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Hsia JZ, Liu D, Haynes L, Cruz-Cosme R, Tang Q. Lipid Droplets: Formation, Degradation, and Their Role in Cellular Responses to Flavivirus Infections. Microorganisms 2024; 12:647. [PMID: 38674592 PMCID: PMC11051834 DOI: 10.3390/microorganisms12040647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 03/18/2024] [Accepted: 03/22/2024] [Indexed: 04/28/2024] Open
Abstract
Lipid droplets (LDs) are cellular organelles derived from the endoplasmic reticulum (ER), serving as lipid storage sites crucial for maintaining cellular lipid homeostasis. Recent attention has been drawn to their roles in viral replication and their interactions with viruses. However, the precise biological functions of LDs in viral replication and pathogenesis remain incompletely understood. To elucidate the interaction between LDs and viruses, it is imperative to comprehend the biogenesis of LDs and their dynamic interactions with other organelles. In this review, we explore the intricate pathways involved in LD biogenies within the cytoplasm, encompassing the uptake of fatty acid from nutrients facilitated by CD36-mediated membranous protein (FABP/FATP)-FA complexes, and FA synthesis via glycolysis in the cytoplasm and the TCL cycle in mitochondria. While LD biogenesis primarily occurs in the ER, matured LDs are intricately linked to multiple organelles. Viral infections can lead to diverse consequences in terms of LD status within cells post-infection, potentially involving the breakdown of LDs through the activation of lipophagy. However, the exact mechanisms underlying LD destruction or accumulation by viruses remain elusive. The significance of LDs in viral replication renders them effective targets for developing broad-spectrum antivirals. Moreover, considering that reducing neutral lipids in LDs is a strategy for anti-obesity treatment, LD depletion may not pose harm to cells. This presents LDs as promising antiviral targets for developing therapeutics that are minimally or non-toxic to the host.
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Affiliation(s)
| | | | | | | | - Qiyi Tang
- Department of Microbiology, Howard University College of Medicine, Washington, DC 20059, USA; (J.Z.H.); (D.L.); (L.H.); (R.C.-C.)
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2
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Maeda K, Goto S, Miura K, Saito K, Morita E. The incorporation of extracellular vesicle markers varies among vesicles with distinct surface charges. J Biochem 2024; 175:299-312. [PMID: 38030385 DOI: 10.1093/jb/mvad097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 11/11/2023] [Indexed: 12/01/2023] Open
Abstract
Extracellular vesicles (EVs) are important mediators of intercellular communication. However, the methods available for distinguishing the heterogeneity of secreted EVs and isolating and purifying them are limited. This study introduced a HiBiT-tag to detect various EV markers, including CD63, CD9, Epidermal Growth Factor Receptor (EGFR), Flotilin1, and Syndecan-1, and investigated whether these marker-containing vesicles were capable of binding to differently charged column carriers. Four column carriers, Diethylaminoethyl (DEAE), Capto Adhere, Blue and Heparin, showed affinity for CD63 containing EVs, but their elution patterns varied. Furthermore, we observed that the elution patterns of the EV markers differed among vesicles with distinct surface charges when a DEAE column was used. This suggests that the incorporation of EV markers varied between these vesicles. The markers showed different subcellular localizations, indicating that the site of vesicle formation may contribute to the production of vesicles with varying charges and marker incorporation. These findings may have implications for the development of methods to purify homogeneous EVs, which could be useful in EV-mediated drug delivery systems.
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Grants
- 20333747, 19fk0108168h0001, 20he0622012h0001, 22fk0108527s0101 AMED
- 23790503, 26460555, 16H01188, 17H06413, 20 K21874, 22 K18378, 22H02873, 22H00553 JSPS KAKENHI
- Japan, and the Takeda Medical Research Foundation
- JPMJCR17H4 JST CREST
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Affiliation(s)
- Koki Maeda
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosakishi, Aomori 036-8561, Japan
- Division of Biomolecular Function, Bioresources Science, United Graduate School of Agricultural Sciences, Iwate University, 3 Bunkyo-cho, Hirosakishi, Aomori 036-8561, Japan
| | - Simon Goto
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosakishi, Aomori 036-8561, Japan
| | - Koya Miura
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosakishi, Aomori 036-8561, Japan
| | - Koki Saito
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosakishi, Aomori 036-8561, Japan
- Division of Biomolecular Function, Bioresources Science, United Graduate School of Agricultural Sciences, Iwate University, 3 Bunkyo-cho, Hirosakishi, Aomori 036-8561, Japan
| | - Eiji Morita
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosakishi, Aomori 036-8561, Japan
- Division of Biomolecular Function, Bioresources Science, United Graduate School of Agricultural Sciences, Iwate University, 3 Bunkyo-cho, Hirosakishi, Aomori 036-8561, Japan
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3
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Jablunovsky A, Jose J. The Dynamic Landscape of Capsid Proteins and Viral RNA Interactions in Flavivirus Genome Packaging and Virus Assembly. Pathogens 2024; 13:120. [PMID: 38392858 PMCID: PMC10893219 DOI: 10.3390/pathogens13020120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024] Open
Abstract
The Flavivirus genus of the Flaviviridae family of enveloped single-stranded RNA viruses encompasses more than 70 members, many of which cause significant disease in humans and livestock. Packaging and assembly of the flavivirus RNA genome is essential for the formation of virions, which requires intricate coordination of genomic RNA, viral structural, and nonstructural proteins in association with virus-induced, modified endoplasmic reticulum (ER) membrane structures. The capsid (C) protein, a small but versatile RNA-binding protein, and the positive single-stranded RNA genome are at the heart of the elusive flavivirus assembly process. The nucleocapsid core, consisting of the genomic RNA encapsidated by C proteins, buds through the ER membrane, which contains viral glycoproteins prM and E organized as trimeric spikes into the lumen, forming an immature virus. During the maturation process, which involves the low pH-mediated structural rearrangement of prM and E and furin cleavage of prM in the secretory pathway, the spiky immature virus with a partially ordered nucleocapsid core becomes a smooth, mature virus with no discernible nucleocapsid. This review focuses on the mechanisms of genome packaging and assembly by examining the structural and functional aspects of C protein and viral RNA. We review the current lexicon of critical C protein features and evaluate interactions between C and genomic RNA in the context of assembly and throughout the life cycle.
