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Liu LL, Yin YQ, Ma KX, Xing JC, Ren XX, Huang JY, Liao M, Qi WB, Huang LH. Identification critical host factors for Japanese encephalitis virus replication via CRISPR screening of human sgRNA library. Vet Microbiol 2024; 293:110099. [PMID: 38677125 DOI: 10.1016/j.vetmic.2024.110099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 04/15/2024] [Accepted: 04/20/2024] [Indexed: 04/29/2024]
Abstract
Japanese encephalitis virus (JEV) is a pathogen with a substantial impact on both livestock and human health. However, the critical host factors in the virus life cycle remain poorly understood. Using a library comprising 123411 small guide RNAs (sgRNAs) targeting 19050 human genes, we conducted a genome-wide clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based screen to identify essential genes for JEV replication. By employing knockout or knockdown techniques on genes, we identified eleven human genes crucial for JEV replication, such as prolactin releasing hormone receptor (PRLHR), activating signal cointegrator 1 complex subunit 3 (ASCC3), acyl-CoA synthetase long chain family member 3 (ACSL3), and others. Notably, we found that PRLHR knockdown blocked the autophagic flux, thereby inhibiting JEV infection. Taken together, these findings provide effective data for studying important host factors of JEV replication and scientific data for selecting antiviral drug targets.
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Affiliation(s)
- Le-le Liu
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China; National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou 510642, China; Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - You-Qin Yin
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China; National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou 510642, China; Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Kai-Xiong Ma
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China
| | - Jin-Chao Xing
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China
| | - Xing-Xing Ren
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China
| | - Jin-Yu Huang
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China; National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou 510642, China; Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Ming Liao
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China; National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou 510642, China; Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Wen-Bao Qi
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China; National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou 510642, China; Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou 510642, China.
| | - Li-Hong Huang
- State Key Laboratory for Animal Disease Control and Prevention, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China; National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou 510642, China; Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou 510642, China.
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Ishida K, Yagi H, Kato Y, Morita E. N-linked glycosylation of flavivirus E protein contributes to viral particle formation. PLoS Pathog 2023; 19:e1011681. [PMID: 37819933 PMCID: PMC10593244 DOI: 10.1371/journal.ppat.1011681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 10/23/2023] [Accepted: 09/12/2023] [Indexed: 10/13/2023] Open
Abstract
In the case of the Japanese encephalitis virus (JEV), the envelope protein (E), a major component of viral particles, contains a highly conserved N-linked glycosylation site (E: N154). Glycosylation of the E protein is thought to play an important role in the ability of the virus to attach to target cells during transmission; however, its role in viral particle formation and release remains poorly understood. In this study, we investigated the role of N-glycosylation of flaviviral structural proteins in viral particle formation and secretion by introducing mutations in viral structural proteins or cellular factors involved in glycoprotein transport and processing. The number of secreted subviral particles (SVPs) was significantly reduced in N154A, a glycosylation-null mutant, but increased in D67N, a mutant containing additional glycosylation sites, indicating that the amount of E glycosylation regulates the release of SVPs. SVP secretion was reduced in cells deficient in galactose, sialic acid, and N-acetylglucosamine modifications in the Golgi apparatus; however, these reductions were not significant, suggesting that glycosylation mainly plays a role in pre-Golgi transport. Fluorescent labeling of SVPs using a split green fluorescent protein (GFP) system and time-lapse imaging by retention using selective hooks (RUSH) system revealed that the glycosylation-deficient mutant was arrested before endoplasmic reticulum (ER)- Golgi transport. However, the absence of ERGIC-53 and ERGIC-L, ER-Golgi transport cargo receptors that recognize sugar chains on cargo proteins, does not impair SVP secretion. In contrast, the solubility of the N154A mutant of E or the N15A/T17A mutant of prM in cells was markedly lower than that of the wild type, and proteasome-mediated rapid degradation of these mutants was observed, indicating the significance of glycosylation of both prM and E in proper protein folding and assembly of viral particles in the ER.
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Affiliation(s)
- Kotaro Ishida
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, Japan
- Division of Biomolecular Function, Bioresources Science, United Graduate School of Agricultural Sciences, Iwate University, Morioka, Japan
| | - Hirokazu Yagi
- Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Japan
| | - Yukinari Kato
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Molecular Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Eiji Morita
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, Japan
- Division of Biomolecular Function, Bioresources Science, United Graduate School of Agricultural Sciences, Iwate University, Morioka, Japan
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Lin CS, Li WJ, Liao CY, Kan JY, Kung SH, Huang SH, Lai HC, Lin CW. A Reverse Mutation E143K within the PrM Protein of Zika Virus Asian Lineage Natal RGN Strain Increases Infectivity and Cytopathicity. Viruses 2022; 14:v14071572. [PMID: 35891552 PMCID: PMC9317194 DOI: 10.3390/v14071572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/14/2022] [Accepted: 07/18/2022] [Indexed: 11/16/2022] Open
Abstract
Zika virus (ZIKV) is a positive-sense single-stranded RNA virus in the Flaviviridae, which is classified into two different lineages Asian and African. The outbreak of ZIKV Asian lineage isolates in 2015–2016 is associated with the increase in cases with prenatal microcephaly and Guillain–Barré syndrome, and has sparked attention throughout the world. Genome sequence alignment and the analysis of Asian and African lineage isolates indicate that amino acid changes, particular in positively charged amino acid substitutions in the pr region of prM protein might involve a phenotypic change that links with the global outbreak of ZIKV Asian-lineage. The study generated and characterized the virological properties of wild type and mutants of single-round infectious particles (SRIPs) and infectious clones (i.c.s) of ZIKV Asian-lineage Natal RGN strain, and then identified the function of amino acid substitutions at the positions 139 [Asn139→Ser139 (N139S)] and 143 [Glu143→Lys143 (E143K)] in ZIKV polyproteins (located within the pr region of prM protein) in the infectivity and cytopathogenicity. The E143K SRIP and i.c. of Natal RGN strain exhibited relatively higher levels of cytopathic effect, EGFP reporter, viral RNA and protein synthesis, and virus yield in three types of human cell lines, TE617, SF268 and HMC3, compared to wild type (WT), N139S SRIPs and i.c.s, which displayed more efficiency in replication kinetics. Additionally, E143K Natal RGN i.c. had greater activities of virus attachment and entry, yielded higher titers of intracellular and extracellular virions, and assembled the E proteins near to the plasma membrane in infected cells than the other i.c.s. The results indicate that the positively charged amino acid residue Lys143, a conserved residue in the pr region of prM of ZIKV African lineages, plays a crucial role in viral replication kinetics, including viral attachment, entry, assembly and egress. Thus, the negatively charged amino acid residue Glu143 within the pr region of prM leads to an alteration of the phenotypes, in particular, a lower replication efficiency of ZIKV Asian-lineage isolates with the attenuation of infectivity and cytopathicity.
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Affiliation(s)
- Chen-Sheng Lin
- Division of Gastroenterology, Kuang Tien General Hospital, No. 117, Shatian Rd, Shalu District, Taichung 433, Taiwan;
| | - Wei-Jing Li
- Department of Medical Laboratory Science and Biotechnology, China Medical University, No. 100, Sec. 1, Jingmao Rd., Beitun Dist., Taichung 404, Taiwan; (W.-J.L.); (C.-Y.L.)
| | - Chih-Yi Liao
- Department of Medical Laboratory Science and Biotechnology, China Medical University, No. 100, Sec. 1, Jingmao Rd., Beitun Dist., Taichung 404, Taiwan; (W.-J.L.); (C.-Y.L.)
| | - Ju-Ying Kan
- The PhD Program of Biotechnology and Biomedical Industry, China Medical University, No. 100, Sec. 1, Jingmao Rd., Beitun Dist., Taichung 404, Taiwan;
| | - Szu-Hao Kung
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan;
| | - Su-Hua Huang
- Department of Medical Laboratory Science and Biotechnology, Asia University, No. 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan;
| | - Hsueh-Chou Lai
- Division of Hepato-Gastroenterology, Department of Internal Medicine, China Medical University Hospital, No. 2, Yude Rd., North Dist., Taichung 404, Taiwan;
| | - Cheng-Wen Lin
- Department of Medical Laboratory Science and Biotechnology, China Medical University, No. 100, Sec. 1, Jingmao Rd., Beitun Dist., Taichung 404, Taiwan; (W.-J.L.); (C.-Y.L.)
- The PhD Program of Biotechnology and Biomedical Industry, China Medical University, No. 100, Sec. 1, Jingmao Rd., Beitun Dist., Taichung 404, Taiwan;
- Department of Medical Laboratory Science and Biotechnology, Asia University, No. 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan;
- Correspondence:
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4
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Schor S, Pu S, Nicolaescu V, Azari S, Kõivomägi M, Karim M, Cassonnet P, Saul S, Neveu G, Yueh A, Demeret C, Skotheim JM, Jacob Y, Randall G, Einav S. The cargo adapter protein CLINT1 is phosphorylated by the Numb-associated kinase BIKE and mediates dengue virus infection. J Biol Chem 2022; 298:101956. [PMID: 35452674 PMCID: PMC9133654 DOI: 10.1016/j.jbc.2022.101956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 03/22/2022] [Accepted: 03/24/2022] [Indexed: 11/25/2022] Open
Abstract
The signaling pathways and cellular functions regulated by the four Numb-associated kinases are largely unknown. We reported that AAK1 and GAK control intracellular trafficking of RNA viruses and revealed a requirement for BIKE in early and late stages of dengue virus (DENV) infection. However, the downstream targets phosphorylated by BIKE have not yet been identified. Here, to identify BIKE substrates, we conducted a barcode fusion genetics-yeast two-hybrid screen and retrieved publicly available data generated via affinity-purification mass spectrometry. We subsequently validated 19 of 47 putative BIKE interactors using mammalian cell-based protein-protein interaction assays. We found that CLINT1, a cargo-specific adapter implicated in bidirectional Golgi-to-endosome trafficking, emerged as a predominant hit in both screens. Our experiments indicated that BIKE catalyzes phosphorylation of a threonine 294 CLINT1 residue both in vitro and in cell culture. Our findings revealed that CLINT1 phosphorylation mediates its binding to the DENV nonstructural 3 protein and subsequently promotes DENV assembly and egress. Additionally, using live-cell imaging we revealed that CLINT1 cotraffics with DENV particles and is involved in mediating BIKE's role in DENV infection. Finally, our data suggest that additional cellular BIKE interactors implicated in the host immune and stress responses and the ubiquitin proteasome system might also be candidate phosphorylation substrates of BIKE. In conclusion, these findings reveal cellular substrates and pathways regulated by the understudied Numb-associated kinase enzyme BIKE, a mechanism for CLINT1 regulation, and control of DENV infection via BIKE signaling, with potential implications for cell biology, virology, and host-targeted antiviral design.
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Affiliation(s)
- Stanford Schor
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, and Department of Microbiology and Immunology, Stanford University, California, USA
| | - Szuyuan Pu
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, and Department of Microbiology and Immunology, Stanford University, California, USA
| | - Vlad Nicolaescu
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
| | - Siavash Azari
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, and Department of Microbiology and Immunology, Stanford University, California, USA
| | | | - Marwah Karim
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, and Department of Microbiology and Immunology, Stanford University, California, USA
| | - Patricia Cassonnet
- Department of Virology, Molecular Genetics of RNA Virus Genetics (GMVR), Pasteur Institute, National Center for Scientific Research, and Paris Diderot University, Paris, France
| | - Sirle Saul
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, and Department of Microbiology and Immunology, Stanford University, California, USA
| | - Gregory Neveu
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, and Department of Microbiology and Immunology, Stanford University, California, USA
| | - Andrew Yueh
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Taiwan
| | - Caroline Demeret
- Department of Virology, Molecular Genetics of RNA Virus Genetics (GMVR), Pasteur Institute, National Center for Scientific Research, and Paris Diderot University, Paris, France
| | - Jan M Skotheim
- Department of Biology, Stanford University, California, USA
| | - Yves Jacob
- Department of Virology, Molecular Genetics of RNA Virus Genetics (GMVR), Pasteur Institute, National Center for Scientific Research, and Paris Diderot University, Paris, France
| | - Glenn Randall
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
| | - Shirit Einav
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, and Department of Microbiology and Immunology, Stanford University, California, USA; Chan Zuckerberg Biohub, San Francisco, California, USA.
