1
|
Defourny KAY, Pei X, van Kuppeveld FJM, Nolte-T Hoen ENM. Picornavirus security proteins promote the release of extracellular vesicle enclosed viruses via the modulation of host kinases. PLoS Pathog 2024; 20:e1012133. [PMID: 38662794 DOI: 10.1371/journal.ppat.1012133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 05/07/2024] [Accepted: 03/18/2024] [Indexed: 05/08/2024] Open
Abstract
The discovery that extracellular vesicles (EVs) serve as carriers of virus particles calls for a reevaluation of the release strategies of non-enveloped viruses. Little is currently known about the molecular mechanisms that determine the release and composition of EVs produced by virus-infected cells, as well as conservation of these mechanisms among viruses. We previously described an important role for the Leader protein of the picornavirus encephalomyocarditis virus (EMCV) in the induction of virus-carrying EV subsets with distinct molecular and physical properties. EMCV L acts as a 'viral security protein' by suppressing host antiviral stress and type-I interferon (IFN) responses. Here, we tested the ability of functionally related picornavirus proteins of Theilers murine encephalitis virus (TMEV L), Saffold virus (SAFV L), and coxsackievirus B3 (CVB3 2Apro), to rescue EV and EV-enclosed virus release when introduced in Leader-deficient EMCV. We show that all viral security proteins tested were able to promote virus packaging in EVs, but that only the expression of EMCV L and CVB3 2Apro increased overall EV production. We provide evidence that one of the main antiviral pathways counteracted by this class of picornaviral proteins, i.e. the inhibition of PKR-mediated stress responses, affected EV and EV-enclosed virus release during infection. Moreover, we show that the enhanced capacity of the viral proteins EMCV L and CVB3 2Apro to promote EV-enclosed virus release is linked to their ability to simultaneously promote the activation of the stress kinase P38 MAPK. Taken together, we demonstrate that cellular stress pathways involving the kinases PKR and P38 are modulated by the activity of non-structural viral proteins to increase the release EV-enclosed viruses during picornavirus infections. These data shed new light on the molecular regulation of EV production in response to virus infection.
Collapse
Affiliation(s)
- Kyra A Y Defourny
- Infection Biology Section, Division of Infectious Diseases & Immunology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Xinyi Pei
- Infection Biology Section, Division of Infectious Diseases & Immunology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Frank J M van Kuppeveld
- Virology Section, Division of Infectious Diseases & Immunology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Esther N M Nolte-T Hoen
- Infection Biology Section, Division of Infectious Diseases & Immunology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
2
|
Ivin Y, Butusova A, Gladneva E, Gmyl A, Ishmukhametov A. Comprehensive Elucidation of the Role of L and 2A Security Proteins on Cell Death during EMCV Infection. Viruses 2024; 16:280. [PMID: 38400055 PMCID: PMC10892303 DOI: 10.3390/v16020280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/03/2024] [Accepted: 02/09/2024] [Indexed: 02/25/2024] Open
Abstract
The EMCV L and 2A proteins are virulence factors that counteract host cell defense mechanisms. Both L and 2A exhibit antiapoptotic properties, but the available data were obtained in different cell lines and under incomparable conditions. This study is aimed at checking the role of these proteins in the choice of cell death type in three different cell lines using three mutants of EMCV lacking functional L, 2A, and both proteins together. We have found that both L and 2A are non-essential for viral replication in HeLa, BHK, and RD cell lines, as evidenced by the viability of the virus in the absence of both functional proteins. L-deficient infection led to the apoptotic death of HeLa and RD cells, and the necrotic death of BHK cells. 2A-deficient infection induced apoptosis in BHK and RD cells. Infection of HeLa cells with the 2A-deficient mutant was finalized with exclusive caspase-dependent death with membrane permeabilization, morphologically similar to pyroptosis. We also demonstrated that inactivation of both proteins, along with caspase inhibition, delayed cell death progression. The results obtained demonstrate that proteins L and 2A play a critical role in choosing the path of cell death during infection, but the result of their influence depends on the properties of the host cells.
