. Furthermore, we will use the well characterized common fragile sites (CFSs) as a model to discuss pathways involved in offsetting transcription-induced RS at these loci with a focus on the recently discovered atypical DNA synthesis repair pathway Mitotic DNA Synthesis (MiDAS).
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Affiliation(s)
- Wei Wu
- Zhejiang Provincial Key Laboratory of Pancreatic Diseases, The First Affiliated Hospital of Zhejiang University, Hangzhou, China
| | - Jing Na He
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong, China
| | - Mengjiao Lan
- Zhejiang Provincial Key Laboratory of Pancreatic Diseases, The First Affiliated Hospital of Zhejiang University, Hangzhou, China
| | - Pumin Zhang
- Zhejiang Provincial Key Laboratory of Pancreatic Diseases, The First Affiliated Hospital of Zhejiang University, Hangzhou, China
| | - Wai Kit Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong, China
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14
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Zhang X, Wang L, Zhang Q, Lyu S, Zhu D, Shen M, Ke X, Qu Y. Small molecule targeting topoisomerase 3β for cancer therapy. Pharmacol Res 2021; 174:105927. [PMID: 34740818 DOI: 10.1016/j.phrs.2021.105927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/30/2021] [Accepted: 09/30/2021] [Indexed: 11/15/2022]
Abstract
DNA topoisomerases are proved cancer therapeutic targets with clinically successful anticancer drugs for decades. However, the role of RNA topoisomerase (TOP3β) remained mysterious especially in cancer, and no targeted agent has been reported yet. In a target identification assay of anti-cancer compound using a modified DrugTargetSeqR strategy, mutation of TOP3B was detected in cancer cells acquired resistance to cinobufagin (CBG), a key compound of Huachansu that has been approved for cancer therapy in China. We demonstrated that CBG directly engaged with TOP3β, and promoted TOP3β depletion in wildtype but not mutant cancer cells. Notably, knockout of TOP3β in cancer cells significantly reduced tumor enlargement but not initiation, and inhibited colony formation upon nutrient deprivation. We also demonstrated that CBG induced formation of stress granule, RNA-loop and asymmetric DNA damages in cancer cells, and all these phenotypes were significantly attenuated in TOP3B knockout cells. Of note, examination of a panel of cancer cell lines revealed associations among cell growth inhibition and induction of DNA damage as well as TOP3B depletion upon CBG treatment. Our findings not only highlighted TOP3β as a promising therapeutic target of cancer, but also identified CBG as a lead chemical inhibitor of TOP3β for cancer therapy.
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Affiliation(s)
- Xue Zhang
- Center for Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, No.1200 Cailun Road, Shanghai 201203, PR China
| | - Lei Wang
- Center for Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, No.1200 Cailun Road, Shanghai 201203, PR China
| | - Qi Zhang
- Center for Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, No.1200 Cailun Road, Shanghai 201203, PR China
| | - Song Lyu
- Center for Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, No.1200 Cailun Road, Shanghai 201203, PR China
| | - Darong Zhu
- Center for Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, No.1200 Cailun Road, Shanghai 201203, PR China
| | - Mengzhen Shen
- Center for Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, No.1200 Cailun Road, Shanghai 201203, PR China
| | - Xisong Ke
- Center for Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, No.1200 Cailun Road, Shanghai 201203, PR China.
| | - Yi Qu
- Center for Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, No.1200 Cailun Road, Shanghai 201203, PR China.
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15
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Feng S, Manley JL. Replication protein A associates with nucleolar R loops and regulates rRNA transcription and nucleolar morphology. Genes Dev 2021; 35:1579-1594. [PMID: 34819354 PMCID: PMC8653787 DOI: 10.1101/gad.348858.121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/22/2021] [Indexed: 11/24/2022]
Abstract
Here, Feng and Manley report novel functions of the DNA replication and repair factor replication protein A (RPA) in control of nucleolar homeostasis. Their findings both indicate new roles for RPA in nucleoli through pre-rRNA transcriptional control and also emphasize that RPA function in nucleolar homeostasis is linked to R-loop resolution under both physiological and pathological conditions. The nucleolus is an important cellular compartment in which ribosomal RNAs (rRNAs) are transcribed and where certain stress pathways that are crucial for cell growth are coordinated. Here we report novel functions of the DNA replication and repair factor replication protein A (RPA) in control of nucleolar homeostasis. We show that loss of the DNA:RNA helicase senataxin (SETX) promotes RPA nucleolar localization, and that this relocalization is dependent on the presence of R loops. Notably, this nucleolar RPA phenotype was also observed in the presence of camptothecin (CPT)-induced genotoxic stress, as well as in SETX-deficient AOA2 patient fibroblasts. Extending these results, we found that RPA is recruited to rDNA following CPT treatment, where RPA prevents R-loop-induced DNA double-strand breaks. Furthermore, we show that loss of RPA significantly decreased 47S pre-rRNA levels, which was accompanied by increased expression of both RNAP II-mediated “promoter and pre-rRNA antisense” RNA as well as RNAP I-transcribed intragenic spacer RNAs. Finally, and likely reflecting the above, we found that loss of RPA promoted nucleolar structural disorganization, characterized by the appearance of reduced size nucleoli. Our findings both indicate new roles for RPA in nucleoli through pre-rRNA transcriptional control and also emphasize that RPA function in nucleolar homeostasis is linked to R-loop resolution under both physiological and pathological conditions.
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Affiliation(s)
- Shuang Feng
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - James L Manley
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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16
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Chatzidoukaki O, Stratigi K, Goulielmaki E, Niotis G, Akalestou-Clocher A, Gkirtzimanaki K, Zafeiropoulos A, Altmüller J, Topalis P, Garinis GA. R-loops trigger the release of cytoplasmic ssDNAs leading to chronic inflammation upon DNA damage. SCIENCE ADVANCES 2021; 7:eabj5769. [PMID: 34797720 PMCID: PMC8604417 DOI: 10.1126/sciadv.abj5769] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
How DNA damage leads to chronic inflammation and tissue degeneration with aging remains to be fully resolved. Here, we show that DNA damage leads to cellular senescence, fibrosis, loss-of-tissue architecture, and chronic pancreatitis in mice with an inborn defect in the excision repair cross complementation group 1 (Ercc1) gene. We find that DNA damage-driven R-loops causally contribute to the active release and buildup of single-stranded DNAs (ssDNAs) in the cytoplasm of cells triggering a viral-like immune response in progeroid and naturally aged pancreata. To reduce the proinflammatory load, we developed an extracellular vesicle (EV)-based strategy to deliver recombinant S1 or ribonuclease H nucleases in inflamed Ercc1−/− pancreatic cells. Treatment of Ercc1−/− animals with the EV-delivered nuclease cargo eliminates DNA damage-induced R-loops and cytoplasmic ssDNAs alleviating chronic inflammation. Thus, DNA damage-driven ssDNAs causally contribute to tissue degeneration, Ercc1−/− paving the way for novel rationalized intervention strategies against age-related chronic inflammation.
