1
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Chang YK, Lin YJ, Cheng CY, Tsai PC, Wang CY, Nielsen BL, Liu HJ. Nucleocytoplasmic shuttling of BEFV M protein-modulated by lamin A/C and chromosome maintenance region 1 through a transcription-, carrier- and energy-dependent pathway. Vet Microbiol 2024; 291:110026. [PMID: 38364467 DOI: 10.1016/j.vetmic.2024.110026] [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: 12/12/2023] [Revised: 01/30/2024] [Accepted: 02/07/2024] [Indexed: 02/18/2024]
Abstract
This study demonstrates for the first time that the matrix (M) protein of BEFV is a nuclear targeting protein that shuttles between the nucleus and the cytoplasm in a transcription-, carrier-, and energy-dependent manner. Experiments performed in both intact cells and digitonin-permeabilized cells revealed that M protein targets the nucleolus and requires carrier, cytosolic factors or energy input. By employing sequence and mutagenesis analyses, we have determined both nuclear localization signal (NLS) 6KKGKSK11 and nuclear export signal (NES) 98LIITSYL TI106 of M protein that are important for the nucleocytoplasmic shuttling of M protein. Furthermore, we found that both lamin A/C and chromosome maintenance region 1 (CRM-1) proteins could be coimmunoprecipitated and colocalized with the BEFV M protein. Knockdown of lamin A/C by shRNA and inhibition of CRM-1 by leptomycin B significantly reduced virus yield. Collectively, this study provides novel insights into nucleocytoplasmic shuttling of the BEFV M protein modulated by lamin A/C and CRM-1 and by a transcription- and carrier- and energy-dependent pathway.
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Affiliation(s)
- Yu-Kang Chang
- Department of Medical Research, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan, ROC; Depertment of Post-Baccalaureate Medicine, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Yi-Jyum Lin
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan, ROC
| | - Ching-Yuan Cheng
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan, ROC
| | - Pei-Chien Tsai
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Chi-Young Wang
- Department of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan, ROC; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Brent L Nielsen
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, USA
| | - Hung-Jen Liu
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan, ROC; Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, ROC; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC; Ph.D Program in Translational Medicine, National Chung Hsing University, Taichung, Taiwan, ROC; Rong Hsing Research Center for Translational Medicine, National Chung Hsing, Taiwan, ROC.
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2
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Sethi A, Rawlinson SM, Dubey A, Ang CS, Choi YH, Yan F, Okada K, Rozario AM, Brice AM, Ito N, Williamson NA, Hatters DM, Bell TDM, Arthanari H, Moseley GW, Gooley PR. Structural insights into the multifunctionality of rabies virus P3 protein. Proc Natl Acad Sci U S A 2023; 120:e2217066120. [PMID: 36989298 PMCID: PMC10083601 DOI: 10.1073/pnas.2217066120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 02/20/2023] [Indexed: 03/30/2023] Open
Abstract
Viruses form extensive interfaces with host proteins to modulate the biology of the infected cell, frequently via multifunctional viral proteins. These proteins are conventionally considered as assemblies of independent functional modules, where the presence or absence of modules determines the overall composite phenotype. However, this model cannot account for functions observed in specific viral proteins. For example, rabies virus (RABV) P3 protein is a truncated form of the pathogenicity factor P protein, but displays a unique phenotype with functions not seen in longer isoforms, indicating that changes beyond the simple complement of functional modules define the functions of P3. Here, we report structural and cellular analyses of P3 derived from the pathogenic RABV strain Nishigahara (Nish) and an attenuated derivative strain (Ni-CE). We identify a network of intraprotomer interactions involving the globular C-terminal domain and intrinsically disordered regions (IDRs) of the N-terminal region that characterize the fully functional Nish P3 to fluctuate between open and closed states, whereas the defective Ni-CE P3 is predominantly open. This conformational difference appears to be due to the single mutation N226H in Ni-CE P3. We find that Nish P3, but not Ni-CE or N226H P3, undergoes liquid-liquid phase separation and this property correlates with the capacity of P3 to interact with different cellular membrane-less organelles, including those associated with immune evasion and pathogenesis. Our analyses propose that discrete functions of a critical multifunctional viral protein depend on the conformational arrangements of distant individual domains and IDRs, in addition to their independent functions.
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Affiliation(s)
- Ashish Sethi
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC3010, Australia
| | - Stephen M. Rawlinson
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC3800, Australia
| | - Abhinav Dubey
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA02115
- Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA02115
| | - Ching-Seng Ang
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC3010, Australia
| | - Yoon Hee Choi
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC3010, Australia
| | - Fei Yan
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC3010, Australia
| | - Kazuma Okada
- Laboratory of Zoonotic Diseases, Joint Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu501-1193, Japan
| | | | - Aaron M. Brice
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC3010, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC3800, Australia
| | - Naoto Ito
- Laboratory of Zoonotic Diseases, Joint Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu501-1193, Japan
- Center for One Medicine Innovative Research, Institute for Advanced Study, Gifu University, Gifu501-1193, Japan
| | - Nicholas A. Williamson
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC3010, Australia
| | - Danny M. Hatters
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC3010, Australia
| | - Toby D. M. Bell
- School of Chemistry, Monash University, Clayton, VIC3800, Australia
| | - Haribabu Arthanari
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA02115
- Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA02115
| | - Gregory W. Moseley
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC3800, Australia
| | - Paul R. Gooley
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC3010, Australia
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3
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Rawlinson SM, Zhao T, Ardipradja K, Zhang Y, Veugelers PF, Harper JA, David CT, Sundaramoorthy V, Moseley GW. Henipaviruses and lyssaviruses target nucleolar treacle protein and regulate ribosomal RNA synthesis. Traffic 2023; 24:146-157. [PMID: 36479968 PMCID: PMC10947316 DOI: 10.1111/tra.12877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022]
Abstract
The nucleolus is a common target of viruses and viral proteins, but for many viruses the functional outcomes and significance of this targeting remains unresolved. Recently, the first intranucleolar function of a protein of a cytoplasmically-replicating negative-sense RNA virus (NSV) was identified, with the finding that the matrix (M) protein of Hendra virus (HeV) (genus Henipavirus, family Paramyxoviridae) interacts with Treacle protein within nucleolar subcompartments and mimics a cellular mechanism of the nucleolar DNA-damage response (DDR) to suppress ribosomal RNA (rRNA) synthesis. Whether other viruses utilise this mechanism has not been examined. We report that sub-nucleolar Treacle targeting and modulation is conserved between M proteins of multiple Henipaviruses, including Nipah virus and other potentially zoonotic viruses. Furthermore, this function is also evident for P3 protein of rabies virus, the prototype virus of a different RNA virus family (Rhabdoviridae), with Treacle depletion in cells also found to impact virus production. These data indicate that unrelated proteins of viruses from different families have independently developed nucleolar/Treacle targeting function, but that modulation of Treacle has distinct effects on infection. Thus, subversion of Treacle may be an important process in infection by diverse NSVs, and so could provide novel targets for antiviral approaches with broad specificity.
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Affiliation(s)
- Stephen M. Rawlinson
- Department of Microbiology, Biomedicine Discovery InstituteMonash UniversityMelbourneVictoriaAustralia
| | - Tianyue Zhao
- Department of Microbiology, Biomedicine Discovery InstituteMonash UniversityMelbourneVictoriaAustralia
| | - Katie Ardipradja
- Commonwealth Scientific and Industrial Research Organisation (CSIRO)Australian Centre for Disease Preparedness (ACDP)East GeelongVictoriaAustralia
| | - Yilin Zhang
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology InstituteThe University of MelbourneMelbourneAustralia
| | - Patrick F. Veugelers
- Department of Microbiology, Biomedicine Discovery InstituteMonash UniversityMelbourneVictoriaAustralia
| | - Jennifer A. Harper
- Commonwealth Scientific and Industrial Research Organisation (CSIRO)Australian Centre for Disease Preparedness (ACDP)East GeelongVictoriaAustralia
| | - Cassandra T. David
- Department of Microbiology, Biomedicine Discovery InstituteMonash UniversityMelbourneVictoriaAustralia
| | - Vinod Sundaramoorthy
- Commonwealth Scientific and Industrial Research Organisation (CSIRO)Australian Centre for Disease Preparedness (ACDP)East GeelongVictoriaAustralia
- School of MedicineDeakin UniversityGeelongVictoriaAustralia
| | - Gregory W. Moseley
- Department of Microbiology, Biomedicine Discovery InstituteMonash UniversityMelbourneVictoriaAustralia
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4
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Lyssavirus P Protein Isoforms Diverge Significantly in Subcellular Interactions Underlying Mechanisms of Interferon Antagonism. J Virol 2022; 96:e0139622. [PMID: 36222519 PMCID: PMC9599249 DOI: 10.1128/jvi.01396-22] [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: 11/20/2022] Open
Abstract
Viral hijacking of microtubule (MT)-dependent transport is well understood, but several viruses also express discrete MT-associated proteins (vMAPs), potentially to modulate MT-dependent processes in the host cell. Specific roles for vMAP-MT interactions include subversion of antiviral responses by P3, an isoform of the P protein of rabies virus (RABV; genus Lyssavirus), which mediates MT-dependent antagonism of interferon (IFN)-dependent signal transducers and activators of transcription 1 (STAT1) signaling. P3 also undergoes nucleocytoplasmic trafficking and inhibits STAT1-DNA binding, indicative of intranuclear roles in a multipronged antagonistic strategy. MT association/STAT1 antagonist functions of P3 correlate with pathogenesis, indicating potential as therapeutic targets. However, key questions remain, including whether other P protein isoforms interact with MTs, the relationship of these interactions with pathogenesis, and the extent of conservation of P3-MT interactions between diverse pathogenic lyssaviruses. Using super-resolution microscopy, live-cell imaging, and immune signaling analyses, we find that multiple P protein isoforms associate with MTs and that association correlates with pathogenesis. Furthermore, P3 proteins from different lyssaviruses exhibit variation in intracellular localization phenotypes that are associated with STAT1 antagonist function, whereby P3-MT association is conserved among lyssaviruses of phylogroup I but not phylogroup II, while nucleocytoplasmic localization varies between P3 proteins of the same phylogroup within both phylogroup I and II. Nevertheless, the divergent P3 proteins retain significant IFN antagonist function, indicative of adaptation to favor different inhibitory mechanisms, with MT interaction important to phylogroup I viruses. IMPORTANCE Lyssaviruses, including rabies virus, cause rabies, a progressive encephalomyelitis that is almost invariably fatal. There are no effective antivirals for symptomatic infection, and effective application of current vaccines is limited in areas of endemicity, such that rabies causes ~59,000 deaths per year. Viral subversion of host cell functions, including antiviral immunity, is critical to disease, and isoforms of the lyssavirus P protein are central to the virus-host interface underpinning immune evasion. Here, we show that specific cellular interactions of P protein isoforms involved in immune evasion vary significantly between different lyssaviruses, indicative of distinct strategies to evade immune responses. These findings highlight the diversity of the virus-host interface, an important consideration in the development of pan-lyssavirus therapeutic approaches.