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Nakayama E, Kato F, Tajima S, Ogawa S, Yan K, Takahashi K, Sato Y, Suzuki T, Kawai Y, Inagaki T, Taniguchi S, Le TT, Tang B, Prow NA, Uda A, Maeki T, Lim CK, Khromykh AA, Suhrbier A, Saijo M. Neuroinvasiveness of the MR766 strain of Zika virus in IFNAR-/- mice maps to prM residues conserved amongst African genotype viruses. PLoS Pathog 2021; 17:e1009788. [PMID: 34310650 PMCID: PMC8341709 DOI: 10.1371/journal.ppat.1009788] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 08/05/2021] [Accepted: 07/07/2021] [Indexed: 12/23/2022] Open
Abstract
Zika virus (ZIKV) strains are classified into the African and Asian genotypes. The higher virulence of the African MR766 strain, which has been used extensively in ZIKV research, in adult IFNα/β receptor knockout (IFNAR-/-) mice is widely viewed as an artifact associated with mouse adaptation due to at least 146 passages in wild-type suckling mouse brains. To gain insights into the molecular determinants of MR766's virulence, a series of genes from MR766 were swapped with those from the Asian genotype PRVABC59 isolate, which is less virulent in IFNAR-/- mice. MR766 causes 100% lethal infection in IFNAR-/- mice, but when the prM gene of MR766 was replaced with that of PRVABC59, the chimera MR/PR(prM) showed 0% lethal infection. The reduced virulence was associated with reduced neuroinvasiveness, with MR766 brain titers ≈3 logs higher than those of MR/PR(prM) after subcutaneous infection, but was not significantly different in brain titers of MR766 and MR/PR(prM) after intracranial inoculation. MR/PR(prM) also showed reduced transcytosis when compared with MR766 in vitro. The high neuroinvasiveness of MR766 in IFNAR-/- mice could be linked to the 10 amino acids that differ between the prM proteins of MR766 and PRVABC59, with 5 of these changes affecting positive charge and hydrophobicity on the exposed surface of the prM protein. These 10 amino acids are highly conserved amongst African ZIKV isolates, irrespective of suckling mouse passage, arguing that the high virulence of MR766 in adult IFNAR-/- mice is not the result of mouse adaptation.
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Affiliation(s)
- Eri Nakayama
- Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Fumihiro Kato
- Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Shigeru Tajima
- Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Shinya Ogawa
- Department of Applied Biological Chemistry, School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kexin Yan
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Kenta Takahashi
- Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yuko Sato
- Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Tadaki Suzuki
- Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yasuhiro Kawai
- Management Department of Biosafety and Laboratory Animal, Division of Biosafety Control and Research, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takuya Inagaki
- Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Satoshi Taniguchi
- Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Thuy T. Le
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Bing Tang
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Natalie A. Prow
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
- Australian Infectious Disease Research Centre, GVN Center of Excellence, The University of Queensland and QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Akihiko Uda
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takahiro Maeki
- Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Chang-Kweng Lim
- Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Alexander A. Khromykh
- Australian Infectious Disease Research Centre, GVN Center of Excellence, The University of Queensland and QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Andreas Suhrbier
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
- Australian Infectious Disease Research Centre, GVN Center of Excellence, The University of Queensland and QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Masayuki Saijo
- Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan
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Embarc-Buh A, Francisco-Velilla R, Martinez-Salas E. RNA-Binding Proteins at the Host-Pathogen Interface Targeting Viral Regulatory Elements. Viruses 2021; 13:952. [PMID: 34064059 PMCID: PMC8224014 DOI: 10.3390/v13060952] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/10/2021] [Accepted: 05/17/2021] [Indexed: 12/16/2022] Open
Abstract
Viral RNAs contain the information needed to synthesize their own proteins, to replicate, and to spread to susceptible cells. However, due to their reduced coding capacity RNA viruses rely on host cells to complete their multiplication cycle. This is largely achieved by the concerted action of regulatory structural elements on viral RNAs and a subset of host proteins, whose dedicated function across all stages of the infection steps is critical to complete the viral cycle. Importantly, not only the RNA sequence but also the RNA architecture imposed by the presence of specific structural domains mediates the interaction with host RNA-binding proteins (RBPs), ultimately affecting virus multiplication and spreading. In marked difference with other biological systems, the genome of positive strand RNA viruses is also the mRNA. Here we focus on distinct types of positive strand RNA viruses that differ in the regulatory elements used to promote translation of the viral RNA, as well as in the mechanisms used to evade the series of events connected to antiviral response, including translation shutoff induced in infected cells, assembly of stress granules, and trafficking stress.
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Affiliation(s)
| | | | - Encarnacion Martinez-Salas
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Nicolás Cabrera 1, 28049 Madrid, Spain; (A.E.-B.); (R.F.-V.)
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Nanoparticles (PLGA and Chitosan)-Entrapped ADP-Ribosylation Factor 1 of Haemonchus contortus Enhances the Immune Responses in ICR Mice. Vaccines (Basel) 2020; 8:vaccines8040726. [PMID: 33276581 PMCID: PMC7761582 DOI: 10.3390/vaccines8040726] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 01/25/2023] Open
Abstract
ADP-ribosylation factor 1 (HcARF1) is one of the Haemonchus contortus (H. contortus) excretory/secretory proteins involved in modulating the immune response of goat peripheral blood mononuclear cells (PBMC). Here, we evaluated the immunogenic potential of recombinant HcARF1 (rHcARF1) against H. contortus infection in Institute of Cancer Research (ICR) mice. Briefly, rHcARF1 was entrapped in poly (D, L-lactide-co-glycolide) (PLGA) and chitosan (CS) nanoparticles (NP) and injected into mice as a vaccine. Fifty-six ICR mice were assigned randomly into seven groups, with eight animals in each group, and they were vaccinated subcutaneously. At the end of the experiment (14th day), the blood and the spleen were collected from euthanized mice to detect lymphocyte proliferation, cytokine analysis, and the production of antigen-specific antibodies. Scanning electron microscope was used to determine the size, morphology, and zeta potential of nanoparticles. Flow cytometry was performed, which presented the increase percentages of CD4+ T cells (CD3e+CD4+), CD8+ T cells (CD3e+CD8+) and dendritic cells (CD11c+CD83+, CD11c+CD86+) in mice vaccinated with rHcARF1+PLGA NP. Immunoassay analysis show raised humoral (Immunoglobulin (Ig)G1, IgG2a, IgM) and cell-mediated immune response (Interleukin (IL)-4, IL-12, and IL-17, and Interferon (IFN)-γ) induced by rHcARF1+PLGA NP. Experimental groups that were treated with the antigen-loaded NP yield higher lymphocyte proliferation than the control groups. Based on these results, we could propose that the rHcARF1 encapsulated in NP could stimulate a strong immune response in mice rather than administering alone against the infection of H. contortus.
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Pu S, Schor S, Karim M, Saul S, Robinson M, Kumar S, Prugar LI, Dorosky DE, Brannan J, Dye JM, Einav S. BIKE regulates dengue virus infection and is a cellular target for broad-spectrum antivirals. Antiviral Res 2020; 184:104966. [PMID: 33137362 DOI: 10.1016/j.antiviral.2020.104966] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 10/07/2020] [Accepted: 10/26/2020] [Indexed: 12/15/2022]
Abstract
Global health is threatened by emerging viruses, many of which lack approved therapies and effective vaccines, including dengue, Ebola, and Venezuelan equine encephalitis. We previously reported that AAK1 and GAK, two of the four members of the understudied Numb-associated kinases (NAK) family, control intracellular trafficking of RNA viruses. Nevertheless, the role of BIKE and STK16 in viral infection remained unknown. Here, we reveal a requirement for BIKE, but not STK-16, in dengue virus (DENV) infection. BIKE mediates both early (postinternalization) and late (assembly/egress) stages in the DENV life cycle, and this effect is mediated in part by phosphorylation of a threonine 156 (T156) residue in the μ subunit of the adaptor protein (AP) 2 complex. Pharmacological compounds with potent anti-BIKE activity, including the investigational anticancer drug 5Z-7-oxozeaenol and more selective inhibitors, suppress DENV infection both in vitro and ex vivo. BIKE overexpression reverses the antiviral activity, validating that the mechanism of antiviral action is, at least in part, mediated by BIKE. Lastly, 5Z-7-oxozeaenol exhibits antiviral activity against viruses from three unrelated RNA viral families with a high genetic barrier to resistance. These findings reveal regulation of poorly understood stages of the DENV life cycle via BIKE signaling and establish a proof-of-principle that pharmacological inhibition of BIKE can be potentially used as a broad-spectrum strategy against acute emerging viral infections.
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Affiliation(s)
- Szuyuan Pu
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Department of Microbiology and Immunology, Stanford University, CA, USA
| | - Stanford Schor
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Department of Microbiology and Immunology, Stanford University, CA, USA
| | - Marwah Karim
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Department of Microbiology and Immunology, Stanford University, CA, USA
| | - Sirle Saul
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Department of Microbiology and Immunology, Stanford University, CA, USA
| | - Makeda Robinson
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Department of Microbiology and Immunology, Stanford University, CA, USA
| | - Sathish Kumar
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Department of Microbiology and Immunology, Stanford University, CA, USA
| | - Laura I Prugar
- US Army Medical Research Institute of Infectious Diseases, Viral Immunology Branch, Fort Detrick, Maryland, USA
| | - Danielle E Dorosky
- US Army Medical Research Institute of Infectious Diseases, Viral Immunology Branch, Fort Detrick, Maryland, USA
| | - Jennifer Brannan
- US Army Medical Research Institute of Infectious Diseases, Viral Immunology Branch, Fort Detrick, Maryland, USA
| | - John M Dye
- US Army Medical Research Institute of Infectious Diseases, Viral Immunology Branch, Fort Detrick, Maryland, USA
| | - Shirit Einav
- Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Department of Microbiology and Immunology, Stanford University, CA, USA.
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Lyn kinase regulates egress of flaviviruses in autophagosome-derived organelles. Nat Commun 2020; 11:5189. [PMID: 33060596 PMCID: PMC7564011 DOI: 10.1038/s41467-020-19028-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 09/25/2020] [Indexed: 02/07/2023] Open
Abstract
Among the various host cellular processes that are hijacked by flaviviruses, few mechanisms have been described with regard to viral egress. Here we investigate how flaviviruses exploit Src family kinases (SFKs) for exit from infected cells. We identify Lyn as a critical component for secretion of Dengue and Zika infectious particles and their corresponding virus like particles (VLPs). Pharmacological inhibition or genetic depletion of the SFKs, Lyn in particular, block virus secretion. Lyn−/− cells are impaired in virus release and are rescued when reconstituted with wild-type Lyn, but not a kinase- or palmitoylation-deficient Lyn mutant. We establish that virus particles are secreted in two distinct populations – one as free virions and the other enclosed within membranes. Lyn is critical for the latter, which consists of proteolytically processed, infectious virus progenies within autophagosome-derived vesicles. This process depends on Ulk1, Rab GTPases and SNARE complexes implicated in secretory but not degradative autophagy and occur with significantly faster kinetics than the conventional secretory pathway. Our study reveals a previously undiscovered Lyn-dependent exit route of flaviviruses in LC3+ secretory organelles that enables them to evade circulating antibodies and might affect tissue tropism. Egress of flaviviruses and involved host pathways are not well understood. Here, the authors show that Lyn is a critical host kinase for Dengue and Zika virus egress resulting in infectious virus progenies within autophagosome-derived vesicles, which might help the virus to evade antibody responses.
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10
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Martínez JL, Arias CF. Role of the Guanine Nucleotide Exchange Factor GBF1 in the Replication of RNA Viruses. Viruses 2020; 12:E682. [PMID: 32599855 PMCID: PMC7354614 DOI: 10.3390/v12060682] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/06/2020] [Accepted: 04/06/2020] [Indexed: 12/12/2022] Open
Abstract
The guanine nucleotide exchange factor GBF1 is a well-known factor that can activate different ADP-ribosylation factor (Arf) proteins during the regulation of different cellular vesicular transport processes. In the last decade, it has become increasingly evident that GBF1 can also regulate different steps of the replication cycle of RNA viruses belonging to different virus families. GBF1 has been shown not only to facilitate the intracellular traffic of different viral and cellular elements during infection, but also to modulate the replication of viral RNA, the formation and maturation of viral replication complexes, and the processing of viral proteins through mechanisms that do not depend on its canonical role in intracellular transport. Here, we review the various roles that GBF1 plays during the replication of different RNA viruses.
