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Wei Q, Wang W, Meng F, Wang Y, Wei N, Tian J, Li H, Hao Q, Zhou Z, Liu H, Yang Z, Xiao S. The W195 Residue of the Newcastle Disease Virus V Protein Is Critical for Multiple Aspects of Viral Self-Regulation through Interactions between V and Nucleoproteins. Viruses 2024; 16:584. [PMID: 38675926 PMCID: PMC11054343 DOI: 10.3390/v16040584] [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: 03/09/2024] [Revised: 04/03/2024] [Accepted: 04/07/2024] [Indexed: 04/28/2024] Open
Abstract
The transcription and replication of the Newcastle disease virus (NDV) strictly rely on the viral ribonucleoprotein (RNP) complex, which is composed of viral NP, P, L and RNA. However, it is not known whether other viral non-RNP proteins participate in this process for viral self-regulation. In this study, we used a minigenome (MG) system to identify the regulatory role of the viral non-RNP proteins V, M, W, F and HN. Among them, V significantly reduced MG-encoded reporter activity compared with the other proteins and inhibited the synthesis of viral mRNA and cRNA. Further, V interacted with NP. A mutation in residue W195 of V diminished V-NP interaction and inhibited inclusion body (IB) formation in NP-P-L-cotransfected cells. Furthermore, a reverse-genetics system for the highly virulent strain F48E9 was established. The mutant rF48E9-VW195R increased viral replication and apparently enhanced IB formation. In vivo experiments demonstrated that rF48E9-VW195R decreased virulence and retarded time of death. Overall, the results indicate that the V-NP interaction of the W195 mutant V decreased, which regulated viral RNA synthesis, IB formation, viral replication and pathogenicity. This study provides insight into the self-regulation of non-RNP proteins in paramyxoviruses.
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Affiliation(s)
- Qiaolin Wei
- College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang 712100, China; (Q.W.); (F.M.); (Y.W.); (N.W.); (J.T.); (H.L.); (Q.H.); (Z.Z.); (H.L.); (Z.Y.)
| | - Wenbin Wang
- Poultry Institute, Shandong Academy of Agricultural Science, Jinan 250100, China;
| | - Fanxing Meng
- College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang 712100, China; (Q.W.); (F.M.); (Y.W.); (N.W.); (J.T.); (H.L.); (Q.H.); (Z.Z.); (H.L.); (Z.Y.)
| | - Ying Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang 712100, China; (Q.W.); (F.M.); (Y.W.); (N.W.); (J.T.); (H.L.); (Q.H.); (Z.Z.); (H.L.); (Z.Y.)
| | - Ning Wei
- College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang 712100, China; (Q.W.); (F.M.); (Y.W.); (N.W.); (J.T.); (H.L.); (Q.H.); (Z.Z.); (H.L.); (Z.Y.)
| | - Jianxia Tian
- College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang 712100, China; (Q.W.); (F.M.); (Y.W.); (N.W.); (J.T.); (H.L.); (Q.H.); (Z.Z.); (H.L.); (Z.Y.)
| | - Hanlue Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang 712100, China; (Q.W.); (F.M.); (Y.W.); (N.W.); (J.T.); (H.L.); (Q.H.); (Z.Z.); (H.L.); (Z.Y.)
| | - Qiqi Hao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang 712100, China; (Q.W.); (F.M.); (Y.W.); (N.W.); (J.T.); (H.L.); (Q.H.); (Z.Z.); (H.L.); (Z.Y.)
| | - Zijie Zhou
- College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang 712100, China; (Q.W.); (F.M.); (Y.W.); (N.W.); (J.T.); (H.L.); (Q.H.); (Z.Z.); (H.L.); (Z.Y.)
| | - Haijin Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang 712100, China; (Q.W.); (F.M.); (Y.W.); (N.W.); (J.T.); (H.L.); (Q.H.); (Z.Z.); (H.L.); (Z.Y.)
| | - Zengqi Yang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang 712100, China; (Q.W.); (F.M.); (Y.W.); (N.W.); (J.T.); (H.L.); (Q.H.); (Z.Z.); (H.L.); (Z.Y.)
| | - Sa Xiao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Xianyang 712100, China; (Q.W.); (F.M.); (Y.W.); (N.W.); (J.T.); (H.L.); (Q.H.); (Z.Z.); (H.L.); (Z.Y.)
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Zhang C, Wu H, Feng H, Zhang YA, Tu J. Grass carp reovirus VP56 and VP35 induce formation of viral inclusion bodies for replication. iScience 2024; 27:108684. [PMID: 38188516 PMCID: PMC10767200 DOI: 10.1016/j.isci.2023.108684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 11/14/2023] [Accepted: 12/05/2023] [Indexed: 01/09/2024] Open
Abstract
Viral inclusion bodies (VIBs) are subcellular structures required for efficient viral replication. How type II grass carp reovirus (GCRV-II), the mainly prevalent strain, forms VIBs is unknown. In this study, we found that GCRV-II infection induced punctate VIBs in grass carp ovary (GCO) cells and that non-structural protein 38 (NS38) functioned as a participant in VIB formation. Furthermore, VP56 and VP35 induced VIBs and recruited other viral proteins via the N-terminal of VP56 and the middle domain of VP35. Additionally, we found that the newly synthesized viral RNAs co-localized with VP56 and VP35 in VIBs during infection. Taken together, VP56 and VP35 induce VIB formation and recruit other viral proteins and viral RNAs to the VIBs for viral replication, which helps identify new targets for developing anti-GCRV-II drugs to disrupt viral replication.
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Affiliation(s)
- Chu Zhang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, China
| | - Hui Wu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Hao Feng
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Yong-An Zhang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, China
| | - Jiagang Tu
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, College of Fisheries, Huazhong Agricultural University, Wuhan, China
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3
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Sabsay KR, te Velthuis AJW. Negative and ambisense RNA virus ribonucleocapsids: more than protective armor. Microbiol Mol Biol Rev 2023; 87:e0008223. [PMID: 37750733 PMCID: PMC10732063 DOI: 10.1128/mmbr.00082-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023] Open
Abstract
SUMMARYNegative and ambisense RNA viruses are the causative agents of important human diseases such as influenza, measles, Lassa fever, and Ebola hemorrhagic fever. The viral genome of these RNA viruses consists of one or more single-stranded RNA molecules that are encapsidated by viral nucleocapsid proteins to form a ribonucleoprotein complex (RNP). This RNP acts as protection, as a scaffold for RNA folding, and as the context for viral replication and transcription by a viral RNA polymerase. However, the roles of the viral nucleoproteins extend beyond these functions during the viral infection cycle. Recent advances in structural biology techniques and analysis methods have provided new insights into the formation, function, dynamics, and evolution of negative sense virus nucleocapsid proteins, as well as the role that they play in host innate immune responses against viral infection. In this review, we discuss the various roles of nucleocapsid proteins, both in the context of RNPs and in RNA-free states, as well as the open questions that remain.
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Affiliation(s)
- Kimberly R. Sabsay
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, USA
| | - Aartjan J. W. te Velthuis
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
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4
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Ferrero DS, Tomás Gilabert O, Verdaguer N. Structural insights on the nucleoprotein C-terminal domain of Měnglà virus. Microbiol Spectr 2023; 11:e0237323. [PMID: 37888996 PMCID: PMC10714759 DOI: 10.1128/spectrum.02373-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/19/2023] [Indexed: 10/28/2023] Open
Abstract
IMPORTANCE Filoviruses are the causative agents of severe and often fatal hemorrhagic disease in humans. Měnglà virus (MLAV) is a recently reported filovirus, isolated from fruit bats that is capable to replicate in human cells, representing a potential risk for human health. An in-depth structural and functional knowledge of MLAV proteins is an essential step for antiviral research on this virus that can also be extended to other emerging filoviruses. In this study, we determined the first crystal structures of the C-terminal domain (CTD) of the MLAV nucleoprotein (NP), showing important similarities to the equivalent domain in MARV. The structural data also show that the NP CTD has the ability to form large helical oligomers that may participate in the control of cytoplasmic inclusion body formation during viral replication.
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Affiliation(s)
| | | | - Nuria Verdaguer
- Molecular Biology Institute of Barcelona (IBMB-CSIC), Barcelona, Spain
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Liang Y, Zhang X, Wu B, Wang S, Kang L, Deng Y, Xie L, Li Z. Actomyosin-driven motility and coalescence of phase-separated viral inclusion bodies are required for efficient replication of a plant rhabdovirus. THE NEW PHYTOLOGIST 2023; 240:1990-2006. [PMID: 37735952 DOI: 10.1111/nph.19255] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 08/21/2023] [Indexed: 09/23/2023]
Abstract
Phase separation has emerged as a fundamental principle for organizing viral and cellular membraneless organelles. Although these subcellular compartments have been recognized for decades, their biogenesis and mechanisms of regulation are poorly understood. Here, we investigate the formation of membraneless inclusion bodies (IBs) induced during the infection of a plant rhabdovirus, tomato yellow mottle-associated virus (TYMaV). We generated recombinant TYMaV encoding a fluorescently labeled IB constituent protein and employed live-cell imaging to characterize the intracellular dynamics and maturation of viral IBs in infected Nicotiana benthamiana cells. We show that TYMaV IBs are phase-separated biomolecular condensates and that viral nucleoprotein and phosphoprotein are minimally required for IB formation in vivo and in vitro. TYMaV IBs move along the microfilaments, likely through the anchoring of viral phosphoprotein to myosin XIs. Furthermore, pharmacological disruption of microfilaments or inhibition of myosin XI functions suppresses IB motility, resulting in arrested IB growth and inefficient virus replication. Our study establishes phase separation as a process driving the formation of liquid viral factories and emphasizes the role of the cytoskeletal system in regulating the dynamics of condensate maturation.