Collapse
Affiliation(s)
- Yury Ivin
- FSASI “M.P. Chumakov Federal Scientific Center for Research and Development of Immunobiological Drugs of the Russian Academy of Sciences (Polio Institute)”, 118819 Moscow, Russia; (A.B.); (E.G.); (A.I.)
| | - Anna Butusova
- FSASI “M.P. Chumakov Federal Scientific Center for Research and Development of Immunobiological Drugs of the Russian Academy of Sciences (Polio Institute)”, 118819 Moscow, Russia; (A.B.); (E.G.); (A.I.)
| | - Ekaterina Gladneva
- FSASI “M.P. Chumakov Federal Scientific Center for Research and Development of Immunobiological Drugs of the Russian Academy of Sciences (Polio Institute)”, 118819 Moscow, Russia; (A.B.); (E.G.); (A.I.)
| | - Anatoly Gmyl
- FSASI “M.P. Chumakov Federal Scientific Center for Research and Development of Immunobiological Drugs of the Russian Academy of Sciences (Polio Institute)”, 118819 Moscow, Russia; (A.B.); (E.G.); (A.I.)
| | - Aydar Ishmukhametov
- FSASI “M.P. Chumakov Federal Scientific Center for Research and Development of Immunobiological Drugs of the Russian Academy of Sciences (Polio Institute)”, 118819 Moscow, Russia; (A.B.); (E.G.); (A.I.)
- Institute of Translational Medicine and Biotechnology, First Moscow State Medical University (Sechenov University), 119991 Moscow, Russia
| |
Collapse
|
3
|
Ivin YY, Butusova AA, Gladneva EE, Kolomijtseva GY, Khapchaev YK, Ishmukhametov AA. [The role of the encephalomyocarditis virus type 1 proteins L and 2A in the inhibition of the synthesis of cellular proteins and the accumulation of viral proteins during infection]. Vopr Virusol 2023; 68:428-444. [PMID: 38156577 DOI: 10.36233/0507-4088-195] [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: 12/04/2020] [Accepted: 12/04/2020] [Indexed: 12/30/2023]
Abstract
INTRODUCTION Infection of cells with encephalomyocarditis virus type 1 (EMCV-1, Cardiovirus A: Picornaviridae) is accompanied by suppression of cellular protein synthesis. The main role in the inhibition of cellular translation is assigned to the L and 2A «security» proteins. The mechanism of the possible influence of the L protein on cellular translation is unknown. There are hypotheses about the mechanism of influence of 2A protein on the efficiency of cap-dependent translation, which are based on interaction with translation factors and ribosome subunits. However, the available experimental data are contradictory, obtained using different approaches, and do not form a unified model of the interaction between the L and 2A proteins and the cellular translation machinery. AIM To study the role of L and 2A «security» proteins in the suppression of translation of cellular proteins and the efficiency of translation and processing of viral proteins in infected cells. MATERIALS AND METHODS Mutant variants of EMCV-1 were obtained to study the properties of L and 2A viral proteins: Zfmut, which has a defective L; Δ2A encoding a partially deleted 2A; Zfmut&Δ2A containing mutations in both proteins. Translational processes in infected cells were studied by Western-blot and the pulse method of incorporating radioactively labeled amino acids (14C) into newly synthesized proteins, followed by radioautography. RESULTS The functional inactivation of the 2A protein does not affect the inhibition of cellular protein synthesis. A direct correlation was found between the presence of active L protein and specific inactivation of cellular protein synthesis at an early stage of viral infection. Nonspecific suppression of the translational processes of the infected cell, accompanied by phosphorylation of eIF2α, occurs at the late stage of infection. Partial removal of the 2A protein from the EMCV-1 genome does not affect the development of this process, while inactivation of the L protein accelerates the onset of complete inhibition of protein synthesis. Partial deletion of the 2A disrupts the processing of viral capsid proteins. Suppression of L protein functions leads to a decrease in the efficiency of viral translation. CONCLUSION A study of the role of EMCV-1 L and 2A proteins during the translational processes of an infected cell, first performed using infectious viral pathogens lacking active L and 2A proteins in one experiment, showed that 2A protein is not implicated in the inhibition of cellular translation in HeLa cells; L protein seems to play an important role not only in the specific inhibition of cellular translation but also in maintaining the efficient synthesis of viral proteins; 2A protein is involved not only in primary but also in secondary processing of EMCV-1 capsid proteins.
