Palmitoylation of Hepatitis C Virus NS2 Regulates Its Subcellular Localization and NS2-NS3 Autocleavage

Wu, Ming; Shanmugam, Saravanabalaji; Welsch, Christoph; Yi, Min Kyung

doi:10.1128/jvi.00906-19

Cited by 16 publications

(18 citation statements)

References 53 publications

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“…The cLD-associated mature Core recruits NS5A, presumably loaded with HCV RNA, to the same cLDs, which would trigger encapsidation [ 67 , 68 , 69 ]. Next, NS2 recruits envelope proteins E1 and E2 to the ER detergent-resistant membranes (ER-DRM) near the Core-decorated cLD [ 70 , 71 , 72 , 73 , 74 ], which likely trigger envelopment/budding of HCV particles into the ER lumen. NS2 palmitoylation facilitates NS2-mediated E2 recruitment to the virus assembly sites located at the ER-DRM, since inhibiting NS2 palmitoylation reduced ER-DRM localization of NS2 and E2, and colocalization of NS2 with cLD-associated Core [ 74 ].…”

Section: Role Of E2–p7 Cleavage Regulation In Hcv Assemblymentioning

confidence: 99%

“…Next, NS2 recruits envelope proteins E1 and E2 to the ER detergent-resistant membranes (ER-DRM) near the Core-decorated cLD [ 70 , 71 , 72 , 73 , 74 ], which likely trigger envelopment/budding of HCV particles into the ER lumen. NS2 palmitoylation facilitates NS2-mediated E2 recruitment to the virus assembly sites located at the ER-DRM, since inhibiting NS2 palmitoylation reduced ER-DRM localization of NS2 and E2, and colocalization of NS2 with cLD-associated Core [ 74 ]. The coordination of HCV RNA replication and virus assembly was captured by the state-of-the-art imaging study by Lee et al, which showed cLD wrapping by the DMV-associated ER membranes and E2 recruitment to these membranes during HCV replication [ 75 ].…”

Section: Role Of E2–p7 Cleavage Regulation In Hcv Assemblymentioning

confidence: 99%

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Delayed by Design: Role of Suboptimal Signal Peptidase Processing of Viral Structural Protein Precursors in Flaviviridae Virus Assembly

Alzahrani

Shanmugam

et al. 2020

Viruses

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The Flaviviridae virus family is classified into four different genera, including flavivirus, hepacivirus, pegivirus, and pestivirus, which cause significant morbidity and mortality in humans and other mammals, including ruminants and pigs. These are enveloped, single-stranded RNA viruses sharing a similar genome organization and replication scheme with certain unique features that differentiate them. All viruses in this family express a single polyprotein that encodes structural and nonstructural proteins at the N- and C-terminal regions, respectively. In general, the host signal peptidase cleaves the structural protein junction sites, while virus-encoded proteases process the nonstructural polyprotein region. It is known that signal peptidase processing is a rapid, co-translational event. Interestingly, certain signal peptidase processing site(s) in different Flaviviridae viral structural protein precursors display suboptimal cleavage kinetics. This review focuses on the recent progress regarding the Flaviviridae virus genus-specific mechanisms to downregulate signal peptidase-mediated processing at particular viral polyprotein junction sites and the role of delayed processing at these sites in infectious virus particle assembly.

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Section: Role Of E2–p7 Cleavage Regulation In Hcv Assemblymentioning

confidence: 99%

Section: Role Of E2–p7 Cleavage Regulation In Hcv Assemblymentioning

confidence: 99%

Delayed by Design: Role of Suboptimal Signal Peptidase Processing of Viral Structural Protein Precursors in Flaviviridae Virus Assembly

Alzahrani

Shanmugam

et al. 2020

Viruses

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“…The requirement of at least one TM for proteolytic activity contrasts data on HCV NS2, where the cytoplasmic domain alone showed protease activity (50). However, the protease domain of HCV NS2 still requires membrane association via several other determinants for efficient protease activity (51,52). Nevertheless, for certain other members of the genus Hepacivirus, like bat hepacivirus (BHV), rodent hepacivirus (RHV), and GB virus B (GBV-B), it was shown that their NS2 protease requires its N-terminal membrane binding domain for catalytic activity (53).…”

Section: Resultsmentioning

confidence: 90%

Membrane Topology of Pestiviral Nonstructural Protein 2 and Determination of the Minimal Autoprotease Domain