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5
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Molecular Basis of Functional Effects of Phosphorylation of the C-Terminal Domain of the Rabies Virus P Protein. J Virol 2022; 96:e0011122. [DOI: 10.1128/jvi.00111-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Rabies virus P protein is a multifunctional protein with critical roles in replication and manipulation of host-cell processes, including subversion of immunity. This functional diversity involves interactions of several P protein isoforms with the cell nucleus and microtubules.
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6
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Brice AM, Watts E, Hirst B, Jans DA, Ito N, Moseley GW. Implication of the nuclear trafficking of rabies virus P3 protein in viral pathogenicity. Traffic 2021; 22:482-489. [PMID: 34622522 DOI: 10.1111/tra.12821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/27/2021] [Accepted: 10/04/2021] [Indexed: 11/27/2022]
Abstract
Although the majority of viruses of the family Mononegvirales replicate exclusively in the host cell cytoplasm, many of these viruses encode proteins that traffic between the nucleus and cytoplasm, which is believed to enable accessory functions in modulating the biology of the infected host cell. Among these, the P3 protein of rabies virus localizes to the nucleus through the activity of several specific nuclear localization and nuclear export signals. The major defined functions of P3 are in evasion of interferon (IFN)-mediated antiviral responses, including through inhibition of DNA-binding by IFN-activated STAT1. P3 also localizes to nucleoli and promyelocytic leukemia (PML) nuclear bodies, and interacts with nucleolin and PML protein, indicative of several intranuclear roles. The relationship of P3 nuclear localization with pathogenicity, however, is unresolved. We report that nucleocytoplasmic localization of P3 proteins from a pathogenic RABV strain, Nishigahara (Ni) and a non-pathogenic Ni-derived strain, Ni-CE, differs significantly, with nuclear accumulation defective for Ni-CE-P3. Molecular mapping indicates that altered localization derives from a coordinated effect, including two residue substitutions that independently disable nuclear localization and augment nuclear export signals, collectively promoting nuclear exclusion. Intriguingly, this appears to relate to effects on protein conformation or regulatory mechanisms, rather than direct modification of defined trafficking signal sequences. These data provide new insights into the role of regulated nuclear trafficking of a viral protein in the pathogenicity of a virus that replicates in the cytoplasm.
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Affiliation(s)
- Aaron M Brice
- Viral Pathogenesis Laboratory, Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Ericka Watts
- Viral Pathogenesis Laboratory, Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Bevan Hirst
- Viral Pathogenesis Laboratory, Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - David A Jans
- Nuclear Signaling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Naoto Ito
- Laboratory of Zoonotic Diseases, Faculty of Applied Biological Sciences, and United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Gregory W Moseley
- Viral Pathogenesis Laboratory, Department of Microbiology, Monash University, Clayton, Victoria, Australia
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7
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Harrison AR, David CT, Rawlinson SM, Moseley GW. The Ebola Virus Interferon Antagonist VP24 Undergoes Active Nucleocytoplasmic Trafficking. Viruses 2021; 13:v13081650. [PMID: 34452514 PMCID: PMC8402725 DOI: 10.3390/v13081650] [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: 06/28/2021] [Revised: 08/13/2021] [Accepted: 08/17/2021] [Indexed: 12/25/2022] Open
Abstract
Viral interferon (IFN) antagonist proteins mediate evasion of IFN-mediated innate immunity and are often multifunctional, with distinct roles in viral replication. The Ebola virus IFN antagonist VP24 mediates nucleocapsid assembly, and inhibits IFN-activated signaling by preventing nuclear import of STAT1 via competitive binding to nuclear import receptors (karyopherins). Proteins of many viruses, including viruses with cytoplasmic replication cycles, interact with nuclear trafficking machinery to undergo nucleocytoplasmic transport, with key roles in pathogenesis; however, despite established karyopherin interaction, potential nuclear trafficking of VP24 has not been investigated. We find that inhibition of nuclear export pathways or overexpression of VP24-binding karyopherin results in nuclear localization of VP24. Molecular mapping indicates that cytoplasmic localization of VP24 depends on a CRM1-dependent nuclear export sequence at the VP24 C-terminus. Nuclear export is not required for STAT1 antagonism, consistent with competitive karyopherin binding being the principal antagonistic mechanism, while export mediates return of nuclear VP24 to the cytoplasm where replication/nucleocapsid assembly occurs.
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8
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Definition of the immune evasion-replication interface of rabies virus P protein. PLoS Pathog 2021; 17:e1009729. [PMID: 34237115 PMCID: PMC8291714 DOI: 10.1371/journal.ppat.1009729] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 07/20/2021] [Accepted: 06/18/2021] [Indexed: 12/24/2022] Open
Abstract
Rabies virus phosphoprotein (P protein) is a multifunctional protein that plays key roles in replication as the polymerase cofactor that binds to the complex of viral genomic RNA and the nucleoprotein (N protein), and in evading the innate immune response by binding to STAT transcription factors. These interactions are mediated by the C-terminal domain of P (PCTD). The colocation of these binding sites in the small globular PCTD raises the question of how these interactions underlying replication and immune evasion, central to viral infection, are coordinated and, potentially, coregulated. While direct data on the binding interface of the PCTD for STAT1 is available, the lack of direct structural data on the sites that bind N protein limits our understanding of this interaction hub. The PCTD was proposed to bind via two sites to a flexible loop of N protein (Npep) that is not visible in crystal structures, but no direct analysis of this interaction has been reported. Here we use Nuclear Magnetic Resonance, and molecular modelling to show N protein residues, Leu381, Asp383, Asp384 and phosphor-Ser389, are likely to bind to a ‘positive patch’ of the PCTD formed by Lys211, Lys214 and Arg260. Furthermore, in contrast to previous predictions we identify a single site of interaction on the PCTD by this Npep. Intriguingly, this site is proximal to the defined STAT1 binding site that includes Ile201 to Phe209. However, cell-based assays indicate that STAT1 and N protein do not compete for P protein. Thus, it appears that interactions critical to replication and immune evasion can occur simultaneously with the same molecules of P protein so that the binding of P protein to activated STAT1 can potentially occur without interrupting interactions involved in replication. These data suggest that replication complexes might be directly involved in STAT1 antagonism. For viruses to infect cells and generate progeny, they must be able to mediate replication, while simultaneously evading the innate immune system. Viruses with small genomes often achieve this through multifunctional proteins that have roles in both replication and immune evasion, such as the phosphoprotein (P protein) of rabies virus. P protein is an essential cofactor in genome replication and transcription, dependent on the well-folded C-terminal domain (PCTD), which binds to the nucleoprotein (N protein) when complexed with RNA. The PCTD can also bind and antagonize signal transducers and activators of transcription (STAT) proteins, that are essential for activating antiviral mechanisms. Here we show using Nuclear Magnetic Resonance spectroscopy and cell-based assays, that the STAT1-binding and N-binding interfaces are proximal but, nevertheless, it appears that the same molecule of PCTD can simultaneously bind STAT1 and N protein. These data suggest that P-protein-STAT1 interaction, critical to immune evasion, can occur without interrupting interactions underlying replication, and so replication complexes might be directly involved in STAT1 antagonism.
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Phenotypic Divergence of P Proteins of Australian Bat Lyssavirus Lineages Circulating in Microbats and Flying Foxes. Viruses 2021; 13:v13050831. [PMID: 34064444 PMCID: PMC8147779 DOI: 10.3390/v13050831] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/12/2021] [Accepted: 04/18/2021] [Indexed: 12/13/2022] Open
Abstract
Bats are reservoirs of many pathogenic viruses, including the lyssaviruses rabies virus (RABV) and Australian bat lyssavirus (ABLV). Lyssavirus strains are closely associated with particular host reservoir species, with evidence of specific adaptation. Associated phenotypic changes remain poorly understood but are likely to involve phosphoprotein (P protein), a key mediator of the intracellular virus-host interface. Here, we examine the phenotype of P protein of ABLV, which circulates as two defined lineages associated with frugivorous and insectivorous bats, providing the opportunity to compare proteins of viruses adapted to divergent bat species. We report that key functions of P protein in the antagonism of interferon/signal transducers and activators of transcription 1 (STAT1) signaling and the capacity of P protein to undergo nuclear trafficking differ between lineages. Molecular mapping indicates that these differences are functionally distinct and appear to involve modulatory effects on regulatory regions or structural impact rather than changes to defined interaction sequences. This results in partial but significant phenotypic divergence, consistent with "fine-tuning" to host biology, and with potentially distinct properties in the virus-host interface between bat families that represent key zoonotic reservoirs.
