1
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Cottrell KA, Andrews RJ, Bass BL. The competitive landscape of the dsRNA world. Mol Cell 2024; 84:107-119. [PMID: 38118451 PMCID: PMC10843539 DOI: 10.1016/j.molcel.2023.11.033] [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: 10/16/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/22/2023]
Abstract
The ability to sense and respond to infection is essential for life. Viral infection produces double-stranded RNAs (dsRNAs) that are sensed by proteins that recognize the structure of dsRNA. This structure-based recognition of viral dsRNA allows dsRNA sensors to recognize infection by many viruses, but it comes at a cost-the dsRNA sensors cannot always distinguish between "self" and "nonself" dsRNAs. "Self" RNAs often contain dsRNA regions, and not surprisingly, mechanisms have evolved to prevent aberrant activation of dsRNA sensors by "self" RNA. Here, we review current knowledge about the life of endogenous dsRNAs in mammals-the biosynthesis and processing of dsRNAs, the proteins they encounter, and their ultimate degradation. We highlight mechanisms that evolved to prevent aberrant dsRNA sensor activation and the importance of competition in the regulation of dsRNA sensors and other dsRNA-binding proteins.
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Affiliation(s)
- Kyle A Cottrell
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA.
| | - Ryan J Andrews
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Brenda L Bass
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA.
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2
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Haque N, Will A, Cook AG, Hogg JR. A network of DZF proteins controls alternative splicing regulation and fidelity. Nucleic Acids Res 2023; 51:6411-6429. [PMID: 37144502 PMCID: PMC10325889 DOI: 10.1093/nar/gkad351] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 04/12/2023] [Accepted: 05/03/2023] [Indexed: 05/06/2023] Open
Abstract
Proteins containing DZF (domain associated with zinc fingers) modules play important roles throughout gene expression, from transcription to translation. Derived from nucleotidyltransferases but lacking catalytic residues, DZF domains serve as heterodimerization surfaces between DZF protein pairs. Three DZF proteins are widely expressed in mammalian tissues, ILF2, ILF3 and ZFR, which form mutually exclusive ILF2-ILF3 and ILF2-ZFR heterodimers. Using eCLIP-Seq, we find that ZFR binds across broad intronic regions to regulate the alternative splicing of cassette and mutually exclusive exons. ZFR preferentially binds dsRNA in vitro and is enriched on introns containing conserved dsRNA elements in cells. Many splicing events are similarly altered upon depletion of any of the three DZF proteins; however, we also identify independent and opposing roles for ZFR and ILF3 in alternative splicing regulation. Along with widespread involvement in cassette exon splicing, the DZF proteins control the fidelity and regulation of over a dozen highly validated mutually exclusive splicing events. Our findings indicate that the DZF proteins form a complex regulatory network that leverages dsRNA binding by ILF3 and ZFR to modulate splicing regulation and fidelity.
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Affiliation(s)
- Nazmul Haque
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD20892, USA
| | - Alexander Will
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Atlanta G Cook
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - J Robert Hogg
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD20892, USA
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3
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Hieber C, Grabbe S, Bros M. Counteracting Immunosenescence-Which Therapeutic Strategies Are Promising? Biomolecules 2023; 13:1085. [PMID: 37509121 PMCID: PMC10377144 DOI: 10.3390/biom13071085] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/30/2023] Open
Abstract
Aging attenuates the overall responsiveness of the immune system to eradicate pathogens. The increased production of pro-inflammatory cytokines by innate immune cells under basal conditions, termed inflammaging, contributes to impaired innate immune responsiveness towards pathogen-mediated stimulation and limits antigen-presenting activity. Adaptive immune responses are attenuated as well due to lowered numbers of naïve lymphocytes and their impaired responsiveness towards antigen-specific stimulation. Additionally, the numbers of immunoregulatory cell types, comprising regulatory T cells and myeloid-derived suppressor cells, that inhibit the activity of innate and adaptive immune cells are elevated. This review aims to summarize our knowledge on the cellular and molecular causes of immunosenescence while also taking into account senescence effects that constitute immune evasion mechanisms in the case of chronic viral infections and cancer. For tumor therapy numerous nanoformulated drugs have been developed to overcome poor solubility of compounds and to enable cell-directed delivery in order to restore immune functions, e.g., by addressing dysregulated signaling pathways. Further, nanovaccines which efficiently address antigen-presenting cells to mount sustained anti-tumor immune responses have been clinically evaluated. Further, senolytics that selectively deplete senescent cells are being tested in a number of clinical trials. Here we discuss the potential use of such drugs to improve anti-aging therapy.
