1
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Ashraf HN, Uversky VN. Intrinsic Disorder in the Host Proteins Entrapped in Rabies Virus Particles. Viruses 2024; 16:916. [PMID: 38932209 PMCID: PMC11209445 DOI: 10.3390/v16060916] [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: 03/20/2024] [Revised: 05/23/2024] [Accepted: 05/28/2024] [Indexed: 06/28/2024] Open
Abstract
A proteomics analysis of purified rabies virus (RABV) revealed 47 entrapped host proteins within the viral particles. Out of these, 11 proteins were highly disordered. Our study was particularly focused on five of the RABV-entrapped mouse proteins with the highest levels of disorder: Neuromodulin, Chmp4b, DnaJB6, Vps37B, and Wasl. We extensively utilized bioinformatics tools, such as FuzDrop, D2P2, UniProt, RIDAO, STRING, AlphaFold, and ELM, for a comprehensive analysis of the intrinsic disorder propensity of these proteins. Our analysis suggested that these disordered host proteins might play a significant role in facilitating the rabies virus pathogenicity, immune system evasion, and the development of antiviral drug resistance. Our study highlighted the complex interaction of the virus with its host, with a focus on how the intrinsic disorder can play a crucial role in virus pathogenic processes, and suggested that these intrinsically disordered proteins (IDPs) and disorder-related host interactions can also be a potential target for therapeutic strategies.
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Affiliation(s)
- Hafiza Nimra Ashraf
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA;
| | - Vladimir N. Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA;
- USF Health Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
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2
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Lin W, Nagy PD. Co-opted cytosolic proteins form condensate substructures within membranous replication organelles of a positive-strand RNA virus. THE NEW PHYTOLOGIST 2024. [PMID: 38515267 DOI: 10.1111/nph.19691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/22/2024] [Indexed: 03/23/2024]
Abstract
Positive-strand RNA viruses co-opt organellar membranes for biogenesis of viral replication organelles (VROs). Tombusviruses also co-opt pro-viral cytosolic proteins to VROs. It is currently not known what type of molecular organization keeps co-opted proteins sequestered within membranous VROs. In this study, we employed tomato bushy stunt virus (TBSV) and carnation Italian ringspot virus (CIRV) - Nicotiana benthamiana pathosystems to identify biomolecular condensate formation in VROs. We show that TBSV p33 and the CIRV p36 replication proteins sequester glycolytic and fermentation enzymes in unique condensate substructures associated with membranous VROs. We find that p33 and p36 form droplets in vitro driven by intrinsically disordered region. The replication protein organizes partitioning of co-opted host proteins into droplets. VRO-associated condensates are critical for local adenosine triphosphate production to support energy for virus replication. We find that co-opted endoplasmic reticulum membranes and actin filaments form meshworks within and around VRO condensates, contributing to unique composition and structure. We propose that p33/p36 organize liquid-liquid phase separation of co-opted concentrated host proteins in condensate substructures within membranous VROs. Overall, we demonstrate that subverted membranes and condensate substructures co-exist and are critical for VRO functions. The replication proteins induce and connect the two substructures within VROs.
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Affiliation(s)
- Wenwu Lin
- Department of Plant Pathology, University of Kentucky, Lexington, KY, 40543, USA
| | - Peter D Nagy
- Department of Plant Pathology, University of Kentucky, Lexington, KY, 40543, USA
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3
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Eltayeb A, Al-Sarraj F, Alharbi M, Albiheyri R, Mattar EH, Abu Zeid IM, Bouback TA, Bamagoos A, Uversky VN, Rubio-Casillas A, Redwan EM. Intrinsic factors behind long COVID: IV. Hypothetical roles of the SARS-CoV-2 nucleocapsid protein and its liquid-liquid phase separation. J Cell Biochem 2024; 125:e30530. [PMID: 38349116 DOI: 10.1002/jcb.30530] [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: 09/09/2023] [Revised: 01/10/2024] [Accepted: 01/24/2024] [Indexed: 03/12/2024]
Abstract
When the SARS-CoV-2 virus infects humans, it leads to a condition called COVID-19 that has a wide spectrum of clinical manifestations, from no symptoms to acute respiratory distress syndrome. The virus initiates damage by attaching to the ACE-2 protein on the surface of endothelial cells that line the blood vessels and using these cells as hosts for replication. Reactive oxygen species levels are increased during viral replication, which leads to oxidative stress. About three-fifths (~60%) of the people who get infected with the virus eradicate it from their body after 28 days and recover their normal activity. However, a large fraction (~40%) of the people who are infected with the virus suffer from various symptoms (anosmia and/or ageusia, fatigue, cough, myalgia, cognitive impairment, insomnia, dyspnea, and tachycardia) beyond 12 weeks and are diagnosed with a syndrome called long COVID. Long-term clinical studies in a group of people who contracted SARS-CoV-2 have been contrasted with a noninfected matched group of people. A subset of infected people can be distinguished by a set of cytokine markers to have persistent, low-grade inflammation and often self-report two or more bothersome symptoms. No medication can alleviate their symptoms efficiently. Coronavirus nucleocapsid proteins have been investigated extensively as potential drug targets due to their key roles in virus replication, among which is their ability to bind their respective genomic RNAs for incorporation into emerging virions. This review highlights basic studies of the nucleocapsid protein and its ability to undergo liquid-liquid phase separation. We hypothesize that this ability of the nucleocapsid protein for phase separation may contribute to long COVID. This hypothesis unlocks new investigation angles and could potentially open novel avenues for a better understanding of long COVID and treating this condition.
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Affiliation(s)
- Ahmed Eltayeb
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Faisal Al-Sarraj
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mona Alharbi
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Raed Albiheyri
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
- Centre of Excellence in Bionanoscience Research, King Abdulaziz University, Jeddah, Saudi Arabia
- Immunology Unit, King Fahad Medical Research Centre, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ehab H Mattar
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Isam M Abu Zeid
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Thamer A Bouback
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Atif Bamagoos
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
- Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Moscow Region, Russia
| | - Alberto Rubio-Casillas
- Autlan Regional Hospital, Health Secretariat, Autlan, Jalisco, Mexico
- Biology Laboratory, Autlan Regional Preparatory School, University of Guadalajara, Autlan, Jalisco, Mexico
| | - Elrashdy M Redwan
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
- Centre of Excellence in Bionanoscience Research, King Abdulaziz University, Jeddah, Saudi Arabia
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4
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Martin EW, Iserman C, Olety B, Mitrea DM, Klein IA. Biomolecular Condensates as Novel Antiviral Targets. J Mol Biol 2024; 436:168380. [PMID: 38061626 DOI: 10.1016/j.jmb.2023.168380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 11/23/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023]
Abstract
Viral infections pose a significant health risk worldwide. There is a pressing need for more effective antiviral drugs to combat emerging novel viruses and the reemergence of previously controlled viruses. Biomolecular condensates are crucial for viral replication and are promising targets for novel antiviral therapies. Herein, we review the role of biomolecular condensates in the viral replication cycle and discuss novel strategies to leverage condensate biology for antiviral drug discovery. Biomolecular condensates may also provide an opportunity to develop antivirals that are broad-spectrum or less prone to acquired drug resistance.
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5
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Ren J, Wang S, Zong Z, Pan T, Liu S, Mao W, Huang H, Yan X, Yang B, He X, Zhou F, Zhang L. TRIM28-mediated nucleocapsid protein SUMOylation enhances SARS-CoV-2 virulence. Nat Commun 2024; 15:244. [PMID: 38172120 PMCID: PMC10764958 DOI: 10.1038/s41467-023-44502-6] [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: 06/15/2023] [Accepted: 12/15/2023] [Indexed: 01/05/2024] Open
Abstract
Viruses, as opportunistic intracellular parasites, hijack the cellular machinery of host cells to support their survival and propagation. Numerous viral proteins are subjected to host-mediated post-translational modifications. Here, we demonstrate that the SARS-CoV-2 nucleocapsid protein (SARS2-NP) is SUMOylated on the lysine 65 residue, which efficiently mediates SARS2-NP's ability in homo-oligomerization, RNA association, liquid-liquid phase separation (LLPS). Thereby the innate antiviral immune response is suppressed robustly. These roles can be achieved through intermolecular association between SUMO conjugation and a newly identified SUMO-interacting motif in SARS2-NP. Importantly, the widespread SARS2-NP R203K mutation gains a novel site of SUMOylation which further increases SARS2-NP's LLPS and immunosuppression. Notably, the SUMO E3 ligase TRIM28 is responsible for catalyzing SARS2-NP SUMOylation. An interfering peptide targeting the TRIM28 and SARS2-NP interaction was screened out to block SARS2-NP SUMOylation and LLPS, and consequently inhibit SARS-CoV-2 replication and rescue innate antiviral immunity. Collectively, these data support SARS2-NP SUMOylation is critical for SARS-CoV-2 virulence, and therefore provide a strategy to antagonize SARS-CoV-2.