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10
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El-Saber Batiha G, Alqahtani A, Ilesanmi OB, Saati AA, El-Mleeh A, Hetta HF, Magdy Beshbishy A. Avermectin Derivatives, Pharmacokinetics, Therapeutic and Toxic Dosages, Mechanism of Action, and Their Biological Effects. Pharmaceuticals (Basel) 2020; 13:ph13080196. [PMID: 32824399 PMCID: PMC7464486 DOI: 10.3390/ph13080196] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/09/2020] [Accepted: 08/13/2020] [Indexed: 12/15/2022] Open
Abstract
Avermectins are a group of drugs that occurs naturally as a product of fermenting Streptomyces avermitilis, an actinomycetes, isolated from the soil. Eight different structures, including ivermectin, abamectin, doramectin, eprinomectin, moxidectin, and selamectin, were isolated and divided into four major components (A1a, A2a, B1a and B2a) and four minor components (A1b, A2b, B1b, and B2b). Avermectins are generally used as a pesticide for the treatment of pests and parasitic worms as a result of their anthelmintic and insecticidal properties. Additionally, they possess anticancer, anti-diabetic, antiviral, antifungal, and are used for treatment of several metabolic disorders. Avermectin generally works by preventing the transmission of electrical impulse in the muscle and nerves of invertebrates, by amplifying the glutamate effects on the invertebrates-specific gated chloride channel. Avermectin has unwanted effects or reactions, especially when administered indiscriminately, which include respiratory failure, hypotension, and coma. The current review examines the mechanism of actions, biosynthesis, safety, pharmacokinetics, biological toxicity and activities of avermectins.
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Affiliation(s)
- Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour 22511, Egypt
- Correspondence: or (G.E.-S.B.); (A.M.B.)
| | - Ali Alqahtani
- Department of Pharmacology, College of Pharmacy, King Khalid University, Guraiger, Abha 62529, Saudi Arabia;
| | - Omotayo B. Ilesanmi
- Department of Biochemistry, Faculty of Science, Federal University Otuoke, Otuoke 561, Nigeria;
| | - Abdullah A. Saati
- Department of Community Medicine & Pilgrims Healthcare, Faculty of Medicine, Umm Al-Qura University Makkah, Mecca 24382, Saudi Arabia;
| | - Amany El-Mleeh
- Department of Pharmacology, Faculty of Veterinary Medicine, Menoufia University, Shibin Al Kawm 32511, Egypt;
| | - Helal F. Hetta
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut 71515, Egypt;
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45221, USA
| | - Amany Magdy Beshbishy
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-13, Inada-cho, Obihiro 080-8555, Hokkaido, Japan
- Correspondence: or (G.E.-S.B.); (A.M.B.)
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11
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Lama Z, Gaudin Y, Blondel D, Lagaudrière-Gesbert C. Kinase inhibitors tyrphostin 9 and rottlerin block early steps of rabies virus cycle. Antiviral Res 2019; 168:51-60. [PMID: 31071352 DOI: 10.1016/j.antiviral.2019.04.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/07/2019] [Accepted: 04/29/2019] [Indexed: 11/26/2022]
Abstract
Rabies virus (RABV) is a neurotropic virus that causes fatal encephalitis in humans and animals and still kills up to 59,000 people worldwide every year. To date, only preventive or post-exposure vaccination protects against the disease but therapeutics are missing. After screening a library of 80 kinases inhibitors, we identified two compounds as potent inhibitors of RABV infection: tyrphostin 9 and rottlerin. Mechanism of action studies show that both inhibitors interfere with an early step of viral cycle and can prevent viral replication. In presence of tyrphostin 9, the viral entry through endocytosis is disturbed leading to improper delivery of viral particles in cytoplasm, whereas rottlerin is inhibiting the transcription, most likely by decreasing intracellular ATP concentration, and therefore the replication of the viral genome.
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Affiliation(s)
- Zoé Lama
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Yves Gaudin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Danielle Blondel
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Cécile Lagaudrière-Gesbert
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.
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12
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Zhan J, Hossain MA, Sethi A, Ose T, Moseley GW, Gooley PR. 1H, 15N and 13C resonance assignments of the C-terminal domain of the P protein of the Nishigahara strain of rabies virus. BIOMOLECULAR NMR ASSIGNMENTS 2019; 13:5-8. [PMID: 30238347 DOI: 10.1007/s12104-018-9841-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 09/14/2018] [Indexed: 06/08/2023]
Abstract
The C-terminal domain of the P protein of rabies virus is a multifunctional domain that interacts with both viral and host cell proteins. Here we report the 1H, 13C and 15N chemical shift assignments of this domain from P protein of the Nishigahara strain of rabies virus, a pathogenic laboratory strain well established for studies of virulence functions of rabies virus proteins, including P protein. The data and secondary structure analysis are in good agreement with the reported predominantly helical structure of the same domain from the CVS strain of rabies solved by crystallography. These assignments will enable future solution studies of the interactions of the P protein with viral and host proteins, and the effects of post-translational modifications.
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Affiliation(s)
- Jingyu Zhan
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Md Alamgir Hossain
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Ashish Sethi
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Toyoyuki Ose
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Gregory W Moseley
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton Campus, Clayton, VIC, 3800, Australia
| | - Paul R Gooley
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia.
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13
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Brice A, Whelan DR, Ito N, Shimizu K, Wiltzer-Bach L, Lo CY, Blondel D, Jans DA, Bell TDM, Moseley GW. Quantitative Analysis of the Microtubule Interaction of Rabies Virus P3 Protein: Roles in Immune Evasion and Pathogenesis. Sci Rep 2016; 6:33493. [PMID: 27649849 PMCID: PMC5030706 DOI: 10.1038/srep33493] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/25/2016] [Indexed: 12/21/2022] Open
Abstract
Although microtubules (MTs) are known to have important roles in intracellular transport of many viruses, a number of reports suggest that specific viral MT-associated proteins (MAPs) target MTs to subvert distinct MT-dependent cellular processes. The precise functional importance of these interactions and their roles in pathogenesis, however, remain largely unresolved. To assess the association with disease of the rabies virus (RABV) MAP, P3, we quantitatively compared the phenotypes of P3 from a pathogenic RABV strain, Nishigahara (Ni) and a non-pathogenic Ni-derivative strain, Ni-CE. Using confocal/live-cell imaging and dSTORM super-resolution microscopy to quantify protein interactions with the MT network and with individual MT filaments, we found that the interaction by Ni-CE-P3 is significantly impaired compared with Ni-P3. This correlated with an impaired capacity to effect association of the transcription factor STAT1 with MTs and to antagonize interferon (IFN)/STAT1-dependent antiviral signaling. Importantly, we identified a single mutation in Ni-CE-P3 that is sufficient to inhibit MT-association and IFN-antagonist function of Ni-P3, and showed that this mutation alone attenuates the pathogenicity of RABV. These data provide evidence that the viral protein-MT interface has important roles in pathogenesis, suggesting that this interface could provide targets for vaccine/antiviral drug development.
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Affiliation(s)
- Aaron Brice
- Viral Pathogenesis Laboratory, Department of Biochemistry and Molecular Biology, Bio21 Institute, The University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Donna R Whelan
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Naoto Ito
- Laboratory of Zoonotic Diseases, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.,The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
| | - Kenta Shimizu
- The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
| | - Linda Wiltzer-Bach
- Nuclear Signaling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia.,Viral Pathogenesis Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Camden Y Lo
- Monash Micro Imaging, 27-31 Wright Street, Clayton, Victoria, 3168, Australia
| | - Danielle Blondel
- Unité de Virologie Moleculaire et Structurale, CNRS, UPR 3296, 91198 Gif sur Yvette Cedex, France
| | - David A Jans
- Nuclear Signaling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Toby D M Bell
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Gregory W Moseley
- Viral Pathogenesis Laboratory, Department of Biochemistry and Molecular Biology, Bio21 Institute, The University of Melbourne, Melbourne, Victoria, 3010, Australia
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14
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Audsley MD, Jans DA, Moseley GW. Roles of nuclear trafficking in infection by cytoplasmic negative-strand RNA viruses: paramyxoviruses and beyond. J Gen Virol 2016; 97:2463-2481. [PMID: 27498841 DOI: 10.1099/jgv.0.000575] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Genome replication and virion production by most negative-sense RNA viruses (NSVs) occurs exclusively in the cytoplasm, but many NSV-expressed proteins undergo active nucleocytoplasmic trafficking via signals that exploit cellular nuclear transport pathways. Nuclear trafficking has been reported both for NSV accessory proteins (including isoforms of the rabies virus phosphoprotein, and V, W and C proteins of paramyxoviruses) and for structural proteins. Trafficking of the former is thought to enable accessory functions in viral modulation of antiviral responses including the type I IFN system, but the intranuclear roles of structural proteins such as nucleocapsid and matrix proteins, which have critical roles in extranuclear replication and viral assembly, are less clear. Nevertheless, nuclear trafficking of matrix protein has been reported to be critical for efficient production of Nipah virus and Respiratory syncytial virus, and nuclear localization of nucleocapsid protein of several morbilliviruses has been linked to mechanisms of immune evasion. Together, these data point to the nucleus as a significant host interface for viral proteins during infection by NSVs with otherwise cytoplasmic life cycles. Importantly, several lines of evidence now suggest that nuclear trafficking of these proteins may be critical to pathogenesis and thus could provide new targets for vaccine development and antiviral therapies.