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Affiliation(s)
- Christoph Hieber
- Department of Dermatology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Stephan Grabbe
- Department of Dermatology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Matthias Bros
- Department of Dermatology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, 55131 Mainz, Germany
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4
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The Polyvalent Role of NF90 in RNA Biology. Int J Mol Sci 2022; 23:ijms232113584. [DOI: 10.3390/ijms232113584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/27/2022] [Accepted: 11/04/2022] [Indexed: 11/10/2022] Open
Abstract
Double-stranded RNA-binding proteins (dsRBPs) are major players in the regulation of gene expression patterns. Among them, Nuclear Factor 90 (NF90) has a plethora of well-known functions in viral infection, transcription, and translation as well as RNA stability and degradation. In addition, NF90 has been identified as a regulator of microRNA (miRNA) maturation by competing with Microprocessor for the binding of pri-miRNAs in the nucleus. NF90 was recently shown to control the biogenesis of a subset of human miRNAs, which ultimately influences, not only the abundance, but also the expression of the host gene and the fate of the mRNA target repertoire. Moreover, recent evidence suggests that NF90 is also involved in RNA-Induced Silencing Complex (RISC)-mediated silencing by binding to target mRNAs and controlling their translation and degradation. Here, we review the many, and growing, functions of NF90 in RNA biology, with a focus on the miRNA pathway and RISC-mediated gene silencing.
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5
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Grasso G, Akkawi C, Franckhauser C, Nait-Saidi R, Bello M, Barbier J, Kiernan R. NF90 interacts with components of RISC and modulates association of Ago2 with mRNA. BMC Biol 2022; 20:194. [PMID: 36050755 PMCID: PMC9438302 DOI: 10.1186/s12915-022-01384-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 08/05/2022] [Indexed: 01/14/2023] Open
Abstract
Background Nuclear factor 90 (NF90) is a double-stranded RNA-binding protein involved in a multitude of different cellular mechanisms such as transcription, translation, viral infection, and mRNA stability. Recent data suggest that NF90 might influence the abundance of target mRNAs in the cytoplasm through miRNA- and Argonaute 2 (Ago2)-dependent activity. Results Here, we identified the interactome of NF90 in the cytoplasm, which revealed several components of the RNA-induced silencing complex (RISC) and associated factors. Co-immunoprecipitation analysis confirmed the interaction of NF90 with the RISC-associated RNA helicase, Moloney leukemia virus 10 (MOV10), and other proteins involved in RISC-mediated silencing, including Ago2. Furthermore, NF90 association with MOV10 and Ago2 was found to be RNA-dependent. Glycerol gradient sedimentation of NF90 immune complexes indicates that these proteins occur in the same protein complex. At target RNAs predicted to bind both NF90 and MOV10 in their 3′ UTRs, NF90 association was increased upon loss of MOV10 and vice versa. Interestingly, loss of NF90 led to an increase in association of Ago2 as well as a decrease in the abundance of the target mRNA. Similarly, during hypoxia, the binding of Ago2 to vascular endothelial growth factor (VEGF) mRNA increased after loss of NF90, while the level of VEGF mRNA decreased. Conclusions These findings reveal that, in the cytoplasm, NF90 can associate with components of RISC such as Ago2 and MOV10. In addition, the data indicate that NF90 and MOV10 may compete for the binding of common target mRNAs, suggesting a role for NF90 in the regulation of RISC-mediated silencing by stabilizing target mRNAs, such as VEGF, during cancer-induced hypoxia. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01384-2.