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Affiliation(s)
- Jiang Ren
- The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518033, China
| | - Shuai Wang
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, 215123, China
| | - Zhi Zong
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, 310058, China
| | - Ting Pan
- Shenzhen Key Laboratory of Systems Medicine for Inflammatory Diseases, School of Medicine, Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, China
| | - Sijia Liu
- International Biomed-X Research Center, Second Affiliated Hospital of Zhejiang University, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Wei Mao
- Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Huizhe Huang
- Faculty of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China
| | - Xiaohua Yan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, 330031, China
| | - Bing Yang
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, 310058, China
- Department of Pharmaceutical Chemistry and the Cardiovascular Research Institute, University of California, San Francisco, CA, 94158, USA
| | - Xin He
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
| | - Fangfang Zhou
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, 215123, China.
| | - Long Zhang
- The Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518033, China.
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, 310058, China.
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6
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Whitehead JD, Decool H, Leyrat C, Carrique L, Fix J, Eléouët JF, Galloux M, Renner M. Structure of the N-RNA/P interface indicates mode of L/P recruitment to the nucleocapsid of human metapneumovirus. Nat Commun 2023; 14:7627. [PMID: 37993464 PMCID: PMC10665349 DOI: 10.1038/s41467-023-43434-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 11/08/2023] [Indexed: 11/24/2023] Open
Abstract
Human metapneumovirus (HMPV) is a major cause of respiratory illness in young children. The HMPV polymerase (L) binds an obligate cofactor, the phosphoprotein (P). During replication and transcription, the L/P complex traverses the viral RNA genome, which is encapsidated within nucleoproteins (N). An essential interaction between N and a C-terminal region of P tethers the L/P polymerase to the template. This N-P interaction is also involved in the formation of cytoplasmic viral factories in infected cells, called inclusion bodies. To define how the polymerase component P recognizes N-encapsidated RNA (N-RNA) we employed cryogenic electron microscopy (cryo-EM) and molecular dynamics simulations, coupled to activity assays and imaging of inclusion bodies in cells. We report a 2.9 Å resolution structure of a triple-complex between multimeric N, bound to both RNA and the C-terminal region of P. Furthermore, we also present cryo-EM structures of assembled N in different oligomeric states, highlighting the plasticity of N. Combined with our functional assays, these structural data delineate in molecular detail how P attaches to N-RNA whilst retaining substantial conformational dynamics. Moreover, the N-RNA-P triple complex structure provides a molecular blueprint for the design of therapeutics to potentially disrupt the attachment of L/P to its template.
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Affiliation(s)
- Jack D Whitehead
- Division of Structural Biology, The Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Hortense Decool
- Université Paris-Saclay, INRAE, UVSQ, VIM, 78350, Jouy-en-Josas, France
| | - Cédric Leyrat
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Loic Carrique
- Division of Structural Biology, The Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Jenna Fix
- Université Paris-Saclay, INRAE, UVSQ, VIM, 78350, Jouy-en-Josas, France
| | | | - Marie Galloux
- Université Paris-Saclay, INRAE, UVSQ, VIM, 78350, Jouy-en-Josas, France.
| | - Max Renner
- Department of Chemistry, Umeå University, Umeå, Sweden.
- Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden.
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7
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Socas LBP, Ambroggio EE. Linking surface tension to water polarization with a new hypothesis: The Ling-Damodaran Isotherm. Colloids Surf B Biointerfaces 2023; 230:113515. [PMID: 37634284 DOI: 10.1016/j.colsurfb.2023.113515] [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: 07/04/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 08/29/2023]
Abstract
Studying aqueous solutions of complex (bio)polymers is essential from both theoretical and practical perspectives. To understand the principles that govern the properties of these solutions is pivotal for the study of biological processes, considering that the most distinguished components of the cells are polymers (proteins, nucleic acids). These macromolecular aqueous systems, known as colloids, has raise the interest of scientists in recent years. It is known that several physicochemical properties deviate from ideal behaviour in this kind of solutions and that the physical state of water is different compared to its pure state. Particularly, the surface tension of such mixtures often shows a peculiar profile at semi-dilute and concentrated conditions. Here, we joined the colloidal concept of water polarization (proposed in the Association-Induction Hypothesis) with Damodaran's formalism for surface tension to theoretically derive a compelling mathematical model that explains the behaviour of polymer solutions. We measured the surface tension and osmolarity of different polyethylene oxide solutions and we used the ACDAN fluorescence probe to assess the water dipolar relaxation (polarization) in these mixtures. As a proof of concept, we also studied the influence of these polymer solutions on lipid interfaces. Our isotherm model explains the experimental observations with a unifying view that correlates with other measured properties, such as osmolarity and water dipolar relaxation. This provides a link between interfacial and bulk physicochemical properties of polymer solutions, also giving a new framework for studying the interaction of colloidal systems with lipid membranes interfaces.
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Affiliation(s)
- L B P Socas
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Química Biológica-Ranwel Caputto, Haya de la Torre y Medina Allende s/n, Córdoba X5000HUA, Argentina; CONICET, Universidad Nacional de Córdoba, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Haya de la Torre y Medina Allende s/n, Córdoba X5000HUA, Argentina.
| | - E E Ambroggio
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Química Biológica-Ranwel Caputto, Haya de la Torre y Medina Allende s/n, Córdoba X5000HUA, Argentina; CONICET, Universidad Nacional de Córdoba, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Haya de la Torre y Medina Allende s/n, Córdoba X5000HUA, Argentina.
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8
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Borodavka A, Acker J. Seeing Biomolecular Condensates Through the Lens of Viruses. Annu Rev Virol 2023; 10:163-182. [PMID: 37040799 DOI: 10.1146/annurev-virology-111821-103226] [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: 04/13/2023]
Abstract
Phase separation of viral biopolymers is a key factor in the formation of cytoplasmic viral inclusions, known as sites of virus replication and assembly. This review describes the mechanisms and factors that affect phase separation in viral replication and identifies potential areas for future research. Drawing inspiration from studies on cellular RNA-rich condensates, we compare the hierarchical coassembly of ribosomal RNAs and proteins in the nucleolus to the coordinated coassembly of viral RNAs and proteins taking place within viral factories in viruses containing segmented RNA genomes. We highlight the common characteristics of biomolecular condensates in viral replication and how this new understanding is reshaping our views of virus assembly mechanisms. Such studies have the potential to uncover unexplored antiviral strategies targeting these phase-separated states.
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Affiliation(s)
- Alexander Borodavka
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom;
| | - Julia Acker
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom;
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9
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Diot C, Richard CA, Risso-Ballester J, Martin D, Fix J, Eléouët JF, Sizun C, Rameix-Welti MA, Galloux M. Hardening of Respiratory Syncytial Virus Inclusion Bodies by Cyclopamine Proceeds through Perturbation of the Interactions of the M2-1 Protein with RNA and the P Protein. Int J Mol Sci 2023; 24:13862. [PMID: 37762166 PMCID: PMC10531356 DOI: 10.3390/ijms241813862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 08/20/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Respiratory syncytial virus (RSV) RNA synthesis takes place in cytoplasmic viral factories also called inclusion bodies (IBs), which are membrane-less organelles concentrating the viral RNA polymerase complex. The assembly of IBs is driven by liquid-liquid phase separation promoted by interactions between the viral nucleoprotein N and the phosphoprotein P. We recently demonstrated that cyclopamine (CPM) inhibits RSV multiplication by disorganizing and hardening IBs. Although a single mutation in the viral transcription factor M2-1 induced resistance to CPM, the mechanism of action of CPM still remains to be characterized. Here, using FRAP experiments on reconstituted pseudo-IBs both in cellula and in vitro, we first demonstrated that CPM activity depends on the presence of M2-1 together with N and P. We showed that CPM impairs the competition between P and RNA binding to M2-1. As mutations on both P and M2-1 induced resistance against CPM activity, we suggest that CPM may affect the dynamics of the M2-1-P interaction, thereby affecting the relative mobility of the proteins contained in RSV IBs. Overall, our results reveal that stabilizing viral protein-protein interactions is an attractive new antiviral approach. They pave the way for the rational chemical optimization of new specific anti-RSV molecules.
