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Devi P, Punga T, Bergqvist A. Activation of the Ca2+/NFAT Pathway by Assembly of Hepatitis C Virus Core Protein into Nucleocapsid-like Particles. Viruses 2022; 14:v14040761. [PMID: 35458491 PMCID: PMC9031069 DOI: 10.3390/v14040761] [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: 03/15/2022] [Revised: 03/31/2022] [Accepted: 04/03/2022] [Indexed: 02/05/2023] Open
Abstract
Hepatitis C virus (HCV) is the primary pathogen responsible for liver cirrhosis and hepatocellular carcinoma. The main virion component, the core (C) protein, has been linked to several aspects of HCV pathology, including oncogenesis, immune evasion and stress responses. We and others have previously shown that C expression in various cell lines activates Ca2+ signaling and alters Ca2+ homeostasis. In this study, we identified two distinct C protein regions that are required for the activation of Ca2+/NFAT signaling. In the basic N-terminal domain, which has been implicated in self-association of C, amino acids 1–68 were critical for NFAT activation. Sedimentation analysis of four mutants in this domain revealed that association of the C protein into nucleocapsid-like particles correlated with NFAT-activated transcription. The internal, lipid droplet-targeting domain was not required for NFAT-activated transcription. Finally, the C-terminal ER-targeting domain was required in extenso for the C protein to function. Our results indicate that targeting of HCV C to the ER is necessary but not sufficient for inducing Ca2+/NFAT signaling. Taken together, our data are consistent with a model whereby proteolytic intermediates of C with an intact transmembrane ER-anchor assemble into pore-like structures in the ER membrane.
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Affiliation(s)
- Priya Devi
- Department of Medical Sciences, Uppsala University, SE 75185 Uppsala, Sweden;
| | - Tanel Punga
- Department of Medical Biochemistry and Microbiology, Uppsala University, SE 75123 Uppsala, Sweden;
| | - Anders Bergqvist
- Department of Medical Sciences, Uppsala University, SE 75185 Uppsala, Sweden;
- Clinical Microbiology and Hospital Infection Control, Uppsala University Hospital, SE 75185 Uppsala, Sweden
- Correspondence: ; Tel.: +46-186113937
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2
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Nanosized Particles Assembled by a Recombinant Virus Protein Are Able to Encapsulate Negatively Charged Molecules and Structured RNA. Polymers (Basel) 2021; 13:polym13060858. [PMID: 33799623 PMCID: PMC7998283 DOI: 10.3390/polym13060858] [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: 02/24/2021] [Revised: 03/07/2021] [Accepted: 03/09/2021] [Indexed: 11/19/2022] Open
Abstract
RNA-based molecules have recently become hot candidates to be developed into therapeutic agents. However, successful applications of RNA-based therapeutics might require suitable carriers to protect the RNA from enzymatic degradation by ubiquitous RNases in vivo. Because of their better biocompatibility and biodegradability, protein-based nanoparticles are considered to be alternatives to their synthetic polymer-based counterparts for drug delivery. Hepatitis C virus (HCV) core protein has been suggested to be able to self-assemble into nucleocapsid-like particles in vitro. In this study, the genomic RNA-binding domain of HCV core protein consisting of 116 amino acids (p116) was overexpressed with E. coli for investigation. The recombinant p116 was able to assemble into particles with an average diameter of approximately 27 nm, as visualized by electron microscopy and atomic force microscopy. Measurements with fluorescence spectroscopy, flow cytometry, and fluorescence quenching indicated that the p116-assembled nanoparticles were able to encapsulate small anionic molecules and structured RNA. This study demonstrates methods that exploit the self-assembly nature of a virus-derived protein for nanoparticle production. This study also suggests that the virus-derived protein-assembled particles could possibly be developed into potential carriers for anionic molecular drugs and structured RNA-based therapeutics.