Collapse
Affiliation(s)
- Y Y Ivin
- Federal State Autonomous Scientific Institution M.P. Chumakov Federal Scientific Center for Research and Development of Immunobiological Drugs of the Russian Academy of Sciences (Polio Institute)
| | - A A Butusova
- Federal State Autonomous Scientific Institution M.P. Chumakov Federal Scientific Center for Research and Development of Immunobiological Drugs of the Russian Academy of Sciences (Polio Institute)
| | - E E Gladneva
- Federal State Autonomous Scientific Institution M.P. Chumakov Federal Scientific Center for Research and Development of Immunobiological Drugs of the Russian Academy of Sciences (Polio Institute)
| | - G Y Kolomijtseva
- A.N. Belozersky Research Institute of Physico-Chemical Biology MSU
| | - Y K Khapchaev
- Federal State Autonomous Scientific Institution M.P. Chumakov Federal Scientific Center for Research and Development of Immunobiological Drugs of the Russian Academy of Sciences (Polio Institute)
| | - A A Ishmukhametov
- Federal State Autonomous Scientific Institution M.P. Chumakov Federal Scientific Center for Research and Development of Immunobiological Drugs of the Russian Academy of Sciences (Polio Institute)
- Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University
| |
Collapse
|
4
|
Insights from structural studies of the Cardiovirus 2A protein. Biosci Rep 2022; 42:230648. [PMID: 35022657 PMCID: PMC8777194 DOI: 10.1042/bsr20210406] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 01/10/2022] [Accepted: 01/10/2022] [Indexed: 11/24/2022] Open
Abstract
Cardioviruses are single-stranded RNA viruses of the family Picornaviridae. In addition to being the first example of internal ribosome entry site (IRES) utilization, cardioviruses also employ a series of alternative translation strategies, such as Stop-Go translation and programmed ribosome frameshifting. Here, we focus on cardiovirus 2A protein, which is not only a primary virulence factor, but also exerts crucial regulatory functions during translation, including activation of viral ribosome frameshifting and inhibition of host cap-dependent translation. Only recently, biochemical and structural studies have allowed us to close the gaps in our knowledge of how cardiovirus 2A is able to act in diverse translation-related processes as a novel RNA-binding protein. This review will summarize these findings, which ultimately may lead to the discovery of other RNA-mediated gene expression strategies across a broad range of RNA viruses.
Collapse
|
5
|
Structural and molecular basis for Cardiovirus 2A protein as a viral gene expression switch. Nat Commun 2021; 12:7166. [PMID: 34887415 PMCID: PMC8660796 DOI: 10.1038/s41467-021-27400-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 11/12/2021] [Indexed: 12/21/2022] Open
Abstract
Programmed –1 ribosomal frameshifting (PRF) in cardioviruses is activated by the 2A protein, a multi-functional virulence factor that also inhibits cap-dependent translational initiation. Here we present the X-ray crystal structure of 2A and show that it selectively binds to a pseudoknot-like conformation of the PRF stimulatory RNA element in the viral genome. Using optical tweezers, we demonstrate that 2A stabilises this RNA element, likely explaining the increase in PRF efficiency in the presence of 2A. Next, we demonstrate a strong interaction between 2A and the small ribosomal subunit and present a cryo-EM structure of 2A bound to initiated 70S ribosomes. Multiple copies of 2A bind to the 16S rRNA where they may compete for binding with initiation and elongation factors. Together, these results define the structural basis for RNA recognition by 2A, show how 2A-mediated stabilisation of an RNA pseudoknot promotes PRF, and reveal how 2A accumulation may shut down translation during virus infection. Many RNA viruses employ programmed –1 ribosomal frameshifting (PRF) to expand their coding capacity and optimize production of viral proteins. Here, the authors report structural and biophysical analysis of protein 2A from a cardiovirus, with insights into the mechanism of its PRF-stimulatory function.
Collapse
|
6
|
Napthine S, Bell S, Hill CH, Brierley I, Firth AE. Characterization of the stimulators of protein-directed ribosomal frameshifting in Theiler's murine encephalomyelitis virus. Nucleic Acids Res 2019; 47:8207-8223. [PMID: 31180502 PMCID: PMC6735917 DOI: 10.1093/nar/gkz503] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/24/2019] [Accepted: 05/29/2019] [Indexed: 01/01/2023] Open
Abstract
Many viruses utilize programmed -1 ribosomal frameshifting (-1 PRF) to express additional proteins or to produce frameshift and non-frameshift protein products at a fixed stoichiometric ratio. PRF is also utilized in the expression of a small number of cellular genes. Frameshifting is typically stimulated by signals contained within the mRNA: a 'slippery' sequence and a 3'-adjacent RNA structure. Recently, we showed that -1 PRF in encephalomyocarditis virus (EMCV) is trans-activated by the viral 2A protein, leading to a temporal change in PRF efficiency from 0% to 70% during virus infection. Here we analyzed PRF in the related Theiler's murine encephalomyelitis virus (TMEV). We show that 2A is also required for PRF in TMEV and can stimulate PRF to levels as high as 58% in rabbit reticulocyte cell-free translations and 81% during virus infection. We also show that TMEV 2A trans-activates PRF on the EMCV signal but not vice versa. We present an extensive mutational analysis of the frameshift stimulators (mRNA signals and 2A protein) analysing activity in in vitro translation, electrophoretic mobility shift and in vitro ribosome pausing assays. We also investigate the PRF mRNA signal with RNA structure probing. Our results substantially extend previous characterization of protein-stimulated PRF.