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Affiliation(s)
| | - Carlos F. Arias
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca 4510, Morelos, Mexico;
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11
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Zhang L, Wang T, Song M, Jin M, Liu S, Guo K, Zhang Y. Rab1b-GBF1-ARFs mediated intracellular trafficking is required for classical swine fever virus replication in swine umbilical vein endothelial cells. Vet Microbiol 2020; 246:108743. [PMID: 32605744 DOI: 10.1016/j.vetmic.2020.108743] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/22/2020] [Accepted: 05/31/2020] [Indexed: 01/24/2023]
Abstract
Classical swine fever virus (CSFV), a plus-sense RNA virus, utilizes host intracellular membrane organelles for its replication. Our previous studies have shown that disruption of the intracellular membrane-trafficking events can inhibit CSFV replication. However, the underlying mechanism of this process in CSFV infection has not been elucidated. To determine the role of Golgi-associated anterograde and retrograde trafficking in CSFV replication, we revealed the effect of vesicular transport between Golgi and ER inhibitors Brefeldin A (BFA) and 2,2-methyl-N-(2,4,6,-trimethoxyphenyl) dodecanamide (CI-976), the GBF1 inhibitor golgicide A (GCA) on virus production. Our results showed that disruption of vesicular trafficking by BFA, CI-976, and GCA significantly inhibited CSFV infection. Subsequent experiments revealed that knockdown of Rab1b by lentiviruses and negative-mutant Rab1b-N121I transfection inhibited CSFV infection. Furthermore, we showed that the Rab1b downstream vesicular component effectors GBF1, and class I and class II ADP-ribosylation factors (ARFs) were also involved in virus replication. In addition, confocal microscopy assay showed that CSFV infection disrupted the Golgi apparatus resulting in extended Golgi distribution around the nucleus. We also showed that cell secretory pathway, measured using Gaussia luciferase flash assay, was blocked in CSFV infected cells. Taken together, these findings demonstrate that CSFV utilizes Rab1b-GBF1-ARFs mediated trafficking to promote its own replication. These findings also provide new insights into the intracellular trafficking pathways utilized for CSFV life cycle.
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Affiliation(s)
- Liang Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Tao Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Mengzhao Song
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Mingxing Jin
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Shanchuan Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Kangkang Guo
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
| | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
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12
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Neufeldt CJ, Cortese M, Scaturro P, Cerikan B, Wideman JG, Tabata K, Moraes T, Oleksiuk O, Pichlmair A, Bartenschlager R. ER-shaping atlastin proteins act as central hubs to promote flavivirus replication and virion assembly. Nat Microbiol 2019; 4:2416-2429. [PMID: 31636417 PMCID: PMC6881184 DOI: 10.1038/s41564-019-0586-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 09/10/2019] [Indexed: 12/13/2022]
Abstract
Flaviviruses, including dengue virus (DV) and Zika virus, extensively remodel the cellular endomembrane network to generate replication organelles that promote viral genome replication and virus production. However, it remains unclear how these membranes and associated cellular proteins act during the virus cycle. Here, we show that atlastins (ATLs), a subset of ER resident proteins involved in neurodegenerative diseases, have dichotomous effects on flaviviruses with ATL2 depletion leading to replication organelle defects and ATL3 depletion to changes in virus production pathways. We characterized non-conserved functional domains in ATL paralogues and show that the ATL interactome is profoundly reprogrammed upon DV infection. Screen analysis confirmed non-redundant ATL functions and identified a specific role for ATL3, and its interactor ARF4, in vesicle trafficking and virion maturation. Our data identify ATLs as central hubs targeted by flaviviruses to establish their replication organelle and to achieve efficient virion maturation and secretion.
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Affiliation(s)
- Christopher J Neufeldt
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany.
| | - Mirko Cortese
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Pietro Scaturro
- Technical University of Munich, School of Medicine, Institute of Virology, Munich, Germany
| | - Berati Cerikan
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Jeremy G Wideman
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada.,Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Keisuke Tabata
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Thaís Moraes
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Olga Oleksiuk
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Andreas Pichlmair
- Technical University of Munich, School of Medicine, Institute of Virology, Munich, Germany.,German Center for Infection Research (DZIF), (Munich Partner Site), Munich, Germany
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany. .,German Center for Infection Research (DZIF), (Heidelberg Partner Site), Heidelberg, Germany. .,Division Virus-Associated Carcinogenesis, German Cancer Research Center, Heidelberg, Germany.
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13
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Dejgaard SY, Presley JF. Rab18 regulates lipolysis via Arf/GBF1 and adipose triglyceride lipase. Biochem Biophys Res Commun 2019; 520:526-531. [PMID: 31610914 DOI: 10.1016/j.bbrc.2019.10.069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 10/06/2019] [Indexed: 01/09/2023]
Abstract
Rab18 is a small GTPase associated with lipid droplets and other membranes. While it likely has multiple functions on lipid droplets, one proposed function is regulation of lipolysis. Previous work has concentrated on regulation of autophagy; however, in this study, we provide evidence that Rab18 plays a role upstream of the cytosolic lipolytic enzyme adipose triglyceride lipase (ATGL) and that recruitment of ATGL by Rab18 is mediated by elements of the Arf/GBF1 machinery. We find that Arf4-GFP is accumulated on the subset of lipid droplets associated with Rab18, and that this association is lost within 5 min upon treatment with 5 μg/ml of the drug brefeldin A, which targets GBF1 and other Sec7-domain containing Arf exchange factors. ATGL-GFP is also recruited to lipid droplets, but is lost more slowly after treatment with 5 μg/ml brefeldin A, with significant loss from lipid droplets after 1 h treatment, and almost complete loss from lipid droplets 4 h after brefeldin A treatment. Upon overexpression of the dominant negative GDP-locked cerulean-Rab18-S22 N, GFP-ATGL and Arf4 are lost from the surface of lipid droplets similarly to BFA treatment. This study establishes, for the first time, an essential role for Rab18 in recruiting ATGL to lipid droplets.
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Affiliation(s)
- Selma Yilmaz Dejgaard
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada; Department of Medical Biology, Near East University, Nicosia, Cyprus
| | - John F Presley
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada.
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14
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Rothan HA, Kumar M. Role of Endoplasmic Reticulum-Associated Proteins in Flavivirus Replication and Assembly Complexes. Pathogens 2019; 8:E148. [PMID: 31547236 PMCID: PMC6789530 DOI: 10.3390/pathogens8030148] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/09/2019] [Accepted: 09/11/2019] [Indexed: 01/29/2023] Open
Abstract
Flavivirus replication in host cells requires the formation of replication and assembly complexes on the cytoplasmic side of the endoplasmic reticulum (ER) membrane. These complexes consist of an ER membrane, viral proteins, and host proteins. Genome-wide investigations have identified a number of ER multiprotein complexes as vital factors for flavivirus replication. The detailed mechanisms of the role of ER complexes in flavivirus replication are still largely elusive. This review highlights the fact that the ER multiprotein complexes are crucial for the formation of flavivirus replication and assembly complexes, and the ER complexes could be considered as a target for developing successful broad-spectrum anti-flavivirus drugs.
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Affiliation(s)
- Hussin A Rothan
- Department of Biology, College of Arts and Sciences, Georgia State University, Atlanta, GA 30303, USA.
| | - Mukesh Kumar
- Department of Biology, College of Arts and Sciences, Georgia State University, Atlanta, GA 30303, USA.
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15
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Makes caterpillars floppy-like effector-containing MARTX toxins require host ADP-ribosylation factor (ARF) proteins for systemic pathogenicity. Proc Natl Acad Sci U S A 2019; 116:18031-18040. [PMID: 31427506 PMCID: PMC6731672 DOI: 10.1073/pnas.1905095116] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
MARTX toxins present across multiple bacterial genera are primary virulence factors that facilitate initial colonization, dissemination, and lethality in a wide range of hosts, including humans. Upon entry into host cells, the toxins undergo a processing event to release their disease-related modularly structured effector domains. However, the mechanisms underlying processing and activation of diverse effector domains within the toxins remain unclear. Here, we use biochemical and structural biological approaches, in combination with cellular microbiological experiments, to demonstrate how Makes caterpillars floppy-like effector (MCF) or its homolog-containing MARTX toxins process effector modules and fully activate effectors. MCF-containing toxins target ADP-ribosylation factor proteins ubiquitously expressed in cells to activate and disseminate effectors across subcellular compartments simultaneously, eventually leading to systemic pathogenicity. Upon invading target cells, multifunctional autoprocessing repeats-in-toxin (MARTX) toxins secreted by bacterial pathogens release their disease-related modularly structured effector domains. However, it is unclear how a diverse repertoire of effector domains within these toxins are processed and activated. Here, we report that Makes caterpillars floppy-like effector (MCF)-containing MARTX toxins require ubiquitous ADP-ribosylation factor (ARF) proteins for processing and activation of intermediate effector modules, which localize in different subcellular compartments following limited processing of holo effector modules by the internal cysteine protease. Effector domains structured tandemly with MCF in intermediate modules become disengaged and fully activated by MCF, which aggressively interacts with ARF proteins present at the same location as intermediate modules and is converted allosterically into a catalytically competent protease. MCF-mediated effector processing leads ultimately to severe virulence in mice via an MCF-mediated ARF switching mechanism across subcellular compartments. This work provides insight into how bacteria take advantage of host systems to induce systemic pathogenicity.
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16
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Fukuhara T, Matsuura Y. Roles of secretory glycoproteins in particle formation of Flaviviridae viruses. Microbiol Immunol 2019; 63:401-406. [PMID: 31342548 DOI: 10.1111/1348-0421.12733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/17/2019] [Accepted: 07/18/2019] [Indexed: 12/12/2022]
Abstract
The family Flaviviridae comprises four genera, namely, Flavivirus, Pestivirus, Pegivirus, and Hepacivirus. These viruses have similar genome structures, but the genomes of Pestivirus and Flavivirus encode the secretory glycoproteins Erns and NS1, respectively. Erns plays an important role in virus particle formation and cell entry, whereas NS1 participates in the formation of replication complexes and virus particles. Conversely, apolipoproteins are known to participate in the formation of infectious particles of hepatitis C virus (HCV) and various secretory glycoproteins play a similar role in HCV particles formation, suggesting that there is no strong specificity for the function of secretory glycoproteins in infectious-particle formation. In addition, recent studies have shown that host-derived apolipoproteins and virus-derived Erns and NS1 play comparable roles in infectious-particle formation of both HCV and pestiviruses. In this review, we summarize the roles of secretory glycoproteins in the formation of Flaviviridae virus particles.