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Affiliation(s)
- Anastazia Jablunovsky
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA;
| | - Joyce Jose
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA;
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
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4
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Jablunovsky A, Narayanan A, Jose J. Identification of a critical role for ZIKV capsid α3 in virus assembly and its genetic interaction with M protein. PLoS Negl Trop Dis 2024; 18:e0011873. [PMID: 38166143 PMCID: PMC10786401 DOI: 10.1371/journal.pntd.0011873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 01/12/2024] [Accepted: 12/19/2023] [Indexed: 01/04/2024] Open
Abstract
Flaviviruses such as Zika and dengue viruses are persistent health concerns in endemic regions worldwide. Efforts to combat the spread of flaviviruses have been challenging, as no antivirals or optimal vaccines are available. Prevention and treatment of flavivirus-induced diseases require a comprehensive understanding of their life cycle. However, several aspects of flavivirus biogenesis, including genome packaging and virion assembly, are not well characterized. In this study, we focused on flavivirus capsid protein (C) using Zika virus (ZIKV) as a model to investigate the role of the externally oriented α3 helix (C α3) without a known or predicted function. Alanine scanning mutagenesis of surface-exposed amino acids on C α3 revealed a critical CN67 residue essential for ZIKV virion production. The CN67A mutation did not affect dimerization or RNA binding of purified C protein in vitro. The virus assembly is severely affected in cells transfected with an infectious cDNA clone of ZIKV with CN67A mutation, resulting in a highly attenuated phenotype. We isolated a revertant virus with a partially restored phenotype by continuous passage of the CN67A mutant virus in Vero E6 cells. Sequence analysis of the revertant revealed a second site mutation in the viral membrane (M) protein MF37L, indicating a genetic interaction between the C and M proteins of ZIKV. Introducing the MF37L mutation on the mutant ZIKV CN67A generated a double-mutant virus phenotypically consistent with the isolated genetic revertant. Similar results were obtained with analogous mutations on C and M proteins of dengue virus, suggesting the critical nature of C α3 and possible C and M residues contributing to virus assembly in other Aedes-transmitted flaviviruses. This study provides the first experimental evidence of a genetic interaction between the C protein and the viral envelope protein M, providing a mechanistic understanding of the molecular interactions involved in the assembly and budding of Aedes-transmitted flaviviruses.
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Affiliation(s)
- Anastazia Jablunovsky
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Anoop Narayanan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Joyce Jose
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
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Mondal S, Ghosh S. Liposome-Mediated Anti-Viral Drug Delivery Across Blood-Brain Barrier: Can Lipid Droplet Target Be Game Changers? Cell Mol Neurobiol 2023; 44:9. [PMID: 38123863 DOI: 10.1007/s10571-023-01443-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 12/02/2023] [Indexed: 12/23/2023]
Abstract
Lipid droplets (LDs) are subcellular organelles secreted from the endoplasmic reticulum (ER) that play a major role in lipid homeostasis. Recent research elucidates additional roles of LDs in cellular bioenergetics and innate immunity. LDs activate signaling cascades for interferon response and secretion of pro-inflammatory cytokines. Since balanced lipid homeostasis is critical for neuronal health, LDs play a crucial role in neurodegenerative diseases. RNA viruses enhance the secretion of LDs to support various phases of their life cycle in neurons which further leads to neurodegeneration. Targeting the excess LD formation in the brain could give us a new arsenal of antiviral therapeutics against neuroviruses. Liposomes are a suitable drug delivery system that could be used for drug delivery in the brain by crossing the Blood-Brain Barrier. Utilizing this, various pharmacological inhibitors and non-coding RNAs can be delivered that could inhibit the biogenesis of LDs or reduce their sizes, reversing the excess lipid-related imbalance in neurons. Liposome-Mediated Antiviral Drug Delivery Across Blood-Brain Barrier. Developing effective antiviral drug is challenging and it doubles against neuroviruses that needs delivery across the Blood-Brain Barrier (BBB). Lipid Droplets (LDs) are interesting targets for developing antivirals, hence targeting LD formation by drugs delivered using Liposomes can be game changers.
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Affiliation(s)
- Sourav Mondal
- CSIR-Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Jadavpur, Kolkata, West Bengal, 700032, India
| | - Sourish Ghosh
- CSIR-Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Jadavpur, Kolkata, West Bengal, 700032, India.
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Yang Y, Luo Y, Yi S, Gao Q, Gong T, Feng Y, Wu D, Zheng X, Wang H, Zhang G, Sun Y. Porcine reproductive and respiratory syndrome virus regulates lipid droplet accumulation in lipid metabolic pathways to promote viral replication. Virus Res 2023; 333:199139. [PMID: 37217033 PMCID: PMC10352717 DOI: 10.1016/j.virusres.2023.199139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 05/16/2023] [Accepted: 05/19/2023] [Indexed: 05/24/2023]
Abstract
Porcine reproductive and respiratory syndrome (PRRS) is a severe respiratory disease caused by porcine reproductive and respiratory syndrome virus (PRRSV) that can lead to the abortion of pregnant sows and decreased boar semen quality. However, the mechanisms of PRRSV replication in the host have not yet been fully elucidated. As lipid metabolism and lipid droplets (LDs) have been reported to play important roles in the replication of various viruses, we aimed to explore the mechanisms through which LDs affect PRRSV replication. Laser confocal and transmission electron microscopy revealed that PRRSV infection promoted intracellular LD accumulation, which was significantly reduced by treatment with the NF-κB signaling pathway inhibitors BAY11-7082 and metformin hydrochloride (MH). In addition, treatment with a DGAT1 inhibitor significantly reduced the protein expression of Phosphorylated NF-ΚB P65and PIκB and the transcription of IL-1β and IL-8 in the NF-κB signaling pathway. Furthermore, we showed that the reduction of the NF-κB signaling pathway and LDs significantly reduced PRRSV replication. Together, the findings of this study suggest a novel mechanism through which PRRSV regulates the NF-κB signaling pathway to increase LD accumulation and promote viral replication. Moreover, we demonstrated that both BAY11-7082 and MH can reduce PRRSV replication by reducing the NF-κB signaling pathway and LD accumulation. This study lays a theoretical foundation for research on the mechanism of PRRS prevention and control, as well as the research and development of antiviral drugs.