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Affiliation(s)
- Ourania Chatzidoukaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, GR70013 Heraklion, Crete, Greece
- Medical School, University of Crete, Heraklion, Crete, Greece
| | - Kalliopi Stratigi
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, GR70013 Heraklion, Crete, Greece
| | - Evi Goulielmaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, GR70013 Heraklion, Crete, Greece
| | - George Niotis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, GR70013 Heraklion, Crete, Greece
- Department of Biology, University of Crete, Heraklion, Crete, Greece
| | - Alexia Akalestou-Clocher
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, GR70013 Heraklion, Crete, Greece
- Department of Biology, University of Crete, Heraklion, Crete, Greece
| | - Katerina Gkirtzimanaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, GR70013 Heraklion, Crete, Greece
| | | | - Janine Altmüller
- Cologne Center for Genomics (CCG), Institute for Genetics, University of Cologne, 50931 Cologne, Germany
| | - Pantelis Topalis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, GR70013 Heraklion, Crete, Greece
| | - George A. Garinis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, GR70013 Heraklion, Crete, Greece
- Department of Biology, University of Crete, Heraklion, Crete, Greece
- Corresponding author.
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17
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Wu T, Nance J, Chu F, Fazzio TG. Characterization of R-Loop-Interacting Proteins in Embryonic Stem Cells Reveals Roles in rRNA Processing and Gene Expression. Mol Cell Proteomics 2021; 20:100142. [PMID: 34478875 PMCID: PMC8461376 DOI: 10.1016/j.mcpro.2021.100142] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 08/21/2021] [Accepted: 08/25/2021] [Indexed: 12/14/2022] Open
Abstract
Chromatin-associated RNAs have diverse roles in the nucleus. However, their mechanisms of action are poorly understood, in part because of the inability to identify proteins that specifically associate with chromatin-bound RNAs. Here, we address this problem for a subset of chromatin-associated RNAs that form R-loops-RNA-DNA hybrid structures that include a displaced strand of ssDNA. R-loops generally form cotranscriptionally and have important roles in regulation of gene expression, immunoglobulin class switching, and other processes. However, unresolved R-loops can lead to DNA damage and chromosome instability. To identify factors that may bind and regulate R-loop accumulation or mediate R-loop-dependent functions, we used a comparative immunoprecipitation/MS approach, with and without RNA-protein crosslinking, to identify a stringent set of R-loop-binding proteins in mouse embryonic stem cells. We identified 364 R-loop-interacting proteins, which were highly enriched for proteins with predicted RNA-binding functions. We characterized several R-loop-interacting proteins of the DEAD-box family of RNA helicases and found that these proteins localize to the nucleolus and, to a lesser degree, the nucleus. Consistent with their localization patterns, we found that these helicases are required for rRNA processing and regulation of gene expression. Surprisingly, depletion of these helicases resulted in misregulation of highly overlapping sets of protein-coding genes, including many genes that function in differentiation and development. We conclude that R-loop-interacting DEAD-box helicases have nonredundant roles that are critical for maintaining the normal embryonic stem cell transcriptome.
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Affiliation(s)
- Tong Wu
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Jennifer Nance
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, USA
| | - Feixia Chu
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, USA
| | - Thomas G Fazzio
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
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18
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Crossley MP, Brickner JR, Song C, Zar SMT, Maw SS, Chédin F, Tsai MS, Cimprich KA. Catalytically inactive, purified RNase H1: A specific and sensitive probe for RNA-DNA hybrid imaging. J Cell Biol 2021; 220:212458. [PMID: 34232287 PMCID: PMC8266564 DOI: 10.1083/jcb.202101092] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 05/24/2021] [Accepted: 06/07/2021] [Indexed: 12/17/2022] Open
Abstract
R-loops are three-stranded nucleic acid structures with both physiological and pathological roles in cells. R-loop imaging generally relies on detection of the RNA-DNA hybrid component of these structures using the S9.6 antibody. We show that the use of this antibody for imaging can be problematic because it readily binds to double-stranded RNA (dsRNA) in vitro and in vivo, giving rise to nonspecific signal. In contrast, purified, catalytically inactive human RNase H1 tagged with GFP (GFP-dRNH1) is a more specific reagent for imaging RNA-DNA hybrids. GFP-dRNH1 binds strongly to RNA-DNA hybrids but not to dsRNA oligonucleotides in fixed human cells and is not susceptible to binding endogenous RNA. Furthermore, we demonstrate that purified GFP-dRNH1 can be applied to fixed cells to detect hybrids after their induction, thereby bypassing the need for cell line engineering. GFP-dRNH1 therefore promises to be a versatile tool for imaging and quantifying RNA-DNA hybrids under a wide range of conditions.
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Affiliation(s)
- Magdalena P Crossley
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA
| | - Joshua R Brickner
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA
| | - Chenlin Song
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA
| | - Su Mon Thin Zar
- Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Su S Maw
- Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Frédéric Chédin
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, Davis, CA
| | - Miaw-Sheue Tsai
- Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Karlene A Cimprich
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA
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19
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Bossaert M, Pipier A, Riou JF, Noirot C, Nguyên LT, Serre RF, Bouchez O, Defrancq E, Calsou P, Britton S, Gomez D. Transcription-associated topoisomerase 2α (TOP2A) activity is a major effector of cytotoxicity induced by G-quadruplex ligands. eLife 2021; 10:65184. [PMID: 34180392 PMCID: PMC8279764 DOI: 10.7554/elife.65184] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 06/16/2021] [Indexed: 12/11/2022] Open
Abstract
G-quadruplexes (G4) are non-canonical DNA structures found in the genome of most species including human. Small molecules stabilizing these structures, called G4 ligands, have been identified and, for some of them, shown to induce cytotoxic DNA double-strand breaks. Through the use of an unbiased genetic approach, we identify here topoisomerase 2α (TOP2A) as a major effector of cytotoxicity induced by two clastogenic G4 ligands, pyridostatin and CX-5461, the latter molecule currently undergoing phase I/II clinical trials in oncology. We show that both TOP2 activity and transcription account for DNA break production following G4 ligand treatments. In contrast, clastogenic activity of these G4 ligands is countered by topoisomerase 1 (TOP1), which limits co-transcriptional G4 formation, and by factors promoting transcriptional elongation. Altogether our results support that clastogenic G4 ligands act as DNA structure-driven TOP2 poisons at transcribed regions bearing G4 structures.