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Affiliation(s)
- Giuseppa Grasso
- UMR9002 CNRS-UM, Institut de Génétique Humaine-Université de Montpellier, Gene Regulation lab, 34396, Montpellier, France
| | - Charbel Akkawi
- UMR9002 CNRS-UM, Institut de Génétique Humaine-Université de Montpellier, Gene Regulation lab, 34396, Montpellier, France
| | - Celine Franckhauser
- UMR9002 CNRS-UM, Institut de Génétique Humaine-Université de Montpellier, Gene Regulation lab, 34396, Montpellier, France
| | - Rima Nait-Saidi
- UMR9002 CNRS-UM, Institut de Génétique Humaine-Université de Montpellier, Gene Regulation lab, 34396, Montpellier, France
| | - Maxime Bello
- UMR9002 CNRS-UM, Institut de Génétique Humaine-Université de Montpellier, Gene Regulation lab, 34396, Montpellier, France
| | - Jérôme Barbier
- UMR9002 CNRS-UM, Institut de Génétique Humaine-Université de Montpellier, Gene Regulation lab, 34396, Montpellier, France
| | - Rosemary Kiernan
- UMR9002 CNRS-UM, Institut de Génétique Humaine-Université de Montpellier, Gene Regulation lab, 34396, Montpellier, France.
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6
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Busa VF, Favorov AV, Fertig EJ, Leung AK. Spatial correlation statistics enable transcriptome-wide characterization of RNA structure binding. CELL REPORTS METHODS 2021; 1:100088. [PMID: 35474897 PMCID: PMC9017189 DOI: 10.1016/j.crmeth.2021.100088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 06/23/2021] [Accepted: 08/30/2021] [Indexed: 11/20/2022]
Abstract
Molecular interactions at identical transcriptomic locations or at proximal but non-overlapping sites can mediate RNA modification and regulation, necessitating tools to uncover these spatial relationships. We present nearBynding, a flexible algorithm and software pipeline that models spatial correlation between transcriptome-wide tracks from diverse data types. nearBynding can process and correlate interval as well as continuous data and incorporate experimentally derived or in silico predicted transcriptomic tracks. nearBynding offers visualization functions for its statistics to identify colocalizations and adjacent features. We demonstrate the application of nearBynding to correlate RNA-binding protein (RBP) binding preferences with other RBPs, RNA structure, or RNA modification. By cross-correlating RBP binding and RNA structure data, we demonstrate that nearBynding recapitulates known RBP binding to structural motifs and provides biological insights into RBP binding preference of G-quadruplexes. nearBynding is available as an R/Bioconductor package and can run on a personal computer, making correlation of transcriptomic features broadly accessible.
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Affiliation(s)
- Veronica F. Busa
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Alexander V. Favorov
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Laboratory of Systems Biology and Computational Genetics, Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Elana J. Fertig
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Biomedical Engineering, Johns Hopkins University Whiting School of Engineering, Baltimore, MD 21205, USA
- Department of Applied Mathematics and Statistics, Johns Hopkins University Whiting School of Engineering, Baltimore, MD 21205, USA
| | - Anthony K.L. Leung
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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7
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Nourreddine S, Lavoie G, Paradis J, Ben El Kadhi K, Méant A, Aubert L, Grondin B, Gendron P, Chabot B, Bouvier M, Carreno S, Roux PP. NF45 and NF90 Regulate Mitotic Gene Expression by Competing with Staufen-Mediated mRNA Decay. Cell Rep 2021; 31:107660. [PMID: 32433969 DOI: 10.1016/j.celrep.2020.107660] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 01/16/2020] [Accepted: 04/28/2020] [Indexed: 12/12/2022] Open
Abstract
In human cells, the expression of ∼1,000 genes is modulated throughout the cell cycle. Although some of these genes are controlled by specific transcriptional programs, very little is known about their post-transcriptional regulation. Here, we analyze the expression signature associated with all 687 RNA-binding proteins (RBPs) and identify 39 that significantly correlate with cell cycle mRNAs. We find that NF45 and NF90 play essential roles in mitosis, and transcriptome analysis reveals that they are necessary for the expression of a subset of mitotic mRNAs. Using proteomics, we identify protein clusters associated with the NF45-NF90 complex, including components of Staufen-mediated mRNA decay (SMD). We show that depletion of SMD components increases the binding of mitotic mRNAs to the NF45-NF90 complex and rescues cells from mitotic defects. Together, our results indicate that the NF45-NF90 complex plays essential roles in mitosis by competing with the SMD machinery for a common set of mRNAs.
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Affiliation(s)
- Sami Nourreddine
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Geneviève Lavoie
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Justine Paradis
- Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA
| | | | - Antoine Méant
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Léo Aubert
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Benoit Grondin
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Patrick Gendron
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Benoit Chabot
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Michel Bouvier
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC H3T 1J4, Canada; Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Sébastien Carreno
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC H3T 1J4, Canada; Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Philippe P Roux
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC H3T 1J4, Canada; Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada.