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Affiliation(s)
- Cédric Diot
- Institut Pasteur, Université Paris Cité, M3P, F-75015 Paris, France;
- INSERM, UMR 1173 (2I), Université Paris-Saclay-Versailles St. Quentin, M3P, F-78180 Versailles, France;
| | - Charles-Adrien Richard
- INRAE, Unité de Virologie et Immunologie Moléculaires (VIM), Université Paris-Saclay-Versailles St. Quentin, F-78350 Jouy-en-Josas, France; (C.-A.R.); (D.M.); (J.F.); (J.-F.E.)
| | - Jennifer Risso-Ballester
- INSERM, UMR 1173 (2I), Université Paris-Saclay-Versailles St. Quentin, M3P, F-78180 Versailles, France;
| | - Davy Martin
- INRAE, Unité de Virologie et Immunologie Moléculaires (VIM), Université Paris-Saclay-Versailles St. Quentin, F-78350 Jouy-en-Josas, France; (C.-A.R.); (D.M.); (J.F.); (J.-F.E.)
| | - Jenna Fix
- INRAE, Unité de Virologie et Immunologie Moléculaires (VIM), Université Paris-Saclay-Versailles St. Quentin, F-78350 Jouy-en-Josas, France; (C.-A.R.); (D.M.); (J.F.); (J.-F.E.)
| | - Jean-François Eléouët
- INRAE, Unité de Virologie et Immunologie Moléculaires (VIM), Université Paris-Saclay-Versailles St. Quentin, F-78350 Jouy-en-Josas, France; (C.-A.R.); (D.M.); (J.F.); (J.-F.E.)
| | - Christina Sizun
- Institut de Chimie des Substances Naturelles, CNRS, Université Paris-Saclay, F-91190 Gif-sur-Yvette, France;
| | - Marie-Anne Rameix-Welti
- INSERM, UMR 1173 (2I), Université Paris-Saclay-Versailles St. Quentin, M3P, F-78180 Versailles, France;
- Laboratoire de Microbiologie, Hôpital Ambroise Paré, Assistance Publique des Hôpitaux de Paris, DMU15, F-75015 Paris, France
| | - Marie Galloux
- INRAE, Unité de Virologie et Immunologie Moléculaires (VIM), Université Paris-Saclay-Versailles St. Quentin, F-78350 Jouy-en-Josas, France; (C.-A.R.); (D.M.); (J.F.); (J.-F.E.)
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10
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Salgueiro M, Camporeale G, Visentin A, Aran M, Pellizza L, Esperante SA, Corbat A, Grecco H, Sousa B, Esperón R, Borkosky SS, de Prat-Gay G. Molten Globule Driven and Self-downmodulated Phase Separation of a Viral Factory Scaffold. J Mol Biol 2023; 435:168153. [PMID: 37210029 DOI: 10.1016/j.jmb.2023.168153] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 05/09/2023] [Accepted: 05/12/2023] [Indexed: 05/22/2023]
Abstract
Viral factories of liquid-like nature serve as sites for transcription and replication in most viruses. The respiratory syncytial virus factories include replication proteins, brought together by the phosphoprotein (P) RNA polymerase cofactor, present across non-segmented negative stranded RNA viruses. Homotypic liquid-liquid phase separation of RSV-P is governed by an α-helical molten globule domain, and strongly self-downmodulated by adjacent sequences. Condensation of P with the nucleoprotein N is stoichiometrically tuned, defining aggregate-droplet and droplet-dissolution boundaries. Time course analysis show small N-P nuclei gradually coalescing into large granules in transfected cells. This behavior is recapitulated in infection, with small puncta evolving to large viral factories, strongly suggesting that P-N nucleation-condensation sequentially drives viral factories. Thus, the tendency of P to undergo phase separation is moderate and latent in the full-length protein but unleashed in the presence of N or when neighboring disordered sequences are deleted. This, together with its capacity to rescue nucleoprotein-RNA aggregates suggests a role as a "solvent-protein".
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Affiliation(s)
- Mariano Salgueiro
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) CONICET, Buenos Aires, Argentina
| | - Gabriela Camporeale
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) CONICET, Buenos Aires, Argentina
| | - Araceli Visentin
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) CONICET, Buenos Aires, Argentina
| | - Martin Aran
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) CONICET, Buenos Aires, Argentina
| | - Leonardo Pellizza
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) CONICET, Buenos Aires, Argentina
| | | | - Agustín Corbat
- Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires, and IFIBA, CONICET, Buenos Aires, Argentina
| | - Hernán Grecco
- Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires, and IFIBA, CONICET, Buenos Aires, Argentina
| | - Belén Sousa
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) CONICET, Buenos Aires, Argentina
| | - Ramiro Esperón
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) CONICET, Buenos Aires, Argentina
| | - Silvia S Borkosky
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) CONICET, Buenos Aires, Argentina
| | - Gonzalo de Prat-Gay
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) CONICET, Buenos Aires, Argentina.
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11
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Zhang X, Zheng R, Li Z, Ma J. Liquid-liquid Phase Separation in Viral Function. J Mol Biol 2023; 435:167955. [PMID: 36642156 DOI: 10.1016/j.jmb.2023.167955] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 01/04/2023] [Accepted: 01/07/2023] [Indexed: 01/15/2023]
Abstract
An emerging set of results suggests that liquid-liquid phase separation (LLPS) is the basis for the formation of membrane-less compartments in cells. Evidence is now mounting that various types of virus-induced membrane-less compartments and organelles are also assembled via LLPS. Specifically, viruses appear to use intracellular phase transitions to form subcellular microenvironments known as viral factories, inclusion bodies, or viroplasms. These compartments - collectively referred to as viral biomolecular condensates - can be used to concentrate replicase proteins, viral genomes, and host proteins that are required for virus replication. They can also be used to subvert or avoid the intracellular immune response. This review examines how certain DNA or RNA viruses drive the formation of viral condensates, the possible biological functions of those condensates, and the biophysical and biochemical basis for their assembly.
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Affiliation(s)
- Xiaoyue Zhang
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China; Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Changsha, China
| | - Run Zheng
- Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Changsha, China
| | - Zhengshuo Li
- Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Changsha, China
| | - Jian Ma
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China; Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Changsha, China.
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12
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Borkosky SS, Fassolari M, Campos-León K, Rossi AH, Salgueiro M, Pascuale CA, Martínez RP, Gaston K, de Prat Gay G. Biomolecular Condensation of the Human Papillomavirus E2 Master Regulator with p53: Implications in Viral Replication. J Mol Biol 2023; 435:167889. [PMID: 36402224 DOI: 10.1016/j.jmb.2022.167889] [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: 07/21/2022] [Revised: 10/21/2022] [Accepted: 11/07/2022] [Indexed: 11/18/2022]
Abstract
p53 exerts its tumour suppressor activity by modulating hundreds of genes and it can also repress viral replication. Such is the case of human papillomavirus (HPV) through targeting the E2 master regulator, but the biochemical mechanism is not known. We show that the C-terminal DNA binding domain of HPV16 E2 protein (E2C) triggers heterotypic condensation with p53 at a precise 2/1 E2C/p53 stoichiometry at the onset for demixing, yielding large regular spherical droplets that increase in size with E2C concentration. Interestingly, transfection experiments show that E2 co-localizes with p53 in the nucleus with a grainy pattern, and recruits p53 to chromatin-associated foci, a function independent of the DNA binding capacity of p53 as judged by a DNA binding impaired mutant. Depending on the length, DNA can either completely dissolve or reshape heterotypic droplets into irregular condensates containing p53, E2C, and DNA, and reminiscent of that observed linked to chromatin. We propose that p53 is a scaffold for condensation in line with its structural and functional features, in particular as a promiscuous hub that binds multiple cellular proteins. E2 appears as both client and modulator, likely based on its homodimeric DNA binding nature. Our results, in line with the known role of condensation in eukaryotic gene enhancement and silencing, point at biomolecular condensation of E2 with p53 as a means to modulate HPV gene function, strictly dependent on host cell replication and transcription machinery.
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Affiliation(s)
- Silvia Susana Borkosky
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina.
| | - Marisol Fassolari
- Fundación para Investigaciones Biológicas Aplicadas (FIBA), Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC)-CONICET, Mar del Plata, Argentina
| | - Karen Campos-León
- Division of Immunity and Infection, School of Medicine, University of Birmingham, United Kingdom
| | - Andrés Hugo Rossi
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina
| | - Mariano Salgueiro
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina
| | - Carla Antonela Pascuale
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina
| | - Ramón Peralta Martínez
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina
| | - Kevin Gaston
- School of Medicine, University of Nottingham Biodiscovery Institute, Nottingham, United Kingdom
| | - Gonzalo de Prat Gay
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - CONICET, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina.
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13
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Boccaccio GL, Thomas MG, García CC. Membraneless Organelles and Condensates Orchestrate Innate Immunity Against Viruses. J Mol Biol 2023; 435:167976. [PMID: 36702393 DOI: 10.1016/j.jmb.2023.167976] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/10/2023] [Accepted: 01/17/2023] [Indexed: 01/24/2023]
Abstract
The cellular defense against viruses involves the assembly of oligomers, granules and membraneless organelles (MLOs) that govern the activation of several arms of the innate immune response. Upon interaction with specific pathogen-derived ligands, a number of pattern recognition receptors (PRRs) undergo phase-separation thus triggering downstream signaling pathways. Among other relevant condensates, inflammasomes, apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) specks, cyclic GMP-AMP synthase (cGAS) foci, protein kinase R (PKR) clusters, ribonuclease L-induced bodies (RLBs), stress granules (SGs), processing bodies (PBs) and promyelocytic leukemia protein nuclear bodies (PML NBs) play different roles in the immune response. In turn, viruses have evolved diverse strategies to evade the host defense. Viral DNA or RNA, as well as viral proteases or proteins carrying intrinsically disordered regions may interfere with condensate formation and function in multiple ways. In this review we discuss current and hypothetical mechanisms of viral escape that involve the disassembly, repurposing, or inactivation of membraneless condensates that govern innate immunity. We summarize emerging interconnections between these diverse condensates that ultimately determine the cellular outcome.