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Affiliation(s)
- Madeleine Bossaert
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
| | - Angélique Pipier
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
| | - Jean-Francois Riou
- Structure et Instabilité des Génomes, Muséum National d'Histoire Naturelle, CNRS, INSERM, Paris, France
| | - Céline Noirot
- INRAE, UR 875, Unité de Mathématique et Informatique Appliquées, Genotoul Bioinfo, Castanet-Tolosan, France
| | - Linh-Trang Nguyên
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | | | - Olivier Bouchez
- INRAE, US 1426, GeT-PlaGe, Genotoul, Castanet-Tolosan, France
| | - Eric Defrancq
- Département de Chimie Moléculaire, UMR CNRS 5250, Université Grenoble Alpes, Grenoble, France
| | - Patrick Calsou
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
| | - Sébastien Britton
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
| | - Dennis Gomez
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
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20
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Liu Y, Ai C, Gan T, Wu J, Jiang Y, Liu X, Lu R, Gao N, Li Q, Ji X, Hu J. Transcription shapes DNA replication initiation to preserve genome integrity. Genome Biol 2021; 22:176. [PMID: 34108027 PMCID: PMC8188667 DOI: 10.1186/s13059-021-02390-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 05/26/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Early DNA replication occurs within actively transcribed chromatin compartments in mammalian cells, raising the immediate question of how early DNA replication coordinates with transcription to avoid collisions and DNA damage. RESULTS We develop a high-throughput nucleoside analog incorporation sequencing assay and identify thousands of early replication initiation zones in both mouse and human cells. The identified early replication initiation zones fall in open chromatin compartments and are mutually exclusive with transcription elongation. Of note, early replication initiation zones are mainly located in non-transcribed regions adjacent to transcribed regions. Mechanistically, we find that RNA polymerase II actively redistributes the chromatin-bound mini-chromosome maintenance complex (MCM), but not the origin recognition complex (ORC), to actively restrict early DNA replication initiation outside of transcribed regions. In support of this finding, we detect apparent MCM accumulation and DNA replication initiation in transcribed regions due to anchoring of nuclease-dead Cas9 at transcribed genes, which stalls RNA polymerase II. Finally, we find that the orchestration of early DNA replication initiation by transcription efficiently prevents gross DNA damage. CONCLUSION RNA polymerase II redistributes MCM complexes, but not the ORC, to prevent early DNA replication from initiating within transcribed regions. This RNA polymerase II-driven MCM redistribution spatially separates transcription and early DNA replication events and avoids the transcription-replication initiation collision, thereby providing a critical regulatory mechanism to preserve genome stability.
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Affiliation(s)
- Yang Liu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Chen Ai
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
| | - Tingting Gan
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Jinchun Wu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Yongpeng Jiang
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Xuhao Liu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
| | - Rusen Lu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Ning Gao
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Qing Li
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Xiong Ji
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Jiazhi Hu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China.
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.
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21
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Smolka JA, Sanz LA, Hartono SR, Chédin F. Recognition of RNA by the S9.6 antibody creates pervasive artifacts when imaging RNA:DNA hybrids. J Cell Biol 2021; 220:211957. [PMID: 33830170 PMCID: PMC8040515 DOI: 10.1083/jcb.202004079] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 02/01/2021] [Accepted: 03/10/2021] [Indexed: 12/11/2022] Open
Abstract
The S9.6 antibody is broadly used to detect RNA:DNA hybrids but has significant affinity for double-stranded RNA. The impact of this off-target RNA binding activity has not been thoroughly investigated, especially in the context of immunofluorescence microscopy. We report that S9.6 immunofluorescence signal observed in fixed human cells arises predominantly from ribosomal RNA, not RNA:DNA hybrids. S9.6 staining was unchanged by pretreatment with the RNA:DNA hybrid–specific nuclease RNase H1, despite verification in situ that S9.6 recognized RNA:DNA hybrids and that RNase H1 was active. S9.6 staining was, however, significantly sensitive to RNase T1, which specifically degrades RNA. Additional imaging and biochemical data indicate that the prominent cytoplasmic and nucleolar S9.6 signal primarily derives from ribosomal RNA. Importantly, genome-wide maps obtained by DNA sequencing after S9.6-mediated DNA:RNA immunoprecipitation (DRIP) are RNase H1 sensitive and RNase T1 insensitive. Altogether, these data demonstrate that imaging using S9.6 is subject to pervasive artifacts without pretreatments and controls that mitigate its promiscuous recognition of cellular RNAs.
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Affiliation(s)
- John A Smolka
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, Davis, CA
| | - Lionel A Sanz
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, Davis, CA
| | - Stella R Hartono
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, Davis, CA
| | - Frédéric Chédin
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, Davis, CA
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22
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Zhang L, Vickers TA, Sun H, Liang XH, Crooke ST. Binding of phosphorothioate oligonucleotides with RNase H1 can cause conformational changes in the protein and alter the interactions of RNase H1 with other proteins. Nucleic Acids Res 2021; 49:2721-2739. [PMID: 33577678 PMCID: PMC7969025 DOI: 10.1093/nar/gkab078] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/23/2021] [Accepted: 01/27/2021] [Indexed: 02/06/2023] Open
Abstract
We recently found that toxic PS-ASOs can cause P54nrb and PSF nucleolar mislocalization in an RNase H1-dependent manner. To better understand the underlying mechanisms of these observations, here we utilize different biochemical approaches to demonstrate that PS-ASO binding can alter the conformations of the bound proteins, as illustrated using recombinant RNase H1, P54nrb, PSF proteins and various isolated domains. While, in general, binding of PS-ASOs or ASO/RNA duplexes stabilizes the conformations of these proteins, PS-ASO binding may also cause the unfolding of RNase H1, including both the hybrid binding domain and the catalytic domain. The extent of conformational change correlates with the binding affinity of PS-ASOs to the proteins. Consequently, PS-ASO binding to RNase H1 induces the interaction of RNase H1 with P54nrb or PSF in a 2′-modification and sequence dependent manner, and toxic PS-ASOs tend to induce more interactions than non-toxic PS-ASOs. PS-ASO binding also enhances the interaction between P54nrb and PSF. However, the interaction between RNase H1 and P32 protein can be disrupted upon binding of PS-ASOs. Together, these results suggest that stronger binding of PS-ASOs can cause greater conformational changes of the bound proteins, subsequently affecting protein–protein interactions. These observations thus provide deeper understanding of the molecular basis of PS-ASO-induced protein mislocalization or degradation observed in cells and advance our understanding of why some PS-ASOs are cytotoxic.
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Affiliation(s)
- Lingdi Zhang
- Core Antisense Research, Ionis Pharmaceuticals, Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Timothy A Vickers
- Core Antisense Research, Ionis Pharmaceuticals, Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Hong Sun
- Antisense Drug discovery, Ionis Pharmaceuticals, Inc. Carlsbad, CA 92010, USA
| | - Xue-Hai Liang
- Core Antisense Research, Ionis Pharmaceuticals, Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Stanley T Crooke
- Core Antisense Research, Ionis Pharmaceuticals, Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
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23
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Chédin F, Hartono SR, Sanz LA, Vanoosthuyse V. Best practices for the visualization, mapping, and manipulation of R-loops. EMBO J 2021; 40:e106394. [PMID: 33411340 PMCID: PMC7883053 DOI: 10.15252/embj.2020106394] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/25/2020] [Accepted: 11/10/2020] [Indexed: 01/12/2023] Open
Abstract
R-loops represent an abundant class of large non-B DNA structures in genomes. Even though they form transiently and at modest frequencies, interfering with R-loop formation or dissolution has significant impacts on genome stability. Addressing the mechanism(s) of R-loop-mediated genome destabilization requires a precise characterization of their distribution in genomes. A number of independent methods have been developed to visualize and map R-loops, but their results are at times discordant, leading to confusion. Here, we review the main existing methodologies for R-loop mapping and assess their limitations as well as the robustness of existing datasets. We offer a set of best practices to improve the reproducibility of maps, hoping that such guidelines could be useful for authors and referees alike. Finally, we propose a possible resolution for the apparent contradictions in R-loop mapping outcomes between antibody-based and RNase H1-based mapping approaches.