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8
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Fasolo F, Patrucco L, Volpe M, Bon C, Peano C, Mignone F, Carninci P, Persichetti F, Santoro C, Zucchelli S, Sblattero D, Sanges R, Cotella D, Gustincich S. The RNA-binding protein ILF3 binds to transposable element sequences in SINEUP lncRNAs. FASEB J 2019; 33:13572-13589. [PMID: 31570000 PMCID: PMC6894054 DOI: 10.1096/fj.201901618rr] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Transposable elements (TEs) compose about half of the mammalian genome and, as embedded sequences, up to 40% of long noncoding RNA (lncRNA) transcripts. Embedded TEs may represent functional domains within lncRNAs, providing a structured RNA platform for protein interaction. Here we show the interactome profile of the mouse inverted short interspersed nuclear element (SINE) of subfamily B2 (invSINEB2) alone and embedded in antisense (AS) ubiquitin C-terminal hydrolase L1 (Uchl1), an lncRNA that is AS to Uchl1 gene. AS Uchl1 is the representative member of a functional class of AS lncRNAs, named SINEUPs, in which the invSINEB2 acts as effector domain (ED)-enhancing translation of sense protein-coding mRNAs. By using RNA-interacting domainome technology, we identify the IL enhancer-binding factor 3 (ILF3) as a protein partner of AS Uchl1 RNA. We determine that this interaction is mediated by the RNA-binding motif 2 of ILF3 and the invSINEB2. Furthermore, we show that ILF3 is able to bind a free right Arthrobacter luteus (Alu) monomer sequence, the embedded TE acting as ED in human SINEUPs. Bioinformatic analysis of Encyclopedia of DNA Elements-enhanced cross-linking immunoprecipitation data reveals that ILF3 binds transcribed human SINE sequences at transcriptome-wide levels. We then demonstrate that the embedded TEs modulate AS Uchl1 RNA nuclear localization to an extent moderately influenced by ILF3. This work unveils the existence of a specific interaction between embedded TEs and an RNA-binding protein, strengthening the model of TEs as functional modules in lncRNAs.-Fasolo, F., Patrucco, L., Volpe, M., Bon, C., Peano, C., Mignone, F., Carninci, P., Persichetti, F., Santoro, C., Zucchelli, S., Sblattero, D., Sanges, R., Cotella, D., Gustincich, S. The RNA-binding protein ILF3 binds to transposable element sequences in SINEUP lncRNAs.
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Affiliation(s)
- Francesca Fasolo
- Area of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Laura Patrucco
- Department of Health Sciences, Università del Piemonte Orientale, Novara, Italy
| | - Massimiliano Volpe
- Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy.,Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Carlotta Bon
- Area of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy.,Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Clelia Peano
- Institute of Genetic and Biomedical Research (IRGB), National Research Council (CNR), Milan, Italy.,Humanitas Clinical and Research Center, Rozzano, Italy
| | - Flavio Mignone
- Department of Sciences and Innovation, Università del Piemonte Orientale, Alessandria, Italy
| | - Piero Carninci
- Division of Genomic Technologies, Riken Center for Life Science Technologies, Yokohama, Japan
| | | | - Claudio Santoro
- Department of Health Sciences, Università del Piemonte Orientale, Novara, Italy
| | - Silvia Zucchelli
- Area of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy.,Department of Health Sciences, Università del Piemonte Orientale, Novara, Italy
| | | | - Remo Sanges
- Area of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy.,Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy.,Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Diego Cotella
- Department of Health Sciences, Università del Piemonte Orientale, Novara, Italy
| | - Stefano Gustincich
- Area of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy.,Central RNA Laboratory, Istituto Italiano di Tecnologia (IIT), Genova, Italy
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9
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Meyer A, Golbik RP, Sänger L, Schmidt T, Behrens SE, Friedrich S. The RGG/RG motif of AUF1 isoform p45 is a key modulator of the protein's RNA chaperone and RNA annealing activities. RNA Biol 2019; 16:960-971. [PMID: 30951406 DOI: 10.1080/15476286.2019.1602438] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The RNA-binding protein AUF1 regulates post-transcriptional gene expression by affecting the steady state and translation levels of numerous target RNAs. Remodeling of RNA structures by the largest isoform AUF1 p45 was recently demonstrated in the context of replicating RNA viruses, and involves two RNA remodeling activities, i.e. an RNA chaperone and an RNA annealing activity. AUF1 contains two non-identical RNA recognition motifs (RRM) and one RGG/RG motif located in the C-terminus. In order to determine the functional significance of each motif to AUF1's RNA-binding and remodeling activities we performed a comprehensive mutagenesis study and characterized the wildtype AUF1, and several variants thereof. We demonstrate that each motif contributes to efficient RNA binding and remodeling by AUF1 indicating a tight cooperation of the RRMs and the RGG/RG motif. Interestingly, the data identify two distinct roles for the arginine residues of the RGG/RG motif for each RNA remodeling activity. First, arginine-mediated stacking interactions promote AUF1's helix-destabilizing RNA chaperone activity. Second, the electropositive character of the arginine residues is the major driving force for the RNA annealing activity. Thus, we provide the first evidence that arginine residues of an RGG/RG motif contribute to the mechanism of RNA annealing and RNA chaperoning.