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Affiliation(s)
- Michelle D Audsley
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - David A Jans
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Gregory W Moseley
- Department of Biochemistry and Molecular Biology, BIO21 Molecular Science and Biotechnology Institute, University of Melbourne, VIC 3000, Australia
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15
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Ito N, Moseley GW, Sugiyama M. The importance of immune evasion in the pathogenesis of rabies virus. J Vet Med Sci 2016; 78:1089-98. [PMID: 27041139 PMCID: PMC4976263 DOI: 10.1292/jvms.16-0092] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Rabies is a zoonotic disease caused by the Lyssavirus rabies virus
(RABV) that can infect most mammals, including humans, where it has a case-fatality rate
of almost 100%. Although preventable by vaccination, rabies causes c. 59,000 human
fatalities every year worldwide. Thus, there exists an urgent need to establish an
effective therapy and/or improve dissemination of vaccines for humans and animals. These
outcomes require greater understanding of the mechanisms of RABV pathogenesis to identify
new molecular targets for the development of therapeutics and/or live vaccines with high
levels of safety. Importantly, a number of studies in recent years have indicated that
RABV specifically suppresses host immunity through diverse mechanisms and that this is a
key process in pathogenicity. Here, we review current understanding of immune modulation
by RABV, with an emphasis on its significance to pathogenicity and the potential
exploitation of this knowledge to develop new vaccines and antivirals.
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Affiliation(s)
- Naoto Ito
- Laboratory of Zoonotic Diseases, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1193, Japan
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16
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Nuclear Trafficking of the Rabies Virus Interferon Antagonist P-Protein Is Regulated by an Importin-Binding Nuclear Localization Sequence in the C-Terminal Domain. PLoS One 2016; 11:e0150477. [PMID: 26939125 PMCID: PMC4777398 DOI: 10.1371/journal.pone.0150477] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 02/14/2016] [Indexed: 12/25/2022] Open
Abstract
Rabies virus P-protein is expressed as five isoforms (P1-P5) which undergo nucleocytoplasmic trafficking important to roles in immune evasion. Although nuclear import of P3 is known to be mediated by an importin (IMP)-recognised nuclear localization sequence in the N-terminal region (N-NLS), the mechanisms underlying nuclear import of other P isoforms in which the N-NLS is inactive or has been deleted have remained unresolved. Based on the previous observation that mutation of basic residues K214/R260 of the P-protein C-terminal domain (P-CTD) can result in nuclear exclusion of P3, we used live cell imaging, protein interaction analysis and in vitro nuclear transport assays to examine in detail the nuclear trafficking properties of this domain. We find that the effect of mutation of K214/R260 on P3 is largely dependent on nuclear export, suggesting that nuclear exclusion of mutated P3 involves the P-CTD-localized nuclear export sequence (C-NES). However, assays using cells in which nuclear export is pharmacologically inhibited indicate that these mutations significantly inhibit P3 nuclear accumulation and, importantly, prevent nuclear accumulation of P1, suggestive of effects on NLS-mediated import activity in these isoforms. Consistent with this, molecular binding and transport assays indicate that the P-CTD mediates IMPα2/IMPβ1-dependent nuclear import by conferring direct binding to the IMPα2/IMPβ1 heterodimer, as well as to a truncated form of IMPα2 lacking the IMPβ-binding autoinhibitory domain (ΔIBB-IMPα2), and IMPβ1 alone. These properties are all dependent on K214 and R260. This provides the first evidence that P-CTD contains a genuine IMP-binding NLS, and establishes the mechanism by which P-protein isoforms other than P3 can be imported to the nucleus. These data underpin a refined model for P-protein trafficking that involves the concerted action of multiple NESs and IMP-binding NLSs, and highlight the intricate regulation of P-protein subcellular localization, consistent with important roles in infection.
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17
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Ross NL, Sullivan MO. Importin-4 Regulates Gene Delivery by Enhancing Nuclear Retention and Chromatin Deposition by Polyplexes. Mol Pharm 2015; 12:4488-97. [PMID: 26465823 PMCID: PMC4733562 DOI: 10.1021/acs.molpharmaceut.5b00645] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
For successful gene delivery, plasmid DNA must be able to access the nucleus in order to be transcribed. Numerous studies have shown that gene delivery occurs more readily in dividing cells, which is attributed to increased nuclear access when the nuclear envelope disassembles during mitosis; however, nonviral carriers continue to have low transfection efficiencies and require large quantities of DNA per cell to achieve reasonable gene transfer, even in dividing cells. Therefore, we hypothesized that using histone-derived nuclear localization sequences (NLS)s to target polyplexes might enhance nuclear delivery by facilitating interactions with histone effectors that mediate nuclear partitioning and retention during mitosis. We discovered a novel interaction between polyplexes linked to histone 3 (H3) N-terminal tail peptides and the histone nuclear import protein importin-4, as evidenced by strong spatial colocalization as well as significantly decreased transfection when importin-4 expression was reduced. A fraction of the histone-targeted polyplexes was also found to colocalize with the retrotranslocon of the endoplasmic reticulum, Sec61. Super resolution microscopy demonstrated a high level of polyplex binding to chromatin postmitosis, and there also was a significant decrease in the amount of chromatin binding following importin-4 knockdown. These results provide evidence that natural histone effectors mediate both nuclear entry and deposition on chromatin by histone-targeted polyplexes, and a translocation event from the endoplasmic reticulum into the cytosol may occur before mitosis to enable the polyplexes to interact with these essential cytoplasmic proteins.
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Affiliation(s)
- Nikki L Ross
- Department of Chemical and Biomolecular Engineering, University of Delaware , 150 Academy Street, Newark, Delaware 19716, United States
| | - Millicent O Sullivan
- Department of Chemical and Biomolecular Engineering, University of Delaware , 150 Academy Street, Newark, Delaware 19716, United States
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18
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Blondel D, Maarifi G, Nisole S, Chelbi-Alix MK. Resistance to Rhabdoviridae Infection and Subversion of Antiviral Responses. Viruses 2015; 7:3675-702. [PMID: 26198243 PMCID: PMC4517123 DOI: 10.3390/v7072794] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 06/29/2015] [Accepted: 07/01/2015] [Indexed: 12/13/2022] Open
Abstract
Interferon (IFN) treatment induces the expression of hundreds of IFN-stimulated genes (ISGs). However, only a selection of their products have been demonstrated to be responsible for the inhibition of rhabdovirus replication in cultured cells; and only a few have been shown to play a role in mediating the antiviral response in vivo using gene knockout mouse models. IFNs inhibit rhabdovirus replication at different stages via the induction of a variety of ISGs. This review will discuss how individual ISG products confer resistance to rhabdoviruses by blocking viral entry, degrading single stranded viral RNA, inhibiting viral translation or preventing release of virions from the cell. Furthermore, this review will highlight how these viruses counteract the host IFN system.
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Affiliation(s)
- Danielle Blondel
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS UMR 9198, Université Paris-Sud, Gif-sur-Yvette 91190, France.
| | - Ghizlane Maarifi
- INSERM UMR-S 1124, Université Paris Descartes, Centre Interdisciplinaire Chimie Biologie-Paris (FR 3567, CNRS), 75270 Paris Cedex 6, France.
| | - Sébastien Nisole
- INSERM UMR-S 1124, Université Paris Descartes, Centre Interdisciplinaire Chimie Biologie-Paris (FR 3567, CNRS), 75270 Paris Cedex 6, France.
| | - Mounira K Chelbi-Alix
- INSERM UMR-S 1124, Université Paris Descartes, Centre Interdisciplinaire Chimie Biologie-Paris (FR 3567, CNRS), 75270 Paris Cedex 6, France.
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19
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Oksayan S, Nikolic J, David CT, Blondel D, Jans DA, Moseley GW. Identification of a role for nucleolin in rabies virus infection. J Virol 2015; 89:1939-43. [PMID: 25428867 PMCID: PMC4300734 DOI: 10.1128/jvi.03320-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 11/17/2014] [Indexed: 12/24/2022] Open
Abstract
Rabies virus replicates in the cytoplasm of host cells, but rabies virus phosphoprotein (P-protein) undergoes active nucleocytoplasmic trafficking. Here we show that the largely nuclear P-protein isoform P3 can localize to nucleoli and forms specific interactions with nucleolin. Importantly, depletion of nucleolin expression inhibits viral protein expression and infectious virus production by infected cells. This provides the first evidence that lyssaviruses interact with nucleolin and that nucleolin is important to lyssavirus infection.