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Affiliation(s)
- Frédéric Chédin
- Department of Molecular and Cellular Biology and Genome CenterUniversity of California, DavisDavisCAUSA
| | - Stella R Hartono
- Department of Molecular and Cellular Biology and Genome CenterUniversity of California, DavisDavisCAUSA
| | - Lionel A Sanz
- Department of Molecular and Cellular Biology and Genome CenterUniversity of California, DavisDavisCAUSA
| | - Vincent Vanoosthuyse
- Laboratoire de Biologie et Modélisation de la CelluleCNRSUMR 5239Univ LyonÉcole Normale Supérieure de LyonLyonFrance
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24
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Liang XH, De Hoyos CL, Shen W, Zhang L, Fazio M, Crooke ST. Solid-Phase Separation of Toxic Phosphorothioate Antisense Oligonucleotide-Protein Nucleolar Aggregates Is Cytoprotective. Nucleic Acid Ther 2021; 31:126-144. [PMID: 33534636 DOI: 10.1089/nat.2020.0923] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Phosphorothioate antisense oligonucleotides (PS-ASOs) interact with proteins and can localize to or induce the formation of a variety of subcellular PS-ASO-protein or PS-ASO-ribonucleoprotein aggregates. In this study, we show that these different aggregates that form with varying compositions at various concentrations in the cytosol, nucleus, and nucleolus may undergo phase separations in cells. Some aggregates can form with both nontoxic and toxic PS-ASOs, such as PS bodies, paraspeckles, and nuclear filaments. However, toxic PS-ASOs have been shown to form unique nucleolar aggregates that result in nucleolar dysfunction and apoptosis. These include liquid-like aggregates that we labeled "cloudy nucleoli" and solid-like perinucleolar filaments. Toxic nucleolar aggregates may undergo solid-phase separation and in the solid phase, protein mobility in and out of the aggregates is limited. Other aggregates appear to undergo liquid-phase separation, including paraspeckles and perinucleolar caps, in which protein mobility is negatively correlated with the binding affinity of the proteins to PS-ASOs. However, PS bodies and nuclear filaments are solid-like aggregates. Importantly, in cells that survived treatment with toxic PS-ASOs, solid-like PS-ASO aggregates accumulated, especially Hsc70-containing nucleolus-like structures, in which modest pre-rRNA transcriptional activity was retained and appeared to mitigate the nucleolar toxicity. This is the first demonstration that exogenous drugs, PS-ASOs, can form aggregates that undergo phase separations and that solid-phase separation of toxic PS-ASO-induced nucleolar aggregates is cytoprotective.
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Affiliation(s)
- Xue-Hai Liang
- Core Antisense Research and Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Cheryl Li De Hoyos
- Core Antisense Research and Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Wen Shen
- Core Antisense Research and Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Lingdi Zhang
- Core Antisense Research and Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Michael Fazio
- Medicinal Chemistry, Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Stanley T Crooke
- Core Antisense Research and Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
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25
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González de Cózar JM, Carretero-Junquera M, Ciesielski GL, Miettinen SM, Varjosalo M, Kaguni LS, Dufour E, Jacobs HT. A second hybrid-binding domain modulates the activity of Drosophila ribonuclease H1. J Biochem 2020; 168:515-533. [PMID: 32589740 PMCID: PMC7657459 DOI: 10.1093/jb/mvaa067] [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: 04/21/2020] [Accepted: 06/15/2020] [Indexed: 11/14/2022] Open
Abstract
In eukaryotes, ribonuclease H1 (RNase H1) is involved in the processing and removal of RNA/DNA hybrids in both nuclear and mitochondrial DNA. The enzyme comprises a C-terminal catalytic domain and an N-terminal hybrid-binding domain (HBD), separated by a linker of variable length, 115 amino acids in Drosophila melanogaster (Dm). Molecular modelling predicted this extended linker to fold into a structure similar to the conserved HBD. Based on a deletion series, both the catalytic domain and the conserved HBD were required for high-affinity binding to heteroduplex substrates, while loss of the novel HBD led to an ∼90% drop in Kcat with a decreased KM, and a large increase in the stability of the RNA/DNA hybrid-enzyme complex, supporting a bipartite-binding model in which the second HBD facilitates processivity. Shotgun proteomics following in vivo cross-linking identified single-stranded DNA-binding proteins from both nuclear and mitochondrial compartments, respectively RpA-70 and mtSSB, as prominent interaction partners of Dm RNase H1. However, we were not able to document direct and stable interactions with mtSSB when the proteins were co-overexpressed in S2 cells, and functional interactions between them in vitro were minor.
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Affiliation(s)
| | | | - Grzegorz L Ciesielski
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
- Department of Chemistry, Auburn University at Montgomery, Montgomery, AL 36117, USA
| | - Sini M Miettinen
- Institute of Biotechnology, FI-00014 University of Helsinki, Finland
| | - Markku Varjosalo
- Institute of Biotechnology, FI-00014 University of Helsinki, Finland
| | - Laurie S Kaguni
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Eric Dufour
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland
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26
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Unoki M, Sharif J, Saito Y, Velasco G, Francastel C, Koseki H, Sasaki H. CDCA7 and HELLS suppress DNA:RNA hybrid-associated DNA damage at pericentromeric repeats. Sci Rep 2020; 10:17865. [PMID: 33082427 PMCID: PMC7576824 DOI: 10.1038/s41598-020-74636-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 09/30/2020] [Indexed: 12/18/2022] Open
Abstract
Immunodeficiency, centromeric instability, facial anomalies (ICF) syndrome is a rare autosomal recessive disorder that is caused by mutations in either DNMT3B, ZBTB24, CDCA7, HELLS, or yet unidentified gene(s). Previously, we reported that the CDCA7/HELLS chromatin remodeling complex facilitates non-homologous end-joining. Here, we show that the same complex is required for the accumulation of proteins on nascent DNA, including the DNMT1/UHRF1 maintenance DNA methylation complex as well as proteins involved in the resolution or prevention of R-loops composed of DNA:RNA hybrids and ssDNA. Consistent with the hypomethylation state of pericentromeric repeats, the transcription and formation of aberrant DNA:RNA hybrids at the repeats were increased in ICF mutant cells. Furthermore, the ectopic expression of RNASEH1 reduced the accumulation of DNA damage at a broad range of genomic regions including pericentromeric repeats in these cells. Hence, we propose that hypomethylation due to inefficient DNMT1/UHRF1 recruitment at pericentromeric repeats by defects in the CDCA7/HELLS complex could induce pericentromeric instability, which may explain a part of the molecular pathogenesis of ICF syndrome.