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Affiliation(s)
- Alexandra Meyer
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Ralph P Golbik
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Lennart Sänger
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Tobias Schmidt
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Sven-Erik Behrens
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
| | - Susann Friedrich
- a Institute of Biochemistry and Biotechnology , Martin Luther University Halle-Wittenberg , Halle , Germany
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10
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Staufen1 Interacts with Multiple Components of the Ebola Virus Ribonucleoprotein and Enhances Viral RNA Synthesis. mBio 2018; 9:mBio.01771-18. [PMID: 30301857 PMCID: PMC6178623 DOI: 10.1128/mbio.01771-18] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Ebola virus (EBOV) is a negative-strand RNA virus with significant public health importance. Currently, no therapeutics are available for Ebola, which imposes an urgent need for a better understanding of EBOV biology. Here we dissected the virus-host interplay between EBOV and host RNA-binding proteins. We identified novel EBOV host factors, including Staufen1, which interacts with multiple viral factors and is required for efficient viral RNA synthesis. Ebola virus (EBOV) genome and mRNAs contain long, structured regions that could hijack host RNA-binding proteins to facilitate infection. We performed RNA affinity chromatography coupled with mass spectrometry to identify host proteins that bind to EBOV RNAs and identified four high-confidence proviral host factors, including Staufen1 (STAU1), which specifically binds both 3′ and 5′ extracistronic regions of the EBOV genome. We confirmed that EBOV infection rate and production of infectious particles were significantly reduced in STAU1-depleted cells. STAU1 was recruited to sites of EBOV RNA synthesis upon infection and enhanced viral RNA synthesis. Furthermore, STAU1 interacts with EBOV nucleoprotein (NP), virion protein 30 (VP30), and VP35; the latter two bridge the viral polymerase to the NP-coated genome, forming the viral ribonucleoprotein (RNP) complex. Our data indicate that STAU1 plays a critical role in EBOV replication by coordinating interactions between the viral genome and RNA synthesis machinery.