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Pechelyulko A, Andreeva-Kovalevskaya Z, Dmitriev D, Lavrov V, Massino Y, Nagel A, Segal O, Sokolova OS, Solonin A, Tarakanova Y, Dmitriev A. A simple method to purify recombinant HCV core protein expressed in Pichia pastoris for obtaining virus-like particles and producing monoclonal antibodies. Protein Expr Purif 2021; 183:105864. [PMID: 33677084 DOI: 10.1016/j.pep.2021.105864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 02/27/2021] [Accepted: 03/01/2021] [Indexed: 11/16/2022]
Abstract
In this study, we describe an optimized method of obtaining virus-like particles (VLPs) of the recombinant hepatitis C virus (HCV) core protein (HCcAg) expressed in yeast cells (Pichia pastoris), which can be used for the construction of diagnostic test systems and vaccine engineering. The described simplified procedure was developed to enable in vitro self-assembly of HCcAg molecules into VLPs during protein purification. In brief, the HCcAg protein was precipitated from yeast cell lysates with ammonium sulfate and renatured by gel filtration on Sephadex G-25 under reducing conditions. VLPs were self-assembled after the removal of the reducing agent by gel filtration on Sephadex G-25. Protein purity and specificity were evaluated by SDS-PAGE and immunoblotting analysis. The molecular mass of VLPs and their relative quantity were measured by HPLC, followed by confirmation of VLPs production and estimation of their shape and size by transmission electron microscopy. As a result, we obtained recombinant HCcAg preparation (with ~90% purity) in the form of VLPs and monomers, which has been used to produce hybridomas secreting monoclonal antibodies (mAbs) against HCcAg.
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Affiliation(s)
- Anastasia Pechelyulko
- Mechnikov Scientific Research Institute of Vaccines and Sera, 5A Maly Kazenny Lane, Moscow, 105064, Russia.
| | - Zhanna Andreeva-Kovalevskaya
- FSBIS G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Dmitriy Dmitriev
- Mechnikov Scientific Research Institute of Vaccines and Sera, 5A Maly Kazenny Lane, Moscow, 105064, Russia
| | - Viacheslav Lavrov
- Mechnikov Scientific Research Institute of Vaccines and Sera, 5A Maly Kazenny Lane, Moscow, 105064, Russia
| | - Yulia Massino
- Mechnikov Scientific Research Institute of Vaccines and Sera, 5A Maly Kazenny Lane, Moscow, 105064, Russia
| | - Alexey Nagel
- FSBIS G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Olga Segal
- Mechnikov Scientific Research Institute of Vaccines and Sera, 5A Maly Kazenny Lane, Moscow, 105064, Russia
| | - Olga S Sokolova
- Department of Bioengineering, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Alexander Solonin
- FSBIS G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Yulia Tarakanova
- Mechnikov Scientific Research Institute of Vaccines and Sera, 5A Maly Kazenny Lane, Moscow, 105064, Russia
| | - Alexander Dmitriev
- Mechnikov Scientific Research Institute of Vaccines and Sera, 5A Maly Kazenny Lane, Moscow, 105064, Russia
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4
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Schuler B, Borgia A, Borgia MB, Heidarsson PO, Holmstrom ED, Nettels D, Sottini A. Binding without folding - the biomolecular function of disordered polyelectrolyte complexes. Curr Opin Struct Biol 2019; 60:66-76. [PMID: 31874413 DOI: 10.1016/j.sbi.2019.12.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/29/2019] [Accepted: 12/05/2019] [Indexed: 12/16/2022]
Abstract
Recent evidence shows that oppositely charged intrinsically disordered proteins (IDPs) can form high-affinity complexes that involve neither the formation of secondary or tertiary structure nor site-specific interactions between individual residues. Similar electrostatically dominated interactions have also been identified for positively charged IDPs binding to nucleic acids. These highly disordered polyelectrolyte complexes constitute an extreme case within the spectrum of biomolecular interactions involving disorder. Such interactions are likely to be widespread, since sequence analysis predicts proteins with highly charged disordered regions to be surprisingly numerous. Here, we summarize the insights that have emerged from the highly disordered polyelectrolyte complexes identified so far, and we highlight recent developments and future challenges in (i) establishing models for the underlying highly dynamic structural ensembles, (ii) understanding the novel binding mechanisms associated with them, and (iii) identifying the functional consequences.