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Affiliation(s)
- Yunlong Yang
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China
| | - Yizhuo Luo
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China
| | - Songqiang Yi
- Agricultural Technology Extension Center of Jiangxi Province, Nanchang, China
| | - Qi Gao
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China
| | - Ting Gong
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Key Laboratory of Animal Vaccine Development, Ministry of Agriculture and Rural Affairs, PR China
| | - Yongzhi Feng
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China
| | - Dongdong Wu
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Key Laboratory of Animal Vaccine Development, Ministry of Agriculture and Rural Affairs, PR China
| | - Xiaoyu Zheng
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Key Laboratory of Animal Vaccine Development, Ministry of Agriculture and Rural Affairs, PR China
| | - Heng Wang
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China
| | - Guihong Zhang
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China; Key Laboratory of Animal Vaccine Development, Ministry of Agriculture and Rural Affairs, PR China
| | - Yankuo Sun
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China; Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China; Key Laboratory of Animal Vaccine Development, Ministry of Agriculture and Rural Affairs, PR China.
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7
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Awadh AA. The Role of Cytosolic Lipid Droplets in Hepatitis C Virus Replication, Assembly, and Release. BIOMED RESEARCH INTERNATIONAL 2023; 2023:5156601. [PMID: 37090186 PMCID: PMC10121354 DOI: 10.1155/2023/5156601] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 03/02/2023] [Accepted: 03/09/2023] [Indexed: 04/25/2023]
Abstract
The hepatitis C virus (HCV) causes chronic hepatitis by establishing a persistent infection. Patients with chronic hepatitis frequently develop hepatic cirrhosis, which can lead to liver cancer-the progressive liver damage results from the host's immune response to the unresolved infection. The HCV replication process, including the entry, replication, assembly, and release stages, while the virus circulates in the bloodstream, it is intricately linked to the host's lipid metabolism, including the dynamic of the cytosolic lipid droplets (cLDs). This review article depicts how this interaction regulates viral cell tropism and aids immune evasion by coining viral particle characteristics. cLDs are intracellular organelles that store most of the cytoplasmic components of neutral lipids and are assumed to play an increasingly important role in the pathophysiology of lipid metabolism and host-virus interactions. cLDs are involved in the replication of several clinically significant viruses, where viruses alter the lipidomic profiles of host cells to improve viral life cycles. cLDs are involved in almost every phase of the HCV life cycle. Indeed, pharmacological modulators of cholesterol synthesis and intracellular trafficking, lipoprotein maturation, and lipid signaling molecules inhibit the assembly of HCV virions. Likewise, small-molecule inhibitors of cLD-regulating proteins inhibit HCV replication. Thus, addressing the molecular architecture of HCV replication will aid in elucidating its pathogenesis and devising preventive interventions that impede persistent infection and prevent disease progression. This is possible via repurposing the available therapeutic agents that alter cLDs metabolism. This review highlights the role of cLD in HCV replication.
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Affiliation(s)
- Abdullah A. Awadh
- Department of Basic Medical Sciences, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia
- King Abdullah International Medical Research Center, Jeddah 21423, Saudi Arabia
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8
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Sallaberry I, Luszczak A, Philipp N, Navarro GSC, Gabriel MV, Gratton E, Gamarnik AV, Estrada LC. In vivo pair correlation microscopy reveals dengue virus capsid protein nucleocytoplasmic bidirectional movement in mammalian infected cells. Sci Rep 2021; 11:24415. [PMID: 34952906 PMCID: PMC8709865 DOI: 10.1038/s41598-021-03854-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 12/09/2021] [Indexed: 12/22/2022] Open
Abstract
Flaviviruses are major human disease-causing pathogens, including dengue virus (DENV), Zika virus, yellow fever virus and others. DENV infects hundreds of millions of people per year around the world, causing a tremendous social and economic burden. DENV capsid (C) protein plays an essential role during genome encapsidation and viral particle formation. It has been previously shown that DENV C enters the nucleus in infected cells. However, whether DENV C protein exhibits nuclear export remains unclear. By spatially cross-correlating different regions of the cell, we investigated DENV C movement across the nuclear envelope during the infection cycle. We observed that transport takes place in both directions and with similar translocation times (in the ms time scale) suggesting a bidirectional movement of both C protein import and export.Furthermore, from the pair cross-correlation functions in cytoplasmic or nuclear regions we found two populations of C molecules in each compartment with fast and slow mobilities. While in the cytoplasm the correlation times were in the 2-6 and 40-110 ms range for the fast and slow mobility populations respectively, in the cell nucleus they were 1-10 and 25-140 ms range, respectively. The fast mobility of DENV C in cytoplasmic and nuclear regions agreed with the diffusion coefficients from Brownian motion previously reported from correlation analysis. These studies provide the first evidence of DENV C shuttling from and to the nucleus in infected cells, opening new venues for antiviral interventions.