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Affiliation(s)
- S Oksayan
- Viral Pathogenesis Laboratory, Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - J Nikolic
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, Gif-sur-Yvette, France
| | - C T David
- Viral Pathogenesis Laboratory, Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia
| | - D Blondel
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, Gif-sur-Yvette, France
| | - D A Jans
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - G W Moseley
- Viral Pathogenesis Laboratory, Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia
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20
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Wongabel rhabdovirus accessory protein U3 targets the SWI/SNF chromatin remodeling complex. J Virol 2014; 89:1377-88. [PMID: 25392228 DOI: 10.1128/jvi.02010-14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
UNLABELLED Wongabel virus (WONV) is an arthropod-borne rhabdovirus that infects birds. It is one of the growing array of rhabdoviruses with complex genomes that encode multiple accessory proteins of unknown function. In addition to the five canonical rhabdovirus structural protein genes (N, P, M, G, and L), the 13.2-kb negative-sense single-stranded RNA (ssRNA) WONV genome contains five uncharacterized accessory genes, one overlapping the N gene (Nx or U4), three located between the P and M genes (U1 to U3), and a fifth one overlapping the G gene (Gx or U5). Here we show that WONV U3 is expressed during infection in insect and mammalian cells and is required for efficient viral replication. A yeast two-hybrid screen against a mosquito cell cDNA library identified that WONV U3 interacts with the 83-amino-acid (aa) C-terminal domain of SNF5, a component of the SWI/SNF chromatin remodeling complex. The interaction was confirmed by affinity chromatography, and nuclear colocalization was established by confocal microscopy. Gene expression studies showed that SNF5 transcripts are upregulated during infection of mosquito cells with WONV, as well as West Nile virus (Flaviviridae) and bovine ephemeral fever virus (Rhabdoviridae), and that SNF5 knockdown results in increased WONV replication. WONV U3 also inhibits SNF5-regulated expression of the cytokine gene CSF1. The data suggest that WONV U3 targets the SWI/SNF complex to block the host response to infection. IMPORTANCE The rhabdoviruses comprise a large family of RNA viruses infecting plants, vertebrates, and invertebrates. In addition to the major structural proteins (N, P, M, G, and L), many rhabdoviruses encode a diverse array of accessory proteins of largely unknown function. Understanding the role of these proteins may reveal much about host-pathogen interactions in infected cells. Here we examine accessory protein U3 of Wongabel virus, an arthropod-borne rhabdovirus that infects birds. We show that U3 enters the nucleus and interacts with SNF5, a component of the chromatin remodeling complex that is upregulated in response to infection and restricts viral replication. We also show that U3 inhibits SNF5-regulated expression of the cytokine colony-stimulating factor 1 (CSF1), suggesting that it targets the chromatin remodeling complex to block the host response to infection. This study appears to provide the first evidence of a virus targeting SNF5 to inhibit host gene expression.
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21
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Lokich E, Singh RK, Han A, Romano N, Yano N, Kim K, Moore RG. HE4 expression is associated with hormonal elements and mediated by importin-dependent nuclear translocation. Sci Rep 2014; 4:5500. [PMID: 24975515 PMCID: PMC4074789 DOI: 10.1038/srep05500] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 06/13/2014] [Indexed: 12/20/2022] Open
Abstract
Antiestrogens including tamoxifen and fulvestrant have been evaluated as chemotherapeutics for ovarian cancer, particularly in cases of platinum resistant disease. Human epididymis protein 4 (HE4) is highly overexpressed in women with ovarian cancer and overexpression of HE4 has been found to correlate with platinum resistance. However, the role of HE4 in modulating responses to hormones and hormonal therapy has not been characterized in ovarian cancer. Here we demonstrate that 17β-estradiol, tamoxifen, and fulvestrant induce nuclear and nucleolar translocation of HE4 and that HE4 overexpression induces resistance to antiestrogens. HE4 was found to interact with estrogen receptor-α (ER-α), and HE4 overexpression resulted in ER-α downregulation in vitro and in human ovarian cancers. We identified a novel role for importin-4 in governing the nuclear transport of HE4. Treatment with ivermectin, an importin inhibitor, blocked HE4/importin-4 nuclear accumulation and sensitized HE4-overexpressing ovarian cancer cells to fulvestrant and tamoxifen.
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Affiliation(s)
- Elizabeth Lokich
- 1] Program in Women's Oncology, Department of Obstetrics and Gynecology, Women and Infants' Hospital, Alpert Medical School at Brown University, Providence, RI, 02905, USA [2]
| | - Rakesh K Singh
- Program in Women's Oncology, Department of Obstetrics and Gynecology, Women and Infants' Hospital, Alpert Medical School at Brown University, Providence, RI, 02905, USA
| | - Alex Han
- 1] Program in Women's Oncology, Department of Obstetrics and Gynecology, Women and Infants' Hospital, Alpert Medical School at Brown University, Providence, RI, 02905, USA [2]
| | - Nicole Romano
- Program in Women's Oncology, Department of Obstetrics and Gynecology, Women and Infants' Hospital, Alpert Medical School at Brown University, Providence, RI, 02905, USA
| | - Naohiro Yano
- Program in Women's Oncology, Department of Obstetrics and Gynecology, Women and Infants' Hospital, Alpert Medical School at Brown University, Providence, RI, 02905, USA
| | - Kyukwang Kim
- Program in Women's Oncology, Department of Obstetrics and Gynecology, Women and Infants' Hospital, Alpert Medical School at Brown University, Providence, RI, 02905, USA
| | - Richard G Moore
- Program in Women's Oncology, Department of Obstetrics and Gynecology, Women and Infants' Hospital, Alpert Medical School at Brown University, Providence, RI, 02905, USA
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22
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Martinez N, Ribeiro EA, Leyrat C, Tarbouriech N, Ruigrok RWH, Jamin M. Structure of the C-terminal domain of lettuce necrotic yellows virus phosphoprotein. J Virol 2013; 87:9569-78. [PMID: 23785215 PMCID: PMC3754093 DOI: 10.1128/jvi.00999-13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 06/14/2013] [Indexed: 12/26/2022] Open
Abstract
Lettuce necrotic yellows virus (LNYV) is a prototype of the plant-adapted cytorhabdoviruses. Through a meta-prediction of disorder, we localized a folded C-terminal domain in the amino acid sequence of its phosphoprotein. This domain consists of an autonomous folding unit that is monomeric in solution. Its structure, solved by X-ray crystallography, reveals a lollipop-shaped structure comprising five helices. The structure is different from that of the corresponding domains of other Rhabdoviridae, Filoviridae, and Paramyxovirinae; only the overall topology of the polypeptide chain seems to be conserved, suggesting that this domain evolved under weak selective pressure and varied in size by the acquisition or loss of functional modules.
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Affiliation(s)
- Nicolas Martinez
- Université Grenoble Alpes, UVHCI, Grenoble, France
- CNRS, UVHCI, Grenoble, France
- Unit for Virus Host-Cell Interactions, Université Grenoble Alpes-EMBL-CNRS, Grenoble, France
- Institut Laue Langevin, Grenoble, France
| | - Euripedes A. Ribeiro
- Université Grenoble Alpes, UVHCI, Grenoble, France
- CNRS, UVHCI, Grenoble, France
- Unit for Virus Host-Cell Interactions, Université Grenoble Alpes-EMBL-CNRS, Grenoble, France
| | - Cédric Leyrat
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Nicolas Tarbouriech
- Université Grenoble Alpes, UVHCI, Grenoble, France
- CNRS, UVHCI, Grenoble, France
- Unit for Virus Host-Cell Interactions, Université Grenoble Alpes-EMBL-CNRS, Grenoble, France
| | - Rob W. H. Ruigrok
- Université Grenoble Alpes, UVHCI, Grenoble, France
- CNRS, UVHCI, Grenoble, France
- Unit for Virus Host-Cell Interactions, Université Grenoble Alpes-EMBL-CNRS, Grenoble, France
| | - Marc Jamin
- Université Grenoble Alpes, UVHCI, Grenoble, France
- CNRS, UVHCI, Grenoble, France
- Unit for Virus Host-Cell Interactions, Université Grenoble Alpes-EMBL-CNRS, Grenoble, France
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23
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Venugopal AK, Ghantasala SSK, Selvan LDN, Mahadevan A, Renuse S, Kumar P, Pawar H, Sahasrabhuddhe NA, Suja MS, Ramachandra YL, Prasad TSK, Madhusudhana SN, HC H, Chaerkady R, Satishchandra P, Pandey A, Shankar SK. Quantitative proteomics for identifying biomarkers for Rabies. Clin Proteomics 2013; 10:3. [PMID: 23521751 PMCID: PMC3660221 DOI: 10.1186/1559-0275-10-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 03/14/2013] [Indexed: 12/25/2022] Open
Abstract
INTRODUCTION Rabies is a fatal acute viral disease of the central nervous system, which is a serious public health problem in Asian and African countries. Based on the clinical presentation, rabies can be classified into encephalitic (furious) or paralytic (numb) rabies. Early diagnosis of this disease is particularly important as rabies is invariably fatal if adequate post exposure prophylaxis is not administered immediately following the bite. METHODS In this study, we carried out a quantitative proteomic analysis of the human brain tissue from cases of encephalitic and paralytic rabies along with normal human brain tissues using an 8-plex isobaric tags for relative and absolute quantification (iTRAQ) strategy. RESULTS AND CONCLUSION We identified 402 proteins, of which a number of proteins were differentially expressed between encephalitic and paralytic rabies, including several novel proteins. The differentially expressed molecules included karyopherin alpha 4 (KPNA4), which was overexpressed only in paralytic rabies, calcium calmodulin dependent kinase 2 alpha (CAMK2A), which was upregulated in paralytic rabies group and glutamate ammonia ligase (GLUL), which was overexpressed in paralytic as well as encephalitic rabies. We validated two of the upregulated molecules, GLUL and CAMK2A, by dot blot assays and further validated CAMK2A by immunohistochemistry. These molecules need to be further investigated in body fluids such as cerebrospinal fluid in a larger cohort of rabies cases to determine their potential use as antemortem diagnostic biomarkers in rabies. This is the first study to systematically profile clinical subtypes of human rabies using an iTRAQ quantitative proteomics approach.