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Affiliation(s)
- Graciela Lidia Boccaccio
- Laboratorio de Biología Celular del ARN, Instituto Leloir (FIL) and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Buenos Aires, Argentina; Departamento de Fisiología y Biología Molecular y Celular (FBMyC), Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires, Buenos Aires, Argentina.
| | - María Gabriela Thomas
- Laboratorio de Biología Celular del ARN, Instituto Leloir (FIL) and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA) - Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Buenos Aires, Argentina. https://www.twitter.com/_gabithomas
| | - Cybele Carina García
- Departamento de Química Biológica (QB), Facultad de Ciencias Exactas y Naturales (FCEN), and IQUIBICEN, Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET) and Universidad de Buenos Aires, Buenos Aires, Argentina
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14
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Kaddis Maldonado R, Lambert GS, Rice BL, Sudol M, Flanagan JM, Parent LJ. The Rous sarcoma virus Gag Polyprotein Forms Biomolecular Condensates Driven by Intrinsically-disordered Regions. J Mol Biol 2023; 435:168182. [PMID: 37328094 PMCID: PMC10527454 DOI: 10.1016/j.jmb.2023.168182] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 06/07/2023] [Accepted: 06/09/2023] [Indexed: 06/18/2023]
Abstract
Biomolecular condensates (BMCs) play important roles incellular structures includingtranscription factories, splicing speckles, and nucleoli. BMCs bring together proteins and other macromolecules, selectively concentrating them so that specific reactions can occur without interference from the surrounding environment. BMCs are often made up of proteins that contain intrinsically disordered regions (IDRs), form phase-separated spherical puncta, form liquid-like droplets that undergo fusion and fission, contain molecules that are mobile, and are disrupted with phase-dissolving drugs such as 1,6-hexanediol. In addition to cellular proteins, many viruses, including influenza A, SARS-CoV-2, and human immunodeficiency virus type 1 (HIV-1) encode proteins that undergo phase separation and rely on BMC formation for replication. In prior studies of the retrovirus Rous sarcoma virus (RSV), we observed that the Gag protein forms discrete spherical puncta in the nucleus, cytoplasm, and at the plasma membrane that co-localize with viral RNA and host factors, raising the possibility that RSV Gag forms BMCs that participate in the intracellular phase of the virion assembly pathway. In our current studies, we found that Gag contains IDRs in the N-terminal (MAp2p10) and C-terminal (NC) regions of the protein and fulfills many criteria of BMCs. Although the role of BMC formation in RSV assembly requires further study, our results suggest the biophysical properties of condensates are required for the formation of Gag complexes in the nucleus and the cohesion of these complexes as they traffic through the nuclear pore, into the cytoplasm, and to the plasma membrane, where the final assembly and release of virus particles occurs.
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Affiliation(s)
- Rebecca Kaddis Maldonado
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA; Department of Microbiology & Immunology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Gregory S Lambert
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Breanna L Rice
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Malgorzata Sudol
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - John M Flanagan
- Department of Biochemistry & Molecular Biology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Leslie J Parent
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA; Department of Microbiology & Immunology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA.
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15
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Visentin A, Demitroff N, Salgueiro M, Borkosky SS, Uversky VN, Camporeale G, de Prat-Gay G. Assembly of the Tripartite and RNA Condensates of the Respiratory Syncytial Virus Factory Proteins In Vitro: Role of the Transcription Antiterminator M 2-1. Viruses 2023; 15:1329. [PMID: 37376628 DOI: 10.3390/v15061329] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
A wide variety of viruses replicate in liquid-like viral factories. Non-segmented negative stranded RNA viruses share a nucleoprotein (N) and a phosphoprotein (P) that together emerge as the main drivers of liquid-liquid phase separation. The respiratory syncytial virus includes the transcription antiterminator M2-1, which binds RNA and maximizes RNA transcriptase processivity. We recapitulate the assembly mechanism of condensates of the three proteins and the role played by RNA. M2-1 displays a strong propensity for condensation by itself and with RNA through the formation of electrostatically driven protein-RNA coacervates based on the amphiphilic behavior of M2-1 and finely tuned by stoichiometry. M2-1 incorporates into tripartite condensates with N and P, modulating their size through an interplay with P, where M2-1 is both client and modulator. RNA is incorporated into the tripartite condensates adopting a heterogeneous distribution, reminiscent of the M2-1-RNA IBAG granules within the viral factories. Ionic strength dependence indicates that M2-1 behaves differently in the protein phase as opposed to the protein-RNA phase, in line with the subcompartmentalization observed in viral factories. This work dissects the biochemical grounds for the formation and fate of the RSV condensates in vitro and provides clues to interrogate the mechanism under the highly complex infection context.
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Affiliation(s)
- Araceli Visentin
- Instituto Leloir, IIB-BA Conicet, Av. Patricias Argentinas 435, Buenos Aires 1405, Argentina
| | - Nicolás Demitroff
- Instituto Leloir, IIB-BA Conicet, Av. Patricias Argentinas 435, Buenos Aires 1405, Argentina
| | - Mariano Salgueiro
- Instituto Leloir, IIB-BA Conicet, Av. Patricias Argentinas 435, Buenos Aires 1405, Argentina
| | - Silvia Susana Borkosky
- Instituto Leloir, IIB-BA Conicet, Av. Patricias Argentinas 435, Buenos Aires 1405, Argentina
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Gabriela Camporeale
- Instituto Leloir, IIB-BA Conicet, Av. Patricias Argentinas 435, Buenos Aires 1405, Argentina
| | - Gonzalo de Prat-Gay
- Instituto Leloir, IIB-BA Conicet, Av. Patricias Argentinas 435, Buenos Aires 1405, Argentina
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas 13083-970, SP, Brazil
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16
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Hagan MF, Mohajerani F. Self-assembly coupled to liquid-liquid phase separation. PLoS Comput Biol 2023; 19:e1010652. [PMID: 37186597 PMCID: PMC10212142 DOI: 10.1371/journal.pcbi.1010652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 05/25/2023] [Accepted: 04/26/2023] [Indexed: 05/17/2023] Open
Abstract
Liquid condensate droplets with distinct compositions of proteins and nucleic acids are widespread in biological cells. While it is known that such droplets, or compartments, can regulate irreversible protein aggregation, their effect on reversible self-assembly remains largely unexplored. In this article, we use kinetic theory and solution thermodynamics to investigate the effect of liquid-liquid phase separation on the reversible self-assembly of structures with well-defined sizes and architectures. We find that, when assembling subunits preferentially partition into liquid compartments, robustness against kinetic traps and maximum achievable assembly rates can be significantly increased. In particular, both the range of solution conditions leading to productive assembly and the corresponding assembly rates can increase by orders of magnitude. We analyze the rate equation predictions using simple scaling estimates to identify effects of liquid-liquid phase separation as a function of relevant control parameters. These results may elucidate self-assembly processes that underlie normal cellular functions or pathogenesis, and suggest strategies for designing efficient bottom-up assembly for nanomaterials applications.
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Affiliation(s)
- Michael F. Hagan
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts, United States of America
| | - Farzaneh Mohajerani
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts, United States of America
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17
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Maldonado RK, Rice BL, Lambert GS, Sudol M, Flanagan JM, Parent LJ. The Rous sarcoma virus Gag polyprotein forms biomolecular condensates driven by intrinsically-disordered regions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.07.536043. [PMID: 37066255 PMCID: PMC10104128 DOI: 10.1101/2023.04.07.536043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Biomolecular condensates (BMCs) play important roles in cellular structures including transcription factories, splicing speckles, and nucleoli. BMCs bring together proteins and other macromolecules, selectively concentrating them so that specific reactions can occur without interference from the surrounding environment. BMCs are often made up of proteins that contain intrinsically disordered regions (IDRs), form phase-separated spherical puncta, form liquid-like droplets that undergo fusion and fission, contain molecules that are mobile, and are disrupted with phase-dissolving drugs such as 1,6-hexanediol. In addition to cellular proteins, many viruses, including influenza A, SARS-CoV-2, and human immunodeficiency virus type 1 (HIV-1) encode proteins that undergo phase separation and rely on BMC formation for replication. In prior studies of the retrovirus Rous sarcoma virus (RSV), we observed that the Gag protein forms discrete spherical puncta in the nucleus, cytoplasm, and at the plasma membrane that co-localize with viral RNA and host factors, raising the possibility that RSV Gag forms BMCs that participate in the virion intracellular assembly pathway. In our current studies, we found that Gag contains IDRs in the N-terminal (MAp2p10) and C-terminal (NC) regions of the protein and fulfills many criteria of BMCs. Although the role of BMC formation in RSV assembly requires further study, our results suggest the biophysical properties of condensates are required for the formation of Gag complexes in the nucleus and the cohesion of these complexes as they traffic through the nuclear pore, into the cytoplasm, and to the plasma membrane, where the final assembly and release of virus particles occurs.