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Affiliation(s)
- Benjamin Schuler
- Department of Biochemistry, University of Zurich, Switzerland; Department of Physics, University of Zurich, Switzerland.
| | - Alessandro Borgia
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Madeleine B Borgia
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Pétur O Heidarsson
- Department of Biochemistry, Science Institute, University of Iceland, Dunhagi 3, 107 Reykjavík, Iceland
| | - Erik D Holmstrom
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside, Lawrence, KS 66045, USA; Department of Chemistry, University of Kansas, 1200 Sunnyside, Lawrence, KS 66045, USA
| | - Daniel Nettels
- Department of Biochemistry, University of Zurich, Switzerland
| | - Andrea Sottini
- Department of Biochemistry, University of Zurich, Switzerland
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Vincenzi M, Mercurio FA, Leone M. About TFE: Old and New Findings. Curr Protein Pept Sci 2019; 20:425-451. [PMID: 30767740 DOI: 10.2174/1389203720666190214152439] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 07/16/2018] [Accepted: 07/18/2018] [Indexed: 01/28/2023]
Abstract
The fluorinated alcohol 2,2,2-Trifluoroethanol (TFE) has been implemented for many decades now in conformational studies of proteins and peptides. In peptides, which are often disordered in aqueous solutions, TFE acts as secondary structure stabilizer and primarily induces an α -helical conformation. The exact mechanism through which TFE plays its stabilizing roles is still debated and direct and indirect routes, relying either on straight interaction between TFE and molecules or indirect pathways based on perturbation of solvation sphere, have been proposed. Another still unanswered question is the capacity of TFE to favor in peptides a bioactive or a native-like conformation rather than simply stimulate the raise of secondary structure elements that reflect only the inherent propensity of a specific amino-acid sequence. In protein studies, TFE destroys unique protein tertiary structure and often leads to the formation of non-native secondary structure elements, but, interestingly, gives some hints about early folding intermediates. In this review, we will summarize proposed mechanisms of TFE actions. We will also describe several examples, in which TFE has been successfully used to reveal structural properties of different molecular systems, including antimicrobial and aggregation-prone peptides, as well as globular folded and intrinsically disordered proteins.
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Affiliation(s)
- Marian Vincenzi
- Institute of Biostructures and Bioimaging, National Research Council (CNR), Via Mezzocannone 16, 80134 Naples, Italy
| | - Flavia A Mercurio
- Institute of Biostructures and Bioimaging, National Research Council (CNR), Via Mezzocannone 16, 80134 Naples, Italy.,Cirpeb, InterUniversity Research Centre on Bioactive Peptides, University of Naples "Federico II", Via Mezzocannone 16, 80134 Naples, Italy
| | - Marilisa Leone
- Institute of Biostructures and Bioimaging, National Research Council (CNR), Via Mezzocannone 16, 80134 Naples, Italy.,Cirpeb, InterUniversity Research Centre on Bioactive Peptides, University of Naples "Federico II", Via Mezzocannone 16, 80134 Naples, Italy
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6
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Disordered RNA chaperones can enhance nucleic acid folding via local charge screening. Nat Commun 2019; 10:2453. [PMID: 31165735 PMCID: PMC6549165 DOI: 10.1038/s41467-019-10356-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/06/2019] [Indexed: 01/14/2023] Open
Abstract
RNA chaperones are proteins that aid in the folding of nucleic acids, but remarkably, many of these proteins are intrinsically disordered. How can these proteins function without a well-defined three-dimensional structure? Here, we address this question by studying the hepatitis C virus core protein, a chaperone that promotes viral genome dimerization. Using single-molecule fluorescence spectroscopy, we find that this positively charged disordered protein facilitates the formation of compact nucleic acid conformations by acting as a flexible macromolecular counterion that locally screens repulsive electrostatic interactions with an efficiency equivalent to molar salt concentrations. The resulting compaction can bias unfolded nucleic acids towards folding, resulting in faster folding kinetics. This potentially widespread mechanism is supported by molecular simulations that rationalize the experimental findings by describing the chaperone as an unstructured polyelectrolyte. RNA chaperones, such as the hepatitic C virus (HCV) core protein, are proteins that aid in the folding of nucleic acids. Here authors use single‐molecule spectroscopy and simulation to show that the HCV core protein acts as a flexible macromolecular counterion which facilitates nucleic acid folding.