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Affiliation(s)
- Abhilash K Venugopal
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India
- Department of Biotechnology, Kuvempu University, Shimoga, 577451, India
| | - S Sameer Kumar Ghantasala
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India
- Department of Biotechnology, Kuvempu University, Shimoga, 577451, India
| | - Lakshmi Dhevi N Selvan
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam, 690525, India
| | - Anita Mahadevan
- Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
| | - Santosh Renuse
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam, 690525, India
| | - Praveen Kumar
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India
| | - Harsh Pawar
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India
- Rajiv Gandhi University of Health Sciences, Bangalore, 560041, India
| | - Nandini A Sahasrabhuddhe
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India
- Manipal University, Madhav Nagar, Manipal, Karnataka, 576104, India
| | - Mooriyath S Suja
- Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
| | | | - Thottethodi S Keshava Prasad
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam, 690525, India
- Manipal University, Madhav Nagar, Manipal, Karnataka, 576104, India
- Bioinformatics Centre, School of Life Sciences, Pondicherry University, Pondicherry, 605014, India
| | - Shampur N Madhusudhana
- Department of Neurovirology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
| | - Harsha HC
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India
| | - Raghothama Chaerkady
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India
| | | | - Akhilesh Pandey
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, 733 N. Broadway, BRB 527, Baltimore, MD, 21205, USA
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Susarla K Shankar
- Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
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Brice A, Moseley GW. Viral interactions with microtubules: orchestrators of host cell biology? Future Virol 2013. [DOI: 10.2217/fvl.12.137] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Viral interaction with the microtubule (MT) cytoskeleton is critical to infection by many viruses. Most data regarding virus–MT interaction indicate key roles in the subcellular transport of virions/viral genomic material to sites of replication, assembly and egress. However, the MT cytoskeleton orchestrates diverse processes in addition to subcellular cargo transport, including regulation of signaling pathways, cell survival and mitosis, suggesting that viruses, expert manipulators of the host cell, may use the virus–MT interface to control multiple aspects of cell biology. Several lines of evidence support this idea, indicating that specific viral proteins can modify MT dynamics and/or structure and regulate processes such as apoptosis and innate immune signaling through MT-dependent mechanisms. Here, the authors review general aspects of virus–MT interactions, with emphasis on viral mechanisms that modify MT dynamics and functions to affect processes beyond virion transport. The emerging importance of discrete viral protein–MT interactions in pathogenic processes indicates that these interfaces may represent new targets for future therapeutics and vaccine development.
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Affiliation(s)
- Aaron Brice
- Viral Immune Evasion & Pathogenicity Laboratory, Department of Biochemistry & Molecular Biology, Monash University, Victoria 3800, Australia
| | - Gregory W Moseley
- Viral Immune Evasion & Pathogenicity Laboratory, Department of Biochemistry & Molecular Biology, Monash University, Victoria 3800, Australia.
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25
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Oksayan S, Wiltzer L, Rowe CL, Blondel D, Jans DA, Moseley GW. A novel nuclear trafficking module regulates the nucleocytoplasmic localization of the rabies virus interferon antagonist, P protein. J Biol Chem 2012; 287:28112-21. [PMID: 22700958 PMCID: PMC3431689 DOI: 10.1074/jbc.m112.374694] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 06/13/2012] [Indexed: 12/25/2022] Open
Abstract
Regulated nucleocytoplasmic transport of proteins is central to cellular function and dysfunction during processes such as viral infection. Active protein trafficking into and out of the nucleus is dependent on the presence within cargo proteins of intrinsic specific modular signals for nuclear import (nuclear localization signals, NLSs) and export (nuclear export signals, NESs). Rabies virus (RabV) phospho (P) protein, which is largely responsible for antagonising the host anti-viral response, is expressed as five isoforms (P1-P5). The subcellular trafficking of these isoforms is thought to depend on a balance between the activities of a dominant N-terminal NES (N-NES) and a distinct C-terminal NLS (C-NLS). Specifically, the N-NES-containing isoforms P1 and P2 are cytoplasmic, whereas the shorter P3-P5 isoforms, which lack the N-NES, are believed to be nuclear through the activity of the C-NLS. Here, we show for the first time that RabV P contains an additional strong NLS in the N-terminal region (N-NLS), which, intriguingly, overlaps with the N-NES. This arrangement represents a novel nuclear trafficking module where the N-NLS is inactive in P1 but becomes activated in P3, concomitant with truncation of the N-NES, to become the principal targeting signal conferring nuclear accumulation. Understanding this unique switch arrangement of overlapping, co-regulated NES/NLS sequences is vital to delineating the critical role of RabV P protein in viral infection.
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Affiliation(s)
- Sibil Oksayan
- From the Viral Immune Evasion and Pathogenicity Laboratory and
- Nuclear Signaling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, 3800 Victoria, Australia and
| | - Linda Wiltzer
- From the Viral Immune Evasion and Pathogenicity Laboratory and
- Nuclear Signaling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, 3800 Victoria, Australia and
| | - Caitlin L. Rowe
- From the Viral Immune Evasion and Pathogenicity Laboratory and
- Nuclear Signaling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, 3800 Victoria, Australia and
| | - Danielle Blondel
- the Laboratoire de Virologie Moléculaire et Structurale, Centre de Recherche de Gif, CNRS 91198 Gif-sur-Yvette, France
| | - David A. Jans
- Nuclear Signaling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, 3800 Victoria, Australia and
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26
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Abstract
The evasion of host innate immunity by Rabies virus, the prototype of the genus Lyssavirus, depends on a unique mechanism of selective targeting of interferon-activated STAT proteins by the viral phosphoprotein (P-protein). However, the immune evasion strategies of other lyssaviruses, including several lethal human pathogens, are unresolved. Here, we show that this mechanism is conserved between the most distantly related members of the genus, providing important insights into the pathogenesis and potential therapeutic targeting of lyssaviruses.
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Ivermectin is a specific inhibitor of importin α/β-mediated nuclear import able to inhibit replication of HIV-1 and dengue virus. Biochem J 2012; 443:851-6. [PMID: 22417684 PMCID: PMC3327999 DOI: 10.1042/bj20120150] [Citation(s) in RCA: 476] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The movement of proteins between the cytoplasm and nucleus mediated by the importin superfamily of proteins is essential to many cellular processes, including differentiation and development, and is critical to disease states such as viral disease and oncogenesis. We recently developed a high-throughput screen to identify specific and general inhibitors of protein nuclear import, from which ivermectin was identified as a potential inhibitor of importin α/β-mediated transport. In the present study, we characterized in detail the nuclear transport inhibitory properties of ivermectin, demonstrating that it is a broad-spectrum inhibitor of importin α/β nuclear import, with no effect on a range of other nuclear import pathways, including that mediated by importin β1 alone. Importantly, we establish for the first time that ivermectin has potent antiviral activity towards both HIV-1 and dengue virus, both of which are strongly reliant on importin α/β nuclear import, with respect to the HIV-1 integrase and NS5 (non-structural protein 5) polymerase proteins respectively. Ivermectin would appear to be an invaluable tool for the study of protein nuclear import, as well as the basis for future development of antiviral agents.
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28
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Walker PJ, Dietzgen RG, Joubert DA, Blasdell KR. Rhabdovirus accessory genes. Virus Res 2011; 162:110-25. [PMID: 21933691 PMCID: PMC7114375 DOI: 10.1016/j.virusres.2011.09.004] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 09/02/2011] [Accepted: 09/04/2011] [Indexed: 12/16/2022]
Abstract
The Rhabdoviridae is one of the most ecologically diverse families of RNA viruses with members infecting a wide range of organisms including placental mammals, marsupials, birds, reptiles, fish, insects and plants. The availability of complete nucleotide sequences for an increasing number of rhabdoviruses has revealed that their ecological diversity is reflected in the diversity and complexity of their genomes. The five canonical rhabdovirus structural protein genes (N, P, M, G and L) that are shared by all rhabdoviruses are overprinted, overlapped and interspersed with a multitude of novel and diverse accessory genes. Although not essential for replication in cell culture, several of these genes have been shown to have roles associated with pathogenesis and apoptosis in animals, and cell-to-cell movement in plants. Others appear to be secreted or have the characteristics of membrane-anchored glycoproteins or viroporins. However, most encode proteins of unknown function that are unrelated to any other known proteins. Understanding the roles of these accessory genes and the strategies by which rhabdoviruses use them to engage, divert and re-direct cellular processes will not only present opportunities to develop new anti-viral therapies but may also reveal aspects of cellar function that have broader significance in biology, agriculture and medicine.
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Affiliation(s)
- Peter J Walker
- CSIRO Livestock Industries, Australian Animal Health Laboratory, 5 Portarlington Road, Geelong, VIC 3220, Australia.
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29
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Gerlier D, Lyles DS. Interplay between innate immunity and negative-strand RNA viruses: towards a rational model. Microbiol Mol Biol Rev 2011; 75:468-90, second page of table of contents. [PMID: 21885681 PMCID: PMC3165544 DOI: 10.1128/mmbr.00007-11] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The discovery of a new class of cytosolic receptors recognizing viral RNA, called the RIG-like receptors (RLRs), has revolutionized our understanding of the interplay between viruses and host cells. A tremendous amount of work has been accumulating to decipher the RNA moieties required for an RLR agonist, the signal transduction pathway leading to activation of the innate immunity orchestrated by type I interferon (IFN), the cellular and viral regulators of this pathway, and the viral inhibitors of the innate immune response. Previous reviews have focused on the RLR signaling pathway and on the negative regulation of the interferon response by viral proteins. The focus of this review is to put this knowledge in the context of the virus replication cycle within a cell. Likewise, there has been an expansion of knowledge about the role of innate immunity in the pathophysiology of viral infection. As a consequence, some discrepancies have arisen between the current models of cell-intrinsic innate immunity and current knowledge of virus biology. This holds particularly true for the nonsegmented negative-strand viruses (Mononegavirales), which paradoxically have been largely used to build presently available models. The aim of this review is to bridge the gap between the virology and innate immunity to favor the rational building of a relevant model(s) describing the interplay between Mononegavirales and the innate immune system.