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Affiliation(s)
- Ignacio Sallaberry
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-National Research Council for Science and Technology (CONICET), 1428, Buenos Aires, Argentina
| | - Alexis Luszczak
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-National Research Council for Science and Technology (CONICET), 1428, Buenos Aires, Argentina
| | - Natalia Philipp
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-National Research Council for Science and Technology (CONICET), 1428, Buenos Aires, Argentina
| | - Guadalupe S Costa Navarro
- Fundación Instituto Leloir-National Research Council for Science and Technology (CONICET), 1405, Buenos Aires, Argentina
| | - Manuela V Gabriel
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-National Research Council for Science and Technology (CONICET), 1428, Buenos Aires, Argentina
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics and Beckman Laser Institute and Medical Clinic, University of California, Irvine, CA, USA
| | - Andrea V Gamarnik
- Fundación Instituto Leloir-National Research Council for Science and Technology (CONICET), 1405, Buenos Aires, Argentina
| | - Laura C Estrada
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-National Research Council for Science and Technology (CONICET), 1428, Buenos Aires, Argentina.
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9
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Lipid droplets are beneficial for rabies virus replication by facilitating viral budding. J Virol 2021; 96:e0147321. [PMID: 34757839 DOI: 10.1128/jvi.01473-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rabies is an old zoonotic disease caused by rabies virus (RABV), but the pathogenic mechanism of RABV is still not completely understood. Lipid droplets have been reported to play a role in pathogenesis of several viruses. However, its role on RABV infection remains unclear. Here, we initially found that RABV infection upregulated lipid droplet (LD) production in multiple cells and mouse brains. After the treatment of atorvastatin, a specific inhibitor of LD, RABV replication in N2a cells decreased. Then we found that RABV infection could upregulate N-myc downstream regulated gene-1 (NDRG1), which in turn enhance the expression of diacylglycerol acyltransferase 1/2 (DGAT1/2). DGAT1/2 could elevate cellular triglycerides synthesis and ultimately promote intracellular LD formation. Furthermore, we found that RABV-M and RABV-G, which were mainly involved in the viral budding process, could colocalize with LDs, indicating that RABV might utilize LDs as a carrier to facilitate viral budding and eventually increase virus production. Taken together, our study reveals that lipid droplets are beneficial for RABV replication and their biogenesis is regulated via NDRG1-DGAT1/2 pathway, which provides novel potential targets for developing anti-RABV drugs. IMPORTANCE Lipid droplets have been proven to play an important role in viral infections, but its role in RABV infection has not yet been elaborated. Here, we find that RABV infection upregulates the generation of LDs by enhancing the expression of N-myc downstream regulated gene-1 (NDRG1). Then NDRG1 elevated cellular triglycerides synthesis by increasing the activity of diacylglycerol acyltransferase 1/2 (DGAT1/2), which promotes the biogenesis of LDs. RABV-M and RABV-G, which are the major proteins involved in viral budding, could utilize LDs as a carrier and transport to cell membrane, resulting in enhanced virus budding. Our findings will extend the knowledge of lipid metabolism in RABV infection and help to explore potential therapeutic targets for RABV.
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Farfan-Morales CN, Cordero-Rivera CD, Reyes-Ruiz JM, Hurtado-Monzón AM, Osuna-Ramos JF, González-González AM, De Jesús-González LA, Palacios-Rápalo SN, Del Ángel RM. Anti-flavivirus Properties of Lipid-Lowering Drugs. Front Physiol 2021; 12:749770. [PMID: 34690817 PMCID: PMC8529048 DOI: 10.3389/fphys.2021.749770] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/20/2021] [Indexed: 12/11/2022] Open
Abstract
Although Flaviviruses such as dengue (DENV) and zika (ZIKV) virus are important human pathogens, an effective vaccine or antiviral treatment against them is not available. Hence, the search for new strategies to control flavivirus infections is essential. Several studies have shown that the host lipid metabolism could be an antiviral target because cholesterol and other lipids are required during the replicative cycle of different Flaviviridae family members. FDA-approved drugs with hypolipidemic effects could be an alternative for treating flavivirus infections. However, a better understanding of the regulation between host lipid metabolism and signaling pathways triggered during these infections is required. The metabolic pathways related to lipid metabolism modified during DENV and ZIKV infection are analyzed in this review. Additionally, the role of lipid-lowering drugs as safe host-targeted antivirals is discussed.
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Affiliation(s)
- Carlos Noe Farfan-Morales
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV-IPN), Mexico City, Mexico
| | - Carlos Daniel Cordero-Rivera
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV-IPN), Mexico City, Mexico
| | - José Manuel Reyes-Ruiz
- Unidad Médica de Alta Especialidad, Hospital de Especialidades No. 14, Centro Médico Nacional "Adolfo Ruiz Cortines," Instituto Mexicano del Seguro Social, Heroica Veracruz, Mexico
| | - Arianna M Hurtado-Monzón
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV-IPN), Mexico City, Mexico
| | - Juan Fidel Osuna-Ramos
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV-IPN), Mexico City, Mexico
| | - Arely M González-González
- Laboratorio de Ingeniería Tisular y Medicina Traslacional, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Luis Adrián De Jesús-González
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV-IPN), Mexico City, Mexico
| | - Selvin Noé Palacios-Rápalo
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV-IPN), Mexico City, Mexico
| | - Rosa María Del Ángel
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies (CINVESTAV-IPN), Mexico City, Mexico
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11
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Monson EA, Trenerry AM, Laws JL, Mackenzie JM, Helbig KJ. Lipid droplets and lipid mediators in viral infection and immunity. FEMS Microbiol Rev 2021; 45:fuaa066. [PMID: 33512504 PMCID: PMC8371277 DOI: 10.1093/femsre/fuaa066] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/02/2020] [Indexed: 12/14/2022] Open
Abstract
Lipid droplets (LDs) contribute to key pathways important for the physiology and pathophysiology of cells. In a homeostatic view, LDs regulate the storage of neutral lipids, protein sequestration, removal of toxic lipids and cellular communication; however, recent advancements in the field show these organelles as essential for various cellular stress response mechanisms, including inflammation and immunity, with LDs acting as hubs that integrate metabolic and inflammatory processes. The accumulation of LDs has become a hallmark of infection, and is often thought to be virally driven; however, recent evidence is pointing to a role for the upregulation of LDs in the production of a successful immune response to viral infection. The fatty acids housed in LDs are also gaining interest due to the role that these lipid species play during viral infection, and their link to the synthesis of bioactive lipid mediators that have been found to have a very complex role in viral infection. This review explores the role of LDs and their subsequent lipid mediators during viral infections and poses a paradigm shift in thinking in the field, whereby LDs may play pivotal roles in protecting the host against viral infection.