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Affiliation(s)
- Yan Liang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou, 310058, China
| | - Xiaoyan Zhang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Binyan Wu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Shuo Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou, 310058, China
| | - Lihua Kang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou, 310058, China
| | - Yinlu Deng
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou, 310058, China
| | - Li Xie
- Analysis Center of Agrobiology and Environmental Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Zhenghe Li
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou, 310058, China
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Wu C, Wagner ND, Moyle AB, Feng A, Sharma N, Stubbs SH, Donahue C, Davey RA, Gross ML, Leung DW, Amarasinghe GK. Disruption of Ebola NP 0VP35 Inclusion Body-like Structures reduce Viral Infection. J Mol Biol 2023; 435:168241. [PMID: 37598728 DOI: 10.1016/j.jmb.2023.168241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 08/04/2023] [Accepted: 08/11/2023] [Indexed: 08/22/2023]
Abstract
Viral inclusion bodies (IBs) are potential sites of viral replication and assembly. How viral IBs form remains poorly defined. Here we describe a combined biophysical and cellular approach to identify the components necessary for IB formation during Ebola virus (EBOV) infection. We find that the eNP0VP35 complex containing Ebola nucleoprotein (eNP) and viral protein 35 (eVP35), the functional equivalents of nucleoprotein (N) and phosphoprotein (P) in non-segmented negative strand viruses (NNSVs), phase separates to form inclusion bodies. Phase separation of eNP0VP35 is reversible and modulated by ionic strength. The multivalency of eVP35, and not eNP, is also critical for phase separation. Furthermore, overexpression of an eVP35 peptide disrupts eNP0VP35 complex formation, leading to reduced frequency of IB formation and limited viral infection. Together, our results show that upon EBOV infection, the eNP0VP35 complex forms the minimum unit to drive IB formation and viral replication.
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Affiliation(s)
- Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
| | - Nicole D Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA; Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Austin B Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Annie Feng
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Nitin Sharma
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Sarah H Stubbs
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Callie Donahue
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Robert A Davey
- Department of Microbiology, National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Daisy W Leung
- Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
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7
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Wang C, Duan L, Wang T, Wang W, Han Y, Hu R, Hou Q, Liu H, Wang J, Wang X, Xiao S, Dang R, Wang J, Zhang G, Yang Z. Newcastle disease virus forms inclusion bodies with features of liquid-liquid phase separation. Vet Microbiol 2023; 284:109800. [PMID: 37295230 DOI: 10.1016/j.vetmic.2023.109800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 06/03/2023] [Accepted: 06/05/2023] [Indexed: 06/12/2023]
Abstract
Formation of inclusion bodies (IBs) is a hallmark of infections with negative-strand RNA viruses. Although the Newcastle disease virus (NDV) IBs had been observed in the 1950s, the characteristics of NDV IBs remained largely unknown. Here, we show that NDV infection triggers the formation of IBs that contain newly synthesized viral RNA. The structures of NDV IBs, observed by electron microscopy, were not membrane-bound. Fluorescence recovery after photobleaching a region of NDV IBs occurred rapidly, and IBs were dissolved by 1,6-hexanediol treatment, demonstrating they exhibited properties consistent with liquid-liquid phase separation (LLPS). We find the nucleoprotein (NP) and phosphoprotein (P) are sufficient to generate IB-like puncta, with the N arm domain and N core region of NP and the C terminus of P playing important roles in this process. In summary, our findings suggest that NDV forms IBs containing viral RNA, and provide insights into the formation of NDV IBs.
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Affiliation(s)
- Chongyang Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Liuyuan Duan
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ting Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Wenbin Wang
- Poultry Institute, Shandong Academy of Agricultural Science, Jinan, China
| | - Yu Han
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ruochen Hu
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Qili Hou
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Haijin Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Juan Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Xinglong Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Sa Xiao
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Ruyi Dang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Junru Wang
- College of Chemistry and Pharmacy, Northwest A&F University, Yangling, China
| | - Gaiping Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China; Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, China.
| | - Zengqi Yang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China.
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Risso-Ballester J, Rameix-Welti MA. Spatial resolution of virus replication: RSV and cytoplasmic inclusion bodies. Adv Virus Res 2023; 116:1-43. [PMID: 37524479 DOI: 10.1016/bs.aivir.2023.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Respiratory Syncytial Virus (RSV) is a major cause of respiratory illness in young children, elderly and immunocompromised individuals worldwide representing a severe burden for health systems. The urgent development of vaccines or specific antivirals against RSV is impaired by the lack of knowledge regarding its replication mechanisms. RSV is a negative-sense single-stranded RNA (ssRNA) virus belonging to the Mononegavirales order (MNV) which includes other viruses pathogenic to humans as Rabies (RabV), Ebola (EBOV), or measles (MeV) viruses. Transcription and replication of viral genomes occur within cytoplasmatic virus-induced spherical inclusions, commonly referred as inclusion bodies (IBs). Recently IBs were shown to exhibit properties of membrane-less organelles (MLO) arising by liquid-liquid phase separation (LLPS). Compartmentalization of viral RNA synthesis steps in viral-induced MLO is indeed a common feature of MNV. Strikingly these key compartments still remain mysterious. Most of our current knowledge on IBs relies on the use of fluorescence microscopy. The ability to fluorescently label IBs in cells has been key to uncover their dynamics and nature. The generation of recombinant viruses expressing a fluorescently-labeled viral protein and the immunolabeling or the expression of viral fusion proteins known to be recruited in IBs are some of the tools used to visualize IBs in infected cells. In this chapter, microscope techniques and the most relevant studies that have shed light on RSV IBs fundamental aspects, including biogenesis, organization and dynamics are being discussed and brought to light with the investigations carried out on other MNV.
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Affiliation(s)
| | - Marie-Anne Rameix-Welti
- Institut Pasteur, Université Paris-Saclay, Université de Versailles St. Quentin, UMR 1173 (2I), INSERM, Paris, France; Assistance Publique des Hôpitaux de Paris, Hôpital Ambroise Paré, Laboratoire de Microbiologie, DMU15, Paris, France.
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9
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Fang J, Castillon G, Phan S, McArdle S, Hariharan C, Adams A, Ellisman MH, Deniz AA, Saphire EO. Spatial and functional arrangement of Ebola virus polymerase inside phase-separated viral factories. Nat Commun 2023; 14:4159. [PMID: 37443171 PMCID: PMC10345124 DOI: 10.1038/s41467-023-39821-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
Ebola virus (EBOV) infection induces the formation of membrane-less, cytoplasmic compartments termed viral factories, in which multiple viral proteins gather and coordinate viral transcription, replication, and assembly. Key to viral factory function is the recruitment of EBOV polymerase, a multifunctional machine that mediates transcription and replication of the viral RNA genome. We show that intracellularly reconstituted EBOV viral factories are biomolecular condensates, with composition-dependent internal exchange dynamics that likely facilitates viral replication. Within the viral factory, we found the EBOV polymerase clusters into foci. The distance between these foci increases when viral replication is enabled. In addition to the typical droplet-like viral factories, we report the formation of network-like viral factories during EBOV infection. Unlike droplet-like viral factories, network-like factories are inactive for EBOV nucleocapsid assembly. This unique view of EBOV propagation suggests a form-to-function relationship that describes how physical properties and internal structures of biomolecular condensates influence viral biogenesis.
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Affiliation(s)
- Jingru Fang
- La Jolla Institute for Immunology, La Jolla, CA, USA
- Scripps Research, La Jolla, CA, USA
| | - Guillaume Castillon
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
| | - Sebastien Phan
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
| | - Sara McArdle
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | | | - Aiyana Adams
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, USA
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10
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Hirai Y, Horie M. Nyamanini Virus Nucleoprotein and Phosphoprotein Organize Viral Inclusion Bodies That Associate with Host Biomolecular Condensates in the Nucleus. Int J Mol Sci 2023; 24:6550. [PMID: 37047525 PMCID: PMC10095084 DOI: 10.3390/ijms24076550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/28/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023] Open
Abstract
Many mononegaviruses form inclusion bodies (IBs) in infected cells. However, little is known about nuclear IBs formed by mononegaviruses, since only a few lineages of animal-derived mononegaviruses replicate in the nucleus. In this study, we characterized the IBs formed by Nyamanini virus (NYMV), a unique tick-borne mononegavirus undergoing replication in the nucleus. We discovered that NYMV forms IBs, consisting of condensates and puncta of various sizes and morphologies, in the host nucleus. Likewise, we found that the expressions of NYMV nucleoprotein (N) and phosphoprotein (P) alone induce the formation of condensates and puncta in the nucleus, respectively, even though their morphologies are somewhat different from the IBs observed in the actual NYMV-infected cells. In addition, IB-like structures can be reconstructed by co-expressions of NYMV N and P, and localization analyses using a series of truncated mutants of P revealed that the C-terminal 27 amino acid residues of P are important for recruiting P to the condensates formed by N. Furthermore, we found that nuclear speckles, cellular biomolecular condensates, are reorganized and recruited to the IB-like structures formed by the co-expressions of N and P, as well as IBs formed in NYMV-infected cells. These features are unique among mononegaviruses, and our study has contributed to elucidating the replication mechanisms of nuclear-replicating mononegaviruses and the virus-host interactions.