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Affiliation(s)
- Motoko Unoki
- Division of Epigenomics and Development, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka, 812-8582, Japan.
| | - Jafar Sharif
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, Kanagawa, 230-0045, Japan
| | - Yuichiro Saito
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Mishima, Shizuoka, 411-8540, Japan
| | - Guillaume Velasco
- CNRS UMR7216, Epigenetics and Cell Fate, Université Paris Diderot, Sorbonne Paris Cité, 75205, Paris, France
| | - Claire Francastel
- CNRS UMR7216, Epigenetics and Cell Fate, Université Paris Diderot, Sorbonne Paris Cité, 75205, Paris, France
| | - Haruhiko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, Kanagawa, 230-0045, Japan
| | - Hiroyuki Sasaki
- Division of Epigenomics and Development, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka, 812-8582, Japan
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27
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Dou P, Li Y, Sun H, Xie W, Zhang X, Zhang X, Zhang D, Qiao S, Ci Y, Nie H, Han F, Li Y. C1orf109L binding DHX9 promotes DNA damage depended on the R-loop accumulation and enhances camptothecin chemosensitivity. Cell Prolif 2020; 53:e12875. [PMID: 32761833 PMCID: PMC7507383 DOI: 10.1111/cpr.12875] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/14/2020] [Accepted: 06/17/2020] [Indexed: 12/15/2022] Open
Abstract
Objectives R‐loop is a three‐stranded nucleic acid structure of RNA/DNA hybrid, which occurs naturally during transcription, and more R‐loop accumulation can trigger serious DNA damage. There has been increasing attention to the issue of R‐loop accumulation acted as a target for cancer therapy. However, the regulation of R‐loop‐associated proteins is poorly explored. Material and method Quantitative real‐time PCR and Western blot were used to measure the expression of C1orf109 in cell lines. In addition, C1orf109L (C1orf109 longest isoform) protein binding partner was identified and validated using immunoprecipitation‐mass spectrometric (IP‐MS) and immunoprecipitation assays. DNA‐RNA immunoprecipitation (DR‐IP) and immunofluorescence determined the C1orf109L location on R‐loop. R‐loop accumulation was determined by immunofluorescence. Cell cycle was determined by flow cytometry. Finally, time‐lapse assay and cell counting were conducted to determined cell survival in response to camptothecin (CPT). Results We found that C1orf109L could mediate cell cycle arrest in the G2/M phase and DNA damage depended on R‐loop accumulation. Meanwhile, C1orf109L could bind with DHX9 to trigger R‐loop accumulation. And C1orf109L was competitive with PARP1 binding to DHX9, which would block the function of DHX9‐PARP1 to prevent the R‐loop accumulation. Furthermore, C1orf109L could enhance the chemosensitivity of CPT, a chemotherapeutic drug capable of promoting R‐loop formation. Conclusions Our data demonstrate that C1orf109L triggers R‐loop accumulation and DNA damage to arrest cell cycle.
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Affiliation(s)
- Peng Dou
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Yiqun Li
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Haoxiu Sun
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Wanqiu Xie
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Xiaoqing Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Xiaohan Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Dandan Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Shupei Qiao
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Yanpeng Ci
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Huan Nie
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Fang Han
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Yu Li
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
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28
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New insight into the biology of R-loops. Mutat Res 2020; 821:111711. [PMID: 32516653 DOI: 10.1016/j.mrfmmm.2020.111711] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/22/2020] [Accepted: 05/23/2020] [Indexed: 11/24/2022]
Abstract
R-loops form when RNA hybridizes with its template DNA generating a three-stranded structure leaving a displaced single strand non-template DNA. During transcription negative supercoiling of DNA behind the advancing RNA polymerase will facilitate the formation of R-loops by the nascent RNA as the DNA is under wound to facilitate transcription. In theory R-loops are classified into pathological and non-pathological depending on the context of its formation. R-loop which are formed normally in various physiological events like in gene regulation and at immunoglobulin class switch regions are considered non-pathological, whereas abnormally stable R-loop which leads to genomic instability are considered pathological. Although pathological R-loop formation is a rare event but once formed completely blocks transcription, mRNA export, elevates mutagenesis, and inhibits gene expression. Hence, R-loop either prevents or induces genomic instability indirectly and are potentially an endogenous source of DNA lesion. Although the existence of R-loop has been reported few decades ago, but only recently we have gained knowledge about its formation and resolution in cells due to the availability of reagents. R-loop biology has generated immense interest in past few years since it connects the important biological processes such as transcription, mRNA splicing, DNA replication, recombination and repair. In this review I will focus on the recent progress made about formation and resolution of R-loop, based on the methodologies that are currently available to study R-loop using biochemical, cell biology and molecular biology approaches.
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29
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Vydzhak O, Luke B, Schindler N. Non-coding RNAs at the Eukaryotic rDNA Locus: RNA-DNA Hybrids and Beyond. J Mol Biol 2020; 432:4287-4304. [PMID: 32446803 DOI: 10.1016/j.jmb.2020.05.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 05/14/2020] [Accepted: 05/15/2020] [Indexed: 12/12/2022]
Abstract
The human ribosomal DNA (rDNA) locus encodes a variety of long non-coding RNAs (lncRNAs). Among them, the canonical ribosomal RNAs that are the catalytic components of the ribosomes, as well as regulatory lncRNAs including promoter-associated RNAs (pRNA), stress-induced promoter and pre-rRNA antisense RNAs (PAPAS), and different intergenic spacer derived lncRNA species (IGSRNA). In addition, externally encoded lncRNAs are imported into the nucleolus, which orchestrate the complex regulation of the nucleolar state in normal and stress conditions via a plethora of molecular mechanisms. This review focuses on the triplex and R-loop formation aspects of lncRNAs at the rDNA locus in yeast and human cells. We discuss the protein players that regulate R-loops at rDNA and how their misregulation contributes to DNA damage and disease. Furthermore, we speculate how DNA lesions such as rNMPs or 8-oxo-dG might affect RNA-DNA hybrid formation. The transcription of lncRNA from rDNA has been observed in yeast, plants, flies, worms, mouse and human cells. This evolutionary conservation highlights the importance of lncRNAs in rDNA function and maintenance.
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Affiliation(s)
- Olga Vydzhak
- Institute of Molecular Biology (IMB), Johannes Gutenberg-University Mainz, Ackermannweg 4, 55128 Mainz, Germany
| | - Brian Luke
- Institute of Molecular Biology (IMB), Johannes Gutenberg-University Mainz, Ackermannweg 4, 55128 Mainz, Germany; Institute of Developmental Biology and Neurobiology (IDN), Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Natalie Schindler
- Institute of Developmental Biology and Neurobiology (IDN), Johannes Gutenberg-University Mainz, 55128 Mainz, Germany.
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30
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Nava GM, Grasso L, Sertic S, Pellicioli A, Muzi Falconi M, Lazzaro F. One, No One, and One Hundred Thousand: The Many Forms of Ribonucleotides in DNA. Int J Mol Sci 2020; 21:E1706. [PMID: 32131532 PMCID: PMC7084774 DOI: 10.3390/ijms21051706] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/26/2020] [Accepted: 02/28/2020] [Indexed: 12/14/2022] Open
Abstract
In the last decade, it has become evident that RNA is frequently found in DNA. It is now well established that single embedded ribonucleoside monophosphates (rNMPs) are primarily introduced by DNA polymerases and that longer stretches of RNA can anneal to DNA, generating RNA:DNA hybrids. Among them, the most studied are R-loops, peculiar three-stranded nucleic acid structures formed upon the re-hybridization of a transcript to its template DNA. In addition, polyribonucleotide chains are synthesized to allow DNA replication priming, double-strand breaks repair, and may as well result from the direct incorporation of consecutive rNMPs by DNA polymerases. The bright side of RNA into DNA is that it contributes to regulating different physiological functions. The dark side, however, is that persistent RNA compromises genome integrity and genome stability. For these reasons, the characterization of all these structures has been under growing investigation. In this review, we discussed the origin of single and multiple ribonucleotides in the genome and in the DNA of organelles, focusing on situations where the aberrant processing of RNA:DNA hybrids may result in multiple rNMPs embedded in DNA. We concluded by providing an overview of the currently available strategies to study the presence of single and multiple ribonucleotides in DNA in vivo.