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Affiliation(s)
- Takasuke Fukuhara
- Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Yoshiharu Matsuura
- Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
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17
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Deletion of Class II ADP-Ribosylation Factors in Mice Causes Tremor by the Nav1.6 Loss in Cerebellar Purkinje Cell Axon Initial Segments. J Neurosci 2019; 39:6339-6353. [PMID: 31201232 DOI: 10.1523/jneurosci.2002-18.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 05/14/2019] [Accepted: 05/31/2019] [Indexed: 12/29/2022] Open
Abstract
ADP-ribosylation factors (ARFs) are a family of small monomeric GTPases comprising six members categorized into three classes: class I (ARF1, 2, and 3), class II (ARF4 and 5), and class III (ARF6). In contrast to class I and III ARFs, which are the key regulators in vesicular membrane trafficking, the cellular function of class II ARFs remains unclear. In the present study, we generated class II ARF-deficient mice and found that ARF4+/-/ARF5-/- mice exhibited essential tremor (ET)-like behaviors. In vivo electrophysiological recordings revealed that ARF4+/-/ARF5-/- mice of both sexes exhibited abnormal brain activity when moving, raising the possibility of abnormal cerebellar excitability. Slice patch-clamp experiments demonstrated the reduced excitability of the cerebellar Purkinje cells (PCs) in ARF4+/-/ARF5-/- mice. Immunohistochemical and electrophysiological analyses revealed a severe and selective decrease of pore-forming voltage-dependent Na+ channel subunit Nav1.6, important for maintaining repetitive action potential firing, in the axon initial segment (AIS) of PCs. Importantly, this decrease in Nav1.6 protein localized in the AIS and the consequent tremors in ARF4+/-/ARF5-/- mice could be alleviated by the PC-specific expression of ARF5 using adeno-associated virus vectors. Together, our data demonstrate that the decreased expression of the class II ARF proteins in ARF4+/-/ARF5-/- mice, leading to a haploinsufficiency of ARF4 in the absence of ARF5, impairs the localization of Nav1.6 to the AIS and hence reduces the membrane excitability in PCs, resulting in the ET-like movement disorder. We suggest that class II ARFs function in localizing specific proteins, such as Nav1.6, to the AIS.SIGNIFICANCE STATEMENT We found that decreasing the expression of class II ARF proteins, through the generation of ARF4+/-/ARF5-/- mice, impairs Nav1.6 distribution to the axon initial segment (AIS) of cerebellar Purkinje cells (PCs), thereby resulting in the impairment of action potential firing of PCs. The ARF4+/-/ARF5-/- mutant mice exhibited movement-associated essential tremor (ET)-like behavior with pharmacological profiles similar to those in ET patients. The exogenous expression of ARF5 reduced the tremor phenotype and restored the localization of Nav1.6 immunoreactivity to the AIS in ARF4+/-/ARF5-/- mice. Thus, our results suggest that class II ARFs are involved in the localization of Nav1.6 to the AISs in cerebellar PCs and that the reduction of class II ARF activity leads to ET-like movement disorder.
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Campos RK, Garcia-Blanco MA, Bradrick SS. Roles of Pro-viral Host Factors in Mosquito-Borne Flavivirus Infections. Curr Top Microbiol Immunol 2019; 419:43-67. [PMID: 28688087 DOI: 10.1007/82_2017_26] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Identification and analysis of viral host factors is a growing area of research which aims to understand the how viruses molecularly interface with the host cell. Investigations into flavivirus-host interactions has led to new discoveries in viral and cell biology, and will potentially bolster strategies to control the important diseases caused by these pathogens. Here, we address the current knowledge of prominent host factors required for the flavivirus life-cycle and mechanisms by which they promote infection.
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Affiliation(s)
- Rafael K Campos
- Department of Molecular Genetics and Microbiology, Center for RNA Biology, Duke University, Durham, NC, USA.,Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Mariano A Garcia-Blanco
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA. .,Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore.
| | - Shelton S Bradrick
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA.
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19
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Wang H, Liu Y, Zhang L, Kundu JK, Liu W, Wang X. ADP ribosylation factor 1 facilitates spread of wheat dwarf virus in its insect vector. Cell Microbiol 2019; 21:e13047. [DOI: 10.1111/cmi.13047] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/01/2019] [Accepted: 05/13/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Hui Wang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing China
| | - Yan Liu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing China
| | - Lu Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing China
| | - Jiban Kumar Kundu
- Division of Crop Protection and Plant HealthCrop Research Institute Praha 6 Czech Republic
| | - Wenwen Liu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing China
| | - Xifeng Wang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing China
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20
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Fernandez-Chamorro J, Francisco-Velilla R, Ramajo J, Martinez-Salas E. Rab1b and ARF5 are novel RNA-binding proteins involved in FMDV IRES-driven RNA localization. Life Sci Alliance 2019; 2:e201800131. [PMID: 30655362 PMCID: PMC6337736 DOI: 10.26508/lsa.201800131] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 01/08/2019] [Accepted: 01/09/2019] [Indexed: 01/07/2023] Open
Abstract
Internal ribosome entry site (IRES) elements are organized in domains that guide internal initiation of translation. Here, we have combined proteomic and imaging analysis to study novel foot-and-mouth disease virus IRES interactors recognizing specific RNA structural subdomains. Besides known picornavirus IRES-binding proteins, we identified novel factors belonging to networks involved in RNA and protein transport. Among those, Rab1b and ARF5, two components of the ER-Golgi, revealed direct binding to IRES transcripts. However, whereas Rab1b stimulated IRES function, ARF5 diminished IRES activity. RNA-FISH studies revealed novel features of the IRES element. First, IRES-RNA formed clusters within the cell cytoplasm, whereas cap-RNA displayed disperse punctate distribution. Second, the IRES-driven RNA localized in close proximity with ARF5 and Rab1b, but not with the dominant-negative of Rab1b that disorganizes the Golgi. Thus, our data suggest a role for domain 3 of the IRES in RNA localization around ER-Golgi, a ribosome-rich cellular compartment.
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Affiliation(s)
- Javier Fernandez-Chamorro
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain
| | - Rosario Francisco-Velilla
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain
| | - Jorge Ramajo
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain
| | - Encarnación Martinez-Salas
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain
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21
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Zhang J, Lan Y, Li MY, Lamers MM, Fusade-Boyer M, Klemm E, Thiele C, Ashour J, Sanyal S. Flaviviruses Exploit the Lipid Droplet Protein AUP1 to Trigger Lipophagy and Drive Virus Production. Cell Host Microbe 2019; 23:819-831.e5. [PMID: 29902443 DOI: 10.1016/j.chom.2018.05.005] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 02/14/2018] [Accepted: 05/15/2018] [Indexed: 11/27/2022]
Abstract
Ubiquitylation is one of the most versatile protein post-translational modifications and is frequently altered during virus infections. Here we employed a functional proteomics screen to identify host proteins that are differentially ubiquitylated upon dengue virus (DENV) infection. Among the several differentially modified proteins identified in infected cells was AUP1, a lipid droplet-localized type-III membrane protein, which exists predominantly in the mono-ubiquitylated form. AUP1 associated with DENV NS4A and relocalized from lipid droplets to autophagosomes upon infection. Virus production was abolished in cells deleted for AUP1 or expressing an AUP1 acyltransferase domain mutant. Ubiquitylation disrupted the AUP1-NS4A interaction, resulting in inhibited acyltransferase activity, defective lipophagy, and attenuated virus production. Our results show that DENV-NS4A exploits the acyltransferase activity of AUP1 to trigger lipophagy, a process regulated by ubiquitylation. This mechanism appears to be a general phenomenon in biogenesis of flaviviruses and underscores the critical role of post-translational modifications in virus infections.
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Affiliation(s)
- Jingshu Zhang
- HKU-Pasteur Research Pole, School of Public Health, University of Hong Kong, Hong Kong
| | - Yun Lan
- HKU-Pasteur Research Pole, School of Public Health, University of Hong Kong, Hong Kong
| | - Ming Yuan Li
- HKU-Pasteur Research Pole, School of Public Health, University of Hong Kong, Hong Kong
| | - Mart Matthias Lamers
- HKU-Pasteur Research Pole, School of Public Health, University of Hong Kong, Hong Kong
| | - Maxime Fusade-Boyer
- HKU-Pasteur Research Pole, School of Public Health, University of Hong Kong, Hong Kong
| | - Elizabeth Klemm
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Christoph Thiele
- Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Joseph Ashour
- Icahn School of Medicine at Mount Sinai, New York City, NY 10029, USA
| | - Sumana Sanyal
- HKU-Pasteur Research Pole, School of Public Health, University of Hong Kong, Hong Kong; School of Biomedical Sciences, LKS Faculty of Medicine, University of Hong Kong, Hong Kong.
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22
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Chellasamy SK, Devarajan S. Identification of Potential Lead Molecules for Zika Envelope Protein from In Silico Perspective. Avicenna J Med Biotechnol 2019; 11:94-103. [PMID: 30800249 PMCID: PMC6359704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Zika virus is the family member of flavivirus with no reported clinically approved drugs or vaccines in the market till date. This virus is spread by Aedes mosquitoes, and can also be transmitted through sexual contact or blood transfusions. There are reported medical conditions like microcephaly among new-borns delivered by infected pregnant women. The envelope protein of Zika virus is associated with virulence, tropism, mediation of receptor binding and membrane fusion. ED1-EDII domain (K1 loop pocket) is an integral part of the envelope protein and a potential drug target. In the present study, the purpose was to identify the potential lead molecules to dock against K1 loop which could be later considered as flavivirus entry inhibitors. METHODS Multiple sequence alignment method was considered for the analysis of indels in envelope protein. Phylogenetic tree was constructed based on the alignment. Aliphatic index, GRAVY scores and hydropathy plot of the envelope proteins were calculated for the flavivirus family members. Zika envelope protein was homology modeled and considered for protein-ligand docking analysis with chemical compounds of known functions. RESULTS As per in silico based analysis, the envelope protein of Zika virus is highly hydrophilic with the least number of amino acid deletions compared to rest of the family members. During docking studies, it was observed that compounds like NITD, compound 6, P02, Doxytetracycline and Rolitetracycline show better binding affinity with Zika envelope protein compared to dengue virus. CONCLUSION These better binding compounds could be the promising lead molecules for Zika envelope protein which could better block the viral entry.
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Affiliation(s)
- Selvaa Kumar Chellasamy
- Corresponding author: Selvaa Kumar Chellasamy, Ph.D., Faculty of Biotechnology and Bioinformatics, D.Y. Patil Deemed to be University, CBD Belapur, Navi Mumbai, India, Tel: +91 22 27563600, E-mail:
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Zakaria MK, Carletti T, Marcello A. Cellular Targets for the Treatment of Flavivirus Infections. Front Cell Infect Microbiol 2018; 8:398. [PMID: 30483483 PMCID: PMC6240593 DOI: 10.3389/fcimb.2018.00398] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 10/23/2018] [Indexed: 12/31/2022] Open
Abstract
Classical antiviral therapy targets viral functions, mostly viral enzymes or receptors. Successful examples include precursor herpesvirus drugs, antiretroviral drugs that target reverse transcriptase and protease, influenza virus directed compounds as well as more recent direct antiviral agents (DAA) applied in the treatment of hepatitis C virus (HCV). However, from early times, the possibility of targeting the host cell to contain the infection has frequently re-emerged as an alternative and complementary antiviral strategy. Advantages of this approach include an increased threshold to the emergence of resistance and the possibility to target multiple viruses. Major pitfalls are related to important cellular side effects and cytotoxicity. In this mini-review, the concept of host directed antiviral therapy will be discussed with a focus on the most recent advances in the field of Flaviviruses, a family of important human pathogens for which we do not have antivirals available in the clinics.
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Affiliation(s)
- Mohammad Khalid Zakaria
- Laboratory of Molecular Virology, International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Tea Carletti
- Laboratory of Molecular Virology, International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Alessandro Marcello
- Laboratory of Molecular Virology, International Center for Genetic Engineering and Biotechnology, Trieste, Italy
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Sager G, Gabaglio S, Sztul E, Belov GA. Role of Host Cell Secretory Machinery in Zika Virus Life Cycle. Viruses 2018; 10:E559. [PMID: 30326556 PMCID: PMC6213159 DOI: 10.3390/v10100559] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 10/11/2018] [Accepted: 10/12/2018] [Indexed: 12/16/2022] Open
Abstract
The high human cost of Zika virus infections and the rapid establishment of virus circulation in novel areas, including the United States, present an urgent need for countermeasures against this emerging threat. The development of an effective vaccine against Zika virus may be problematic because of the cross reactivity of the antibodies with other flaviviruses leading to antibody-dependent enhancement of infection. Moreover, rapidly replicating positive strand RNA viruses, including Zika virus, generate large spectrum of mutant genomes (quasi species) every replication round, allowing rapid selection of variants resistant to drugs targeting virus-specific proteins. On the other hand, viruses are ultimate cellular parasites and rely on the host metabolism for every step of their life cycle, thus presenting an opportunity to manipulate host processes as an alternative approach to suppress virus replication and spread. Zika and other flaviviruses critically depend on the cellular secretory pathway, which transfers proteins and membranes from the ER through the Golgi to the plasma membrane, for virion assembly, maturation and release. In this review, we summarize the current knowledge of interactions of Zika and similar arthropod-borne flaviviruses with the cellular secretory machinery with a special emphasis on virus-specific changes of the secretory pathway. Identification of the regulatory networks and effector proteins required to accommodate the trafficking of virions, which represent a highly unusual cargo for the secretory pathway, may open an attractive and virtually untapped reservoir of alternative targets for the development of superior anti-viral drugs.