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Affiliation(s)
- Yuya Hirai
- Department of Biology, Osaka Dental University, 8-1 Kuzuha Hanazono-Cho, Hirakata 573-1121, Osaka, Japan
| | - Masayuki Horie
- Laboratory of Veterinary Microbiology, Graduate School of Veterinary Science, Osaka Metropolitan University, 1-58 Rinku-Oraikita, Izumisano 598-8531, Osaka, Japan
- Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Izumisano 598-8531, Osaka, Japan
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11
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Quek RT, Hardy KS, Walker SG, Nguyen DT, de Almeida
Magalhães T, Salic A, Gopalakrishnan SM, Silver PA, Mitchison TJ. Screen for Modulation of Nucleocapsid Protein Condensation Identifies Small Molecules with Anti-Coronavirus Activity. ACS Chem Biol 2023; 18:583-594. [PMID: 36795767 PMCID: PMC9942534 DOI: 10.1021/acschembio.2c00908] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 02/03/2023] [Indexed: 02/17/2023]
Abstract
Biomolecular condensates formed by liquid-liquid phase separation have been implicated in multiple diseases. Modulation of condensate dynamics by small molecules has therapeutic potential, but so far, few condensate modulators have been disclosed. The SARS-CoV-2 nucleocapsid (N) protein forms phase-separated condensates that are hypothesized to play critical roles in viral replication, transcription, and packaging, suggesting that N condensation modulators might have anti-coronavirus activity across multiple strains and species. Here, we show that N proteins from all seven human coronaviruses (HCoVs) vary in their tendency to undergo phase separation when expressed in human lung epithelial cells. We developed a cell-based high-content screening platform and identified small molecules that both promote and inhibit condensation of SARS-CoV-2 N. Interestingly, these host-targeted small molecules exhibited condensate-modulatory effects across all HCoV Ns. Some have also been reported to exhibit antiviral activity against SARS-CoV-2, HCoV-OC43, and HCoV-229E viral infections in cell culture. Our work reveals that the assembly dynamics of N condensates can be regulated by small molecules with therapeutic potential. Our approach allows for screening based on viral genome sequences alone and might enable rapid paths to drug discovery with value for confronting future pandemics.
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Affiliation(s)
- Rui Tong Quek
- Department of Systems Biology, Harvard
Medical School, Boston, Massachusetts 02115, United
States
- Wyss Institute for Biologically Inspired Engineering,
Harvard University, Boston, Massachusetts 02115,
United States
| | - Kierra S. Hardy
- Department of Systems Biology, Harvard
Medical School, Boston, Massachusetts 02115, United
States
- Wyss Institute for Biologically Inspired Engineering,
Harvard University, Boston, Massachusetts 02115,
United States
| | - Stephen G. Walker
- Drug Discovery Science and Technology,
AbbVie Inc., North Chicago, Illinois 60064, United
States
| | - Dan T. Nguyen
- Department of Systems Biology, Harvard
Medical School, Boston, Massachusetts 02115, United
States
- Wyss Institute for Biologically Inspired Engineering,
Harvard University, Boston, Massachusetts 02115,
United States
| | | | - Adrian Salic
- Department of Cell Biology, Harvard
Medical School, Boston, Massachusetts 02115, United
States
| | | | - Pamela A. Silver
- Department of Systems Biology, Harvard
Medical School, Boston, Massachusetts 02115, United
States
- Wyss Institute for Biologically Inspired Engineering,
Harvard University, Boston, Massachusetts 02115,
United States
| | - Timothy J. Mitchison
- Department of Systems Biology, Harvard
Medical School, Boston, Massachusetts 02115, United
States
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12
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Sagan SM, Weber SC. Let's phase it: viruses are master architects of biomolecular condensates. Trends Biochem Sci 2023; 48:229-243. [PMID: 36272892 DOI: 10.1016/j.tibs.2022.09.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 11/15/2022]
Abstract
Viruses compartmentalize their replication and assembly machinery to both evade detection and concentrate the viral proteins and nucleic acids necessary for genome replication and virion production. Accumulating evidence suggests that diverse RNA and DNA viruses form replication organelles and nucleocapsid assembly sites using phase separation. In general, the biogenesis of these compartments is regulated by two types of viral protein, collectively known as antiterminators and nucleocapsid proteins, respectively. Herein, we discuss how RNA viruses establish replication organelles and nucleocapsid assembly sites, and the evidence that these compartments form through phase separation. While this review focuses on RNA viruses, accumulating evidence suggests that all viruses rely on phase separation and form biomolecular condensates important for completing the infectious cycle.
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Affiliation(s)
- Selena M Sagan
- Department of Microbiology & Immunology, McGill University, Montreal, QC, Canada; Department of Biochemistry, McGill University, Montreal, QC, Canada.
| | - Stephanie C Weber
- Department of Biology, McGill University, Montreal, QC, Canada; Department of Physics, McGill University, Montreal, QC, Canada
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13
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Becker N, Maisner A. Nipah Virus Impairs Autocrine IFN Signaling by Sequestering STAT1 and STAT2 into Inclusion Bodies. Viruses 2023; 15:554. [PMID: 36851768 PMCID: PMC9967463 DOI: 10.3390/v15020554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/19/2023] Open
Abstract
Nipah virus (NiV) is an emerging zoonotic paramyxovirus that causes fatal infections in humans. As with most disease-causing viruses, the pathogenic potential of NiV is linked to its ability to block antiviral responses, e.g., by antagonizing IFN signaling through blocking STAT proteins. One of the STAT1/2-binding proteins of NiV is the phosphoprotein (P), but its functional role in IFN antagonism in a full viral context is not well defined. As NiV P is required for genome replication and specifically accumulates in cytosolic inclusion bodies (IBs) of infected cells, we hypothesized that this compartmentalization might play a role in P-mediated IFN antagonism. Supporting this notion, we show here that NiV can inhibit IFN-dependent antiviral signaling via a NiV P-dependent sequestration of STAT1 and STAT2 into viral IBs. Consequently, the phosphorylation/activation and nuclear translocation of STAT proteins in response to IFN is limited, as indicated by the lack of nuclear pSTAT in NiV-infected cells. Blocking autocrine IFN signaling by sequestering STAT proteins in IBs is a not yet described mechanism by which NiV could block antiviral gene expression and provides the first evidence that cytosolic NiV IBs may play a functional role in IFN antagonism.
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Affiliation(s)
| | - Andrea Maisner
- Institute of Virology, Philipps University Marburg, Hans-Meerwein-Str. 2, 35043 Marburg, Germany
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14
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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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15
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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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16
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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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17
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The pathogenesis of Nipah virus: A review. Microb Pathog 2022; 170:105693. [DOI: 10.1016/j.micpath.2022.105693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 07/07/2022] [Accepted: 07/22/2022] [Indexed: 11/24/2022]
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18
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Norris MJ, Husby ML, Kiosses WB, Yin J, Saxena R, Rennick LJ, Heiner A, Harkins SS, Pokhrel R, Schendel SL, Hastie KM, Landeras-Bueno S, Salie ZL, Lee B, Chapagain PP, Maisner A, Duprex WP, Stahelin RV, Saphire EO. Measles and Nipah virus assembly: Specific lipid binding drives matrix polymerization. SCIENCE ADVANCES 2022; 8:eabn1440. [PMID: 35857835 PMCID: PMC9299542 DOI: 10.1126/sciadv.abn1440] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 06/06/2022] [Indexed: 05/03/2023]
Abstract
Measles virus, Nipah virus, and multiple other paramyxoviruses cause disease outbreaks in humans and animals worldwide. The paramyxovirus matrix (M) protein mediates virion assembly and budding from host cell membranes. M is thus a key target for antivirals, but few high-resolution structures of paramyxovirus M are available, and we lack the clear understanding of how viral M proteins interact with membrane lipids to mediate viral assembly and egress that is needed to guide antiviral design. Here, we reveal that M proteins associate with phosphatidylserine and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] at the plasma membrane. Using x-ray crystallography, electron microscopy, and molecular dynamics, we demonstrate that PI(4,5)P2 binding induces conformational and electrostatic changes in the M protein surface that trigger membrane deformation, matrix layer polymerization, and virion assembly.