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Affiliation(s)
| | | | | | | | - Marco Muzi Falconi
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy; (G.M.N.); (L.G.); (S.S.); (A.P.)
| | - Federico Lazzaro
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy; (G.M.N.); (L.G.); (S.S.); (A.P.)
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31
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Reyes A, Rusecka J, Tońska K, Zeviani M. RNase H1 Regulates Mitochondrial Transcription and Translation via the Degradation of 7S RNA. Front Genet 2020; 10:1393. [PMID: 32082360 PMCID: PMC7006045 DOI: 10.3389/fgene.2019.01393] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/19/2019] [Indexed: 02/02/2023] Open
Abstract
RNase H1 is able to recognize DNA/RNA heteroduplexes and to degrade their RNA component. As a consequence, it has been implicated in different aspects of mtDNA replication such as primer formation, primer removal, and replication termination, and significant differences have been reported between control and mutant RNASEH1 skin fibroblasts from patients. However, neither mtDNA depletion nor the presence of deletions have been described in skin fibroblasts while still presenting signs of mitochondrial dysfunction (lower mitochondrial membrane potential, reduced oxygen consumption, slow growth in galactose). Here, we show that RNase H1 has an effect on mtDNA transcripts, most likely through the regulation of 7S RNA and other R-loops. The observed effect on both mitochondrial mRNAs and 16S rRNA results in decreased mitochondrial translation and subsequently mitochondrial dysfunction in cells carrying mutations in RNASEH1.
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Affiliation(s)
- Aurelio Reyes
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom,*Correspondence: Aurelio Reyes, ; Massimo Zeviani,
| | - Joanna Rusecka
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom,Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Katarzyna Tońska
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Massimo Zeviani
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom,*Correspondence: Aurelio Reyes, ; Massimo Zeviani,
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32
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Velichko AK, Petrova NV, Luzhin AV, Strelkova OS, Ovsyannikova N, Kireev II, Petrova NV, Razin SV, Kantidze OL. Hypoosmotic stress induces R loop formation in nucleoli and ATR/ATM-dependent silencing of nucleolar transcription. Nucleic Acids Res 2020; 47:6811-6825. [PMID: 31114877 PMCID: PMC6648358 DOI: 10.1093/nar/gkz436] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/03/2019] [Accepted: 05/08/2019] [Indexed: 12/16/2022] Open
Abstract
The contribution of nucleoli to the cellular stress response has been discussed for over a decade. Stress-induced inhibition of RNA polymerase I-dependent transcription is hypothesized as a possible effector program in such a response. In this study, we report a new mechanism by which ribosomal DNA transcription can be inhibited in response to cellular stress. Specifically, we demonstrate that mild hypoosmotic stress induces stabilization of R loops in ribosomal genes and thus provokes the nucleoli-specific DNA damage response, which is governed by the ATM- and Rad3-related (ATR) kinase. Activation of ATR in nucleoli strongly depends on Treacle, which is needed for efficient recruitment/retention of TopBP1 in nucleoli. Subsequent ATR-mediated activation of ATM results in repression of nucleolar transcription.
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Affiliation(s)
- Artem K Velichko
- Laboratory of Genome Stability, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia.,Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Nadezhda V Petrova
- Laboratory of Genome Stability, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Artem V Luzhin
- Laboratory of Genome Stability, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Olga S Strelkova
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
| | - Natalia Ovsyannikova
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
| | - Igor I Kireev
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia.,V.I. Kulakov National Medical Research Center for Obstetrics, Gynecology, and Perinatology, 117997 Moscow, Russia
| | - Natalia V Petrova
- Laboratory of Structural and Functional Organization of Chromosomes, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Sergey V Razin
- Laboratory of Structural and Functional Organization of Chromosomes, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia.,Department of Molecular Biology, Moscow State University, 119234 Moscow, Russia.,LFR2O, Institute Gustave Roussy, F-94805 Villejuif, France
| | - Omar L Kantidze
- Laboratory of Genome Stability, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia.,LFR2O, Institute Gustave Roussy, F-94805 Villejuif, France
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33
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Kawaguchi T, Rollins MG, Moinpour M, Morera AA, Ebmeier CC, Old WM, Schwartz JC. Changes to the TDP-43 and FUS Interactomes Induced by DNA Damage. J Proteome Res 2020; 19:360-370. [PMID: 31693373 PMCID: PMC6947635 DOI: 10.1021/acs.jproteome.9b00575] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Indexed: 12/13/2022]
Abstract
The RNA-binding proteins TDP-43 and FUS are tied as the third leading known genetic cause for amyotrophic lateral sclerosis (ALS), and TDP-43 proteopathies are found in nearly all ALS patients. Both the natural function and contribution to pathology for TDP-43 remain unclear. The intersection of functions between TDP-43 and FUS can focus attention for those natural functions mostly likely to be relevant to disease. Here, we compare the role played by TDP-43 and FUS, maintaining chromatin stability for dividing HEK293T cells. We also determine and compare the interactomes of TDP-43 and FUS, quantitating changes in those before and after DNA damage. Finally, selected interactions with known importance to DNA damage repair were validated by co-immunoprecipitation assays. This study uncovered TDP-43 and FUS binding to several factors important to DNA repair mechanisms that can be replication-dependent, -independent, or both. These results provide further evidence that TDP-43 has an important role in DNA stability and provide new ways that TDP-43 can bind to the machinery that guards DNA integrity in cells.
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Affiliation(s)
- Tetsuya Kawaguchi
- Department
of Chemistry and Biochemistry and Department of Molecular and Cellular
Biology, University of Arizona, Tucson, Arizona 85721, United States
| | - Matthew G. Rollins
- Department
of Chemistry and Biochemistry and Department of Molecular and Cellular
Biology, University of Arizona, Tucson, Arizona 85721, United States
| | - Mahta Moinpour
- Department
of Chemistry and Biochemistry and Department of Molecular and Cellular
Biology, University of Arizona, Tucson, Arizona 85721, United States
| | - Andres A. Morera
- Department
of Chemistry and Biochemistry and Department of Molecular and Cellular
Biology, University of Arizona, Tucson, Arizona 85721, United States
| | - Christopher C. Ebmeier
- Department
of Molecular and Cellular Biology, University
of Colorado, Boulder, Colorado 80309, United States
| | - William M. Old
- Department
of Molecular and Cellular Biology, University
of Colorado, Boulder, Colorado 80309, United States
| | - Jacob C. Schwartz
- Department
of Chemistry and Biochemistry and Department of Molecular and Cellular
Biology, University of Arizona, Tucson, Arizona 85721, United States
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34
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Shen W, De Hoyos CL, Sun H, Vickers TA, Liang XH, Crooke ST. Acute hepatotoxicity of 2' fluoro-modified 5-10-5 gapmer phosphorothioate oligonucleotides in mice correlates with intracellular protein binding and the loss of DBHS proteins. Nucleic Acids Res 2019; 46:2204-2217. [PMID: 29390093 PMCID: PMC5861398 DOI: 10.1093/nar/gky060] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 01/23/2018] [Indexed: 01/06/2023] Open
Abstract
We reported previously that a 2′ fluoro-modified (2′ F) phosphorothioate (PS) antisense oligonucleotides (ASOs) with 5–10–5 gapmer configuration interacted with proteins from Drosophila behavior/human splicing (DBHS) family with higher affinity than PS-ASOs modified with 2′-O-(2-methoxyethyl) (2′ MOE) or 2′,4′-constrained 2′-O-ethyl (cEt) did. Rapid degradation of these proteins and cytotoxicity were observed in cells treated with 2′ F PS-ASO. Here, we report that 2′ F gapmer PS-ASOs of different sequences caused reduction in levels of DBHS proteins and hepatotoxicity in mice. 2′ F PS-ASOs induced activation of the P53 pathway and downregulation of metabolic pathways. Altered levels of RNA and protein markers for hepatotoxicity, liver necrosis, and apoptosis were observed as early as 24 to 48 hours after a single administration of the 2′ F PS-ASO. The observed effects were not likely due to the hybridization-dependent RNase H1 cleavage of on- or potential off-target RNAs, or due to potential toxicity of 2′ F nucleoside metabolites. Instead, we found that 2′ F PS-ASO associated with more intra-cellular proteins including proteins from DBHS family. Our results suggest that protein-binding correlates positively with the 2′ F modification-dependent loss of DBHS proteins and the toxicity of gapmer 2′ F PS-ASO in vivo.