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7
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Hepatitis C virus core protein interacts with cellular metastasis suppressor Nm23-H1 and promotes cell migration and invasion. Arch Virol 2019; 164:1271-1285. [PMID: 30859475 DOI: 10.1007/s00705-019-04151-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 12/18/2018] [Indexed: 12/24/2022]
Abstract
Hepatitis C virus (HCV) is the major etiological agent of hepatocellular carcinoma (HCC), which is the fourth most common cause of cancer-related deaths worldwide and second in terms of deaths of males (Bray et al. in CA Cancer J Clin 68(6):394-424, 2018). HCV-induced HCC is a multi-step process that involves alteration of several host regulatory pathways. One of the key features of HCV-associated hepatocellular carcinoma is the metastasis of cancer cells to different organs. Human Nm23-H1 is one of the best-studied metastasis suppressor proteins, and it has been shown to be modulated in many human cancers. Our study shows that the core protein of HCV genotype 2a can co-localize and interact directly with Nm23-H1 within cancer cells, resulting in modulation of the anti-metastasis properties of Nm23-H1. The HCV core protein promotes SUMOylation and degradation of the Nm23-H1 protein, as well as transcriptional downregulation. This study provides evidence that the HCV core protein is a pro-metastatic protein that can interact directly with and modulate the functions of cellular metastasis suppressor Nm23-H1.
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8
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Venkatesh AG, Brickner H, Looney D, Hall DA, Aronoff-Spencer E. Clinical detection of Hepatitis C viral infection by yeast-secreted HCV-core:Gold-binding-peptide. Biosens Bioelectron 2018; 119:230-236. [PMID: 30144754 DOI: 10.1016/j.bios.2018.07.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/01/2018] [Accepted: 07/13/2018] [Indexed: 01/03/2023]
Abstract
Access to affordable and field deployable diagnostics are key barriers to the control and eradication of many endemic and emerging infectious diseases. While cost, accuracy, and usability have all improved in recent years, there remains a pressing need for even less expensive and more scalable technologies. To that end, we explored new methods to inexpensively produce and couple protein-based biosensing molecules (affinity reagents) with scalable electrochemical sensors. Previous whole-cell constructs resulted in confounding measurements in clinical testing due to significant cross-reactivity when probing for host-immune (antibody) response to infection. To address this, we developed two complimentary strategies based on either the release of surface displayed or secretion of fusion proteins. These dual affinity biosensing elements couple antibody recognition (using antigen) and sensor surface adhesion (using gold-binding peptide-GBP) to allow single-step reagent production, purification, and biosensor assembly. As a proof-of-concept, we developed Hepatitis C virus (HCV)-core antigen-GBP fusion proteins. These constructs were first tested and optimized for consistent surface adhesion then the assembled immunosensors were tested for cross-reactivity and evaluated for performance in vitro. We observed loss of function of the released reagents while secreted constructs performed well in in vitro testing with 2 orders of dynamic range, and a limit of detection of 32 nM. Finally, we validated the secreted platform with clinical isolates (n = 3) with statistically significant differentiation of positive vs. non-infected serum (p < 0.0001) demonstrating the ability to clearly distinguish HCV positive and negative clinical samples.
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Affiliation(s)
- A G Venkatesh
- Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - H Brickner
- School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - D Looney
- School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - D A Hall
- Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - E Aronoff-Spencer
- School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
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9
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Li W, Kou X, Xu J, Zhou W, Zhao R, Zhang Z, Fang X. Characterization of Hepatitis C Virus Core Protein Dimerization by Atomic Force Microscopy. Anal Chem 2018; 90:4596-4602. [DOI: 10.1021/acs.analchem.7b05070] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Wenhui Li
- Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaolong Kou
- Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiachao Xu
- Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Zhou
- Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rong Zhao
- Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhen Zhang
- Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaohong Fang
- Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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10
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Holmstrom ED, Nettels D, Schuler B. Conformational Plasticity of Hepatitis C Virus Core Protein Enables RNA-Induced Formation of Nucleocapsid-like Particles. J Mol Biol 2017; 430:2453-2467. [PMID: 29045818 DOI: 10.1016/j.jmb.2017.10.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/29/2017] [Accepted: 10/02/2017] [Indexed: 02/08/2023]
Abstract
Many of the unanswered questions associated with hepatitis C virus assembly are related to the core protein (HCVcp), which forms an oligomeric nucleocapsid encompassing the viral genome. The structural properties of HCVcp have been difficult to quantify, at least in part because it is an intrinsically disordered protein. We have used single-molecule Förster Resonance Energy Transfer techniques to study the conformational dimensions and dynamics of the HCVcp nucleocapsid domain (HCVncd) at various stages during the RNA-induced formation of nucleocapsid-like particles. Our results indicate that HCVncd is a typical intrinsically disordered protein. When it forms small ribonucleoprotein complexes with various RNA hairpins from the 3' end of the HCV genome, it compacts but remains intrinsically disordered and conformationally dynamic. Above a critical RNA concentration, these ribonucleoprotein complexes rapidly and cooperatively assemble into large nucleocapsid-like particles, wherein the individual HCVncd subunits become substantially more extended.