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Affiliation(s)
- Michael J. Norris
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Monica L. Husby
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
| | - William B. Kiosses
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Jieyun Yin
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Roopashi Saxena
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
| | - Linda J. Rennick
- Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Anja Heiner
- Institute of Virology, Philipps University Marburg, Marburg, Germany
| | - Stephanie S. Harkins
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Rudramani Pokhrel
- Department of Physics, Florida International University, Miami, FL 33199, USA
| | - Sharon L. Schendel
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Kathryn M. Hastie
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Sara Landeras-Bueno
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Zhe Li Salie
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
| | - Benhur Lee
- Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Prem P. Chapagain
- Department of Physics, Florida International University, Miami, FL 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Andrea Maisner
- Institute of Virology, Philipps University Marburg, Marburg, Germany
| | - W. Paul Duprex
- Center for Vaccine Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Robert V. Stahelin
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
| | - Erica Ollmann Saphire
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, CA 92037, USA
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19
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Nipah Virus Infection Generates Ordered Structures in Cellulo. Viruses 2022; 14:v14071523. [PMID: 35891503 PMCID: PMC9317923 DOI: 10.3390/v14071523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/16/2022] [Accepted: 07/08/2022] [Indexed: 02/06/2023] Open
Abstract
Nipah virus (NiV) is a zoonotic paramyxovirus with a fatality rate of up to 92% in humans. While several pathogenic mechanisms used by NiV to counteract host immune defense responses have been described, all of the processes that take place in cells during infection are not fully characterized. Here, we describe the formation of ordered intracellular structures during NiV infection. We observed that these structures are formed specifically during NiV infection, but not with other viruses from the same Mononegavirales order (namely Ebola virus) or from other orders such as Bunyavirales (Junín virus). We also determined the kinetics of the appearance of these structures and their cellular localization at the cellular periphery. Finally, we confirmed the presence of these NiV-specific ordered structures using structured illumination microscopy (SIM), as well as their localization by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and correlative light and electron microscopy (CLEM). Herein, we describe a cytopathogenic mechanism that provides a new insight into NiV biology. These newly described ordered structures could provide a target for novel antiviral approaches.
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20
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Boggs KB, Edmonds K, Cifuentes-Munoz N, El Najjar F, Ossandón C, Roe M, Wu C, Moncman CL, Creamer TP, Amarasinghe GK, Leung DW, Dutch RE. Human Metapneumovirus Phosphoprotein Independently Drives Phase Separation and Recruits Nucleoprotein to Liquid-Like Bodies. mBio 2022; 13:e0109922. [PMID: 35536005 PMCID: PMC9239117 DOI: 10.1128/mbio.01099-22] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 11/20/2022] Open
Abstract
Human metapneumovirus (HMPV) inclusion bodies (IBs) are dynamic structures required for efficient viral replication and transcription. The minimum components needed to form IB-like structures in cells are the nucleoprotein (N) and the tetrameric phosphoprotein (P). HMPV P binds to the following two versions of the N protein in infected cells: N-terminal P residues interact with monomeric N (N0) to maintain a pool of protein to encapsidate new RNA and C-terminal P residues interact with oligomeric, RNA-bound N (N-RNA). Recent work on other negative-strand viruses has suggested that IBs are, at least in part, liquid-like phase-separated membraneless organelles. Here, HMPV IBs in infected or transfected cells were shown to possess liquid organelle properties, such as fusion and fission. Recombinant versions of HMPV N and P proteins were purified to analyze the interactions required to drive phase separation in vitro. Purified HMPV P was shown to form liquid droplets in isolation. This observation is distinct from other viral systems that also form IBs. Partial removal of nucleic acid from purified P altered phase-separation dynamics, suggesting that nucleic acid interactions play a role in IB formation. HMPV P also recruits monomeric N (N0-P) and N-RNA to droplets in vitro. These findings suggest that HMPV P may also act as a scaffold protein to mediate multivalent interactions with monomeric and oligomeric N, as well as RNA, to promote phase separation of IBs. Together, these findings highlight an additional layer of regulation in HMPV replication by the viral P and N proteins. IMPORTANCE Human metapneumovirus (HMPV) is a leading cause of respiratory disease among children, immunocompromised individuals, and the elderly. Currently, no vaccines or antivirals are available for the treatment of HMPV infections. Cytoplasmic inclusion bodies (IBs), where HMPV replication and transcription occur, represent a promising target for the development of novel antivirals. The HMPV nucleoprotein (N) and phosphoprotein (P) are the minimal components needed for IB formation in eukaryotic cells. However, interactions that regulate the formation of these dynamic structures are poorly understood. Here, we showed that HMPV IBs possess the properties of liquid organelles and that purified HMPV P phase separates independently in vitro. Our work suggests that HMPV P phase-separation dynamics are altered by nucleic acid. We provide strong evidence that, unlike results reported from other viral systems, HMPV P alone can serve as a scaffold for multivalent interactions with monomeric (N0) and oligomeric (N-RNA) HMPV N for IB formation.
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Affiliation(s)
- Kerri Beth Boggs
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, Kentucky, USA
| | - Kearstin Edmonds
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, Kentucky, USA
| | - Nicolas Cifuentes-Munoz
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Farah El Najjar
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, Kentucky, USA
| | - Conny Ossandón
- Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile
| | - McKenna Roe
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, Kentucky, USA
| | - Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Carole L. Moncman
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, Kentucky, USA
| | - Trevor P. Creamer
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, Kentucky, USA
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Daisy W. Leung
- Department of Medicine, 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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21
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Wang C, Wang T, Duan L, Chen H, Hu R, Wang X, Jia Y, Chu Z, Liu H, Wang X, Zhang S, Xiao S, Wang J, Dang R, Yang Z. Evasion of Host Antiviral Innate Immunity by Paramyxovirus Accessory Proteins. Front Microbiol 2022; 12:790191. [PMID: 35173691 PMCID: PMC8841848 DOI: 10.3389/fmicb.2021.790191] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 12/22/2021] [Indexed: 01/01/2023] Open
Abstract
For efficient replication, viruses have developed multiple strategies to evade host antiviral innate immunity. Paramyxoviruses are a large family of enveloped RNA viruses that comprises diverse human and animal pathogens which jeopardize global public health and the economy. The accessory proteins expressed from the P gene by RNA editing or overlapping open reading frames (ORFs) are major viral immune evasion factors antagonizing type I interferon (IFN-I) production and other antiviral innate immune responses. However, the antagonistic mechanisms against antiviral innate immunity by accessory proteins differ among viruses. Here, we summarize the current understandings of immune evasion mechanisms by paramyxovirus accessory proteins, specifically how accessory proteins directly or indirectly target the adaptors in the antiviral innate immune signaling pathway to facilitate virus replication. Additionally, some cellular responses, which are also involved in viral replication, will be briefly summarized.
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22
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Hirai Y, Tomonaga K, Horie M. Borna disease virus phosphoprotein triggers the organization of viral inclusion bodies by liquid-liquid phase separation. Int J Biol Macromol 2021; 192:55-63. [PMID: 34606793 DOI: 10.1016/j.ijbiomac.2021.09.153] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/02/2021] [Accepted: 09/20/2021] [Indexed: 12/19/2022]
Abstract
Inclusion bodies (IBs) are characteristic biomolecular condensates organized by the non-segmented negative-strand RNA viruses belonging to the order Mononegavirales. Although recent studies have revealed the characteristics of IBs formed by cytoplasmic mononegaviruses, that of Borna disease virus 1 (BoDV-1), a unique mononegavirus that forms IBs in the cell nucleus and establishes persistent infection remains elusive. Here, we characterize the IBs of BoDV-1 in terms of liquid-liquid phase separation (LLPS). The BoDV-1 phosphoprotein (P) alone induces LLPS and the nucleoprotein (N) is incorporated into the P droplets in vitro. In contrast, co-expression of N and P is required for the formation of IB-like structure in cells. Furthermore, while BoDV-1 P binds to RNA, an excess amount of RNA dissolves the liquid droplets formed by N and P in vitro. Notably, the intrinsically disordered N-terminal region of BoDV-1 P is essential to drive LLPS and to bind to RNA, suggesting that both abilities could compete with one another. These features are unique among mononegaviruses, and thus this study will contribute to a deeper understanding of LLPS-driven organization and RNA-mediated regulation of biomolecular condensates.
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Affiliation(s)
- Yuya Hirai
- Department of Biology, Osaka Dental University, 8-1, Kuzuha Hanazono-cho, Hirakata, Osaka 573-1121, Japan.
| | - Keizo Tomonaga
- Laboratory of RNA viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences (InFRONT), Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan; Laboratory of RNA Viruses, Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, 606-8507 Kyoto, Japan; Department of Molecular Virology, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, 606-8507 Kyoto, Japan.
| | - Masayuki Horie
- Laboratory of RNA viruses, Department of Virus Research, Institute for Frontier Life and Medical Sciences (InFRONT), Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan; Hakubi Center for Advanced Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan; Laboratory of Veterinary Microbiology, Division of Veterinary Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano, Osaka 598-8531, Japan.
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23
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Guseva S, Perez LM, Camacho-Zarco A, Bessa LM, Salvi N, Malki A, Maurin D, Blackledge M. 1H, 13C and 15N Backbone chemical shift assignments of the n-terminal and central intrinsically disordered domains of SARS-CoV-2 nucleoprotein. BIOMOLECULAR NMR ASSIGNMENTS 2021; 15:255-260. [PMID: 33730325 PMCID: PMC7967780 DOI: 10.1007/s12104-021-10014-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 03/07/2021] [Indexed: 05/10/2023]
Abstract
The nucleoprotein (N) from SARS-CoV-2 is an essential cofactor of the viral replication transcription complex and as such represents an important target for viral inhibition. It has also been shown to colocalize to the transcriptase-replicase complex, where many copies of N decorate the viral genome, thereby protecting it from the host immune system. N has also been shown to phase separate upon interaction with viral RNA. N is a 419 amino acid multidomain protein, comprising two folded, RNA-binding and dimerization domains spanning residues 45-175 and 264-365 respectively. The remaining 164 amino acids are predicted to be intrinsically disordered, but there is currently no atomic resolution information describing their behaviour. Here we assign the backbone resonances of the first two intrinsically disordered domains (N1, spanning residues 1-44 and N3, spanning residues 176-263). Our assignment provides the basis for the identification of inhibitors and functional and interaction studies of this essential protein.