Walther¹,

Fellenberg²,

Klemens³

et al. 2021

J Virol

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Pestiviruses like bovine viral diarrhea virus (BVDV) belong to the family Flaviviridae. A distinctive feature of the Flaviviridae is the importance of non-structural (NS) proteins for RNA genome replication and virus morphogenesis. For pestiviruses, the NS2 protease-mediated release of NS3 is essential for RNA replication, whereas uncleaved NS2-3 is indispensable for producing viral progeny. Accordingly, in the pestiviral life cycle the switch from RNA replication to virion morphogenesis is temporally regulated by the extent of NS2-3 cleavage, which is catalyzed by the NS2 autoprotease. A detailed knowledge of the structural and functional properties of pestiviral NS2 and NS2-3 is mandatory for a better understanding of these processes. In the present study, we experimentally determined the membrane topology of NS2 of BVDV-1 strain NCP7 by the Substituted Cysteine Accessibility Method (SCAM) assay. According to the resulting model, the N terminus of NS2 resides in the ER lumen and is followed by three transmembrane segments (TM) and a cytoplasmic C-terminal protease domain. We used the resulting model for fine mapping of the minimal autoprotease domain. Only one TM segment was found to be essential for maintaining residual autoprotease activity. While the topology of pestiviral NS2 is overall comparable to the one of hepatitis C virus (HCV) NS2, our data also reveal potentially important differences between the two molecules. The improved knowledge about structural and functional properties of this protein will support future functional and structural studies on pestiviral NS2. Importance Pestiviral NS2 is central to the regulation of RNA replication and virion morphogenesis via its autoprotease activity. This activity is temporally regulated by the cellular DNAJC14 as a cofactor: while free NS3 is required for RNA replication as a component of the viral replicase, only uncleaved NS2-3 supports virion morphogenesis. For a better understanding of the underlying molecular interactions, topological and structural data are required. The topology-based determination of the minimal NS2-protease domain in the present study will facilitate future attempts to determine the structure of this unusual protease cofactor complex. In the hepatitis C virus system, NS2 functions as a hub in virion morphogenesis by interacting with structural as well as non-structural proteins. Our knowledge of the membrane topology will significantly support future detailed interaction studies for pestiviral NS2.

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“…FASN contributes to the replication of other viruses, like hepatitis C virus [129], HIV [130], dengue virus [131], and rotavirus [132]. And palmitoylation of viral proteins promotes binding to membranes, virus replication, entry into host cells and release of viral particles [133][134][135]. It is intriguing whether enhanced FASN palmitoylation could be a missing link in the molecular mechanism of virus infection and serve as a promising therapeutic target.…”

Section: Palmitoylation In Inflammation and Infection In Response To Fatty Acidsmentioning

confidence: 99%

Lipid-induced S-palmitoylation as a Vital Regulator of Cell Signaling and Disease Development

Qu¹,

Zhou²,

Wang³

et al. 2021

Int. J. Biol. Sci.

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Lipid metabolites are emerging as pivotal regulators of protein function and cell signaling. The availability of intracellular fatty acid is tightly regulated by glycolipid metabolism and may affect human body through many biological mechanisms. Recent studies have demonstrated palmitate, either from exogenous fatty acid uptake or de novo fatty acid synthesis, may serve as the substrate for protein palmitoylation and regulate protein function via palmitoylation. Palmitoylation, the most-studied protein lipidation, encompasses the reversible covalent attachment of palmitate moieties to protein cysteine residues. It controls various cellular physiological processes and alters protein stability, conformation, localization, membrane association and interaction with other effectors. Dysregulation of palmitoylation has been implicated in a plethora of diseases, such as metabolic syndrome, cancers, neurological disorders and infections. Accordingly, it could be one of the molecular mechanisms underlying the impact of palmitate metabolite on cellular homeostasis and human diseases. Herein, we explore the relationship between lipid metabolites and the regulation of protein function through palmitoylation. We review the current progress made on the putative role of palmitate in altering the palmitoylation of key proteins and thus contributing to the pathogenesis of various diseases, among which we focus on metabolic disorders, cancers, inflammation and infections, neurodegenerative diseases. We also highlight the opportunities and new therapeutics to target palmitoylation in disease development.

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Palmitoylation of Hepatitis C Virus NS2 Regulates Its Subcellular Localization and NS2-NS3 Autocleavage

Cited by 16 publications

References 53 publications

Delayed by Design: Role of Suboptimal Signal Peptidase Processing of Viral Structural Protein Precursors in Flaviviridae Virus Assembly

Delayed by Design: Role of Suboptimal Signal Peptidase Processing of Viral Structural Protein Precursors in Flaviviridae Virus Assembly

Membrane Topology of Pestiviral Nonstructural Protein 2 and Determination of the Minimal Autoprotease Domain

Lipid-induced S-palmitoylation as a Vital Regulator of Cell Signaling and Disease Development

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