Collapse
Affiliation(s)
- Sawsan Napthine
- Division of Virology, Department of Pathology, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Susanne Bell
- Division of Virology, Department of Pathology, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Chris H Hill
- Division of Virology, Department of Pathology, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Ian Brierley
- Division of Virology, Department of Pathology, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Andrew E Firth
- Division of Virology, Department of Pathology, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| |
Collapse
|
7
|
Freundt EC, Drappier M, Michiels T. Innate Immune Detection of Cardioviruses and Viral Disruption of Interferon Signaling. Front Microbiol 2018; 9:2448. [PMID: 30369921 PMCID: PMC6194174 DOI: 10.3389/fmicb.2018.02448] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 09/25/2018] [Indexed: 12/24/2022] Open
Abstract
Cardioviruses are members of the Picornaviridae family and infect a variety of mammals, from mice to humans. Replication of cardioviruses produces double stranded RNA that is detected by helicases in the RIG-I-like receptor family and leads to a signaling cascade to produce type I interferon. Like other viruses within Picornaviridae, however, cardioviruses have evolved several mechanisms to inhibit interferon production. In this review, we summarize recent findings that have uncovered several proteins enabling efficient detection of cardiovirus dsRNA and discuss which cell types may be most important for interferon production in vivo. Additionally, we describe how cardiovirus proteins L, 3C and L∗ disrupt interferon production and antagonize the antiviral activity of interferon effector molecules.
Collapse
Affiliation(s)
- Eric C Freundt
- Department of Biology, The University of Tampa, Tampa, FL, United States
| | - Melissa Drappier
- de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Thomas Michiels
- de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| |
Collapse
|
8
|
Yang X, Cheng A, Wang M, Jia R, Sun K, Pan K, Yang Q, Wu Y, Zhu D, Chen S, Liu M, Zhao XX, Chen X. Structures and Corresponding Functions of Five Types of Picornaviral 2A Proteins. Front Microbiol 2017; 8:1373. [PMID: 28785248 PMCID: PMC5519566 DOI: 10.3389/fmicb.2017.01373] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 07/06/2017] [Indexed: 11/27/2022] Open
Abstract
Among the few non-structural proteins encoded by the picornaviral genome, the 2A protein is particularly special, irrespective of structure or function. During the evolution of the Picornaviridae family, the 2A protein has been highly non-conserved. We believe that the 2A protein in this family can be classified into at least five distinct types according to previous studies. These five types are (A) chymotrypsin-like 2A, (B) Parechovirus-like 2A, (C) hepatitis-A-virus-like 2A, (D) Aphthovirus-like 2A, and (E) 2A sequence of the genus Cardiovirus. We carried out a phylogenetic analysis and found that there was almost no homology between each type. Subsequently, we aligned the sequences within each type and found that the functional motifs in each type are highly conserved. These different motifs perform different functions. Therefore, in this review, we introduce the structures and functions of these five types of 2As separately. Based on the structures and functions, we provide suggestions to combat picornaviruses. The complexity and diversity of the 2A protein has caused great difficulties in functional and antiviral research. In this review, researchers can find useful information on the 2A protein and thus conduct improved antiviral research.
Collapse
Affiliation(s)
- Xiaoyao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Kunfeng Sun
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Kangcheng Pan
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Dekang Zhu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Xin-Xin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Xiaoyue Chen
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural UniversityChengdu, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| |
Collapse
|
9
|
Ciomperlik JJ, Basta HA, Palmenberg AC. Cardiovirus Leader proteins bind exportins: Implications for virus replication and nucleocytoplasmic trafficking inhibition. Virology 2016; 487:19-26. [PMID: 26492198 PMCID: PMC4679524 DOI: 10.1016/j.virol.2015.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 09/28/2015] [Accepted: 10/01/2015] [Indexed: 10/22/2022]
Abstract
Cardiovirus Leader proteins (LX) inhibit cellular nucleocytoplasmic trafficking by directing host kinases to phosphorylate Phe/Gly-containing nuclear pore proteins (Nups). Resolution of the Mengovirus LM structure bound to Ran GTPase, suggested this complex would further recruit specific exportins (karyopherins), which in turn mediate kinase selection. Pull-down experiments and recombinant complex reconstitution now confirm that Crm1 and CAS exportins form stable dimeric complexes with encephalomyocarditis virus LE, and also larger complexes with LE:Ran. shRNA knockdown studies support this idea. Similar activities could be demonstrated for recombinant LS and LT from Theiloviruses. When mutations were introduced to alter the LE zinc finger domain, acidic domain, or dual phosphorylation sites, there was reduced exportin selection. These regions are not involved in Ran interactions, so the Ran and Crm1 binding sites on LE must be non-overlapping. The involvement of exportins in this mechanism is important to viral replication and the observation of trafficking inhibition by LE.