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Affiliation(s)
- Serafima Guseva
- University Grenoble Alpes, CNRS, CEA, IBS, 38000, Grenoble, France
| | | | | | | | - Nicola Salvi
- University Grenoble Alpes, CNRS, CEA, IBS, 38000, Grenoble, France
| | - Anas Malki
- University Grenoble Alpes, CNRS, CEA, IBS, 38000, Grenoble, France
| | - Damien Maurin
- University Grenoble Alpes, CNRS, CEA, IBS, 38000, Grenoble, France
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Salladini E, Gondelaud F, Nilsson JF, Pesce G, Bignon C, Murrali MG, Fabre R, Pierattelli R, Kajava AV, Horvat B, Gerlier D, Mathieu C, Longhi S. Identification of a Region in the Common Amino-terminal Domain of Hendra Virus P, V, and W Proteins Responsible for Phase Transition and Amyloid Formation. Biomolecules 2021; 11:1324. [PMID: 34572537 PMCID: PMC8471210 DOI: 10.3390/biom11091324] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 12/14/2022] Open
Abstract
Henipaviruses are BSL-4 zoonotic pathogens responsible in humans for severe encephalitis. Their V protein is a key player in the evasion of the host innate immune response. We previously showed that the Henipavirus V proteins consist of a long intrinsically disordered N-terminal domain (NTD) and a β-enriched C-terminal domain (CTD). These terminals are critical for V binding to DDB1, which is a cellular protein that is a component of the ubiquitin ligase E3 complex, as well as binding to MDA5 and LGP2, which are two host sensors of viral RNA. Here, we serendipitously discovered that the Hendra virus V protein undergoes a liquid-to-hydrogel phase transition and identified the V region responsible for this phenomenon. This region, referred to as PNT3 and encompassing residues 200-310, was further investigated using a combination of biophysical and structural approaches. Congo red binding assays, together with negative-staining transmisison electron microscopy (TEM) studies, show that PNT3 forms amyloid-like fibrils. Fibrillation abilities are dramatically reduced in a rationally designed PNT3 variant in which a stretch of three contiguous tyrosines, falling within an amyloidogenic motif, were replaced by three alanines. Worthy to note, Congo red staining experiments provided hints that these amyloid-like fibrils form not only in vitro but also in cellula after transfection or infection. The present results set the stage for further investigations aimed at assessing the functional role of phase separation and fibrillation by the Henipavirus V proteins.
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Affiliation(s)
- Edoardo Salladini
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Frank Gondelaud
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Juliet F. Nilsson
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Giulia Pesce
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Christophe Bignon
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
| | - Maria Grazia Murrali
- Magnetic Resonance Center (CERM) and Department of Chemistry “Ugo Schiff”, University of Florence, 50019 Sesto Fiorentino, Italy; (M.G.M.); (R.P.)
| | - Roxane Fabre
- Centre d’Immunologie de Marseille-Luminy (CIML), CNRS, Institut National de la Santé et de la Recherche Médicale (INSERM), Aix Marseille University, CEDEX 9, 13288 Marseille, France;
| | - Roberta Pierattelli
- Magnetic Resonance Center (CERM) and Department of Chemistry “Ugo Schiff”, University of Florence, 50019 Sesto Fiorentino, Italy; (M.G.M.); (R.P.)
| | - Andrey V. Kajava
- Centre de Recherche en Biologie Cellulaire de Montpellier, UMR 5237, CNRS, Université Montpellier, 34293 Montpellier, France;
| | - Branka Horvat
- Team Immunobiology of the Viral Infections, Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, INSERM, U1111, CNRS, UMR 5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007 Lyon, France; (B.H.); (D.G.); (C.M.)
| | - Denis Gerlier
- Team Immunobiology of the Viral Infections, Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, INSERM, U1111, CNRS, UMR 5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007 Lyon, France; (B.H.); (D.G.); (C.M.)
| | - Cyrille Mathieu
- Team Immunobiology of the Viral Infections, Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, INSERM, U1111, CNRS, UMR 5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007 Lyon, France; (B.H.); (D.G.); (C.M.)
| | - Sonia Longhi
- Laboratory Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS), Aix Marseille University, CEDEX 9, 13288 Marseille, France; (E.S.); (F.G.); (J.F.N.); (G.P.); (C.B.)
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Dolnik O, Gerresheim GK, Biedenkopf N. New Perspectives on the Biogenesis of Viral Inclusion Bodies in Negative-Sense RNA Virus Infections. Cells 2021; 10:cells10061460. [PMID: 34200781 PMCID: PMC8230417 DOI: 10.3390/cells10061460] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/06/2021] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
Infections by negative strand RNA viruses (NSVs) induce the formation of viral inclusion bodies (IBs) in the host cell that segregate viral as well as cellular proteins to enable efficient viral replication. The induction of those membrane-less viral compartments leads inevitably to structural remodeling of the cellular architecture. Recent studies suggested that viral IBs have properties of biomolecular condensates (or liquid organelles), as have previously been shown for other membrane-less cellular compartments like stress granules or P-bodies. Biomolecular condensates are highly dynamic structures formed by liquid-liquid phase separation (LLPS). Key drivers for LLPS in cells are multivalent protein:protein and protein:RNA interactions leading to specialized areas in the cell that recruit molecules with similar properties, while other non-similar molecules are excluded. These typical features of cellular biomolecular condensates are also a common characteristic in the biogenesis of viral inclusion bodies. Viral IBs are predominantly induced by the expression of the viral nucleoprotein (N, NP) and phosphoprotein (P); both are characterized by a special protein architecture containing multiple disordered regions and RNA-binding domains that contribute to different protein functions. P keeps N soluble after expression to allow a concerted binding of N to the viral RNA. This results in the encapsidation of the viral genome by N, while P acts additionally as a cofactor for the viral polymerase, enabling viral transcription and replication. Here, we will review the formation and function of those viral inclusion bodies upon infection with NSVs with respect to their nature as biomolecular condensates.
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New Look at RSV Infection: Tissue Clearing and 3D Imaging of the Entire Mouse Lung at Cellular Resolution. Viruses 2021; 13:v13020201. [PMID: 33525646 PMCID: PMC7912480 DOI: 10.3390/v13020201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/16/2021] [Accepted: 01/19/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Respiratory Syncytial Virus (RSV) is the major cause of severe acute respiratory tract illness in young children worldwide and a main pathogen for the elderly and immune-compromised people. In the absence of vaccines or effective treatments, a better characterization of the pathogenesis of RSV infection is required. To date, the pathophysiology of the disease and its diagnosis has mostly relied on chest X-ray and genome detection in nasopharyngeal swabs. The development of new imaging approaches is instrumental to further the description of RSV spread, virus-host interactions and related acute respiratory disease, at the level of the entire lung. METHODS By combining tissue clearing, 3D microscopy and image processing, we developed a novel visualization tool of RSV infection in undissected mouse lungs. RESULTS Whole tissue analysis allowed the identification of infected cell subtypes, based on both morphological traits and position within the cellular network. Furthermore, 3D imaging was also valuable to detect the cytoplasmic viral factories, also called inclusion bodies, a hallmark of RSV infection. CONCLUSIONS Whole lung clearing and 3D deep imaging represents an unprecedented visualization method of infected lungs to allow insight into RSV pathophysiology and improve the 2D histology analyses.
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Su JM, Wilson MZ, Samuel CE, Ma D. Formation and Function of Liquid-Like Viral Factories in Negative-Sense Single-Stranded RNA Virus Infections. Viruses 2021; 13:126. [PMID: 33477448 PMCID: PMC7835873 DOI: 10.3390/v13010126] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 12/11/2022] Open
Abstract
Liquid-liquid phase separation (LLPS) represents a major physiochemical principle to organize intracellular membrane-less structures. Studies with non-segmented negative-sense (NNS) RNA viruses have uncovered a key role of LLPS in the formation of viral inclusion bodies (IBs), sites of viral protein concentration in the cytoplasm of infected cells. These studies further reveal the structural and functional complexity of viral IB factories and provide a foundation for their future research. Herein, we review the literature leading to the discovery of LLPS-driven formation of IBs in NNS RNA virus-infected cells and the identification of viral scaffold components involved, and then outline important questions and challenges for IB assembly and disassembly. We discuss the functional implications of LLPS in the life cycle of NNS RNA viruses and host responses to infection. Finally, we speculate on the potential mechanisms underlying IB maturation, a phenomenon relevant to many human diseases.
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Affiliation(s)
| | | | | | - Dzwokai Ma
- Department of Molecular, Cellular and Developmental Biology & Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; (J.M.S.); (M.Z.W.); (C.E.S.)