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18
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Di Nunzio F, Uversky VN, Mouland AJ. Biomolecular condensates: insights into early and late steps of the HIV-1 replication cycle. Retrovirology 2023; 20:4. [PMID: 37029379 PMCID: PMC10081342 DOI: 10.1186/s12977-023-00619-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 03/16/2023] [Indexed: 04/09/2023] Open
Abstract
A rapidly evolving understanding of phase separation in the biological and physical sciences has led to the redefining of virus-engineered replication compartments in many viruses with RNA genomes. Condensation of viral, host and genomic and subgenomic RNAs can take place to evade the innate immunity response and to help viral replication. Divergent viruses prompt liquid-liquid phase separation (LLPS) to invade the host cell. During HIV replication there are several steps involving LLPS. In this review, we characterize the ability of individual viral and host partners that assemble into biomolecular condensates (BMCs). Of note, bioinformatic analyses predict models of phase separation in line with several published observations. Importantly, viral BMCs contribute to function in key steps retroviral replication. For example, reverse transcription takes place within nuclear BMCs, called HIV-MLOs while during late replication steps, retroviral nucleocapsid acts as a driver or scaffold to recruit client viral components to aid the assembly of progeny virions. Overall, LLPS during viral infections represents a newly described biological event now appreciated in the virology field, that can also be considered as an alternative pharmacological target to current drug therapies especially when viruses become resistant to antiviral treatment.
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Affiliation(s)
- Francesca Di Nunzio
- Advanced Molecular Virology Unit, Department of Virology, Institut Pasteur, Université Paris Cité, 75015, Paris, France
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Andrew J Mouland
- Lady Davis Institute at the Jewish General Hospital, Montréal, QC, H3T 1E2, Canada.
- Department of Microbiology and Immunology, McGill University, Montréal, QC, H3A 2B4, Canada.
- Department of Medicine, McGill University, Montréal, QC, H4A 3J1, Canada.
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19
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Volpato A, Ollech D, Alvelid J, Damenti M, Müller B, York AG, Ingaramo M, Testa I. Extending fluorescence anisotropy to large complexes using reversibly switchable proteins. Nat Biotechnol 2023; 41:552-559. [PMID: 36217028 PMCID: PMC10110461 DOI: 10.1038/s41587-022-01489-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 08/26/2022] [Indexed: 11/08/2022]
Abstract
The formation of macromolecular complexes can be measured by detection of changes in rotational mobility using time-resolved fluorescence anisotropy. However, this method is limited to relatively small molecules (~0.1-30 kDa), excluding the majority of the human proteome and its complexes. We describe selective time-resolved anisotropy with reversibly switchable states (STARSS), which overcomes this limitation and extends the observable mass range by more than three orders of magnitude. STARSS is based on long-lived reversible molecular transitions of switchable fluorescent proteins to resolve the relatively slow rotational diffusivity of large complexes. We used STARSS to probe the rotational mobility of several molecular complexes in cells, including chromatin, the retroviral Gag lattice and activity-regulated cytoskeleton-associated protein oligomers. Because STARSS can probe arbitrarily large structures, it is generally applicable to the entire human proteome.
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Affiliation(s)
- Andrea Volpato
- Department of Applied Physics and Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Dirk Ollech
- Department of Applied Physics and Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Jonatan Alvelid
- Department of Applied Physics and Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Martina Damenti
- Department of Applied Physics and Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Barbara Müller
- Department of Infectious Diseases, Virology, Centre for Integrative Infectious Disease Research, University Hospital Heidelberg, Heidelberg, Germany
| | - Andrew G York
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | | | - Ilaria Testa
- Department of Applied Physics and Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden.
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20
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Membraneless Compartmentalization of Nuclear Assembly Sites during Murine Cytomegalovirus Infection. Viruses 2023; 15:v15030766. [PMID: 36992475 PMCID: PMC10053344 DOI: 10.3390/v15030766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/28/2023] [Accepted: 03/14/2023] [Indexed: 03/19/2023] Open
Abstract
Extensive reorganization of infected cells and the formation of large structures known as the nuclear replication compartment (RC) and cytoplasmic assembly compartment (AC) is a hallmark of beta-herpesvirus infection. These restructurings rely on extensive compartmentalization of the processes that make up the virus manufacturing chain. Compartmentalization of the nuclear processes during murine cytomegalovirus (MCMV) infection is not well described. In this study, we visualized five viral proteins (pIE1, pE1, pM25, pm48.2, and pM57) and replicated viral DNA to reveal the nuclear events during MCMV infection. As expected, these events can be matched with those described for other beta and alpha herpesviruses and contribute to the overall picture of herpesvirus assembly. Imaging showed that four viral proteins (pE1, pM25, pm48.2, and pM57) and replicated viral DNA condense in the nucleus into membraneless assemblies (MLAs) that undergo a maturation sequence to form the RC. One of these proteins (pM25), which is also expressed in a cytoplasmic form (pM25l), showed similar MLAs in the AC. Bioinformatics tools for predicting biomolecular condensates showed that four of the five proteins had a high propensity for liquid–liquid phase separation (LLPS), suggesting that LLPS may be a mechanism for compartmentalization within RC and AC. Examination of the physical properties of MLAs formed during the early phase of infection by 1,6-hexanediol treatment in vivo revealed liquid-like properties of pE1 MLAs and more solid-like properties of pM25 MLAs, indicating heterogeneity of mechanisms in the formation of virus-induced MLAs. Analysis of the five viral proteins and replicated viral DNA shows that the maturation sequence of RC and AC is not completed in many cells, suggesting that virus production and release is carried out by a rather limited number of cells. This study thus lays the groundwork for further investigation of the replication cycle of beta-herpesviruses, and the results should be incorporated into plans for high-throughput and single-cell analytic approaches.
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21
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Flexibility of the Rotavirus NSP2 C-Terminal Region Supports Factory Formation via Liquid-Liquid Phase Separation. J Virol 2023; 97:e0003923. [PMID: 36749077 PMCID: PMC9973012 DOI: 10.1128/jvi.00039-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Many viruses sequester the materials needed for their replication into discrete subcellular factories. For rotaviruses (RVs), these factories are called viroplasms, and they are formed in the host cell cytosol via the process of liquid-liquid phase separation (LLPS). The nonstructural protein 2 (NSP2) and its binding partner, nonstructural protein 5 (NSP5), are critical for viroplasm biogenesis. Yet it is not fully understood how NSP2 and NSP5 cooperate to form factories. The C-terminal region (CTR) of NSP2 (residues 291 to 317) is flexible, allowing it to participate in domain-swapping interactions that promote interoctamer interactions and, presumably, viroplasm formation. Molecular dynamics simulations showed that a lysine-to-glutamic acid change at position 294 (K294E) reduces NSP2 CTR flexibility in silico. To test the impact of reduced NSP2 CTR flexibility during infection, we engineered a mutant RV bearing this change (rRV-NSP2K294E). Single-cycle growth assays revealed a >1.2-log reduction in endpoint titers for rRV-NSP2K294E versus the wild-type control (rRV-WT). Using immunofluorescence assays, we found that rRV-NSP2K294E formed smaller, more numerous viroplasms than rRV-WT. Live-cell imaging experiments confirmed these results and revealed that rRV-NSP2K294E factories had delayed fusion kinetics. Moreover, NSP2K294E and several other CTR mutants formed fewer viroplasm-like structures in NSP5 coexpressing cells than did control NSP2WT. Finally, NSP2K294E exhibited defects in its capacity to induce LLPS droplet formation in vitro when incubated alongside NSP5. These results underscore the importance of NSP2 CTR flexibility in supporting the biogenesis of RV factories. IMPORTANCE Viruses often condense the materials needed for their replication into discrete intracellular factories. For rotaviruses, agents of severe gastroenteritis in children, factory formation is mediated in part by an octameric protein called NSP2. A flexible C-terminal region of NSP2 has been proposed to link several NSP2 octamers together, a feature that might be important for factory formation. Here, we created a change in NSP2 that reduced C-terminal flexibility and analyzed the impact on rotavirus factories. We found that the change caused the formation of smaller and more numerous factories that could not readily fuse together like those of the wild-type virus. The altered NSP2 protein also had a reduced capacity to form factory-like condensates in a test tube. Together, these results add to our growing understanding of how NSP2 supports rotavirus factory formation-a key step of viral replication.
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22
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A Fijivirus Major Viroplasm Protein Shows RNA-Stimulated ATPase Activity by Adopting Pentameric and Hexameric Assemblies of Dimers. mBio 2023; 14:e0002323. [PMID: 36786587 PMCID: PMC10128069 DOI: 10.1128/mbio.00023-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
Fijiviruses replicate and package their genomes within viroplasms in a process involving RNA-RNA and RNA-protein interactions. Here, we demonstrate that the 24 C-terminal residues (C-arm) of the P9-1 major viroplasm protein of the mal de Río Cuarto virus (MRCV) are required for its multimerization and the formation of viroplasm-like structures. Using an integrative structural approach, the C-arm was found to be dispensable for P9-1 dimer assembly but essential for the formation of pentamers and hexamers of dimers (decamers and dodecamers), which favored RNA binding. Although both P9-1 and P9-1ΔC-arm catalyzed ATP with similar activities, an RNA-stimulated ATPase activity was only detected in the full-length protein, indicating a C-arm-mediated interaction between the ATP catalytic site and the allosteric RNA binding sites in the (do)decameric assemblies. A stronger preference to bind phosphate moieties in the decamer was predicted, suggesting that the allosteric modulation of ATPase activity by RNA is favored in this structural conformation. Our work reveals the structural versatility of a fijivirus major viroplasm protein and provides clues to its mechanism of action. IMPORTANCE The mal de Río Cuarto virus (MRCV) causes an important maize disease in Argentina. MRCV replicates in several species of Gramineae plants and planthopper vectors. The viral factories, also called viroplasms, have been studied in detail in animal reovirids. This work reveals that a major viroplasm protein of MRCV forms previously unidentified structural arrangements and provides evidence that it may simultaneously adopt two distinct quaternary assemblies. Furthermore, our work uncovers an allosteric communication between the ATP and RNA binding sites that is favored in the multimeric arrangements. Our results contribute to the understanding of plant reovirids viroplasm structure and function and pave the way for the design of antiviral strategies for disease control.