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Affiliation(s)
- Garrett Sager
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham AL 35294, UK.
| | - Samuel Gabaglio
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA.
| | - Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham AL 35294, UK.
| | - George A Belov
- Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA.
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Ferlin J, Farhat R, Belouzard S, Cocquerel L, Bertin A, Hober D, Dubuisson J, Rouillé Y. Investigation of the role of GBF1 in the replication of positive-sense single-stranded RNA viruses. J Gen Virol 2018; 99:1086-1096. [PMID: 29923822 DOI: 10.1099/jgv.0.001099] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
GBF1 has emerged as a host factor required for the replication of positive-sense single-stranded RNA viruses of different families, but its mechanism of action is still unknown. GBF1 is a guanine nucleotide exchange factor for Arf family members. Recently, we identified Arf4 and Arf5 (class II Arfs) as host factors required for the replication of hepatitis C virus (HCV), a GBF1-dependent virus. To assess whether a GBF1/class II Arf pathway is conserved among positive-sense single-stranded RNA viruses, we investigated yellow fever virus (YFV), Sindbis virus (SINV), coxsackievirus B4 (CVB4) and human coronavirus 229E (HCoV-229E). We found that GBF1 is involved in the replication of these viruses. However, using siRNA or CRISPR-Cas9 technologies, it was seen that the depletion of Arf1, Arf3, Arf4 or Arf5 had no impact on viral replication. In contrast, the depletion of Arf pairs suggested that class II Arfs could be involved in HCoV-229E, YFV and SINV infection, as for HCV, but not in CVB4 infection. In addition, another Arf pair, Arf1 and Arf4, appears to be essential for YFV and SINV infection, but not for infection by other viruses. Finally, CVB4 infection was not inhibited by any combination of Arf depletion. We conclude that the mechanism of action of GBF1 in viral replication appears not to be conserved, and that a subset of positive-sense single-stranded RNA viruses from different families might require class II Arfs for their replication.
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Affiliation(s)
- Juliette Ferlin
- 1Center for Infection and Immunity of Lille, Inserm U1019, CNRS UMR-8204, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Rayan Farhat
- 1Center for Infection and Immunity of Lille, Inserm U1019, CNRS UMR-8204, Institut Pasteur de Lille, Université de Lille, Lille, France.,†Present address: Inserm U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR-5286, Centre Léon Bérard, Lyon, France
| | - Sandrine Belouzard
- 1Center for Infection and Immunity of Lille, Inserm U1019, CNRS UMR-8204, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Laurence Cocquerel
- 1Center for Infection and Immunity of Lille, Inserm U1019, CNRS UMR-8204, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Antoine Bertin
- 2Université de Lille, Faculté de Médecine, CHU Lille, Laboratoire de Virologie EA3610, Lille, France
| | - Didier Hober
- 2Université de Lille, Faculté de Médecine, CHU Lille, Laboratoire de Virologie EA3610, Lille, France
| | - Jean Dubuisson
- 1Center for Infection and Immunity of Lille, Inserm U1019, CNRS UMR-8204, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Yves Rouillé
- 1Center for Infection and Immunity of Lille, Inserm U1019, CNRS UMR-8204, Institut Pasteur de Lille, Université de Lille, Lille, France
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Abraham R, Singh S, Nair SR, Hulyalkar NV, Surendran A, Jaleel A, Sreekumar E. Nucleophosmin (NPM1)/B23 in the Proteome of Human Astrocytic Cells Restricts Chikungunya Virus Replication. J Proteome Res 2017; 16:4144-4155. [PMID: 28959884 DOI: 10.1021/acs.jproteome.7b00513] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chikungunya virus (CHIKV), a positive-stranded RNA virus, can cause neurological complications by infecting the major parenchymal cells of the brain such as neurons and astrocytes. A proteomic analysis of CHIKV-infected human astrocytic cell line U-87 MG revealed tight functional associations among the modulated proteins. The predominant cellular pathways involved were of transcription-translation machinery, cytoskeletol reorganization, apoptosis, ubiquitination, and metabolism. In the proteome, we could also identify a few proteins that are reported to be involved in host-virus interactions. One such protein, Nucleophosmin (NPM1)/B23, a nucleolar protein, showed enhanced cytoplasmic aggregation in CHIKV-infected cells. NPM1 aggregation was predominantly localized in areas wherein CHIKV antigen could be detected. Furthermore, we observed that inhibition of this aggregation using a specific NPM1 oligomerization inhibitor, NSC348884, caused a significant dose-dependent enhancement in virus replication. There was a marked increase in the amount of intracellular viral RNA, and ∼105-fold increase in progeny virions in infected cells. Our proteomic analysis provides a comprehensive spectrum of host proteins modulated in response to CHIKV infection in astrocytic cells. Our results also show that NPM1/B23, a multifunctional chaperone, plays a critical role in restricting CHIKV replication and is a possible target for antiviral strategies.
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Affiliation(s)
- Rachy Abraham
- Molecular Virology Laboratory and ‡Proteomics Core Facility, Rajiv Gandhi Centre for Biotechnology (RGCB) , Thiruvananthapram 695014, Kerala, India
| | - Sneha Singh
- Molecular Virology Laboratory and ‡Proteomics Core Facility, Rajiv Gandhi Centre for Biotechnology (RGCB) , Thiruvananthapram 695014, Kerala, India
| | - Sreeja R Nair
- Molecular Virology Laboratory and ‡Proteomics Core Facility, Rajiv Gandhi Centre for Biotechnology (RGCB) , Thiruvananthapram 695014, Kerala, India
| | - Neha Vijay Hulyalkar
- Molecular Virology Laboratory and ‡Proteomics Core Facility, Rajiv Gandhi Centre for Biotechnology (RGCB) , Thiruvananthapram 695014, Kerala, India
| | - Arun Surendran
- Molecular Virology Laboratory and ‡Proteomics Core Facility, Rajiv Gandhi Centre for Biotechnology (RGCB) , Thiruvananthapram 695014, Kerala, India
| | - Abdul Jaleel
- Molecular Virology Laboratory and ‡Proteomics Core Facility, Rajiv Gandhi Centre for Biotechnology (RGCB) , Thiruvananthapram 695014, Kerala, India
| | - Easwaran Sreekumar
- Molecular Virology Laboratory and ‡Proteomics Core Facility, Rajiv Gandhi Centre for Biotechnology (RGCB) , Thiruvananthapram 695014, Kerala, India
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Zhang N, Zhang L. Key components of COPI and COPII machineries are required for chikungunya virus replication. Biochem Biophys Res Commun 2017; 493:1190-1196. [PMID: 28962860 DOI: 10.1016/j.bbrc.2017.09.142] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 09/25/2017] [Indexed: 10/18/2022]
Abstract
The infection of CHIKV is associated with cellular membranes; however whether early secretory pathways are involved in CHIKV replication remains unclear. In the present study, we have provided initial evidences that CHIKV requires both COPI and COPII for its replication. Small interfering RNAs against COPI components, including coatomer, ARFs or GBF1, suppress CHIKV replication. Moreover, CHIKV infection is abolished by the presence of ARF1 inhibitor brefeldin A or GBF1 inhibitor golgicide A. In addition, perturbation of COPII by silencing key components of COPII pathways leads to a reduction in CHIKV replication. Collectively, these observations demonstrate the importance of functional secretory pathways in the infectivity of CHIKV.
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Affiliation(s)
- Na Zhang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100176, China
| | - Leiliang Zhang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100176, China.
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28
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Quintana VM, Piccini LE, Panozzo Zénere JD, Damonte EB, Ponce MA, Castilla V. Antiviral activity of natural and synthetic β-carbolines against dengue virus. Antiviral Res 2016; 134:26-33. [DOI: 10.1016/j.antiviral.2016.08.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/20/2016] [Indexed: 12/17/2022]
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29
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Systems Biology-Based Investigation of Cellular Antiviral Drug Targets Identified by Gene-Trap Insertional Mutagenesis. PLoS Comput Biol 2016; 12:e1005074. [PMID: 27632082 PMCID: PMC5025164 DOI: 10.1371/journal.pcbi.1005074] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/22/2016] [Indexed: 02/05/2023] Open
Abstract
Viruses require host cellular factors for successful replication. A comprehensive systems-level investigation of the virus-host interactome is critical for understanding the roles of host factors with the end goal of discovering new druggable antiviral targets. Gene-trap insertional mutagenesis is a high-throughput forward genetics approach to randomly disrupt (trap) host genes and discover host genes that are essential for viral replication, but not for host cell survival. In this study, we used libraries of randomly mutagenized cells to discover cellular genes that are essential for the replication of 10 distinct cytotoxic mammalian viruses, 1 gram-negative bacterium, and 5 toxins. We herein reported 712 candidate cellular genes, characterizing distinct topological network and evolutionary signatures, and occupying central hubs in the human interactome. Cell cycle phase-specific network analysis showed that host cell cycle programs played critical roles during viral replication (e.g. MYC and TAF4 regulating G0/1 phase). Moreover, the viral perturbation of host cellular networks reflected disease etiology in that host genes (e.g. CTCF, RHOA, and CDKN1B) identified were frequently essential and significantly associated with Mendelian and orphan diseases, or somatic mutations in cancer. Computational drug repositioning framework via incorporating drug-gene signatures from the Connectivity Map into the virus-host interactome identified 110 putative druggable antiviral targets and prioritized several existing drugs (e.g. ajmaline) that may be potential for antiviral indication (e.g. anti-Ebola). In summary, this work provides a powerful methodology with a tight integration of gene-trap insertional mutagenesis testing and systems biology to identify new antiviral targets and drugs for the development of broadly acting and targeted clinical antiviral therapeutics. Infectious diseases result in millions of deaths and cost billions of dollars annually. Hence, there is urgency for developing more innovative and effective antiviral therapeutics. In this study, we used libraries of randomly mutagenized cells to discover cellular genes that are essential for the replication of 10 distinct cytotoxic mammalian viruses. We herein reported over 700 candidate cellular genes, over 20% of which were independently selected by multiple viruses in one or more cell types. Using systems biology-based analysis, we found that host genes associated with viral replication tended to occupy central hubs in the human protein interactome and to be ancient genes with low evolutionary rates, compared to non-virus-associated genes. Cell cycle phase-specific sub-network analysis showed that host cell cycle program played important roles during viral replication by regulating specific cell cycle phases. Moreover, we presented novel evidences to suggest that host genes supporting viral replication were frequently implicated in Mendelian and orphan diseases, or played critical roles in cancer. Importantly, we found approximately 110 new putative druggable antiviral targets by merging genome-wide gene-trap insertional mutagenesis, drug-gene network, and bioinformatics data. Furthermore, we have demonstrated the use of a computable representation of genetic testing to effectively identify new potential antiviral indications for existing drugs. In summary, this study presents new and important methodologies for developing broadly active antiviral therapeutics.
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30
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Karyala P, Metri R, Bathula C, Yelamanchi SK, Sahoo L, Arjunan S, Sastri NP, Chandra N. DenHunt - A Comprehensive Database of the Intricate Network of Dengue-Human Interactions. PLoS Negl Trop Dis 2016; 10:e0004965. [PMID: 27618709 PMCID: PMC5019383 DOI: 10.1371/journal.pntd.0004965] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 08/09/2016] [Indexed: 01/01/2023] Open
Abstract
Dengue virus (DENV) is a human pathogen and its etiology has been widely established. There are many interactions between DENV and human proteins that have been reported in literature. However, no publicly accessible resource for efficiently retrieving the information is yet available. In this study, we mined all publicly available dengue-human interactions that have been reported in the literature into a database called DenHunt. We retrieved 682 direct interactions of human proteins with dengue viral components, 382 indirect interactions and 4120 differentially expressed human genes in dengue infected cell lines and patients. We have illustrated the importance of DenHunt by mapping the dengue-human interactions on to the host interactome and observed that the virus targets multiple host functional complexes of important cellular processes such as metabolism, immune system and signaling pathways suggesting a potential role of these interactions in viral pathogenesis. We also observed that 7 percent of the dengue virus interacting human proteins are also associated with other infectious and non-infectious diseases. Finally, the understanding that comes from such analyses could be used to design better strategies to counteract the diseases caused by dengue virus. The whole dataset has been catalogued in a searchable database, called DenHunt (http://proline.biochem.iisc.ernet.in/DenHunt/).