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Affiliation(s)
- Ebony A Monson
- School of Life Sciences, La Trobe University, Melbourne, Australia, 3083
| | - Alice M Trenerry
- Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia, 3000
| | - Jay L Laws
- School of Life Sciences, La Trobe University, Melbourne, Australia, 3083
| | - Jason M Mackenzie
- Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia, 3000
| | - Karla J Helbig
- School of Life Sciences, La Trobe University, Melbourne, Australia, 3083
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12
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Saito A, Shofa M, Ode H, Yumiya M, Hirano J, Okamoto T, Yoshimura SH. How Do Flaviviruses Hijack Host Cell Functions by Phase Separation? Viruses 2021; 13:v13081479. [PMID: 34452345 PMCID: PMC8402827 DOI: 10.3390/v13081479] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/21/2021] [Accepted: 07/26/2021] [Indexed: 11/17/2022] Open
Abstract
Viral proteins interact with different sets of host cell components throughout the viral life cycle and are known to localize to the intracellular membraneless organelles (MLOs) of the host cell, where formation/dissolution is regulated by phase separation of intrinsically disordered proteins and regions (IDPs/IDRs). Viral proteins are rich in IDRs, implying that viruses utilize IDRs to regulate phase separation of the host cell organelles and augment replication by commandeering the functions of the organelles and/or sneaking into the organelles to evade the host immune response. This review aims to integrate current knowledge of the structural properties and intracellular localizations of viral IDPs to understand viral strategies in the host cell. First, the properties of viral IDRs are reviewed and similarities and differences with those of eukaryotes are described. The higher IDR content in viruses with smaller genomes suggests that IDRs are essential characteristics of viral proteins. Then, the interactions of the IDRs of flaviviruses with the MLOs of the host cell are investigated with emphasis on the viral proteins localized in the nucleoli and stress granules. Finally, the possible roles of viral IDRs in regulation of the phase separation of organelles and future possibilities for antiviral drug development are discussed.
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Affiliation(s)
- Akatsuki Saito
- Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan;
- Center for Animal Disease Control, University of Miyazaki, Miyazaki 889-2192, Japan
- Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
- Correspondence: (A.S.); (T.O.); (S.H.Y.)
| | - Maya Shofa
- Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan;
- Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Hirotaka Ode
- Clinical Research Center, National Hospital Organization Nagoya Medical Center, Nagoya 460-0001, Japan;
| | - Maho Yumiya
- Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; (M.Y.); (J.H.)
| | - Junki Hirano
- Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; (M.Y.); (J.H.)
| | - Toru Okamoto
- Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; (M.Y.); (J.H.)
- Center for Infectious Diseases Education and Research, Osaka University, Osaka 565-0871, Japan
- Correspondence: (A.S.); (T.O.); (S.H.Y.)
| | - Shige H. Yoshimura
- Laboratory of Plasma Membrane and Nuclear Signaling, Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
- Correspondence: (A.S.); (T.O.); (S.H.Y.)
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13
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Endoplasmic Reticulum-Associated Degradation Controls Virus Protein Homeostasis, Which Is Required for Flavivirus Propagation. J Virol 2021; 95:e0223420. [PMID: 33980593 DOI: 10.1128/jvi.02234-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Many positive-stranded RNA viruses encode polyproteins from which viral proteins are generated by processing the polyproteins. This system produces an equal amount of each viral protein, though the required amounts for each protein are not the same. In this study, we found the extra membrane-anchored nonstructural (NS) proteins of Japanese encephalitis virus and dengue virus are rapidly and selectively degraded by the endoplasmic reticulum-associated degradation (ERAD) pathway. Our gene targeting study revealed that ERAD involving Derlin2 and SEL1L, but not Derlin1, is required for the viral genome replication. Derlin2 is predominantly localized in the convoluted membrane (CM) of the viral replication organelle, and viral NS proteins are degraded in the CM. Hence, these results suggest that viral protein homeostasis is regulated by Derlin2-mediated ERAD in the CM, and this process is critical for the propagation of these viruses. IMPORTANCE The results of this study reveal the cellular ERAD system controls the amount of each viral protein in virus-infected cells and that this "viral protein homeostasis" is critical for viral propagation. Furthermore, we clarified that the "convoluted membrane (CM)," which was previously considered a structure with unknown function, serves as a kind of waste dump where viral protein degradation occurs. We also found that the Derlin2/SEL1L/HRD1-specific pathway is involved in this process, whereas the Derlin1-mediated pathway is not. This novel ERAD-mediated fine-tuning system for the stoichiometries of polyprotein-derived viral proteins may represent a common feature among polyprotein-encoding viruses.
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14
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Zhang X, Zhang Y, Jia R, Wang M, Yin Z, Cheng A. Structure and function of capsid protein in flavivirus infection and its applications in the development of vaccines and therapeutics. Vet Res 2021; 52:98. [PMID: 34193256 PMCID: PMC8247181 DOI: 10.1186/s13567-021-00966-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/27/2021] [Indexed: 01/03/2023] Open
Abstract
Flaviviruses are enveloped single positive-stranded RNA viruses. The capsid (C), a structural protein of flavivirus, is dimeric and alpha-helical, with several special structural and functional features. The functions of the C protein go far beyond a structural role in virions. It is not only responsible for encapsidation to protect the viral RNA but also able to interact with various host proteins to promote virus proliferation. Therefore, the C protein plays an important role in infected host cells and the viral life cycle. Flaviviruses have been shown to affect the health of humans and animals. Thus, there is an urgent need to effectively control flavivirus infections. The structure of the flavivirus virion has been determined, but there is relatively little information about the function of the C protein. Hence, a greater understanding of the role of the C protein in viral infections will help to discover novel antiviral strategies and provide a promising starting point for the further development of flavivirus vaccines or therapeutics.