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Chau BA, Chen V, Cochrane AW, Parent LJ, Mouland AJ. Liquid-liquid phase separation of nucleocapsid proteins during SARS-CoV-2 and HIV-1 replication. Cell Rep 2023; 42:111968. [PMID: 36640305 PMCID: PMC9790868 DOI: 10.1016/j.celrep.2022.111968] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 10/27/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
The leap of retroviruses and coronaviruses from animal hosts to humans has led to two ongoing pandemics and tens of millions of deaths worldwide. Retrovirus and coronavirus nucleocapsid proteins have been studied extensively as potential drug targets due to their central roles in virus replication, among which is their capacity to bind their respective genomic RNAs for packaging into nascent virions. This review focuses on fundamental studies of these nucleocapsid proteins and how their intrinsic abilities to condense through liquid-liquid phase separation (LLPS) contribute to viral replication. Therapeutic targeting of these condensates and methodological advances are also described to address future questions on how phase separation contributes to viral replication.
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Affiliation(s)
- Bao-An Chau
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Venessa Chen
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Alan W Cochrane
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Leslie J Parent
- Division of Infectious Diseases and Epidemiology, Departments of Medicine and Microbiology and Immunology, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Andrew J Mouland
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, QC H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, QC H3A 2B4, Canada; Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada.
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Liaisons dangereuses: Intrinsic Disorder in Cellular Proteins Recruited to Viral Infection-Related Biocondensates. Int J Mol Sci 2023; 24:ijms24032151. [PMID: 36768473 PMCID: PMC9917183 DOI: 10.3390/ijms24032151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/11/2023] [Accepted: 01/19/2023] [Indexed: 01/25/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) is responsible for the formation of so-called membrane-less organelles (MLOs) that are essential for the spatio-temporal organization of the cell. Intrinsically disordered proteins (IDPs) or regions (IDRs), either alone or in conjunction with nucleic acids, are involved in the formation of these intracellular condensates. Notably, viruses exploit LLPS at their own benefit to form viral replication compartments. Beyond giving rise to biomolecular condensates, viral proteins are also known to partition into cellular MLOs, thus raising the question as to whether these cellular phase-separating proteins are drivers of LLPS or behave as clients/regulators. Here, we focus on a set of eukaryotic proteins that are either sequestered in viral factories or colocalize with viral proteins within cellular MLOs, with the primary goal of gathering organized, predicted, and experimental information on these proteins, which constitute promising targets for innovative antiviral strategies. Using various computational approaches, we thoroughly investigated their disorder content and inherent propensity to undergo LLPS, along with their biological functions and interactivity networks. Results show that these proteins are on average, though to varying degrees, enriched in disorder, with their propensity for phase separation being correlated, as expected, with their disorder content. A trend, which awaits further validation, tends to emerge whereby the most disordered proteins serve as drivers, while more ordered cellular proteins tend instead to be clients of viral factories. In light of their high disorder content and their annotated LLPS behavior, most proteins in our data set are drivers or co-drivers of molecular condensation, foreshadowing a key role of these cellular proteins in the scaffolding of viral infection-related MLOs.
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Investigation of the Fuzzy Complex between RSV Nucleoprotein and Phosphoprotein to Optimize an Inhibition Assay by Fluorescence Polarization. Int J Mol Sci 2022; 24:ijms24010569. [PMID: 36614009 PMCID: PMC9820559 DOI: 10.3390/ijms24010569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 12/30/2022] Open
Abstract
The interaction between Respiratory Syncytial Virus phosphoprotein P and nucleoprotein N is essential for the formation of the holo RSV polymerase that carries out replication. In vitro screening of antivirals targeting the N-P protein interaction requires a molecular interaction model, ideally consisting of a complex between N protein and a short peptide corresponding to the C-terminal tail of the P protein. However, the flexibility of C-terminal P peptides as well as their phosphorylation status play a role in binding and may bias the outcome of an inhibition assay. We therefore investigated binding affinities and dynamics of this interaction by testing two N protein constructs and P peptides of different lengths and composition, using nuclear magnetic resonance and fluorescence polarization (FP). We show that, although the last C-terminal Phe241 residue is the main determinant for anchoring P to N, only longer peptides afford sub-micromolar affinity, despite increasing mobility towards the N-terminus. We investigated competitive binding by peptides and small compounds, including molecules used as fluorescent labels in FP. Based on these results, we draw optimized parameters for a robust RSV N-P inhibition assay and validated this assay with the M76 molecule, which displays antiviral properties, for further screening of chemical libraries.
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Functional benefit of structural disorder for the replication of measles, Nipah and Hendra viruses. Essays Biochem 2022; 66:915-934. [PMID: 36148633 DOI: 10.1042/ebc20220045] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/18/2022] [Accepted: 08/25/2022] [Indexed: 12/24/2022]
Abstract
Measles, Nipah and Hendra viruses are severe human pathogens within the Paramyxoviridae family. Their non-segmented, single-stranded, negative-sense RNA genome is encapsidated by the nucleoprotein (N) within a helical nucleocapsid that is the substrate used by the viral RNA-dependent-RNA-polymerase (RpRd) for transcription and replication. The RpRd is a complex made of the large protein (L) and of the phosphoprotein (P), the latter serving as an obligate polymerase cofactor and as a chaperon for N. Both the N and P proteins are enriched in intrinsically disordered regions (IDRs), i.e. regions devoid of stable secondary and tertiary structure. N possesses a C-terminal IDR (NTAIL), while P consists of a large, intrinsically disordered N-terminal domain (NTD) and a C-terminal domain (CTD) encompassing alternating disordered and ordered regions. The V and W proteins, two non-structural proteins that are encoded by the P gene via a mechanism of co-transcriptional edition of the P mRNA, are prevalently disordered too, sharing with P the disordered NTD. They are key players in the evasion of the host antiviral response and were shown to phase separate and to form amyloid-like fibrils in vitro. In this review, we summarize the available information on IDRs within the N, P, V and W proteins from these three model paramyxoviruses and describe their molecular partnership. We discuss the functional benefit of disorder to virus replication in light of the critical role of IDRs in affording promiscuity, multifunctionality, fine regulation of interaction strength, scaffolding functions and in promoting liquid-liquid phase separation and fibrillation.
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Li H, Ernst C, Kolonko-Adamska M, Greb-Markiewicz B, Man J, Parissi V, Ng BWL. Phase separation in viral infections. Trends Microbiol 2022; 30:1217-1231. [PMID: 35902318 DOI: 10.1016/j.tim.2022.06.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 01/13/2023]
Abstract
Viruses rely on the reprogramming of cellular processes to enable efficient viral replication; this often requires subcompartmentalization within the host cell. Liquid-liquid phase separation (LLPS) has emerged as a fundamental principle to organize and subdivide cellular processes, and plays an important role in viral life cycles. Despite substantial advances in the field, elucidating the exact organization and function of these organelles remains a major challenge. In this review, we summarize the biochemical basis of condensate formation, the role of LLPS during viral infection, and interplay of LLPS with innate immune responses. Finally, we discuss possible strategies and molecules to modulate LLPS during viral infections.
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Affiliation(s)
- Haohua Li
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong; Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Christina Ernst
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Marta Kolonko-Adamska
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland
| | - Beata Greb-Markiewicz
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland
| | - Jackie Man
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong; Faculty of Medicine, Imperial College, London, UK
| | - Vincent Parissi
- Microbiologie Fondamentale et Pathogénicité Laboratory (MPF), UMR 5234, « Mobility of pathogenic genomes and chromatin dynamics » team (MobilVIR), CNRS-University of Bordeaux, Bordeaux, France
| | - Billy Wai-Lung Ng
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
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Staufer O, Gantner G, Platzman I, Tanner K, Berger I, Spatz JP. Bottom-up assembly of viral replication cycles. Nat Commun 2022; 13:6530. [PMID: 36323671 PMCID: PMC9628313 DOI: 10.1038/s41467-022-33661-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 09/27/2022] [Indexed: 11/05/2022] Open
Abstract
Bottom-up synthetic biology provides new means to understand living matter by constructing minimal life-like systems. This principle can also be applied to study infectious diseases. Here we summarize approaches and ethical considerations for the bottom-up assembly of viral replication cycles.