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Affiliation(s)
- Prashanthi Karyala
- Department of Biochemistry, Center of Research and Post Graduate Studies, Indian Academy Degree College, Bengaluru, Karnataka, India
- * E-mail:
| | - Rahul Metri
- IISc Mathematics Initiative, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Christopher Bathula
- Department of Biochemistry, Center of Research and Post Graduate Studies, Indian Academy Degree College, Bengaluru, Karnataka, India
| | - Syam K. Yelamanchi
- Department of Biochemistry, Center of Research and Post Graduate Studies, Indian Academy Degree College, Bengaluru, Karnataka, India
| | - Lipika Sahoo
- LifeIntelect Consultancy Pvt Ltd, Marathahalli, Bengaluru, Karnataka, India
| | - Selvam Arjunan
- Department of Biotechnology, Center of Research and Post Graduate Studies, Indian Academy Degree College, Bengaluru, Karnataka, India
| | - Narayan P. Sastri
- Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Nagasuma Chandra
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
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Brault JB, Khou C, Basset J, Coquand L, Fraisier V, Frenkiel MP, Goud B, Manuguerra JC, Pardigon N, Baffet AD. Comparative Analysis Between Flaviviruses Reveals Specific Neural Stem Cell Tropism for Zika Virus in the Mouse Developing Neocortex. EBioMedicine 2016; 10:71-6. [PMID: 27453325 PMCID: PMC5006693 DOI: 10.1016/j.ebiom.2016.07.018] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 07/06/2016] [Accepted: 07/14/2016] [Indexed: 02/04/2023] Open
Abstract
The recent Zika outbreak in South America and French Polynesia was associated with an epidemic of microcephaly, a disease characterized by a reduced size of the cerebral cortex. Other members of the Flavivirus genus, including West Nile virus (WNV), can cause encephalitis but were not demonstrated to cause microcephaly. It remains unclear whether Zika virus (ZIKV) and other flaviviruses may infect different cell populations in the developing neocortex and lead to distinct developmental defects. Here, we describe an assay to infect mouse E15 embryonic brain slices with ZIKV, WNV and dengue virus serotype 4 (DENV-4). We show that this tissue is able to support viral replication of ZIKV and WNV, but not DENV-4. Cell fate analysis reveals a remarkable tropism of ZIKV infection for neural stem cells. Closely related WNV displays a very different tropism of infection, with a bias towards neurons. We further show that ZIKV infection, but not WNV infection, impairs cell cycle progression of neural stem cells. Both viruses inhibited apoptosis at early stages of infection. This work establishes a powerful comparative approach to identify ZIKV-specific alterations in the developing neocortex and reveals specific preferential infection of neural stem cells by ZIKV. Mouse embryonic brain slices sustain Zika and West Nile, but not Dengue-4, virus replication. Zika virus, but not West Nile virus, exhibits a selective tropism of infection for neural stem cells. Zika virus, but not West Nile virus, alters cell cycle progression of neural stem cells.
A Zika virus outbreak in South America is currently responsible for a large burst of microcephaly cases, a congenital brain malformation characterized by a reduced brain size. We describe here an assay to infect cultured mouse embryonic brain slices with Zika virus as well as other closely related flaviviruses not demonstrated to cause microcephaly. We show that Zika virus displays a specific pattern of infection in the developing brain, almost exclusively infecting neural stem cells. Zika virus impairs neural stem cell proliferation, an effect not seen for other flaviviruses and that may participate in the induction of microcephaly.
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Affiliation(s)
| | - Cécile Khou
- Institut Pasteur, ERI/CIBU Arbovirus Group, 25 rue du Dr Roux, 75015 Paris, France
| | - Justine Basset
- Institut Pasteur, ERI/CIBU Arbovirus Group, 25 rue du Dr Roux, 75015 Paris, France
| | - Laure Coquand
- Institut Curie, PSL Research University, CNRS, UMR144, F-75005 Paris, France
| | - Vincent Fraisier
- Institut Curie, PSL Research University, CNRS, UMR144, F-75005 Paris, France
| | | | - Bruno Goud
- Institut Curie, PSL Research University, CNRS, UMR144, F-75005 Paris, France
| | | | - Nathalie Pardigon
- Institut Pasteur, ERI/CIBU Arbovirus Group, 25 rue du Dr Roux, 75015 Paris, France
| | - Alexandre D Baffet
- Institut Curie, PSL Research University, CNRS, UMR144, F-75005 Paris, France.
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Farhat R, Séron K, Ferlin J, Fénéant L, Belouzard S, Goueslain L, Jackson CL, Dubuisson J, Rouillé Y. Identification of class II ADP-ribosylation factors as cellular factors required for hepatitis C virus replication. Cell Microbiol 2016; 18:1121-33. [PMID: 26814617 DOI: 10.1111/cmi.12572] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 01/12/2016] [Accepted: 01/21/2016] [Indexed: 12/21/2022]
Abstract
GBF1 is a host factor required for hepatitis C virus (HCV) replication. GBF1 functions as a guanine nucleotide exchange factor for G-proteins of the Arf family, which regulate membrane dynamics in the early secretory pathway and the metabolism of cytoplasmic lipid droplets. Here we established that the Arf-guanine nucleotide exchange factor activity of GBF1 is critical for its function in HCV replication, indicating that it promotes viral replication by activating one or more Arf family members. Arf involvement was confirmed with the use of two dominant negative Arf1 mutants. However, siRNA-mediated depletion of Arf1, Arf3 (class I Arfs), Arf4 or Arf5 (class II Arfs), which potentially interact with GBF1, did not significantly inhibit HCV infection. In contrast, the simultaneous depletion of both Arf4 and Arf5, but not of any other Arf pair, imposed a significant inhibition of HCV infection. Interestingly, the simultaneous depletion of both Arf4 and Arf5 had no impact on the activity of the secretory pathway and induced a compaction of the Golgi and an accumulation of lipid droplets. A similar phenotype of lipid droplet accumulation was also observed when GBF1 was inhibited by brefeldin A. In contrast, the simultaneous depletion of both Arf1 and Arf4 resulted in secretion inhibition and Golgi scattering, two actions reminiscent of GBF1 inhibition. We conclude that GBF1 could regulate different metabolic pathways through the activation of different pairs of Arf proteins.
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Affiliation(s)
- Rayan Farhat
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204, CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Karin Séron
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204, CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Juliette Ferlin
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204, CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Lucie Fénéant
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204, CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Sandrine Belouzard
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204, CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Lucie Goueslain
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204, CIIL - Center for Infection and Immunity of Lille, Lille, France.,Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Catherine L Jackson
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Jean Dubuisson
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204, CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Yves Rouillé
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204, CIIL - Center for Infection and Immunity of Lille, Lille, France
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A Single Amino Acid Substitution in the M Protein Attenuates Japanese Encephalitis Virus in Mammalian Hosts. J Virol 2015; 90:2676-89. [PMID: 26656690 DOI: 10.1128/jvi.01176-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 11/30/2015] [Indexed: 02/04/2023] Open
Abstract
UNLABELLED Japanese encephalitis virus (JEV) membrane (M) protein plays important structural roles in the processes of fusion and maturation of progeny virus during cellular infection. The M protein is anchored in the viral membrane, and its ectodomain is composed of a flexible N-terminal loop and a perimembrane helix. In this study, we performed site-directed mutagenesis on residue 36 of JEV M protein and showed that the resulting mutation had little or no effect on the entry process but greatly affected virus assembly in mammalian cells. Interestingly, this mutant virus had a host-dependent phenotype and could develop a wild-type infection in insect cells. Experiments performed on infectious virus as well as in a virus-like particle (VLP) system indicate that the JEV mutant expresses structural proteins but fails to form infectious particles in mammalian cells. Using a mouse model for JEV pathogenesis, we showed that the mutation conferred complete attenuation in vivo. The production of JEV neutralizing antibodies in challenged mice was indicative of the immunogenicity of the mutant virus in vivo. Together, our results indicate that the introduction of a single mutation in the M protein, while being tolerated in insect cells, strongly impacts JEV infection in mammalian hosts. IMPORTANCE JEV is a mosquito-transmitted flavivirus and is a medically important pathogen in Asia. The M protein is thought to be important for accommodating the structural rearrangements undergone by the virion during viral assembly and may play additional roles in the JEV infectious cycle. In the present study, we show that a sole mutation in the M protein impairs the JEV infection cycle in mammalian hosts but not in mosquito cells. This finding highlights differences in flavivirus assembly pathways among hosts. Moreover, infection of mice indicated that the mutant was completely attenuated and triggered a strong immune response to JEV, thus providing new insights for further development of JEV vaccines.
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Millet JK, Nal B. Investigation of the functional roles of host cell proteins involved in coronavirus infection using highly specific and scalable RNA interference (RNAi) approach. Methods Mol Biol 2015; 1282:231-40. [PMID: 25720484 PMCID: PMC7121302 DOI: 10.1007/978-1-4939-2438-7_19] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Since its identification in the 1990s, the RNA interference (RNAi) pathway has proven extremely useful in elucidating the function of proteins in the context of cells and even whole organisms. In particular, this sequence-specific and powerful loss-of-function approach has greatly simplified the study of the role of host cell factors implicated in the life cycle of viruses. Here, we detail the RNAi method we have developed and used to specifically knock down the expression of ezrin, an actin binding protein that was identified by yeast two-hybrid screening to interact with the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) spike (S) protein. This method was used to study the role of ezrin, specifically during the entry stage of SARS-CoV infection.
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Affiliation(s)
- Jean Kaoru Millet
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, 14853, USA
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Scaturro P, Cortese M, Chatel-Chaix L, Fischl W, Bartenschlager R. Dengue Virus Non-structural Protein 1 Modulates Infectious Particle Production via Interaction with the Structural Proteins. PLoS Pathog 2015; 11:e1005277. [PMID: 26562291 PMCID: PMC4643051 DOI: 10.1371/journal.ppat.1005277] [Citation(s) in RCA: 147] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 10/22/2015] [Indexed: 12/15/2022] Open
Abstract
Non-structural protein 1 (NS1) is one of the most enigmatic proteins of the Dengue virus (DENV), playing distinct functions in immune evasion, pathogenesis and viral replication. The recently reported crystal structure of DENV NS1 revealed its peculiar three-dimensional fold; however, detailed information on NS1 function at different steps of the viral replication cycle is still missing. By using the recently reported crystal structure, as well as amino acid sequence conservation, as a guide for a comprehensive site-directed mutagenesis study, we discovered that in addition to being essential for RNA replication, DENV NS1 is also critically required for the production of infectious virus particles. Taking advantage of a trans-complementation approach based on fully functional epitope-tagged NS1 variants, we identified previously unreported interactions between NS1 and the structural proteins Envelope (E) and precursor Membrane (prM). Interestingly, coimmunoprecipitation revealed an additional association with capsid, arguing that NS1 interacts via the structural glycoproteins with DENV particles. Results obtained with mutations residing either in the NS1 Wing domain or in the β-ladder domain suggest that NS1 might have two distinct functions in the assembly of DENV particles. By using a trans-complementation approach with a C-terminally KDEL-tagged ER-resident NS1, we demonstrate that the secretion of NS1 is dispensable for both RNA replication and infectious particle production. In conclusion, our results provide an extensive genetic map of NS1 determinants essential for viral RNA replication and identify a novel role of NS1 in virion production that is mediated via interaction with the structural proteins. These studies extend the list of NS1 functions and argue for a central role in coordinating replication and assembly/release of infectious DENV particles. Dengue virus (DENV) is a major arthropod-borne human pathogen, infecting more than 400 million individuals annually worldwide; however, neither a therapeutic drug nor a prophylactic vaccine is currently available. Amongst the DENV proteins, non-structural protein 1 (NS1) is one of the most enigmatic, being required for RNA replication, but also secreted from infected cells to counteract antiviral immune response, thus contributing to pathogenesis. Despite its essential role at early stages of the viral replication cycle, the molecular determinants governing NS1 functions are unknown. Here, we used a combination of genetic, high-resolution imaging and biochemical approaches and found that NS1 additionally plays an important role for the production of infectious virus particles. By using a novel trans-complementation system with fully functional epitope-tagged NS1, we show that NS1 interacts with the structural proteins residing in the envelope of the virus particle. An NS1 variant retained in the endoplasmic reticulum still supported efficient DENV particle production, demonstrating that secretion of NS1 is dispensable for virion production. This study expands the list of functions exerted by NS1 for the DENV replication cycle. Given this multi-functional nature, NS1 appears to be an attractive target for antiviral therapy.