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Affiliation(s)
- Xingcui Zhang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Yanting Zhang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Renyong Jia
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China. .,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China. .,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China.
| | - Mingshu Wang
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Zhongqiong Yin
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Anchun Cheng
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China. .,Institute of Preventive Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China. .,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China.
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15
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A purified inactivated vaccine derived from Vero cell-adapted zika virus elicits protection in mice. Virology 2021; 560:124-130. [PMID: 34087565 DOI: 10.1016/j.virol.2021.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 04/14/2021] [Accepted: 05/07/2021] [Indexed: 11/21/2022]
Abstract
The Zika virus (ZIKV) outbreak in 2015-2016 raised public health concerns and created a pressing need for vaccine development. However, no vaccine has been developed and most of the ones under development use a single serotype of ZIKV. In this study, we established a Vero cell-adapted ZIKV strain (GMZ-002) and developed a purified inactivated virus (PIV) vaccine. GMZ-002 presented significantly increased productivity in Vero cells, and IFNAR1-blocked C57BL/6 mice administered two doses of the PIV were fully protected against lethal challenge. Vaccine efficacy was illustrated by the high level of serum neutralizing antibodies and strong innate immune response, along with an absence of detectable viremia in vaccinated mice. Furthermore, anti-sera neutralized both African and Asian genetic lineages of the virus in vitro. Our results suggest that GMZ-002 PIV elicited robust and persistent protective immunity, and therefore represents a promising vaccine candidate for ZIKV.
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16
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Efficient immunogenic peptide antigen delivery to dendritic cells using an ESCRT-mediated extracellular vesicle formation method. Vaccine 2021; 39:2976-2982. [PMID: 33926749 DOI: 10.1016/j.vaccine.2021.04.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 04/05/2021] [Accepted: 04/10/2021] [Indexed: 11/23/2022]
Abstract
In the activation of cell-mediated adaptive immune responses that play major roles in the elimination of virus-infected or tumor cells, it is important that dendritic cells present antigen peptides on major histocompatibility complex (MHC) class I molecules and activate pathogen-specific cytotoxic T lymphocytes (CTL). As exogenous peptide antigens are generally presented on MHC class II but not class I, the development of a method for exogenous antigen delivery that facilitates MHC class I presentation is necessary for a potentially effective vaccine that is expected to provoke cell-mediated adaptive immune responses. Here, we developed extracellular vesicles that incorporate antigenic proteins by utilizing endosomal sorting complexes required for transport (ESCRT)-mediated vesicle formation pathway. Furthermore, we proved that these vesicles could deliver their contents to the cytoplasm of dendritic cells and activate antigen-specific CTLs. These technologies could be applied to the development of novel CTL-inducing peptide vaccines.
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17
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Neves-Martins TC, Mebus-Antunes NC, Caruso IP, Almeida FCL, Da Poian AT. Unique structural features of flaviviruses' capsid proteins: new insights on structure-function relationship. Curr Opin Virol 2021; 47:106-112. [PMID: 33721656 DOI: 10.1016/j.coviro.2021.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/11/2021] [Accepted: 02/17/2021] [Indexed: 10/21/2022]
Abstract
The Flaviviridae family comprises important human pathogens, including Dengue, Zika, West Nile, Yellow Fever and Japanese Encephalitis viruses. The viral genome, a positive-sense single-stranded RNA, is packaged by a single protein, the capsid protein, which is a small and highly basic protein that form intertwined homodimers in solution. Atomic-resolution structures of four flaviviruses capsid proteins were solved either in solution by nuclear magnetic resonance spectroscopy, or after protein crystallization by X-ray diffraction. Analyses of these structures revealed very particular properties, namely (i) the predominance of quaternary contacts maintaining the structure; (ii) a highly electropositive surface throughout the protein; and (iii) a flexible helix (α1). The goal of this review is to discuss the role of these features in protein structure-function relationship.
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Affiliation(s)
- Thais C Neves-Martins
- Institute of Medical Biochemistry Leopoldo de Meis (IBqM), Federal University of Rio de Janeiro (UFRJ), 21941-590, Rio de Janeiro, RJ, Brazil
| | - Nathane C Mebus-Antunes
- Institute of Medical Biochemistry Leopoldo de Meis (IBqM), Federal University of Rio de Janeiro (UFRJ), 21941-590, Rio de Janeiro, RJ, Brazil
| | - Icaro P Caruso
- Institute of Medical Biochemistry Leopoldo de Meis (IBqM), Federal University of Rio de Janeiro (UFRJ), 21941-590, Rio de Janeiro, RJ, Brazil; Multiuser Center for Biomolecular Innovation (CMIB) and Department of Physics, Institute of Biosciences, Letters and Exact Sciences (IBILCE), São Paulo State University (UNESP), 15054-000, São José do Rio Preto, SP, Brazil
| | - Fabio C L Almeida
- Institute of Medical Biochemistry Leopoldo de Meis (IBqM), Federal University of Rio de Janeiro (UFRJ), 21941-590, Rio de Janeiro, RJ, Brazil; National Center for Structural Biology and Bioimaging (CENABIO), Federal University of Rio de Janeiro (UFRJ), 21941-590, Rio de Janeiro, RJ, Brazil.
| | - Andrea T Da Poian
- Institute of Medical Biochemistry Leopoldo de Meis (IBqM), Federal University of Rio de Janeiro (UFRJ), 21941-590, Rio de Janeiro, RJ, Brazil.