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11
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Garcia-Moreno M, Järvelin AI, Castello A. Unconventional RNA-binding proteins step into the virus-host battlefront. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1498. [PMID: 30091184 PMCID: PMC7169762 DOI: 10.1002/wrna.1498] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/01/2018] [Accepted: 06/05/2018] [Indexed: 12/15/2022]
Abstract
The crucial participation of cellular RNA‐binding proteins (RBPs) in virtually all steps of virus infection has been known for decades. However, most of the studies characterizing this phenomenon have focused on well‐established RBPs harboring classical RNA‐binding domains (RBDs). Recent proteome‐wide approaches have greatly expanded the census of RBPs, discovering hundreds of proteins that interact with RNA through unconventional RBDs. These domains include protein–protein interaction platforms, enzymatic cores, and intrinsically disordered regions. Here, we compared the experimentally determined census of RBPs to gene ontology terms and literature, finding that 472 proteins have previous links with viruses. We discuss what these proteins are and what their roles in infection might be. We also review some of the pioneering examples of unorthodox RBPs whose RNA‐binding activity has been shown to be critical for virus infection. Finally, we highlight the potential of these proteins for host‐based therapies against viruses. This article is categorized under:
RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes
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Affiliation(s)
| | - Aino I Järvelin
- Department of Biochemistry, University of Oxford, Oxford, UK
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12
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Nuclear factor 90 promotes angiogenesis by regulating HIF-1α/VEGF-A expression through the PI3K/Akt signaling pathway in human cervical cancer. Cell Death Dis 2018; 9:276. [PMID: 29449553 PMCID: PMC5833414 DOI: 10.1038/s41419-018-0334-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 01/17/2018] [Accepted: 01/19/2018] [Indexed: 01/28/2023]
Abstract
Vascular endothelial growth factor A (VEGF-A), a fundamental component of angiogenesis, provides nutrients and oxygen to solid tumors, and enhances tumor cell survival, invasion, and migration. Nuclear factor 90 (NF90), a double-stranded RNA-binding protein, is strongly expressed in several human cancers, promotes tumor growth by reducing apoptosis, and increasing cell cycle process. The mechanisms by which cervical cancer cells inducing VEGF-A expression and angiogenesis upon NF90 upregulation remain to be fully established. We demonstrated that NF90 is upregulated in human cervical cancer specimens and the expression of NF90 is paralleled with that of VEGF-A under hypoxia. The expressions of hypoxia inducible factor-1α (HIF-1α) and VEGF-A are downregulated upon NF90 knockdown, which can be rescued by ectopic expression of NF90. Suppression of NF90 decreases the tube formation and cell migration of HUVECs. Moreover, the PI3K/Akt signaling pathway participates in the regulation. Knockdown of NF90 also reduces the tumor growth and angiogenesis of cervical cancer cell line in the mouse xenograft model. Taken together, suppression of NF90 in cervical cancer cell lines can decrease VEGF-A expression, inhibit angiogenesis, and reduce tumorigenic capacity in vivo.
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Schmidt T, Friedrich S, Golbik RP, Behrens SE. NF90-NF45 is a selective RNA chaperone that rearranges viral and cellular riboswitches: biochemical analysis of a virus host factor activity. Nucleic Acids Res 2017; 45:12441-12454. [PMID: 29040738 PMCID: PMC5716087 DOI: 10.1093/nar/gkx931] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/10/2017] [Indexed: 01/28/2023] Open
Abstract
The heterodimer NF90-NF45 is an RNA-binding protein complex that modulates the expression of various cellular mRNAs on the post-transcriptional level. Furthermore, it acts as a host factor that supports the replication of several RNA viruses. The molecular mechanisms underlying these activities have yet to be elucidated. Recently, we showed that the RNA-binding capabilities and binding specificity of NF90 considerably improves when it forms a complex with NF45. Here, we demonstrate that NF90 has a substrate-selective RNA chaperone activity (RCA) involving RNA annealing and strand displacement activities. The mechanism of the NF90-catalyzed RNA annealing was elucidated to comprise a combination of 'matchmaking' and compensation of repulsive charges, which finally results in the population of dsRNA products. Heterodimer formation with NF45 enhances 'matchmaking' of complementary ssRNAs and substantially increases the efficiency of NF90's RCA. During investigations of the relevance of the NF90-NF45 RCA, the complex was shown to stimulate the first step in the RNA replication process of hepatitis C virus (HCV) in vitro and to stabilize a regulatory element within the mRNA of vascular endothelial growth factor (VEGF) by protein-guided changes of the RNAs' structures. Thus, our study reveals how the intrinsic properties of an RNA-binding protein determine its biological activities.
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Affiliation(s)
- Tobias Schmidt
- Institute of Biochemistry and Biotechnology (NFI), Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, D-06120 Halle/Saale, Germany
- To whom correspondence should be addressed. Tel: +49 3455 5249 60; Fax: +49 3455 5273 87; . Correspondence may also be addressed to Tobias Schmidt.
| | - Susann Friedrich
- Institute of Biochemistry and Biotechnology (NFI), Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, D-06120 Halle/Saale, Germany
| | - Ralph Peter Golbik
- Institute of Biochemistry and Biotechnology (NFI), Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, D-06120 Halle/Saale, Germany
| | - Sven-Erik Behrens
- Institute of Biochemistry and Biotechnology (NFI), Section Microbial Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, D-06120 Halle/Saale, Germany
- To whom correspondence should be addressed. Tel: +49 3455 5249 60; Fax: +49 3455 5273 87; . Correspondence may also be addressed to Tobias Schmidt.
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