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28
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Brocca S, Grandori R, Longhi S, Uversky V. Liquid-Liquid Phase Separation by Intrinsically Disordered Protein Regions of Viruses: Roles in Viral Life Cycle and Control of Virus-Host Interactions. Int J Mol Sci 2020; 21:E9045. [PMID: 33260713 PMCID: PMC7730420 DOI: 10.3390/ijms21239045] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 12/13/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) are unable to adopt a unique 3D structure under physiological conditions and thus exist as highly dynamic conformational ensembles. IDPs are ubiquitous and widely spread in the protein realm. In the last decade, compelling experimental evidence has been gathered, pointing to the ability of IDPs and intrinsically disordered regions (IDRs) to undergo liquid-liquid phase separation (LLPS), a phenomenon driving the formation of membrane-less organelles (MLOs). These biological condensates play a critical role in the spatio-temporal organization of the cell, where they exert a multitude of key biological functions, ranging from transcriptional regulation and silencing to control of signal transduction networks. After introducing IDPs and LLPS, we herein survey available data on LLPS by IDPs/IDRs of viral origin and discuss their functional implications. We distinguish LLPS associated with viral replication and trafficking of viral components, from the LLPS-mediated interference of viruses with host cell functions. We discuss emerging evidence on the ability of plant virus proteins to interfere with the regulation of MLOs of the host and propose that bacteriophages can interfere with bacterial LLPS, as well. We conclude by discussing how LLPS could be targeted to treat phase separation-associated diseases, including viral infections.
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Affiliation(s)
- Stefania Brocca
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milano, Italy
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milano, Italy
| | - Sonia Longhi
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), Aix-Marseille University and CNRS, 13288 Marseille, France
| | - Vladimir Uversky
- Department of Molecular Medicine, Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33601, USA
- Laboratory of New Methods in Biology, Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, 142290 Pushchino, Russia
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29
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Ji L, Yang E, He S, Jin Y, Chen D. Enterovirus 2C Protein Suppresses IKK α Phosphorylation by Recruiting IKK β and IKK α into Viral Inclusion Bodies. Viral Immunol 2020; 34:218-226. [PMID: 33226912 DOI: 10.1089/vim.2020.0173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The nuclear factor-kappa B (NF-κB) signaling network constitutes a first line of defense against the invading viruses. However, viruses also adopted multiple strategies to interfere with NF-κB activation. Enterovirus 71 (EV71), in the family Picornaviridae, has become the main pathogen responsible for hand, foot, and mouth disease. Recent studies have reported that the nonstructural protein 2C of EV71 inhibits TNF-α induced NF-κB activation by suppressing IKKβ phosphorylation. In our study, we found that 2C can form inclusion bodies (IBs) in infected and transfected cells. Furthermore, 2C was able to sequester IKKβ into IBs through direct interaction with IKKβ. Although 2C did not directly interact with IKKα, viral protein 2C was able to sequester the IKKα into the IBs mediated by IKKβ. Our in vitro data further demonstrated that EV71 2C could suppress IKKα phosphorylation. These all together support a novel mechanism for EV71 to escape from NF-κB response, in which the phosphorylation of IKKα was suppressed by being recruited into viral IBs in the presence of 2C and IKKβ.
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Affiliation(s)
- Lianfu Ji
- Department of Cardiovascular Medicine, Children's Hospital of Nanjing Medical University, Nanjing, P.R. China
| | - Enhui Yang
- Department of Infectious Disease, Children's Hospital of Nanjing Medical University, Nanjing, P.R. China
| | - Susu He
- Center for Public Health Research, Medical School of Nanjing University, Nanjing, P.R. China
| | - Yu Jin
- Department of Gastroenterology, Children's Hospital of Nanjing Medical University, Nanjing, P.R. China
| | - Deyan Chen
- Center for Public Health Research, Medical School of Nanjing University, Nanjing, P.R. China
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30
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Jobe F, Simpson J, Hawes P, Guzman E, Bailey D. Respiratory Syncytial Virus Sequesters NF-κB Subunit p65 to Cytoplasmic Inclusion Bodies To Inhibit Innate Immune Signaling. J Virol 2020; 94:JVI.01380-20. [PMID: 32878896 PMCID: PMC7592213 DOI: 10.1128/jvi.01380-20] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 08/28/2020] [Indexed: 12/20/2022] Open
Abstract
Viruses routinely employ strategies to prevent the activation of innate immune signaling in infected cells. Respiratory syncytial virus (RSV) is no exception, as it encodes two accessory proteins (NS1 and NS2) which are well established to block interferon signaling. However, RSV-encoded mechanisms for inhibiting NF-κB signaling are less well characterized. In this study, we identified RSV-mediated antagonism of this pathway, independent of the NS1 and NS2 proteins and indeed distinct from other known viral mechanisms of NF-κB inhibition. In both human and bovine RSV-infected cells, we demonstrated that the p65 subunit of NF-κB is rerouted to perinuclear puncta in the cytoplasm, which are synonymous with viral inclusion bodies (IBs), the site for viral RNA replication. Captured p65 was unable to translocate to the nucleus or transactivate a NF-κB reporter following tumor necrosis factor alpha (TNF-α) stimulation, confirming the immune-antagonistic nature of this sequestration. Subsequently, we used correlative light electron microscopy (CLEM) to colocalize the RSV N protein and p65 within bovine RSV (bRSV) IBs, which are granular, membraneless regions of cytoplasm with liquid organelle-like properties. Additional characterization of bRSV IBs indicated that although they are likely formed by liquid-liquid phase separation (LLPS), they have a differential sensitivity to hypotonic shock proportional to their size. Together, these data identify a novel mechanism for viral antagonism of innate immune signaling which relies on sequestration of the NF-κB subunit p65 to a biomolecular condensate-a mechanism conserved across the Orthopneumovirus genus and not host-cell specific. More generally, they provide additional evidence that RNA virus IBs are important immunomodulatory complexes within infected cells.IMPORTANCE Many viruses replicate almost entirely in the cytoplasm of infected cells; however, how these pathogens are able to compartmentalize their life cycle to provide favorable conditions for replication and to avoid the litany of antiviral detection mechanisms in the cytoplasm remains relatively uncharacterized. In this manuscript, we show that bovine respiratory syncytial virus (bRSV), which infects cattle, does this by generating inclusion bodies in the cytoplasm of infected cells. We confirm that both bRSV and human RSV viral RNA replication takes place in these inclusion bodies, likely meaning these organelles are a functionally conserved feature of this group of viruses (the orthopneumoviruses). Importantly, we also showed that these organelles are able to capture important innate immune transcription factors (in this case NF-KB), blocking the normal signaling processes that tell the nucleus the cell is infected, which may help us to understand how these viruses cause disease.
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Affiliation(s)
| | | | - Philippa Hawes
- The Pirbright Institute, Guildford, Surrey, United Kingdom
| | - Efrain Guzman
- The Pirbright Institute, Guildford, Surrey, United Kingdom
| | - Dalan Bailey
- The Pirbright Institute, Guildford, Surrey, United Kingdom
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31
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Donnelly CM, Roby JA, Scott CJ, Raidal SR, Forwood JK. The Structural Features of Henipavirus Matrix Protein Driving Intracellular Trafficking. Viral Immunol 2020; 34:27-40. [PMID: 33021467 DOI: 10.1089/vim.2020.0056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Henipaviruses are single-stranded RNA viruses that have recently emerged as zoonotic pathogens, capable of causing severe acute respiratory disease and encephalitis in humans. The prototypical henipaviruses, Hendra henipavirus and Nipah henipavirus, are a major health concern as they have high mortality rates and no currently approved human vaccine or drug therapy. Understanding the mechanisms of viral replication and pathogenicity is of critical importance for therapeutic developments. A novel target for such therapies is the Henipavirus Matrix (M) protein, a multifunctional protein that drives viral assembly and inhibits the innate immune response. These multifunctional attributes promote a complicated lifecycle: while viral replication occurs in the cytoplasm, M traffics to the nucleus, where it is ubiquitinated, for correct cellular targeting and virion packaging. In this study, we review the relationship between the structure and functions of M. In specific cases, the compatibility between structural accessibility and protein functionality is not always evident, and we highlight areas that require further investigation.
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Affiliation(s)
- Camilla M Donnelly
- School of Biomedical Sciences and Charles Sturt University, Wagga Wagga, Australia
| | - Justin A Roby
- School of Biomedical Sciences and Charles Sturt University, Wagga Wagga, Australia
| | - Christopher J Scott
- School of Biomedical Sciences and Charles Sturt University, Wagga Wagga, Australia
| | - Shane R Raidal
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, Australia
| | - Jade K Forwood
- School of Biomedical Sciences and Charles Sturt University, Wagga Wagga, Australia
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32
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Blanchard EL, Braun MR, Lifland AW, Ludeke B, Noton SL, Vanover D, Zurla C, Fearns R, Santangelo PJ. Polymerase-tagged respiratory syncytial virus reveals a dynamic rearrangement of the ribonucleocapsid complex during infection. PLoS Pathog 2020; 16:e1008987. [PMID: 33031461 PMCID: PMC7575074 DOI: 10.1371/journal.ppat.1008987] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 10/20/2020] [Accepted: 09/16/2020] [Indexed: 12/20/2022] Open
Abstract
The ribonucleocapsid complex of respiratory syncytial virus (RSV) is responsible for both viral mRNA transcription and viral replication during infection, though little is known about how this dual function is achieved. Here, we report the use of a recombinant RSV virus with a FLAG-tagged large polymerase protein, L, to characterize and localize RSV ribonucleocapsid structures during the early and late stages of viral infection. Through proximity ligation assays and super-resolution microscopy, viral RNA and proteins in the ribonucleocapsid complex were revealed to dynamically rearrange over time, particularly between 6 and 8 hours post infection, suggesting a connection between the ribonucleocapsid structure and its function. The timing of ribonucleocapsid rearrangement corresponded with an increase in RSV genome RNA accumulation, indicating that this rearrangement is likely involved with the onset of RNA replication and secondary transcription. Additionally, early overexpression of RSV M2-2 from in vitro transcribed mRNA was shown to inhibit virus infection by rearranging the ribonucleocapsid complex. Collectively, these results detail a critical understanding into the localization and activity of RSV L and the ribonucleocapsid complex during RSV infection.