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18
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Barnard TR, Abram QH, Lin QF, Wang AB, Sagan SM. Molecular Determinants of Flavivirus Virion Assembly. Trends Biochem Sci 2021; 46:378-390. [PMID: 33423940 DOI: 10.1016/j.tibs.2020.12.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 01/07/2023]
Abstract
Virion assembly is an important step in the life cycle of all viruses. For viruses of the Flavivirus genus, a group of enveloped positive-sense RNA viruses, the assembly step represents one of the least understood processes in the viral life cycle. While assembly is primarily driven by the viral structural proteins, recent studies suggest that several nonstructural proteins also play key roles in coordinating the assembly and packaging of the viral genome. This review focuses on describing recent advances in our understanding of flavivirus virion assembly, including the intermolecular interactions between the viral structural (capsid) and nonstructural proteins (NS2A and NS2B-NS3), host factors, as well as features of the viral genomic RNA required for efficient flavivirus virion assembly.
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Affiliation(s)
- Trisha R Barnard
- Department of Microbiology & Immunology, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Quinn H Abram
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Qi Feng Lin
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Alex B Wang
- Department of Microbiology & Immunology, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Selena M Sagan
- Department of Microbiology & Immunology, McGill University, Montreal, Quebec H3G 1Y6, Canada; Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada.
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19
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Zhao X, Tikoo SK. Nuclear and Nucleolar Localization of Bovine Adenovirus-3 Protein V. Front Microbiol 2021; 11:579593. [PMID: 33488533 PMCID: PMC7815533 DOI: 10.3389/fmicb.2020.579593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 12/03/2020] [Indexed: 02/01/2023] Open
Abstract
The L2 region of bovine adenovirus-3 (BAdV-3) encodes a Mastadenovirus genus-specific protein, designated as pV, which is important for the production of progeny viruses. Here, we demonstrate that BAdV-3 pV, expressed as 55 kDa protein, localizes to the nucleus and specifically targets nucleolus of the infected cells. Analysis of deletion mutants of pV suggested that amino acids 81–120, 190–210, and 380–389 act as multiple nuclear localization signals (NLS), which also appear to serve as the binding sites for importin α-3 protein, a member of the importin α/β nuclear import receptor pathway. Moreover, pV amino acids 21–50 and 380–389 appear to act as nucleolar localization signals (NoLs). Interestingly, amino acids 380–389 appear to act both as NLS and as NoLS. The presence of NoLS is essential for the production of infectious progeny virions, as deletion of both NoLs are lethal for the production of infectious BAdV-3. Analysis of mutant BAV.pVd1d3 (isolated in pV completing CRL cells) containing deletion/mutation of both NoLS in non-complementing CRL cells not only revealed the altered intracellular localization of mutant pV but also reduced the expression of some late proteins. However, it does not appear to affect the incorporation of viral proteins, including mutant pV, in BAV.pVd1d3 virions. Further analysis of CsCl purified BAV.pVd1d3 suggested the presence of thermo-labile virions with disrupted capsids, which appear to affect the infectivity of the progeny virions. Our results suggest that pV contains overlapping and non-overlapping NoLS/NLS. Moreover, the presence of both NoLS appear essential for the production of stable and infectious progeny BAV.pVd1d3 virions.
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Affiliation(s)
- Xin Zhao
- VIDO-InterVac, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Suresh K Tikoo
- VIDO-InterVac, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, SK, Canada.,Vaccinology and Imuunothepapeutics Program, School of Public Health, University of Saskatchewan, Saskatoon, SK, Canada
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20
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Sarkar R, Sharma KB, Kumari A, Asthana S, Kalia M. Japanese encephalitis virus capsid protein interacts with non-lipidated MAP1LC3 on replication membranes and lipid droplets. J Gen Virol 2021; 102. [DOI: 10.1099/jgv.0.001508] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Microtubule-associated protein 1 light chain 3 (MAP1LC3) is a protein with a well-defined function in autophagy, but still incompletely understood roles in several other autophagy-independent processess. Studies have shown MAP1LC3 is a host-dependency factor for the replication of several viruses. Japanese encephalitis virus (JEV), a neurotropic flavivirus, replicates on ER-derived membranes that are marked by autophagosome-negative non-lipidated MAP1LC3 (LC3-I). Depletion of LC3 exerts a profound inhibition on virus replication and egress. Here, we further characterize the role of LC3 in JEV replication, and through immunofluorescence and immunoprecipitation show that LC3-I interacts with the virus capsid protein in infected cells. This association was observed on capsid localized to both the replication complex and lipid droplets (LDs). JEV infection decreased the number of LDs per cell indicating a link between lipid metabolism and virus replication. This capsid-LC3 interaction was independent of the autophagy adaptor protein p62/Sequestosome 1 (SQSTM1). Further, no association of capsid was seen with the Gamma-aminobutyric acid receptor-associated protein family, suggesting that this interaction was specific for LC3. High-resolution protein-protein docking studies identified a putative LC3-interacting region in capsid, 56FTAL59,
and other key residues that could mediate a direct interaction between the two proteins.