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Affiliation(s)
- Pietro Scaturro
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
- * E-mail: (PS); (RB)
| | - Mirko Cortese
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Laurent Chatel-Chaix
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Wolfgang Fischl
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
- * E-mail: (PS); (RB)
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Affiliation(s)
- Ming Yuan Li
- HKU-Pasteur Research Pole, School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR
| | - Roberto Bruzzone
- HKU-Pasteur Research Pole, School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR
| | - Pei Gang Wang
- Key Laboratory of Protein and Peptide Pharmaceuticals, Institute of Biophysics, Chinese Academy of Sciences, Beijing, PR China
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Genome-Wide Screen Reveals Valosin-Containing Protein Requirement for Coronavirus Exit from Endosomes. J Virol 2015; 89:11116-28. [PMID: 26311884 DOI: 10.1128/jvi.01360-15] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 08/22/2015] [Indexed: 12/28/2022] Open
Abstract
UNLABELLED Coronaviruses are RNA viruses with a large zoonotic reservoir and propensity for host switching, representing a real threat for public health, as evidenced by severe acute respiratory syndrome (SARS) and the emerging Middle East respiratory syndrome (MERS). Cellular factors required for their replication are poorly understood. Using genome-wide small interfering RNA (siRNA) screening, we identified 83 novel genes supporting infectious bronchitis virus (IBV) replication in human cells. Thirty of these hits can be placed in a network of interactions with viral proteins and are involved in RNA splicing, membrane trafficking, and ubiquitin conjugation. In addition, our screen reveals an unexpected role for valosin-containing protein (VCP/p97) in early steps of infection. Loss of VCP inhibits a previously uncharacterized degradation of the nucleocapsid N protein. This inhibition derives from virus accumulation in early endosomes, suggesting a role for VCP in the maturation of virus-loaded endosomes. The several host factors identified in this study may provide avenues for targeted therapeutics. IMPORTANCE Coronaviruses are RNA viruses representing a real threat for public health, as evidenced by SARS and the emerging MERS. However, cellular factors required for their replication are poorly understood. Using genome-wide siRNA screening, we identified novel genes supporting infectious bronchitis virus (IBV) replication in human cells. The several host factors identified in this study may provide directions for future research on targeted therapeutics.
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Iglesias NG, Mondotte JA, Byk LA, De Maio FA, Samsa MM, Alvarez C, Gamarnik AV. Dengue Virus Uses a Non-Canonical Function of the Host GBF1-Arf-COPI System for Capsid Protein Accumulation on Lipid Droplets. Traffic 2015; 16:962-77. [PMID: 26031340 DOI: 10.1111/tra.12305] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 05/22/2015] [Accepted: 05/24/2015] [Indexed: 12/14/2022]
Abstract
Dengue viruses cause the most important human viral disease transmitted by mosquitoes. In recent years, a great deal has been learned about molecular details of dengue virus genome replication; however, little is known about genome encapsidation and the functions of the viral capsid protein. During infection, dengue virus capsid progressively accumulates around lipid droplets (LDs) by an unknown mechanism. Here, we examined the process by which the viral capsid is transported from the endoplasmic reticulum (ER) membrane, where the protein is synthesized, to LDs. Using different methods of intervention, we found that the GBF1-Arf1/Arf4-COPI pathway is necessary for capsid transport to LDs, while the process is independent of both COPII components and Golgi integrity. The transport was sensitive to Brefeldin A, while a drug resistant form of GBF1 was sufficient to restore capsid subcellular distribution in infected cells. The mechanism by which LDs gain or lose proteins is still an open question. Our results support a model in which the virus uses a non-canonical function of the COPI system for capsid accumulation on LDs, providing new ideas for antiviral strategies.
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Affiliation(s)
- Nestor G Iglesias
- Fundación Instituto Leloir-CONICET, Avenida Patricias Argentinas 435, Buenos Aires, 1405, Argentina
| | - Juan A Mondotte
- Fundación Instituto Leloir-CONICET, Avenida Patricias Argentinas 435, Buenos Aires, 1405, Argentina
| | - Laura A Byk
- Fundación Instituto Leloir-CONICET, Avenida Patricias Argentinas 435, Buenos Aires, 1405, Argentina
| | - Federico A De Maio
- Fundación Instituto Leloir-CONICET, Avenida Patricias Argentinas 435, Buenos Aires, 1405, Argentina
| | - Marcelo M Samsa
- Fundación Instituto Leloir-CONICET, Avenida Patricias Argentinas 435, Buenos Aires, 1405, Argentina
| | - Cecilia Alvarez
- Centro de Investigaciones en Bioquímica Clínica e Inmunología-CONICET, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, UNC, 5000, Córdoba, Argentina
| | - Andrea V Gamarnik
- Fundación Instituto Leloir-CONICET, Avenida Patricias Argentinas 435, Buenos Aires, 1405, Argentina
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Yasamut U, Tongmuang N, Yenchitsomanus PT, Junking M, Noisakran S, Puttikhunt C, Chu JJH, Limjindaporn T. Adaptor Protein 1A Facilitates Dengue Virus Replication. PLoS One 2015; 10:e0130065. [PMID: 26090672 PMCID: PMC4474434 DOI: 10.1371/journal.pone.0130065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/15/2015] [Indexed: 11/23/2022] Open
Abstract
Rearrangement of membrane structure induced by dengue virus (DENV) is essential for replication, and requires host cellular machinery. Adaptor protein complex (AP)-1 is a host component, which can be recruited to components required for membrane rearrangement. Therefore, dysfunction of AP-1 may affect membrane organization, thereby decreasing replication of virus in infected cells. In the present study, AP-1-dependent traffic inhibitor inhibited DENV protein expression and virion production. We further clarified the role of AP-1A in the life cycle of DENV by RNA interference. AP-1A was not involved in DENV entry into cells. However, it facilitated DENV RNA replication. Viral RNA level was reduced significantly in Huh7 cells transfected with AP-1A small interfering RNA (siRNA) compared with control siRNA. Transfection of naked DENV viral RNA into Huh7 cells transfected with AP-1A siRNA resulted in less viral RNA and virion production than transfection into Huh7 cells transfected with control siRNA. Huh7 cells transfected with AP-1A siRNA showed greater modification of membrane structures and fewer vesicular packets compared with cells transfected with control siRNA. Therefore, AP-1A may partly control DENV-induced rearrangement of membrane structures required for viral replication.
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Affiliation(s)
- Umpa Yasamut
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Nopprarat Tongmuang
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Pa-thai Yenchitsomanus
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Mutita Junking
- Division of Molecular Medicine, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Sansanee Noisakran
- Medical Biotechnology Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok, Thailand
| | - Chunya Puttikhunt
- Medical Biotechnology Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok, Thailand
| | - Justin Jang Hann Chu
- Laboratory of Molecular RNA Virology and Antiviral Strategies, Department of Microbiology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore
| | - Thawornchai Limjindaporn
- Department of Anatomy, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- * E-mail:
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Setoh YX, Tan CSE, Prow NA, Hobson-Peters J, Young PR, Khromykh AA, Hall RA. The I22V and L72S substitutions in West Nile virus prM protein promote enhanced prM/E heterodimerisation and nucleocapsid incorporation. Virol J 2015; 12:72. [PMID: 25946997 PMCID: PMC4424586 DOI: 10.1186/s12985-015-0303-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/28/2015] [Indexed: 11/10/2022] Open
Abstract
Background Amino acid substitutions I22V and L72S in the prM protein of West Nile virus Kunjin strain (WNVKUN) were previously shown to enhance virus secretion and virulence, but a mechanism by which this occurred was not determined. Findings Using pulse-chase experiments followed by co-immunoprecipitation with anti-E antibody, we demonstrated that the I22V and L72S substitutions enhanced prM/E heterodimerization for both the E-glycosylated and E-unglycosylated virus. Furthermore, analysis of secreted particles revealed that I22V and L72S substitutions also enhanced nucleocapsid incorporation. Conclusions We have demonstrated mechanistically that improved secretion of virus particles in the presence of I22V and L72S substitutions was contributed by more efficient prM/E heterodimerization.
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Affiliation(s)
- Yin Xiang Setoh
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
| | - Cindy Si En Tan
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia. .,Present Address: Sir Albert Sakzewski Virus Research Centre, Clinical Medical Virology Centre, Herston, QLD, Australia.
| | - Natalie A Prow
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia. .,Present Address: QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
| | - Jody Hobson-Peters
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
| | - Paul R Young
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
| | - Alexander A Khromykh
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
| | - Roy A Hall
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
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KDEL Receptors Assist Dengue Virus Exit from the Endoplasmic Reticulum. Cell Rep 2015; 10:1496-1507. [PMID: 25753416 DOI: 10.1016/j.celrep.2015.02.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 10/16/2014] [Accepted: 02/04/2015] [Indexed: 11/23/2022] Open
Abstract
Membrane receptors at the surface of target cells are key host factors for virion entry; however, it is unknown whether trafficking and secretion of progeny virus requires host intracellular receptors. In this study, we demonstrate that dengue virus (DENV) interacts with KDEL receptors (KDELR), which cycle between the ER and Golgi apparatus, for vesicular transport from ER to Golgi. Depletion of KDELR by siRNA reduced egress of both DENV progeny and recombinant subviral particles (RSPs). Coimmunoprecipitation of KDELR with dengue structural protein prM required three positively charged residues at the N terminus, whose mutation disrupted protein interaction and inhibited RSP transport from the ER to the Golgi. Finally, siRNA depletion of class II Arfs, which results in KDELR accumulation in the Golgi, phenocopied results obtained with mutagenized prME and KDELR knockdown. Our results have uncovered a function for KDELR as an internal receptor involved in DENV trafficking.
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Ding ZF, Ren J, Tan JM, Wang Z, Yin SW, Huang Y, Huang X, Wang W, Lan JF, Ren Q. Characterization of two novel ADP ribosylation factors from giant freshwater prawn Macrobrachium rosenbergii and their responses to WSSV challenge. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2015; 48:204-209. [PMID: 25451300 PMCID: PMC7124501 DOI: 10.1016/j.dci.2014.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/10/2014] [Accepted: 10/13/2014] [Indexed: 06/04/2023]
Abstract
ADP-ribosylation factors (Arfs) are small GTP-binding proteins that have an essential function in intracellular trafficking and organelle structure. To date, little information is available on the Arfs in the economically important giant freshwater prawn Macrobrachium rosenbergii and their relationship to viral infection. Here we identified two Arf genes from M. rosenbergii (MrArf1 and MrArf2) for the first time. Phylogenetic analysis showed that MrArf1, together with MjArf1 from shrimp Marsupenaeus japonicus belonged to Class I Arfs. By contrast, MrArf2 didn't not match any of the Arfs classes of I/II/III, although it could be clustered with an Arf protein from M. japonicas called MjArfn, which may represent an analog of the Arf. MrArf1 was ubiquitously expressed in all the examined tissues, with the highest transcription level in the hepatopancreas, whereas MrArf2 was only highly expressed in the hepatopancreas and exhibited very low levels in the heart, stomach, gills and intestine. The expression level of MrArf1 in the gills was down-regulated post 24 h WSSV challenge, and reached the maximal level at 48 h. MrArf1 in the hepatopancreas went up from 24 to 48 h WSSV challenge. MrArf2 transcript in the gill also went down at 24 h and then was upregulated at 48 h WSSV challenge. MrArf2 increased significantly in the hepatopancreas 24 h after infection and then went down at 48 h WSSV challenge. RNAi results showed that knockdown of MrArf1 or MrArf2 could inhibit the expression of the envelope protein gene vp28 of the WSSV. So, it could be speculated that MrArf1 and MrArf2 might play important roles in the innate immune system against WSSV infection.