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Affiliation(s)
- Emmeline L. Blanchard
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States of America
| | - Molly R. Braun
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
| | - Aaron W. Lifland
- Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Barbara Ludeke
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
| | - Sarah L. Noton
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
| | - Daryll Vanover
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States of America
| | - Chiara Zurla
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States of America
| | - Rachel Fearns
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
| | - Philip J. Santangelo
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States of America
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Minimal Elements Required for the Formation of Respiratory Syncytial Virus Cytoplasmic Inclusion Bodies In Vivo and In Vitro. mBio 2020; 11:mBio.01202-20. [PMID: 32963000 PMCID: PMC7512546 DOI: 10.1128/mbio.01202-20] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract illness in infants, elderly, and immunocompromised people. No vaccine or efficient antiviral treatment is available against this virus. The replication and transcription steps of the viral genome are appealing mechanisms to target for the development of new antiviral strategies. These activities take place within cytoplasmic inclusion bodies (IBs) that assemble during infection. Although expression of both the viral nucleoprotein (N) and phosphoprotein (P) allows induction of the formation of these IBs, the mechanism sustaining their assembly remains poorly characterized. Here, we identified key elements of N and P required for the scaffolding of IBs and managed for the first time to reconstitute RSV pseudo-IBs in vitro by coincubating recombinant N and P proteins. Our results provide strong evidence that the biogenesis of RSV IBs occurs through liquid-liquid phase transition mediated by N-P interactions. Infection of host cells by the respiratory syncytial virus (RSV) is characterized by the formation of spherical cytoplasmic inclusion bodies (IBs). These structures, which concentrate all the proteins of the polymerase complex as well as some cellular proteins, were initially considered aggresomes formed by viral dead-end products. However, recent studies revealed that IBs are viral factories where viral RNA synthesis, i.e., replication and transcription, occurs. The analysis of IBs by electron microscopy revealed that they are membrane-less structures, and accumulated data on their structure, organization, and kinetics of formation revealed that IBs share the characteristics of cellular organelles, such as P-bodies or stress granules, suggesting that their morphogenesis depends on a liquid-liquid phase separation mechanism. It was previously shown that expression of the RSV nucleoprotein N and phosphoprotein P of the polymerase complex is sufficient to induce the formation of pseudo-IBs. Here, using a series of truncated P proteins, we identified the domains of P required for IB formation and show that the oligomeric state of N, provided it can interact with RNA, is critical for their morphogenesis. We also show that pseudo-IBs can form in vitro when recombinant N and P proteins are mixed. Finally, using fluorescence recovery after photobleaching approaches, we reveal that in cellula and in vitro IBs are liquid organelles. Our results strongly support the liquid-liquid phase separation nature of IBs and pave the way for further characterization of their dynamics.
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34
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Nevers Q, Albertini AA, Lagaudrière-Gesbert C, Gaudin Y. Negri bodies and other virus membrane-less replication compartments. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118831. [PMID: 32835749 PMCID: PMC7442162 DOI: 10.1016/j.bbamcr.2020.118831] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/14/2020] [Accepted: 08/14/2020] [Indexed: 12/25/2022]
Abstract
Viruses reshape the organization of the cell interior to achieve different steps of their cellular cycle. Particularly, viral replication and assembly often take place in viral factories where specific viral and cellular proteins as well as nucleic acids concentrate. Viral factories can be either membrane-delimited or devoid of any cellular membranes. In the latter case, they are referred as membrane-less replication compartments. The most emblematic ones are the Negri bodies, which are inclusion bodies that constitute the hallmark of rabies virus infection. Interestingly, Negri bodies and several other viral replication compartments have been shown to arise from a liquid-liquid phase separation process and, thus, constitute a new class of liquid organelles. This is a paradigm shift in the field of virus replication. Here, we review the different aspects of membrane-less virus replication compartments with a focus on the Mononegavirales order and discuss their interactions with the host cell machineries and the cytoskeleton. We particularly examine the interplay between viral factories and the cellular innate immune response, of which several components also form membrane-less condensates in infected cells. Viral factories harbor essential steps of the viral cycle. Some viral factories are devoid of membranes and have liquid organelle properties. Liquid viral factories concentrate cellular factors required for replication. Innate immunity sensors and several ISGs are found in membrane-less condensates. A subtle interplay exists between liquid viral factories and innate immunity actors.
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Affiliation(s)
- Quentin Nevers
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Aurélie A Albertini
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Cécile Lagaudrière-Gesbert
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Yves Gaudin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France.
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35
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Miyake T, Farley CM, Neubauer BE, Beddow TP, Hoenen T, Engel DA. Ebola Virus Inclusion Body Formation and RNA Synthesis Are Controlled by a Novel Domain of Nucleoprotein Interacting with VP35. J Virol 2020; 94:e02100-19. [PMID: 32493824 PMCID: PMC7394894 DOI: 10.1128/jvi.02100-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/24/2020] [Indexed: 12/15/2022] Open
Abstract
Ebola virus (EBOV) inclusion bodies (IBs) are cytoplasmic sites of nucleocapsid formation and RNA replication, housing key steps in the virus life cycle that warrant further investigation. During infection, IBs display dynamic properties regarding their size and location. The contents of IBs also must transition prior to further viral maturation, assembly, and release, implying additional steps in IB function. Interestingly, the expression of the viral nucleoprotein (NP) alone is sufficient for the generation of IBs, indicating that it plays an important role in IB formation during infection. In addition to NP, other components of the nucleocapsid localize to IBs, including VP35, VP24, VP30, and the RNA polymerase L. We previously defined and solved the crystal structure of the C-terminal domain of NP (NP-Ct), but its role in virus replication remained unclear. Here, we show that NP-Ct is necessary for IB formation when NP is expressed alone. Interestingly, we find that NP-Ct is also required for the production of infectious virus-like particles (VLPs), and that defective VLPs with NP-Ct deletions are significantly reduced in viral RNA content. Furthermore, coexpression of the nucleocapsid component VP35 overcomes deletion of NP-Ct in triggering IB formation, demonstrating a functional interaction between the two proteins. Of all the EBOV proteins, only VP35 is able to overcome the defect in IB formation caused by the deletion of NP-Ct. This effect is mediated by a novel protein-protein interaction between VP35 and NP that controls both regulation of IB formation and RNA replication itself and that is mediated by a newly identified functional domain of NP, the central domain.IMPORTANCE Inclusion bodies (IBs) are cytoplasmic sites of RNA synthesis for a variety of negative-sense RNA viruses, including Ebola virus. In addition to housing important steps in the viral life cycle, IBs protect new viral RNA from innate immune attack and contain specific host proteins whose function is under study. A key viral factor in Ebola virus IB formation is the nucleoprotein, NP, which also is important in RNA encapsidation and synthesis. In this study, we have identified two domains of NP that control inclusion body formation. One of these, the central domain (CD), interacts with viral protein VP35 to control both inclusion body formation and RNA synthesis. The other is the NP C-terminal domain (NP-Ct), whose function has not previously been reported. These findings contribute to a model in which NP and its interactions with VP35 link the establishment of IBs to the synthesis of viral RNA.
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Affiliation(s)
- Tsuyoshi Miyake
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Charlotte M Farley
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Benjamin E Neubauer
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Thomas P Beddow
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Thomas Hoenen
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Daniel A Engel
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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Zhou H, Liu LP, Fang M, Li YM, Zheng YW. A potential ex vivo infection model of human induced pluripotent stem cell-3D organoids beyond coronavirus disease 2019. Histol Histopathol 2020; 35:1077-1082. [PMID: 32339250 DOI: 10.14670/hh-18-223] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The novel coronavirus disease 2019 (COVID-19) outbreak began in the city of Wuhan, whereupon it rapidly spread throughout China and subsequently across the world. Rapid transmission of COVID-19 has caused wide-spread panic. Many established medications have been used to treat the disease symptoms; however, no specific drugs or vaccines have been developed. Organoids derived from human induced pluripotent stem cells (iPSCs) may serve as suitable infection models for ex vivo mimicking of the viral life cycle and drug screening. Human iPSC-3D organoids, self-organised tissues with multiple cell environments, have a similar structure and function as real human organs; hence, these organoids allow greater viral infection efficiency, mimic the natural host-virus interactions, and are suitable for long-term experimentation. Here, we suggest the use of a functional human iPSC-organoid that could act as a reliable and feasible ex vivo infection model for investigation of the virus. This approach will provide much needed insight into the underlying molecular dynamics of COVID-19 for the development of novel treatment and prevention strategies.