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Affiliation(s)
- Wen Shen
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc. 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Cheryl L De Hoyos
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc. 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Hong Sun
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc. 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Timothy A Vickers
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc. 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Xue-Hai Liang
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc. 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Stanley T Crooke
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc. 2855 Gazelle Court, Carlsbad, CA 92010, USA
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35
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Girstun A, Ishikawa T, Staron K. Effects of SRSF1 on subnuclear localization of topoisomerase I. J Cell Biochem 2019; 120:11794-11808. [PMID: 30775805 DOI: 10.1002/jcb.28459] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 11/30/2018] [Accepted: 12/06/2018] [Indexed: 01/24/2023]
Abstract
Subnuclear localization of topoisomerase I (top I) is determined by its DNA relaxation activity and a net of its interactions with in majority unidentified nucleolar and nucleoplasmic elements. Here, we recognized SR protein SRSF1 (Serine/arginine-rich splicing factor 1, previously known as SF2/ASF) as a new element of the net. In HeLa cells, overexpression of SRSF1 recruited top I to the nucleoplasm whereas its silencing concentrated it in the nucleolus. Effect of SRSF1 was independent of top I relaxation activity and was the best pronounced for the mutant inactive in relaxation reaction. In HCT116 cells where top I was not released from the nucleolus upon halting relaxation activity, it was also not relocated by elevated level of SRSF1. Out of remaining SR proteins, SRSF5, SRSF7, and SRSF9 did not influence the localization of top I in HeLa cells whereas overexpression of SRSF2, SRSF3, SRSF6, and partly SRSF4 concentrated top I in the nucleolus, most possibly due to the reduction of the SRSF1 accessibility. Specific effect of SRSF1 was exerted because of its distinct RS domain. Silencing of SRSF1 compensated the deletion of the top I N-terminal region, individually responsible for nucleoplasmic localization of the mutant, and restored the wild-type phenotype of deletion mutant localization. SRSF1 was essential for the camptothecin-induced clearance from the nucleolus. These results suggest a possible role of SRSF1 in establishing partition of top I between the nucleolus and the nucleoplasm in some cell types with distinct combinations of SR proteins levels.
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Affiliation(s)
- Agnieszka Girstun
- Department of Molecular Biology, Institute of Biochemistry, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Takao Ishikawa
- Department of Molecular Biology, Institute of Biochemistry, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Krzysztof Staron
- Department of Molecular Biology, Institute of Biochemistry, Faculty of Biology, University of Warsaw, Warsaw, Poland
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36
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Shen W, De Hoyos CL, Migawa MT, Vickers TA, Sun H, Low A, Bell TA, Rahdar M, Mukhopadhyay S, Hart CE, Bell M, Riney S, Murray SF, Greenlee S, Crooke RM, Liang XH, Seth PP, Crooke ST. Chemical modification of PS-ASO therapeutics reduces cellular protein-binding and improves the therapeutic index. Nat Biotechnol 2019; 37:640-650. [PMID: 31036929 DOI: 10.1038/s41587-019-0106-2] [Citation(s) in RCA: 180] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 03/15/2019] [Indexed: 12/13/2022]
Abstract
The molecular mechanisms of toxicity of chemically modified phosphorothioate antisense oligonucleotides (PS-ASOs) are not fully understood. Here, we report that toxic gapmer PS-ASOs containing modifications such as constrained ethyl (cEt), locked nucleic acid (LNA) and 2'-O-methoxyethyl (2'-MOE) bind many cellular proteins with high avidity, altering their function, localization and stability. We show that RNase H1-dependent delocalization of paraspeckle proteins to nucleoli is an early event in PS-ASO toxicity, followed by nucleolar stress, p53 activation and apoptotic cell death. Introduction of a single 2'-O-methyl (2'-OMe) modification at gap position 2 reduced protein-binding, substantially decreasing hepatotoxicity and improving the therapeutic index with minimal impairment of antisense activity. We validated the ability of this modification to generally mitigate PS-ASO toxicity with more than 300 sequences. Our findings will guide the design of PS-ASOs with optimal therapeutic profiles.
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Affiliation(s)
- Wen Shen
- Ionis Pharmaceuticals, Inc., Carlsbad, CA, USA
| | | | | | | | - Hong Sun
- Ionis Pharmaceuticals, Inc., Carlsbad, CA, USA
| | - Audrey Low
- Ionis Pharmaceuticals, Inc., Carlsbad, CA, USA
| | | | | | | | | | | | - Stan Riney
- Ionis Pharmaceuticals, Inc., Carlsbad, CA, USA
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37
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Seth PP, Swayze EE. The Medicinal Chemistry of RNase H-activating Antisense Oligonucleotides. ADVANCES IN NUCLEIC ACID THERAPEUTICS 2019. [DOI: 10.1039/9781788015714-00032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This review focuses on the properties that an RNase H-activating antisense oligonucleotide (ASO) drug must have to function effectively in animals, as well as on medicinal chemistry strategies to achieve these properties. The biochemistry and structural requirements for activating RNase H are briefly summarized, as well as chemical modifications that can effect activation of RNase H when an ASO is bound to target RNA. The key modifications available to the medicinal chemist to engineer desired properties of the ASO are briefly reviewed, as are ASO design strategies to achieve optimal activity in animal systems. Lastly, the interactions of ASOs with proteins and strategies to control these interactions to improve the profile of ASOs are discussed.