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Affiliation(s)
- Denis Gerlier
- INSERM U758, CERVI, 21 avenue Tony Garnier, 69007 Lyon, France.
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30
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Abstract
Rabies is among the longest known and most dangerous and feared infectious diseases for humans and animals and still is responsible for tenth of thousands of human deaths per year. The rabies virus (RABV) is a rather atypical member of the Rhabdoviridae family as it has completely adapted during evolution to warm-blooded hosts and is directly transmitted between them, whereas most other rhabdoviruses are transmitted by insect vectors. The virus is also unique with respect to its extremely broad host species range and a very narrow host organ range, namely its strict neurotropism. It is becoming increasingly clear that the host innate immune system, particularly the type I interferon system, and the viral counteractions profoundly shape this virus-host relationship. In the past few years, exciting new insight was obtained on how viruses are sensed by innate immune receptors, how the downstream signaling networks for activation of interferon are working, and how viruses can interfere with the system. While RABV 5'-triphosphate RNAs were identified as the major pathogen-associated molecular pattern sensed by cytoplasmic RIG-I-like receptors (RLR), the RABV phosphoprotein (P) has emerged as a potent multifunctional antagonist able to counteract the signaling cascades leading to transcriptional activation of interferon genes as well as interferon signaling pathways, thereby limiting expression of antiviral and immune-stimulatory genes.
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Affiliation(s)
- Martina Rieder
- Max von Pettenkofer Institute and Gene Center, Ludwig-Maximilians-University Munich, Munich, Germany
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31
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Wagstaff KM, Rawlinson SM, Hearps AC, Jans DA. An AlphaScreen®-based assay for high-throughput screening for specific inhibitors of nuclear import. ACTA ACUST UNITED AC 2011; 16:192-200. [PMID: 21297106 DOI: 10.1177/1087057110390360] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Specific viral proteins enter the nucleus of infected cells to perform essential functions, as part of the viral life cycle. The integrase (IN) molecule of human immunodeficiency virus (HIV)-1 is of particular interest in this context due to its integral role in integrating the HIV genome into that of the infected host cell. Most IN-based antiviral compounds target the IN/DNA interaction, but since IN must first enter the nucleus before it can perform these critical functions, nuclear transport of IN is also an attractive target for therapeutic intervention. Here the authors describe a novel high-throughput screening assay for identifying inhibitors of nuclear import, particularly IN, based on amplified luminescent proximity homogeneous assay (AlphaScreen(®)) technology, which is high throughput, requires low amounts of material, and is efficient and cost-effective. The authors use the assay to screen for specific inhibitors of the interaction between IN and its nuclear transport receptor importin α/β, successfully identifying several inhibitors of the IN/importin α/β interaction. Importantly, they demonstrate that one of the identified compounds, mifepristone, is effective in preventing active nuclear transport of IN in transfected cells and hence may represent a useful anti-HIV therapeutic. The screen also identified broad-spectrum importin α/β inhibitors such as ivermectin, which may represent useful tools for nuclear transport research in the future. The authors validate the activity and specificity of mifepristone and ivermectin in inhibiting nuclear protein import in living cells, underlining the utility of the screening approach.
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Affiliation(s)
- Kylie M Wagstaff
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
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32
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Regulation of nucleocytoplasmic trafficking of viral proteins: an integral role in pathogenesis? BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:2176-90. [PMID: 21530593 PMCID: PMC7114211 DOI: 10.1016/j.bbamcr.2011.03.019] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 03/15/2011] [Accepted: 03/30/2011] [Indexed: 12/24/2022]
Abstract
Signal-dependent targeting of proteins into and out of the nucleus is mediated by members of the importin (IMP) family of transport receptors, which recognise targeting signals within a cargo protein and mediate passage through the nuclear envelope-embedded nuclear pore complexes. Regulation of this process is paramount to processes such as cell division and differentiation, but is also critically important for viral replication and pathogenesis; phosphorylation appears to play a major role in regulating viral protein nucleocytoplasmic trafficking, along with other posttranslational modifications. This review focuses on viral proteins that utilise the host cell IMP machinery in order to traffic into/out of the nucleus, and in particular those where trafficking is critical to viral replication and/or pathogenesis, such as simian virus SV40 large tumour antigen (T-ag), human papilloma virus E1 protein, human cytomegalovirus processivity factor ppUL44, and various gene products from RNA viruses such as Rabies. Understanding of the mechanisms regulating viral protein nucleocytoplasmic trafficking is paramount to the future development of urgently needed specific and effective anti-viral therapeutics. This article was originally intended for the special issue "Regulation of Signaling and Cellular Fate through Modulation of Nuclear Protein Import". The Publisher apologizes for any inconvenience caused.
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33
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Leyrat C, Ribeiro EA, Gérard FCA, Ivanov I, Ruigrok RWH, Jamin M. Structure, interactions with host cell and functions of rhabdovirus phosphoprotein. Future Virol 2011. [DOI: 10.2217/fvl.11.10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Rabies is an incurable albeit preventable disease that remains an important human health issue, with the number of deaths exceeding 50,000 people each year. Its causative agent, the rabies virus, is a negative-sense RNA virus, the genome of which encodes five proteins. Three of these proteins, the nucleoprotein, the phosphoprotein (P) and the large protein, are required to synthesize viral RNA in an efficient and regulated manner. P plays multiple roles during the transcription and replication of the RNA genome. It acts as a noncatalytic cofactor of the large protein polymerase and it chaperones nucleoprotein. Recent structural characterizations of rabies virus P revealed that P forms elongated and flexible dimers and uncovered the structural basis of its modular organization, revealing the existence of two independent structured domains and two long intrinsically disordered regions. In addition, recent studies also revealed that P interacts with nucleocytoplasmic trafficking carriers and with the host cell cytoskeleton, probably allowing viral components to be transported within the host cell and blocking the innate immune response by inhibiting different steps of the interferon pathway. With multiple binding sites for different viral and cellular partners located in either its structured or disordered regions, P appears to be a flexible ‘hub’ protein that connects viral or cellular proteins and allows their assembly into multimolecular complexes. These new findings shed light on the mechanism of replication of the virus and on the intimate interactions between the virus and its host cell, and will also help to identify new targets for the development of antiviral treatments.
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Affiliation(s)
- Cédric Leyrat
- UMI 3265 UJF-EMBL-CNRS, Unit of Virus Host Cell Interactions, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France
| | - Euripedes A Ribeiro
- UMI 3265 UJF-EMBL-CNRS, Unit of Virus Host Cell Interactions, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France
| | - Francine CA Gérard
- UMI 3265 UJF-EMBL-CNRS, Unit of Virus Host Cell Interactions, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France
| | - Ivan Ivanov
- UMI 3265 UJF-EMBL-CNRS, Unit of Virus Host Cell Interactions, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France
| | - Rob WH Ruigrok
- UMI 3265 UJF-EMBL-CNRS, Unit of Virus Host Cell Interactions, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France
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34
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Marschalek A, Drechsel L, Conzelmann KK. The importance of being short: the role of rabies virus phosphoprotein isoforms assessed by differential IRES translation initiation. Eur J Cell Biol 2011; 91:17-23. [PMID: 21397980 DOI: 10.1016/j.ejcb.2011.01.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 01/23/2011] [Indexed: 10/18/2022] Open
Abstract
The rabies virus (RV) phosphoprotein P is a multifunctional protein involved in viral RNA synthesis and in counteracting host innate immune responses. We have previously shown that RV P gene expression levels can be regulated by using picornavirus internal ribosome entry site (IRES) elements. Here we exploited a particular feature of the foot-and-mouth disease virus (FMDV) IRES, namely, preferential initiation at a downstream initiation codon, to address the role of N-terminally truncated RV phosphoproteins usually generated in RV-infected cells through ribosomal leaky scanning. Recombinant RVs in which P synthesis was directed by the poliovirus or FMDV IRES produced full-length P (P1) or a truncated form (P2), as the dominant product, respectively. While the P2 overexpressing virus showed attenuated growth in interferon-incompetent cells, it was superior to the P1 overexpressing virus in preventing expression of host interferon-stimulated genes. This indicates that in RV infected cells the availability of the truncated P2 protein is critical for viral resistance to interferon.
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Affiliation(s)
- Adriane Marschalek
- Max von Pettenkofer-Institute & Gene Center, Ludwig-Maximilians-University Munich, Feodor-Lynen-Strasse 25, Munich, Germany
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35
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Nadin-Davis SA, Fehlner-Gardiner C, Sheen M, Wandeler AI. Characterization of a panel of anti-phosphoprotein monoclonal antibodies generated against the raccoon strain of rabies virus. Virus Res 2010; 152:126-36. [PMID: 20600390 DOI: 10.1016/j.virusres.2010.06.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 06/15/2010] [Accepted: 06/16/2010] [Indexed: 10/19/2022]
Abstract
The generation of a new panel of 32 monoclonal antibodies (MAbs) reactive with the P protein of the raccoon strain of rabies virus is described. Through a series of analyses employing competitive ELISA and immunoblotting, these MAbs were classified into eight groups, each defining an antigenic site, thereby increasing the number of sites now recognized along the length of the P protein. Studies on MAb reactivity with a collection of diverse lyssaviruses identified sites that were highly conserved, moderately conserved and highly variable. Several groups of MAbs were highly specific for the raccoon rabies virus (RRV) strain and may be useful for inclusion into panels used for antigenic typing of rabies viruses. The utility of these MAbs to detect truncated versions of the P product may facilitate more fundamental studies on the function of this rabies virus protein.