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Affiliation(s)
- Riya Sarkar
- Translational Health Science & Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Kiran Bala Sharma
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, Haryana, India
- Translational Health Science & Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Anita Kumari
- Translational Health Science & Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Shailendra Asthana
- Translational Health Science & Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Manjula Kalia
- Translational Health Science & Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, Haryana, India
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21
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Cloherty AP, Olmstead AD, Ribeiro CM, Jean F. Hijacking of Lipid Droplets by Hepatitis C, Dengue and Zika Viruses-From Viral Protein Moonlighting to Extracellular Release. Int J Mol Sci 2020; 21:E7901. [PMID: 33114346 PMCID: PMC7662613 DOI: 10.3390/ijms21217901] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/15/2020] [Accepted: 10/20/2020] [Indexed: 02/06/2023] Open
Abstract
Hijacking and manipulation of host cell biosynthetic pathways by human enveloped viruses are essential for the viral lifecycle. Flaviviridae members, including hepatitis C, dengue and Zika viruses, extensively manipulate host lipid metabolism, underlining the importance of lipid droplets (LDs) in viral infection. LDs are dynamic cytoplasmic organelles that can act as sequestration platforms for a unique subset of host and viral proteins. Transient recruitment and mobilization of proteins to LDs during viral infection impacts host-cell biological properties, LD functionality and canonical protein functions. Notably, recent studies identified LDs in the nucleus and also identified that LDs are transported extracellularly via an autophagy-mediated mechanism, indicating a novel role for autophagy in Flaviviridae infections. These developments underline an unsuspected diversity and localization of LDs and potential moonlighting functions of LD-associated proteins during infection. This review summarizes recent breakthroughs concerning the LD hijacking activities of hepatitis C, dengue and Zika viruses and potential roles of cytoplasmic, nuclear and extracellular LD-associated viral proteins during infection.
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Affiliation(s)
- Alexandra P.M. Cloherty
- Amsterdam UMC, Amsterdam Institute for Infection & Immunity, Department of Experimental Immunology, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (A.P.M.C.); (C.M.S.R.)
| | - Andrea D. Olmstead
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, 3559–2350 Health Sciences Mall, Vancouver, BC V6T1Z3, Canada;
| | - Carla M.S. Ribeiro
- Amsterdam UMC, Amsterdam Institute for Infection & Immunity, Department of Experimental Immunology, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (A.P.M.C.); (C.M.S.R.)
| | - François Jean
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, 3559–2350 Health Sciences Mall, Vancouver, BC V6T1Z3, Canada;
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22
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He Y, Wang M, Chen S, Cheng A. The role of capsid in the flaviviral life cycle and perspectives for vaccine development. Vaccine 2020; 38:6872-6881. [PMID: 32950301 PMCID: PMC7495249 DOI: 10.1016/j.vaccine.2020.08.053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 02/09/2023]
Abstract
The structure and function of flaviviral capsid are very flexible. The capsid gene contains conserved RNA secondary structures. Both steps of assembly and dissociation of nucleocapsid complexes are obscure. Capsid mutant viruses are highly attenuated and immunogenic. ΔC-replicon and single-round infectious particles are promising vaccine approaches.
The arthropod-borne flaviviruses cause a series of diseases in humans and pose a significant threat to global public health. In this review, we aimed to summarize the structure of the capsid protein (CP), its relevant multiple functions in the viral life cycle and innovative vaccines targeting CP. The flaviviral CP is the smallest structural protein and forms a homodimer by antiparallel α-helixes. Its primary function is to package the genomic RNA; however, both steps of assembly and dissociation of nucleocapsid complexes (NCs) have been obscure until now; in fact, flaviviral budding is NC-free, demonstrated by the subviral particles that generally exist in flavivirus infection. In infected cells, CPs associate with lipid droplets, which possibly store CPs prior to packaging. However, the function of nuclear localization of CPs remains unknown. Moreover, introducing deletions into CPs can be used to rationally design safe and effective live-attenuated vaccines or noninfectious replicon vaccines and single-round infectious particles, the latter two representing promising approaches for innovative flaviviral vaccine development.
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Affiliation(s)
- Yu He
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
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23
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Goto S, Ishida K, Suzuki R, Morita E. Split Nano Luciferase-based Assay to Measure Assembly of Japanese Encephalitis Virus. Bio Protoc 2020; 10:e3606. [PMID: 33659571 DOI: 10.21769/bioprotoc.3606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/25/2020] [Accepted: 03/29/2020] [Indexed: 11/02/2022] Open
Abstract
Cells infected with flavivirus release various forms of infectious and non-infectious particles as products and by-products. Comprehensive profiling of the released particles by density gradient centrifugation is informative for understanding viral particle assembly. However, it is difficult to detect low-abundance minor particles in such analyses. We developed a method for viral particle analysis that integrates a high-sensitivity split luciferase system and density gradient centrifugation. This protocol enables high-resolution profiling of particles produced by cells expressing Japanese encephalitis virus factors.
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Affiliation(s)
- Simon Goto
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki-shi, Aomori, Japan
| | - Kotaro Ishida
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki-shi, Aomori, Japan
| | - Ryosuke Suzuki
- Department of Virology II, National Institute of Infectious Diseases, 1-23-1, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Eiji Morita
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki-shi, Aomori, Japan
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Understanding Flavivirus Capsid Protein Functions: The Tip of the Iceberg. Pathogens 2020; 9:pathogens9010042. [PMID: 31948047 PMCID: PMC7168633 DOI: 10.3390/pathogens9010042] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/01/2020] [Accepted: 01/03/2020] [Indexed: 12/18/2022] Open
Abstract
Flaviviruses are enveloped positive-sense single-stranded RNA arboviruses, infectious to humans and many other animals and are transmitted primarily via tick or mosquito vectors. Capsid is the primary structural protein to interact with viral genome within virus particles and is therefore necessary for efficient packaging. However, in cells, capsid interacts with many proteins and nucleic acids and we are only beginning to understand the broad range of functions of flaviviral capsids. It is known that capsid dimers interact with the membrane of lipid droplets, aiding in both viral packaging and storage of capsid prior to packaging. However, capsid dimers can bind a range of nucleic acid templates in vitro, and likely interact with a range of targets during the flavivirus lifecycle. Capsid may interact with host RNAs, resulting in altered RNA splicing and RNA transcription. Capsid may also bind short interfering-RNAs and has been proposed to sequester these species to protect flaviviruses from the invertebrate siRNA pathways. Capsid can also be found in the nucleolus, where it wreaks havoc on ribosome biogenesis. Here we review flavivirus capsid structure, nucleic acid interactions and how these give rise to multiple functions. We also discuss how these features might be exploited either in the design of effective antivirals or novel vaccine strategies.
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