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Affiliation(s)
- Oskar Staufer
- Max Planck-Bristol Center for Minimal Biology, University of Bristol, 1 Tankard's Close, Bristol, BS8 1TD, UK.
- Kennedy Institute of Rheumatology, University of Oxford, Roosevelt Drive, OX3 7FY, UK.
- Max Planck School Matter to Life, Jahnstraße 29, 69120, Heidelberg, Germany.
| | - Gösta Gantner
- Max Planck School Matter to Life, Jahnstraße 29, 69120, Heidelberg, Germany
- Theological Seminary, Heidelberg University, Kisselgasse 1, 69117, Heidelberg, Germany
| | - Ilia Platzman
- Max Planck-Bristol Center for Minimal Biology, University of Bristol, 1 Tankard's Close, Bristol, BS8 1TD, UK
- Department for Cellular Biophysics, Max Planck Institute for Medical Research, Jahnstraße 29, 69120, Heidelberg, Germany
- Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM), University of Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Klaus Tanner
- Max Planck School Matter to Life, Jahnstraße 29, 69120, Heidelberg, Germany
- Theological Seminary, Heidelberg University, Kisselgasse 1, 69117, Heidelberg, Germany
| | - Imre Berger
- Max Planck-Bristol Center for Minimal Biology, University of Bristol, 1 Tankard's Close, Bristol, BS8 1TD, UK
- School of Biochemistry, Biomedical Sciences, University of Bristol, 1 Tankard's Close, Bristol, BS8 1TD, UK
- Bristol Synthetic Biology Centre BrisSynBio, University of Bristol, 4 Tyndall Ave, Bristol, BS8 1TQ, UK
| | - Joachim P Spatz
- Max Planck-Bristol Center for Minimal Biology, University of Bristol, 1 Tankard's Close, Bristol, BS8 1TD, UK
- Max Planck School Matter to Life, Jahnstraße 29, 69120, Heidelberg, Germany
- Department for Cellular Biophysics, Max Planck Institute for Medical Research, Jahnstraße 29, 69120, Heidelberg, Germany
- Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM), University of Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
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29
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Wu C, Holehouse AS, Leung DW, Amarasinghe GK, Dutch RE. Liquid Phase Partitioning in Virus Replication: Observations and Opportunities. Annu Rev Virol 2022; 9:285-306. [PMID: 35709511 DOI: 10.1146/annurev-virology-093020-013659] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Viruses frequently carry out replication in specialized compartments within cells. The effect of these structures on virus replication is poorly understood. Recent research supports phase separation as a foundational principle for organization of cellular components with the potential to influence viral replication. In this review, phase separation is described in the context of formation of viral replication centers, with an emphasis on the nonsegmented negative-strand RNA viruses. Consideration is given to the interplay between phase separation and the critical processes of viral transcription and genome replication, and the role of these regions in pathogen-host interactions is discussed. Finally, critical questions that must be addressed to fully understand how phase separation influences viral replication and the viral life cycle are presented, along with information about new approaches that could be used to make important breakthroughs in this emerging field.
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Affiliation(s)
- Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA
- Center for Science and Engineering Living Systems, Washington University, St. Louis, Missouri, USA
| | - Daisy W Leung
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Rebecca Ellis Dutch
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, Kentucky, USA;
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30
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Vazquez DS, Toledo PL, Gianotti AR, Ermácora MR. Protein conformation and biomolecular condensates. Curr Res Struct Biol 2022; 4:285-307. [PMID: 36164646 PMCID: PMC9508354 DOI: 10.1016/j.crstbi.2022.09.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/08/2022] [Accepted: 09/13/2022] [Indexed: 10/27/2022] Open
Abstract
Protein conformation and cell compartmentalization are fundamental concepts and subjects of vast scientific endeavors. In the last two decades, we have witnessed exciting advances that unveiled the conjunction of these concepts. An avalanche of studies highlighted the central role of biomolecular condensates in membraneless subcellular compartmentalization that permits the spatiotemporal organization and regulation of myriads of simultaneous biochemical reactions and macromolecular interactions. These studies have also shown that biomolecular condensation, driven by multivalent intermolecular interactions, is mediated by order-disorder transitions of protein conformation and by protein domain architecture. Conceptually, protein condensation is a distinct level in protein conformational landscape in which collective folding of large collections of molecules takes place. Biomolecular condensates arise by the physical process of phase separation and comprise a variety of bodies ranging from membraneless organelles to liquid condensates to solid-like conglomerates, spanning lengths from mesoscopic clusters (nanometers) to micrometer-sized objects. In this review, we summarize and discuss recent work on the assembly, composition, conformation, material properties, thermodynamics, regulation, and functions of these bodies. We also review the conceptual framework for future studies on the conformational dynamics of condensed proteins in the regulation of cellular processes.
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Affiliation(s)
- Diego S. Vazquez
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes and Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Argentina
| | - Pamela L. Toledo
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes and Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Argentina
| | - Alejo R. Gianotti
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes and Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Argentina
| | - Mario R. Ermácora
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes and Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Argentina
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31
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Multiscale characterization reveals oligomerization dependent phase separation of primer-independent RNA polymerase nsp8 from SARS-CoV-2. Commun Biol 2022; 5:925. [PMID: 36071105 PMCID: PMC9451113 DOI: 10.1038/s42003-022-03892-x] [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] [Received: 12/06/2021] [Accepted: 08/25/2022] [Indexed: 11/09/2022] Open
Abstract
RNA replication and transcription machinery is an important drug target for fighting against coronavirus. Non-structure protein nsp8 was proposed harboring primase activity. However, the RNA primer synthesis mechanism of nsp8 is still largely unknown. Here, we purified dimer and tetramer forms of SARS-CoV-2 nsp8. Combined with dynamic light scattering, small-angle neutron scattering and thermo-stability analysis, we found that both dimer and tetramer become loosened and destabilized with decreasing salt concentration, and the dimer form is more stable than the tetramer form. Further investigation showed that nsp8 dimer and tetramer can undergo phase separation but exhibit different phase separation behaviors. Nsp8 dimer can form liquid-like droplets in the buffer with a low concentration of NaCl; phase separation of nsp8 tetramer depends on the assistance of RNA. Our findings on different phase separation behaviors of nsp8 dimer and tetramer may provide insight into the functional studies of nsp8 in coronavirus. The phase separation behaviour of non-structure protein nsp8 of SARS CoV2 in the primer synthesis mechanism is presented, underpinning the replication of coronavirus.
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32
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Liu P, Zhang S, Ma J, Jin D, Qin Y, Chen M. Vimentin inhibits α-tubulin acetylation via enhancing α-TAT1 degradation to suppress the replication of human parainfluenza virus type 3. PLoS Pathog 2022; 18:e1010856. [PMID: 36108090 PMCID: PMC9524669 DOI: 10.1371/journal.ppat.1010856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 09/30/2022] [Accepted: 09/03/2022] [Indexed: 11/24/2022] Open
Abstract
We previously found that, among human parainfluenza virus type 3 (HPIV3) proteins, the interaction of nucleoprotein (N) and phosphoprotein (P) provides the minimal requirement for the formation of cytoplasmic inclusion bodies (IBs), which are sites of RNA synthesis, and that acetylated α-tubulin enhances IB fusion and viral replication. In this study, using immunoprecipitation and mass spectrometry assays, we determined that vimentin (VIM) specifically interacted with the N-P complex of HPIV3, and that the head domain of VIM was responsible for this interaction, contributing to the inhibition of IB fusion and viral replication. Furthermore, we found that VIM promoted the degradation of α-tubulin acetyltransferase 1 (α-TAT1), through its head region, thereby inhibiting the acetylation of α-tubulin, IB fusion, and viral replication. In addition, we identified a 20-amino-acid peptide derived from the head region of VIM that participated in the interaction with the N-P complex and inhibited viral replication. Our findings suggest that VIM inhibits the formation of HPIV3 IBs by downregulating α-tubulin acetylation via enhancing the degradation of α-TAT1. Our work sheds light on a new mechanism by which VIM suppresses HPIV3 replication.
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Affiliation(s)
- Pengfei Liu
- State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Luo Jia Hill, Wuhan, China
| | - Shengwei Zhang
- School of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan, China
| | - Jingyi Ma
- State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Luo Jia Hill, Wuhan, China
| | - Dongning Jin
- State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Luo Jia Hill, Wuhan, China
| | - Yali Qin
- State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Luo Jia Hill, Wuhan, China
| | - Mingzhou Chen
- State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Luo Jia Hill, Wuhan, China
- Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan, China
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33
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Monette A, Niu M, Nijhoff Asser M, Gorelick RJ, Mouland AJ. Scaffolding viral protein NC nucleates phase separation of the HIV-1 biomolecular condensate. Cell Rep 2022; 40:111251. [PMID: 36001979 DOI: 10.1016/j.celrep.2022.111251] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 06/20/2022] [Accepted: 08/01/2022] [Indexed: 11/26/2022] Open
Abstract
Membraneless biomolecular condensates (BMCs) contribute to the replication of a growing number of viruses but remain to be functionally characterized. Previously, we demonstrated that pan-retroviral nucleocapsid (NC) proteins phase separated into condensates regulating virus assembly. Here we discover that intrinsically disordered human immunodeficiency virus-type 1 (HIV-1) core proteins condense with the viral genomic RNA (vRNA) to assemble as BMCs attaining a geometry characteristic of viral reverse transcription complexes. We explore the predisposition, mechanisms, and pharmacologic sensitivity of HIV-1 core BMCs in living cells. HIV-1 vRNA-interacting NC condensates were found to be scaffolds onto which client capsid, reverse transcriptase, and integrase condensates assemble. HIV-1 core BMCs exhibit fundamental characteristics of BMCs and are drug-sensitive. Lastly, protease-mediated maturation of Gag and Gag-Pol precursor proteins yield abundant and visible BMCs in cells. This study redefines HIV-1 core components as fluid BMCs and advances our understanding of the nature of viral cores during ingress.