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Affiliation(s)
- Susan A Nadin-Davis
- Centre of Expertise for Rabies, Ottawa Laboratory (Fallowfield), Canadian Food Inspection Agency, 3851 Fallowfield Rd., Ottawa, Ontario, Canada.
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36
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Role of interferon antagonist activity of rabies virus phosphoprotein in viral pathogenicity. J Virol 2010; 84:6699-710. [PMID: 20427527 DOI: 10.1128/jvi.00011-10] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The fixed rabies virus (RV) strain Nishigahara kills adult mice after intracerebral inoculation, whereas the chicken embryo fibroblast cell-adapted strain Ni-CE causes nonlethal infection in adult mice. We previously reported that the chimeric CE(NiP) strain, which has the phosphoprotein (P protein) gene from the Nishigahara strain in the genetic background of the Ni-CE strain, causes lethal infection in adult mice, indicating that the P gene is responsible for the different pathogenicities of the Nishigahara and Ni-CE strains. Previous studies demonstrated that RV P protein binds to the interferon (IFN)-activated transcription factor STAT1 and blocks IFN signaling by preventing its translocation to the nucleus. In this study, we examine the molecular mechanism by which RV P protein determines viral pathogenicity by comparing the IFN antagonist activities of the Nishigahara and Ni-CE P proteins. The results, obtained from both RV-infected cells and cells transfected to express P protein only, show that Ni-CE P protein is significantly impaired for its capacity to block IFN-activated STAT1 nuclear translocation and, consequently, inhibits IFN signaling less efficiently than Nishigahara P protein. Further, it was demonstrated that a defect in the nuclear export of Ni-CE P protein correlates with a defect in its ability to cause the mislocalization of STAT1. These data provide the first evidence that the capacity of the RV P protein to inhibit STAT1 nuclear translocation and IFN signaling correlates with the viral pathogenicity.
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37
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Moseley GW, Lahaye X, Roth DM, Oksayan S, Filmer RP, Rowe CL, Blondel D, Jans DA. Dual modes of rabies P-protein association with microtubules: a novel strategy to suppress the antiviral response. J Cell Sci 2009; 122:3652-62. [PMID: 19773364 DOI: 10.1242/jcs.045542] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Conventional nuclear import is independent of the cytoskeleton, but recent data have shown that the import of specific proteins can be either facilitated or inhibited by microtubules (MTs). Nuclear import of the P-protein from rabies virus involves a MT-facilitated mechanism, but here, we show that P-protein is unique in that it also undergoes MT-inhibited import, with the mode of MT-interaction being regulated by the oligomeric state of the P-protein. This is the first demonstration that a protein can utilise both MT-inhibited and MT-facilitated import mechanisms, and can switch between these different modes of MT interaction to regulate its nuclear trafficking. Importantly, we show that the P-protein exploits MT-dependent mechanisms to manipulate host cell processes by switching the import of the interferon-activated transcription factor STAT1 from a conventional to a MT-inhibited mechanism. This prevents STAT1 nuclear import and signalling in response to interferon, which is vital to the host innate antiviral response. This is the first report of MT involvement in the viral subversion of interferon signalling that is central to virus pathogenicity, and identifies novel targets for the development of antiviral drugs or attenuated viruses for vaccine applications.
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Affiliation(s)
- Gregory W Moseley
- Department of Biochemistry and Molecular Biology, Nuclear Signalling Laboratory, Monash University, Clayton, Victoria 3800, Australia.
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38
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Peptides that mimic the amino-terminal end of the rabies virus phosphoprotein have antiviral activity. J Virol 2009; 83:10808-20. [PMID: 19706704 DOI: 10.1128/jvi.00977-09] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
We wanted to develop a therapeutic approach against rabies disease by targeting the lyssavirus transcription/replication complex. Because this complex (nucleoprotein N-RNA template processed by the L polymerase and its cofactor, the phosphoprotein P) is similar to that of other negative-strand RNA viruses, we aimed to design broad-spectrum antiviral drugs that could be used as a complement to postexposure vaccination and immunotherapy. Recent progress in understanding the structure/function of the rabies virus P, N, and L proteins predicts that the amino-terminal end of P is an excellent target for destabilizing the replication complex because it interacts with both L (for positioning onto the N-RNA template) and N (for keeping N soluble, as needed for viral RNA encapsidation). Thus, peptides mimicking various lengths of the amino-terminal end of P have been evaluated, as follows: (i) for binding properties to the N-P-L partners by the two-hybrid method; (ii) for their capacity to inhibit the transcription/replication of a rabies virus minigenome encoding luciferase in BHK-21-T7 cells; and (iii) for their capacity to inhibit rabies virus infection of BHK-21-T7 cells and of two derivatives of the neuronal SK-N-SH cell line. Peptides P60 and P57 (the first 60 and first 57 NH2 residues of P, respectively) exhibited a rapid, strong, and long-lasting inhibitory potential on luciferase expression (>95% from 24 h to 55 h). P42 was less efficient in its inhibition level (75% for 18 to 30 h) and duration (40% after 48 h). The most promising peptides were synthesized in tandem with the Tat sequence, allowing cell penetration. Their inhibitory effects were observed on BHK-21-T7 cells infected with rabies virus and Lagos bat virus but not with vesicular stomatitis virus. In neuronal cells, a significant inhibition of both nucleocapsid inclusions and rabies virus release was observed.
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39
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Rawlinson SM, Pryor MJ, Wright PJ, Jans DA. CRM1-mediated nuclear export of dengue virus RNA polymerase NS5 modulates interleukin-8 induction and virus production. J Biol Chem 2009; 284:15589-97. [PMID: 19297323 PMCID: PMC2708855 DOI: 10.1074/jbc.m808271200] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 02/27/2009] [Indexed: 11/06/2022] Open
Abstract
Although all established functions of dengue virus NS5 (nonstructural protein 5) occur in the cytoplasm, its nuclear localization, mediated by dual nuclear localization sequences, is essential for virus replication. Here, we have determined the mechanism by which NS5 can localize in the cytoplasm to perform its role in replication, establishing for the first time that it is able to be exported from the nucleus by the exportin CRM1 and hence can shuttle between the nucleus and cytoplasm. We define the nuclear export sequence responsible to be residues 327-343 and confirm interaction of NS5 and CRM1 by pulldown assay. Significantly, greater nuclear accumulation of NS5 during infection due to CRM1 inhibition coincided with altered kinetics of virus production and decreased induction of the antiviral chemokine interleukin-8. This is the first report of a nuclear export sequence within NS5 for any member of the Flavivirus genus; because of its high conservation within the genus, it may represent a target for the treatment of diseases caused by several medically important flaviviruses.
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Affiliation(s)
| | | | | | - David A. Jans
- From the Departments ofBiochemistry and Molecular Biology and
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40
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Gerard FCA, Ribeiro EDA, Leyrat C, Ivanov I, Blondel D, Longhi S, Ruigrok RWH, Jamin M. Modular organization of rabies virus phosphoprotein. J Mol Biol 2009; 388:978-96. [PMID: 19341745 DOI: 10.1016/j.jmb.2009.03.061] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 03/23/2009] [Accepted: 03/25/2009] [Indexed: 10/20/2022]
Abstract
A phosphoprotein (P) is found in all viruses of the Mononegavirales order. These proteins form homo-oligomers, fulfil similar roles in the replication cycles of the various viruses, but differ in their length and oligomerization state. Sequence alignments reveal no sequence similarity among proteins from viruses belonging to the same family. Sequence analysis and experimental data show that phosphoproteins from viruses of the Paramyxoviridae contain structured domains alternating with intrinsically disordered regions. Here, we used predictions of disorder of secondary structure, and an analysis of sequence conservation to predict the domain organization of the phosphoprotein from Sendai virus, vesicular stomatitis virus (VSV) and rabies virus (RV P). We devised a new procedure for combining the results from multiple prediction methods and locating the boundaries between disordered regions and structured domains. To validate the proposed modular organization predicted for RV P and to confirm that the putative structured domains correspond to autonomous folding units, we used two-hybrid and biochemical approaches to characterize the properties of several fragments of RV P. We found that both central and C-terminal domains can fold in isolation, that the central domain is the oligomerization domain, and that the C-terminal domain binds to nucleocapsids. Our results suggest a conserved organization of P proteins in the Rhabdoviridae family in concatenated functional domains resembling that of the P proteins in the Paramyxoviridae family.
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Affiliation(s)
- Francine C A Gerard
- UJF-EMBL-CNRS UMI 3265 - Unit of Virus Host Cell Interactions, Grenoble, France
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Abstract
Various technological developments have revitalized the approaches employed to study the disease of rabies. In particular, reverse genetics has facilitated the generation of novel viruses used to improve our understanding of the fundamental aspects of rabies virus (RABV) biology and pathogenicity and yielded novel constructs potentially useful as vaccines against rabies and other diseases. Other techniques such as high throughput methods to examine the impact of rabies virus infection on host cell gene expression and two hybrid systems to explore detailed protein-protein interactions also contribute substantially to our understanding of virus-host interactions. This review summarizes much of the increased knowledge about rabies that has resulted from such studies but acknowledges that this is still insufficient to allow rational attempts at curing those who present with clinical disease.
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Affiliation(s)
- Susan A Nadin-Davis
- Centre of Expertise for Rabies, Ottawa Laboratory (Fallowfield), Canadian Food Inspection Agency, Ottawa, ON, Canada
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