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Affiliation(s)
- Hang Zhou
- Institute of Regenerative Medicine, Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Li-Ping Liu
- Institute of Regenerative Medicine, Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Mei Fang
- Institute of Regenerative Medicine, Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Yu-Mei Li
- Institute of Regenerative Medicine, Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang, Jiangsu, China.
| | - Yun-Wen Zheng
- Institute of Regenerative Medicine, Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang, Jiangsu, China.,Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan. .,School of Medicine, Yokohama City University, Yokohama, Kanagawa, Japan.,Center for Stem Cell Biology and Regenerative Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.,School of Biotechnology and Healt Sciences, Wuyi University, Jiangmen, Guandong, P.R. China
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37
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Takamatsu Y, Kajikawa J, Muramoto Y, Nakano M, Noda T. Microtubule-dependent transport of arenavirus matrix protein demonstrated using live-cell imaging microscopy. Microscopy (Oxf) 2019; 68:450-456. [PMID: 31722015 DOI: 10.1093/jmicro/dfz034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/07/2019] [Accepted: 08/14/2019] [Indexed: 12/15/2022] Open
Abstract
Lassa virus (LASV), belonging to the family Arenaviridae, causes severe haemorrhagic manifestations and is associated with a high mortality rate in humans. Thus, it is classified as a biosafety level (BSL)-4 agent. Since countermeasures for LASV diseases are yet to be developed, it is important to elucidate the molecular mechanisms underlying the life cycle of the virus, including its viral and host cellular protein interactions. These underlying molecular mechanisms may serve as the key for developing novel therapeutic options. Lymphocytic choriomeningitis virus (LCMV), a close relative of LASV, is usually asymptomatic and is categorized as a BSL-2 agent. In the present study, we visualized the transport of viral matrix Z protein in LCMV-infected cells using live-cell imaging microscopy. We demonstrated that the transport of Z protein is mediated by polymerized microtubules. Interestingly, the transport of LASV Z protein showed characteristics similar to those of Z protein in LCMV-infected cells. The live-cell imaging system using LCMV provides an attractive surrogate measure for studying arenavirus matrix protein transport in BSL-2 laboratories. In addition, it could be also utilized to analyze the interactions between viral matrix proteins and the cellular cytoskeleton, as well as to evaluate the antiviral compounds that target the transport of viral matrix proteins.
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Affiliation(s)
- Yuki Takamatsu
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Japan.,Institut für Virologie, Philipps-Universität Marburg, Germany
| | - Junichi Kajikawa
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Japan
| | - Yukiko Muramoto
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Japan
| | - Masahiro Nakano
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Japan
| | - Takeshi Noda
- Laboratory of Ultrastructural Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Japan
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38
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Zhou Y, Su JM, Samuel CE, Ma D. Measles Virus Forms Inclusion Bodies with Properties of Liquid Organelles. J Virol 2019; 93:e00948-19. [PMID: 31375591 PMCID: PMC6803276 DOI: 10.1128/jvi.00948-19] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 07/26/2019] [Indexed: 12/17/2022] Open
Abstract
Nonsegmented negative-strand RNA viruses, including measles virus (MeV), a member of the Paramyxoviridae family, are assumed to replicate in cytoplasmic inclusion bodies. These cytoplasmic viral factories are not membrane bound, and they serve to concentrate the viral RNA replication machinery. Although inclusion bodies are a prominent feature in MeV-infected cells, their biogenesis and regulation are not well understood. Here, we show that infection with MeV triggers inclusion body formation via liquid-liquid phase separation (LLPS), a process underlying the formation of membraneless organelles. We find that the viral nucleoprotein (N) and phosphoprotein (P) are sufficient to trigger MeV phase separation, with the C-terminal domains of the viral N and P proteins playing a critical role in the phase transition. We provide evidence suggesting that the phosphorylation of P and dynein-mediated transport facilitate the growth of these organelles, implying that they may have key regulatory roles in the biophysical assembly process. In addition, our findings support the notion that these inclusions change from liquid to gel-like structures as a function of time after infection, leaving open the intriguing possibility that the dynamics of these organelles can be tuned during infection to optimally suit the changing needs during the viral replication cycle. Our study provides novel insight into the process of formation of viral inclusion factories, and taken together with earlier studies, suggests that Mononegavirales have broadly evolved to utilize LLPS as a common strategy to assemble cytoplasmic replication factories in infected cells.IMPORTANCE Measles virus remains a pathogen of significant global concern. Despite an effective vaccine, outbreaks continue to occur, and globally ∼100,000 measles-related deaths are seen annually. Understanding the molecular basis of virus-host interactions that impact the efficiency of virus replication is essential for the further development of prophylactic and therapeutic strategies. Measles virus replication occurs in the cytoplasm in association with discrete bodies, though little is known of the nature of the inclusion body structures. We recently established that the cellular protein WD repeat-containing protein 5 (WDR5) enhances MeV growth and is enriched in cytoplasmic viral inclusion bodies that include viral proteins responsible for RNA replication. Here, we show that MeV N and P proteins are sufficient to trigger the formation of WDR5-containing inclusion bodies, that these structures display properties characteristic of phase-separated liquid organelles, and that P phosphorylation together with the host dynein motor affect the efficiency of the liquid-liquid phase separation process.
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Affiliation(s)
- Yuqin Zhou
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
| | - Justin M Su
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
| | - Charles E Samuel
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
| | - Dzwokai Ma
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
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Ringel M, Behner L, Heiner A, Sauerhering L, Maisner A. Replication of a Nipah Virus Encoding a Nuclear-Retained Matrix Protein. J Infect Dis 2019; 221:S389-S394. [DOI: 10.1093/infdis/jiz440] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Nipah virus (NiV) matrix protein (NiV M) plays a major role in virus assembly. It undergoes nuclear transit before accumulating at the plasma membrane and recruiting nucleocapsids to the budding sites. Because nuclear NiV M cannot be detected in all cell types, we wondered whether it can reach the cell surface by bypassing the nucleus. Using an M mutant with a defective nuclear export signal (MNESmut), however, we revealed that the nuclear import of M is ubiquitous, because MNESmut was retained in the nuclei of all cell types tested. Because a functional nuclear transit is a general prerequisite for M surface transport, we wanted to characterize the effect of nuclear-retained M protein in a full viral context and generated a recombinant NiV-MNESmut. Mutant NiV-MNESmut caused increased cell-cell fusion and produced lower virus titers. As expected for an assembly defective NiV, perinuclear inclusions (IBperi) were formed, but inclusions at the plasma membrane (IBPM), which probably represent the viral assembly platforms, were not found. It is interesting to note that the transport-defective MNESmut was recruited to IBperi. This probably prevents overaccumulation of nonfunctional M proteins in the cytoplasm and nuclei of NiV-infected cells and thus provides first evidence that IBperi are functionally relevant aggresome-like compartments.
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Affiliation(s)
- Marc Ringel
- Institute of Virology, Philipps University Marburg, Marburg, Germany
| | - Laura Behner
- Institute of Virology, Philipps University Marburg, Marburg, Germany
| | - Anja Heiner
- Institute of Virology, Philipps University Marburg, Marburg, Germany
| | - Lucie Sauerhering
- Institute of Virology, Philipps University Marburg, Marburg, Germany
| | - Andrea Maisner
- Institute of Virology, Philipps University Marburg, Marburg, Germany
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40
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Stroh E, Fischer K, Schwaiger T, Sauerhering L, Franzke K, Maisner A, Groschup MH, Blohm U, Diederich S. Henipavirus-like particles induce a CD8 T cell response in C57BL/6 mice. Vet Microbiol 2019; 237:108405. [PMID: 31561922 DOI: 10.1016/j.vetmic.2019.108405] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/01/2019] [Accepted: 09/02/2019] [Indexed: 12/13/2022]
Abstract
Nipah virus (NiV), a BSL-4 pathogen, belongs to the genus Henipavirus within the family Paramyxoviridae. To date, no effective vaccine is available. Although most of the current vaccine studies aim to induce a neutralizing antibody response, it has become evident that a promising vaccine should target both, humoral and cell-mediated immune response. Virus-like particles (VLPs) have been shown to activate both arms of the adaptive immune response. In our study, VLPs composed of the NiV surface glycoproteins G and F and the matrix protein of the closely related Hendra virus (HeV M) induced both, a neutralizing antibody response and an antigen-specific CD8 T cell response with proliferation, IFN-γ expression and Th1 cytokine secretion in C57BL/6 mice. In contrast, in BALB/c mice only a neutralizing antibody response was observed. All three viral proteins included in the VLPs were shown to harbor CD8 T cell epitopes; however, the combination of all three proteins enhanced the magnitude of the CD8 T cell response. To conclude, VLPs represent a promising vaccine candidate, as they induce humoral as well as CD8 T cell-mediated immune responses.
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Affiliation(s)
- Eileen Stroh
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Kerstin Fischer
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Theresa Schwaiger
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Lucie Sauerhering
- Institute for Virology, Philipps-University Marburg, Marburg, Germany
| | - Kati Franzke
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Andrea Maisner
- Institute for Virology, Philipps-University Marburg, Marburg, Germany
| | - Martin H Groschup
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Ulrike Blohm
- Institute of Immunology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Sandra Diederich
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany.
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