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Affiliation(s)
- Punit P. Seth
- Ionis Pharmaceuticals 2855 Gazelle Court Carlsbad CA 92010 USA
| | - Eric E. Swayze
- Ionis Pharmaceuticals 2855 Gazelle Court Carlsbad CA 92010 USA
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38
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González de Cózar JM, Gerards M, Teeri E, George J, Dufour E, Jacobs HT, Jõers P. RNase H1 promotes replication fork progression through oppositely transcribed regions of Drosophila mitochondrial DNA. J Biol Chem 2019; 294:4331-4344. [PMID: 30635398 PMCID: PMC6433063 DOI: 10.1074/jbc.ra118.007015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/09/2019] [Indexed: 11/12/2022] Open
Abstract
Mitochondrial DNA (mtDNA) replication uses a simple core machinery similar to those of bacterial viruses and plasmids, but its components are challenging to unravel. Here, we found that, as in mammals, the single Drosophila gene for RNase H1 (rnh1) has alternative translational start sites, resulting in two polypeptides, targeted to either mitochondria or the nucleus. RNAi-mediated rnh1 knockdown did not influence growth or viability of S2 cells, but compromised mtDNA integrity and copy number. rnh1 knockdown in intact flies also produced a phenotype of impaired mitochondrial function, characterized by respiratory chain deficiency, locomotor dysfunction, and decreased lifespan. Its overexpression in S2 cells resulted in cell lethality after 5–9 days, attributable to the nuclearly localized isoform. rnh1 knockdown and overexpression produced opposite effects on mtDNA replication intermediates. The most pronounced effects were seen in genome regions beyond the major replication pauses where the replication fork needs to progress through a gene cluster that is transcribed in the opposite direction. RNase H1 deficiency led to an accumulation of replication intermediates in these zones, abundant mtDNA molecules joined by four-way junctions, and species consistent with fork regression from the origin. These findings indicate replication stalling due to the presence of unprocessed RNA/DNA heteroduplexes, potentially leading to the degradation of collapsed forks or to replication restart by a mechanism involving strand invasion. Both mitochondrial RNA and DNA syntheses were affected by rnh1 knockdown, suggesting that RNase H1 also plays a role in integrating or coregulating these processes in Drosophila mitochondria.
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Affiliation(s)
- Jose M González de Cózar
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Mike Gerards
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Eveliina Teeri
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Jack George
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Eric Dufour
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland
| | - Howard T Jacobs
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland, .,Institute of Biotechnology, FI-00014 University of Helsinki, Finland, and
| | - Priit Jõers
- From the Faculty of Medicine and Health Technology and Tampere University Hospital, FI-33014 Tampere University, Finland.,Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia
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39
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Benitez-Guijarro M, Lopez-Ruiz C, Tarnauskaitė Ž, Murina O, Mian Mohammad M, Williams TC, Fluteau A, Sanchez L, Vilar-Astasio R, Garcia-Canadas M, Cano D, Kempen MJH, Sanchez-Pozo A, Heras SR, Jackson AP, Reijns MA, Garcia-Perez JL. RNase H2, mutated in Aicardi-Goutières syndrome, promotes LINE-1 retrotransposition. EMBO J 2018; 37:e98506. [PMID: 29959219 PMCID: PMC6068448 DOI: 10.15252/embj.201798506] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 05/23/2018] [Accepted: 05/28/2018] [Indexed: 12/03/2022] Open
Abstract
Long INterspersed Element class 1 (LINE-1) elements are a type of abundant retrotransposons active in mammalian genomes. An average human genome contains ~100 retrotransposition-competent LINE-1s, whose activity is influenced by the combined action of cellular repressors and activators. TREX1, SAMHD1 and ADAR1 are known LINE-1 repressors and when mutated cause the autoinflammatory disorder Aicardi-Goutières syndrome (AGS). Mutations in RNase H2 are the most common cause of AGS, and its activity was proposed to similarly control LINE-1 retrotransposition. It has therefore been suggested that increased LINE-1 activity may be the cause of aberrant innate immune activation in AGS Here, we establish that, contrary to expectations, RNase H2 is required for efficient LINE-1 retrotransposition. As RNase H1 overexpression partially rescues the defect in RNase H2 null cells, we propose a model in which RNase H2 degrades the LINE-1 RNA after reverse transcription, allowing retrotransposition to be completed. This also explains how LINE-1 elements can retrotranspose efficiently without their own RNase H activity. Our findings appear to be at odds with LINE-1-derived nucleic acids driving autoinflammation in AGS.
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Affiliation(s)
- Maria Benitez-Guijarro
- GENYO, Centro de Genómica e Investigación Oncológica: Pfizer - Universidad de Granada - Junta de Andalucía, PTS, Granada, Spain
| | - Cesar Lopez-Ruiz
- GENYO, Centro de Genómica e Investigación Oncológica: Pfizer - Universidad de Granada - Junta de Andalucía, PTS, Granada, Spain
| | - Žygimantė Tarnauskaitė
- MRC Human Genetics Unit, MRC, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | - Olga Murina
- MRC Human Genetics Unit, MRC, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | - Mahwish Mian Mohammad
- MRC Human Genetics Unit, MRC, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | - Thomas C Williams
- MRC Human Genetics Unit, MRC, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | - Adeline Fluteau
- MRC Human Genetics Unit, MRC, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | - Laura Sanchez
- GENYO, Centro de Genómica e Investigación Oncológica: Pfizer - Universidad de Granada - Junta de Andalucía, PTS, Granada, Spain
| | - Raquel Vilar-Astasio
- GENYO, Centro de Genómica e Investigación Oncológica: Pfizer - Universidad de Granada - Junta de Andalucía, PTS, Granada, Spain
| | - Marta Garcia-Canadas
- GENYO, Centro de Genómica e Investigación Oncológica: Pfizer - Universidad de Granada - Junta de Andalucía, PTS, Granada, Spain
| | - David Cano
- GENYO, Centro de Genómica e Investigación Oncológica: Pfizer - Universidad de Granada - Junta de Andalucía, PTS, Granada, Spain
| | - Marie-Jeanne Hc Kempen
- MRC Human Genetics Unit, MRC, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | - Antonio Sanchez-Pozo
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Sara R Heras
- GENYO, Centro de Genómica e Investigación Oncológica: Pfizer - Universidad de Granada - Junta de Andalucía, PTS, Granada, Spain
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Andrew P Jackson
- MRC Human Genetics Unit, MRC, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | - Martin Am Reijns
- MRC Human Genetics Unit, MRC, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | - Jose L Garcia-Perez
- GENYO, Centro de Genómica e Investigación Oncológica: Pfizer - Universidad de Granada - Junta de Andalucía, PTS, Granada, Spain
- MRC Human Genetics Unit, MRC, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
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40
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Strengths and Weaknesses of the Current Strategies to Map and Characterize R-Loops. Noncoding RNA 2018; 4:ncrna4020009. [PMID: 29657305 PMCID: PMC6027298 DOI: 10.3390/ncrna4020009] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 03/22/2018] [Accepted: 03/23/2018] [Indexed: 12/26/2022] Open
Abstract
R-loops are evolutionarily conserved three-stranded structures that result from the formation of stable DNA:RNA hybrids in the genome. R-loops have attracted increasing interest in recent years as potent regulators of gene expression and genome stability. In particular, their strong association with severe replication stress makes them potential oncogenic structures. Despite their importance, the rules that govern their formation and their dynamics are still controversial and an in-depth description of their direct impact on chromatin organization and DNA transactions is still lacking. To better understand the diversity of R-loop functions, reliable, accurate, and quantitative mapping techniques, as well as functional assays are required. Here, I review the different approaches that are currently used to do so and to highlight their individual strengths and weaknesses. In particular, I review the advantages and disadvantages of using the S9.6 antibody to map R-loops in vivo in an attempt to propose guidelines for best practices.
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