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Affiliation(s)
- Anne Monette
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.
| | - Meijuan Niu
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada
| | - Maya Nijhoff Asser
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Robert J Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Andrew J Mouland
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, Quebec H3A 2B4, Canada; Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada.
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34
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Peng Q, Tan S, Xia L, Wu N, Oyang L, Tang Y, Su M, Luo X, Wang Y, Sheng X, Zhou Y, Liao Q. Phase separation in Cancer: From the Impacts and Mechanisms to Treatment potentials. Int J Biol Sci 2022; 18:5103-5122. [PMID: 35982902 PMCID: PMC9379413 DOI: 10.7150/ijbs.75410] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/16/2022] [Indexed: 12/14/2022] Open
Abstract
Cancer is a public health problem of great concern, and it is also one of the main causes of death in the world. Cancer is a disease characterized by dysregulation of diverse cellular processes, including avoiding growth inhibitory factors, avoiding immune damage and promoting metastasis, etc. However, the precise mechanism of tumorigenesis and tumor progression still needs to be further elucidated. Formations of liquid-liquid phase separation (LLPS) condensates are a common strategy for cells to achieve diverse functions, such as chromatin organization, signal transduction, DNA repair and transcriptional regulation, etc. The biomolecular aggregates formed by LLPS are mainly driven by multivalent weak interactions mediated by intrinsic disordered regions (IDRs) in proteins. In recent years, aberrant phase separations and transition have been reported to be related to the process of various diseases, such as neurodegenerative diseases and cancer. Herein, we discussed recent findings that phase separation regulates tumor-related signaling pathways and thus contributes to tumor progression. We also reviewed some tumor virus-associated proteins to regulate the development of virus-associated tumors via phase separation. Finally, we discussed some possible strategies for treating tumors by targeting phase separation.
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Affiliation(s)
- Qiu Peng
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Shiming Tan
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Longzheng Xia
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Nayiyuan Wu
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Linda Oyang
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Yanyan Tang
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Min Su
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Xia Luo
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Ying Wang
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Xiaowu Sheng
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
| | - Yujuan Zhou
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China.,Hunan Key Laboratory of Translational Radiation Oncology, 283 Tongzipo Road, Changsha 410013, Hunan, China
| | - Qianjin Liao
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China.,Hunan Key Laboratory of Translational Radiation Oncology, 283 Tongzipo Road, Changsha 410013, Hunan, China
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Gallo GL, López N, Loureiro ME. The Virus–Host Interplay in Junín Mammarenavirus Infection. Viruses 2022; 14:v14061134. [PMID: 35746604 PMCID: PMC9228484 DOI: 10.3390/v14061134] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/26/2022] [Accepted: 04/28/2022] [Indexed: 02/06/2023] Open
Abstract
Junín virus (JUNV) belongs to the Arenaviridae family and is the causative agent of Argentine hemorrhagic fever (AHF), a severe human disease endemic to agricultural areas in Argentina. At this moment, there are no effective antiviral therapeutics to battle pathogenic arenaviruses. Cumulative reports from recent years have widely provided information on cellular factors playing key roles during JUNV infection. In this review, we summarize research on host molecular determinants that intervene in the different stages of the viral life cycle: viral entry, replication, assembly and budding. Alongside, we describe JUNV tight interplay with the innate immune system. We also review the development of different reverse genetics systems and their use as tools to study JUNV biology and its close teamwork with the host. Elucidating relevant interactions of the virus with the host cell machinery is highly necessary to better understand the mechanistic basis beyond virus multiplication, disease pathogenesis and viral subversion of the immune response. Altogether, this knowledge becomes essential for identifying potential targets for the rational design of novel antiviral treatments to combat JUNV as well as other pathogenic arenaviruses.
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Targeting the Nucleosome Acidic Patch by Viral Proteins: Two Birds with One Stone? mBio 2022; 13:e0173321. [PMID: 35343785 PMCID: PMC9040877 DOI: 10.1128/mbio.01733-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The past decade illuminated the H2A-H2B acidic patch as a cornerstone for both nucleosome recognition and chromatin structure regulation. Higher-order folding of chromatin arrays is mediated by interactions of histone H4 tail with an adjacent nucleosome acidic patch. Dynamic chromatin folding ensures a proper regulation of nuclear functions fundamental to cellular homeostasis. Many cellular factors have been shown to act on chromatin by tethering nucleosomes via an arginine anchor binding to the acidic patch. This tethering mechanism has also been described for several viral proteins. In this minireview, we will discuss the structural basis for acidic patch engagement by viral proteins and the implications during respective viral infections. We will also discuss a model in which acidic patch occupancy by these non-self viral proteins alters the local chromatin state by preventing H4 tail-mediated higher-order chromatin folding.
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Uversky VN. Protein folding, misfolding, and un/non-folding: overview of the SP16 Session at the 20 th IUPAB congress, 45 th Annual Meeting of SBBf, and 50 th Annual Meeting of SBBq. Biophys Rev 2022; 13:879-882. [PMID: 35059012 DOI: 10.1007/s12551-021-00885-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 11/01/2021] [Indexed: 12/16/2022] Open
Abstract
The classical and idealistic consideration of the protein universe as a set of well-ordered proteinaceous machines with unique spatial organizations conducting unique biological functions is changed because of the recognition that proteins can fold, misfold, or be disordered to different degree. Functional repertoires of intrinsically disordered proteins complement functions of ordered proteins, whereas protein misfolding and concomitant oligomerization, aggregation, and fibrillation are related to the pathogenesis of numerous human diseases. Flexible proteins can undergo liquid-liquid phase separation, which is at the heart of the biogenesis of numerous membrane-less organelles. Many of these aspects were highlighted in four talks delivered at the SP16 Session at the 20th IUPAB congress, 45th Annual Meeting of SBBf, and 50th Annual Meeting of SBBq.
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Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd, Tampa, FL MDC07 USA
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Interactions between the Nucleoprotein and the Phosphoprotein of Pneumoviruses: Structural Insight for Rational Design of Antivirals. Viruses 2021; 13:v13122449. [PMID: 34960719 PMCID: PMC8706346 DOI: 10.3390/v13122449] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 11/17/2022] Open
Abstract
Pneumoviruses include pathogenic human and animal viruses, the most known and studied being the human respiratory syncytial virus (hRSV) and the metapneumovirus (hMPV), which are the major cause of severe acute respiratory tract illness in young children worldwide, and main pathogens infecting elderly and immune-compromised people. The transcription and replication of these viruses take place in specific cytoplasmic inclusions called inclusion bodies (IBs). These activities depend on viral polymerase L, associated with its cofactor phosphoprotein P, for the recognition of the viral RNA genome encapsidated by the nucleoprotein N, forming the nucleocapsid (NC). The polymerase activities rely on diverse transient protein-protein interactions orchestrated by P playing the hub role. Among these interactions, P interacts with the NC to recruit L to the genome. The P protein also plays the role of chaperone to maintain the neosynthesized N monomeric and RNA-free (called N0) before specific encapsidation of the viral genome and antigenome. This review aims at giving an overview of recent structural information obtained for hRSV and hMPV P, N, and more specifically for P-NC and N0-P complexes that pave the way for the rational design of new antivirals against those viruses.
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Sołtys K, Ożyhar A. Transcription Regulators and Membraneless Organelles Challenges to Investigate Them. Int J Mol Sci 2021; 22:12758. [PMID: 34884563 PMCID: PMC8657783 DOI: 10.3390/ijms222312758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/19/2021] [Accepted: 11/23/2021] [Indexed: 12/13/2022] Open
Abstract
Eukaryotic cells are composed of different bio-macromolecules that are divided into compartments called organelles providing optimal microenvironments for many cellular processes. A specific type of organelles is membraneless organelles. They are formed via a process called liquid-liquid phase separation that is driven by weak multivalent interactions between particular bio-macromolecules. In this review, we gather crucial information regarding different classes of transcription regulators with the propensity to undergo liquid-liquid phase separation and stress the role of intrinsically disordered regions in this phenomenon. We also discuss recently developed experimental systems for studying formation and properties of membraneless organelles.
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Affiliation(s)
- Katarzyna Sołtys
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wroclaw, Poland;
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