Collapse
Affiliation(s)
- Jessica J Ciomperlik
- Institute for Molecular Virology and Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Holly A Basta
- Department of Biology, Rocky Mountain College, Billings, MT, United States
| | - Ann C Palmenberg
- Institute for Molecular Virology and Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States.
| |
Collapse
|
10
|
Ciomperlik JJ, Basta HA, Palmenberg AC. Three cardiovirus Leader proteins equivalently inhibit four different nucleocytoplasmic trafficking pathways. Virology 2015; 484:194-202. [PMID: 26115166 PMCID: PMC4567469 DOI: 10.1016/j.virol.2015.06.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 05/07/2015] [Accepted: 06/04/2015] [Indexed: 11/17/2022]
Abstract
Cardiovirus infections inhibit nucleocytoplasmic trafficking by Leader protein-induced phosphorylation of Phe/Gly-containing nucleoporins (Nups). Recombinant Leader from encephalomyocarditis virus, Theiler׳s murine encephalomyelitis virus and Saffold virus target the same subset of Nups, including Nup62 and Nup98, but not Nup50. Reporter cell lines with fluorescence mCherry markers for M9, RS and classical SV40 import pathways, as well as the Crm1-mediated export pathway, all responded to transfection with the full panel of Leader proteins, showing consequent cessation of path-specific active import/export. For this to happen, the Nups had to be presented in the context of intact nuclear pores and exposed to cytoplasmic extracts. The Leader phosphorylation cascade was not effective against recombinant Nup proteins. The findings support a model of Leader-dependent Nup phosphorylation with the purpose of disrupting Nup-transportin interactions.
Collapse
Affiliation(s)
- Jessica J Ciomperlik
- Institute for Molecular Virology, and Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States
| | - Holly A Basta
- Department of Biology, Rocky Mountain College, Billings, MT, United States
| | - Ann C Palmenberg
- Institute for Molecular Virology, and Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States.
| |
Collapse
|
11
|
Zhu S, Guo X, Keyes LR, Yang H, Ge X. Recombinant Encephalomyocarditis Viruses Elicit Neutralizing Antibodies against PRRSV and CSFV in Mice. PLoS One 2015; 10:e0129729. [PMID: 26076449 PMCID: PMC4468123 DOI: 10.1371/journal.pone.0129729] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 05/12/2015] [Indexed: 11/30/2022] Open
Abstract
Encephalomyocarditis virus (EMCV) is capable of infecting a wide range of species and the infection can cause myocarditis and reproductive failure in pigs as well as febrile illness in human beings. In this study, we introduced the entire ORF5 of the porcine reproductive and respiratory syndrome virus (PRRSV) or the neutralization epitope regions in the E2 gene of the classical swine fever virus (CSFV), into the genome of a stably attenuated EMCV strain, T1100I. The resultant viable recombinant viruses, CvBJC3m/I-ΔGP5 and CvBJC3m/I-E2, respectively expressed partial PRRSV envelope protein GP5 or CSFV neutralization epitope A1A2 along with EMCV proteins. These heterologous proteins fused to the N-terminal of the nonstructural leader protein could be recognized by anti-GP5 or anti-E2 antibody. We also tested the immunogenicity of these fusion proteins by immunizing BALB/c mice with the recombinant viruses. The immunized animals elicited neutralizing antibodies against PRRSV and CSFV. Our results suggest that EMCV can be engineered as an expression vector and serve as a tool in the development of novel live vaccines in various animal species.
Collapse
Affiliation(s)
- Shu Zhu
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, People's Republic of China
| | - Xin Guo
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, People's Republic of China
| | - Lisa R. Keyes
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Hanchun Yang
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, People's Republic of China
- * E-mail: (XG), (HY)
| | - Xinna Ge
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, People's Republic of China
- * E-mail: (XG), (HY)
| |
Collapse
|