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Affiliation(s)
- Zheng-Feng Ding
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China; Freshwater Fisheries Research Institute of Jiangsu Province, 79 Chating East Street, Nanjing 210017, China
| | - Jie Ren
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China
| | - Jing-Min Tan
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China
| | - Zheng Wang
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China
| | - Shao-Wu Yin
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China
| | - Ying Huang
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China
| | - Xin Huang
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China
| | - Wen Wang
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China
| | - Jiang-Feng Lan
- College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
| | - Qian Ren
- Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China.
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Abstract
Dengue virus (DENV) is an emerging mosquito-borne human pathogen that affects millions of individuals each year by causing severe and potentially fatal syndromes. Despite intense research efforts, no approved vaccine or antiviral therapy is yet available. Overcoming this limitation requires detailed understanding of the intimate relationship between the virus and its host cell, providing the basis to devise optimal prophylactic and therapeutic treatment options. With the advent of novel high-throughput technologies including functional genomics, transcriptomics, proteomics, and lipidomics, new important insights into the DENV replication cycle and the interaction of this virus with its host cell have been obtained. In this chapter, we provide a comprehensive overview on the current status of the DENV research field, covering every step of the viral replication cycle with a particular focus on virus-host cell interaction. We will also review specific chemical inhibitors targeting cellular factors and processes of relevance for the DENV replication cycle and their possible exploitation for the development of next generation antivirals.
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44
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Characterization of the mode of action of a potent dengue virus capsid inhibitor. J Virol 2014; 88:11540-55. [PMID: 25056895 DOI: 10.1128/jvi.01745-14] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Dengue viruses (DV) represent a significant global health burden, with up to 400 million infections every year and around 500,000 infected individuals developing life-threatening disease. In spite of attempts to develop vaccine candidates and antiviral drugs, there is a lack of approved therapeutics for the treatment of DV infection. We have previously reported the identification of ST-148, a small-molecule inhibitor exhibiting broad and potent antiviral activity against DV in vitro and in vivo (C. M. Byrd et al., Antimicrob. Agents Chemother. 57:15-25, 2013, doi:10 .1128/AAC.01429-12). In the present study, we investigated the mode of action of this promising compound by using a combination of biochemical, virological, and imaging-based techniques. We confirmed that ST-148 targets the capsid protein and obtained evidence of bimodal antiviral activity affecting both assembly/release and entry of infectious DV particles. Importantly, by using a robust bioluminescence resonance energy transfer-based assay, we observed an ST-148-dependent increase of capsid self-interaction. These results were corroborated by molecular modeling studies that also revealed a plausible model for compound binding to capsid protein and inhibition by a distinct resistance mutation. These results suggest that ST-148-enhanced capsid protein self-interaction perturbs assembly and disassembly of DV nucleocapsids, probably by inducing structural rigidity. Thus, as previously reported for other enveloped viruses, stabilization of capsid protein structure is an attractive therapeutic concept that also is applicable to flaviviruses. IMPORTANCE Dengue viruses are arthropod-borne viruses representing a significant global health burden. They infect up to 400 million people and are endemic to subtropical and tropical areas of the world. Currently, there are neither vaccines nor approved therapeutics for the prophylaxis or treatment of DV infections, respectively. This study reports the characterization of the mode of action of ST-148, a small-molecule capsid inhibitor with potent antiviral activity against all DV serotypes. Our results demonstrate that ST-148 stabilizes capsid protein self-interaction, thereby likely perturbing assembly and disassembly of viral nucleocapsids by inducing structural rigidity. This, in turn, might interfere with the release of viral RNA from incoming nucleocapsids (uncoating) as well as assembly of progeny virus particles. As previously reported for other enveloped viruses, we propose the capsid as a novel tractable target for flavivirus inhibitors.
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45
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Wang J, Du J, Jin Q. Class I ADP-ribosylation factors are involved in enterovirus 71 replication. PLoS One 2014; 9:e99768. [PMID: 24911624 PMCID: PMC4049829 DOI: 10.1371/journal.pone.0099768] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 05/16/2014] [Indexed: 12/16/2022] Open
Abstract
Enterovirus 71 is one of the major causative agents of hand, foot, and mouth disease in infants and children. Replication of enterovirus 71 depends on host cellular factors. The viral replication complex is formed in novel, cytoplasmic, vesicular compartments. It has not been elucidated which cellular pathways are hijacked by the virus to create these vesicles. Here, we investigated whether proteins associated with the cellular secretory pathway were involved in enterovirus 71 replication. We used a loss-of-function assay, based on small interfering RNA. We showed that enterovirus 71 RNA replication was dependent on the activity of Class I ADP-ribosylation factors. Simultaneous depletion of ADP-ribosylation factors 1 and 3, but not three others, inhibited viral replication in cells. We also demonstrated with various techniques that the brefeldin-A-sensitive guanidine nucleotide exchange factor, GBF1, was critically important for enterovirus 71 replication. Our results suggested that enterovirus 71 replication depended on GBF1-mediated activation of Class I ADP-ribosylation factors. These results revealed a connection between enterovirus 71 replication and the cellular secretory pathway; this pathway may represent a novel target for antiviral therapies.
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Affiliation(s)
- Jianmin Wang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Jiang Du
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
| | - Qi Jin
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China
- * E-mail:
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Follit JA, San Agustin JT, Jonassen JA, Huang T, Rivera-Perez JA, Tremblay KD, Pazour GJ. Arf4 is required for Mammalian development but dispensable for ciliary assembly. PLoS Genet 2014; 10:e1004170. [PMID: 24586199 PMCID: PMC3930517 DOI: 10.1371/journal.pgen.1004170] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 12/25/2013] [Indexed: 02/06/2023] Open
Abstract
The primary cilium is a sensory organelle, defects in which cause a wide range of human diseases including retinal degeneration, polycystic kidney disease and birth defects. The sensory functions of cilia require specific receptors to be targeted to the ciliary subdomain of the plasma membrane. Arf4 has been proposed to sort cargo destined for the cilium at the Golgi complex and deemed a key regulator of ciliary protein trafficking. In this work, we show that Arf4 binds to the ciliary targeting sequence (CTS) of fibrocystin. Knockdown of Arf4 indicates that it is not absolutely required for trafficking of the fibrocystin CTS to cilia as steady-state CTS levels are unaffected. However, we did observe a delay in delivery of newly synthesized CTS from the Golgi complex to the cilium when Arf4 was reduced. Arf4 mutant mice are embryonic lethal and die at mid-gestation shortly after node formation. Nodal cilia appeared normal and functioned properly to break left-right symmetry in Arf4 mutant embryos. At this stage of development Arf4 expression is highest in the visceral endoderm but we did not detect cilia on these cells. In the visceral endoderm, the lack of Arf4 caused defects in cell structure and apical protein localization. This work suggests that while Arf4 is not required for ciliary assembly, it is important for the efficient transport of fibrocystin to cilia, and also plays critical roles in non-ciliary processes. Primary cilia are ubiquitous sensory organelles that play vital roles in an ever-growing class of human diseases termed ciliopathies including obesity, retinal degeneration and polycystic kidney disease. The proper function of the primary cilium relies on a cell's ability to target and concentrate specific receptors to the ciliary membrane – a unique subdomain of the plasma membrane yet little is known about how receptors are trafficked to the primary cilium. Mutations affecting the ciliary localized receptor fibrocystin (PKHD1) cause autosomal recessive polycystic kidney disease, which affects approximately 1∶20,000 individuals. Previously we identified a motif located in the cytoplasmic domain of fibrocystin that is required for its ciliary localization. In this work we demonstrate that the ciliary targeting sequence (CTS) of fibrocystin interacts with the small G protein Arf4 and this interaction is important for the efficient delivery of the CTS to cilia in cultured cells. Disruption of Arf4 in mice results in defects in the non-ciliated visceral endoderm and death at mid-gestation indicating Arf4 has vital functions in addition to ciliary protein trafficking.
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Affiliation(s)
- John A. Follit
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Worcester, Massachusetts, United States of America
| | - Jovenal T. San Agustin
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Worcester, Massachusetts, United States of America
| | - Julie A. Jonassen
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Tingting Huang
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Jaime A. Rivera-Perez
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Kimberly D. Tremblay
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Amherst, Massachusetts, United States of America
| | - Gregory J. Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Worcester, Massachusetts, United States of America
- * E-mail:
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Hamlin JNR, Schroeder LK, Fotouhi M, Dokainish H, Ioannou MS, Girard M, Summerfeldt N, Melançon P, McPherson PS. Scyl1 scaffolds class II Arfs to specific subcomplexes of coatomer through the γ-COP appendage domain. J Cell Sci 2014; 127:1454-63. [PMID: 24481816 DOI: 10.1242/jcs.136481] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Coatomer (COPI)-coated vesicles mediate membrane trafficking in the early secretory pathway. There are at least three subclasses of COPI coats and two classes of Arf GTPases that couple COPI coat proteins to membranes. Whether mechanisms exist to link specific Arfs to specific COPI subcomplexes is unknown. We now demonstrate that Scy1-like protein 1 (Scyl1), a member of the Scy1-like family of catalytically inactive protein kinases, oligomerizes through centrally located HEAT repeats and uses a C-terminal RKXX-COO(-) motif to interact directly with the appendage domain of coatomer subunit γ-2 (also known as COPG2 or γ2-COP). Through a distinct site, Scyl1 interacts selectively with class II Arfs, notably Arf4, thus linking class II Arfs to γ2-bearing COPI subcomplexes. Therefore, Scyl1 functions as a scaffold for key components of COPI coats, and disruption of the scaffolding function of Scyl1 causes tubulation of the endoplasmic reticulum (ER)-Golgi intermediate compartment (ERGIC) and the cis-Golgi, similar to that observed following the loss of Arf and Arf-guanine-nucleotide-exchange factor (GEF) function. Our data reveal that Scyl1 is a key organizer of a subset of the COPI machinery.
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Affiliation(s)
- Jason N R Hamlin
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
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Flipse J, Wilschut J, Smit JM. Molecular mechanisms involved in antibody-dependent enhancement of dengue virus infection in humans. Traffic 2012; 14:25-35. [PMID: 22998156 DOI: 10.1111/tra.12012] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 09/19/2012] [Accepted: 09/21/2012] [Indexed: 12/19/2022]
Abstract
Dengue is the most common arthropod-borne viral infection in humans with ∼50 million cases annually worldwide. In recent decades, a steady increase in the number of severe dengue cases has been seen. Severe dengue disease is most often observed in individuals that have pre-existing immunity against heterotypic dengue subtypes and in infants with low levels of maternal dengue antibodies. The generally accepted hypothesis explaining the immunopathogenesis of severe dengue is called antibody-dependent enhancement of dengue infection. Here, circulating antibodies bind to the newly infecting virus but do not neutralize infection. Rather, these antibodies increase the infected cell mass and virus production. Additionally, antiviral responses are diminished allowing massive virus particle production early in infection. The large infected cell mass and the high viral load are prelude for severe disease development. In this review, we discuss what is known about the trafficking of dengue virus in its human host cells, and the signalling pathways activated after virus detection, both in the absence and presence of antibodies against the virus. This review summarizes work that aims to better understand the complex immunopathogenesis of severe dengue disease.
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Affiliation(s)
- Jacky Flipse
- Department of Medical Microbiology, Molecular Virology Section, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Mutations in the West Nile prM protein affect VLP and virion secretion in vitro. Virology 2012; 433:35-44. [PMID: 22858174 DOI: 10.1016/j.virol.2012.07.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 05/25/2012] [Accepted: 07/13/2012] [Indexed: 12/22/2022]
Abstract
Mutation of the West Nile virus-like particle (WN VLP) prM protein (T20D, K31A, K31V, or K31T) results in undetectable VLP secretion from transformed COS-1 cells. K31 mutants formed intracellular prM-E heterodimers; however these proteins remained in the ER and ER-Golgi intermediary compartments of transfected cells. The T20D mutation affected glycosylation, heterodimer formation, and WN VLP secretion. When infectious viruses bearing the same mutations were used to infect COS-1 cells, K31 mutant viruses exhibited delayed growth and reduced infectivity compared to WT virus. Epitope maps of WN VLP and WNV prM were also different. These results suggest that while mutations in the prM protein can reduce or eliminate secretion of WN VLPs, they have less effect on virus. This difference may be due to the quantity of prM in WN VLPs compared to WNV or to differences in maturation, structure, and symmetry of these particles.
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