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Affiliation(s)
- Erik D Holmstrom
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
| | - Daniel Nettels
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
| | - Benjamin Schuler
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
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11
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Pène V, Lemasson M, Harper F, Pierron G, Rosenberg AR. Role of cleavage at the core-E1 junction of hepatitis C virus polyprotein in viral morphogenesis. PLoS One 2017; 12:e0175810. [PMID: 28437468 PMCID: PMC5402940 DOI: 10.1371/journal.pone.0175810] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 03/31/2017] [Indexed: 12/17/2022] Open
Abstract
In hepatitis C virus (HCV) polyprotein sequence, core protein terminates with E1 envelope signal peptide. Cleavage by signal peptidase (SP) separates E1 from the complete form of core protein, anchored in the endoplasmic reticulum (ER) membrane by the signal peptide. Subsequent cleavage of the signal peptide by signal-peptide peptidase (SPP) releases the mature form of core protein, which preferentially relocates to lipid droplets. Both of these cleavages are required for the HCV infectious cycle, supporting the idea that HCV assembly begins at the surface of lipid droplets, yet SPP-catalyzed cleavage is dispensable for initiation of budding in the ER. Here we have addressed at what step(s) of the HCV infectious cycle SP-catalyzed cleavage at the core-E1 junction is required. Taking advantage of the sole system that has allowed visualization of HCV budding events in the ER lumen of mammalian cells, we showed that, unexpectedly, mutations abolishing this cleavage did not prevent but instead tended to promote the initiation of viral budding. Moreover, even though no viral particles were released from Huh-7 cells transfected with a full-length HCV genome bearing these mutations, intracellular viral particles containing core protein protected by a membrane envelope were formed. These were visualized by electron microscopy as capsid-containing particles with a diameter of about 70 nm and 40 nm before and after delipidation, respectively, comparable to intracellular wild-type particle precursors except that they were non-infectious. Thus, our results show that SP-catalyzed cleavage is dispensable for HCV budding per se, but is required for the viral particles to acquire their infectivity and secretion. These data support the idea that HCV assembly occurs in concert with budding at the ER membrane. Furthermore, capsid-containing particles did not accumulate in the absence of SP-catalyzed cleavage, suggesting the quality of newly formed viral particles is controlled before secretion.
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Affiliation(s)
- Véronique Pène
- Université Paris Descartes, EA 4474 “Virologie de l’Hépatite C”, Paris, France
- * E-mail: (VP); (AR)
| | - Matthieu Lemasson
- Université Paris Descartes, EA 4474 “Virologie de l’Hépatite C”, Paris, France
| | - Francis Harper
- CNRS UMR 9196, Institut Gustave Roussy, Villejuif, France
| | - Gérard Pierron
- CNRS UMR 9196, Institut Gustave Roussy, Villejuif, France
| | - Arielle R. Rosenberg
- Université Paris Descartes, EA 4474 “Virologie de l’Hépatite C”, Paris, France
- AP-HP, Hôpital Cochin, Service de Virologie, Paris, France
- * E-mail: (VP); (AR)
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Abstract
Viruses use synthetic mechanism and organelles of the host cells to facilitate their replication and make new viruses. Host's ATP provides necessary energy. Hepatitis C virus (HCV) is a major cause of liver disease. Like other positive-strand RNA viruses, the HCV genome is thought to be synthesized by the replication complex, which consists of viral- and host cell-derived factors, in tight association with structurally rearranged vesicle-like cytoplasmic membranes. The virus-induced remodeling of subcellular membranes, which protect the viral RNA from nucleases in the cytoplasm, promotes efficient replication of HCV genome. The assembly of HCV particle involves interactions between viral structural and nonstructural proteins and pathways related to lipid metabolisms in a concerted fashion. Association of viral core protein, which forms the capsid, with lipid droplets appears to be a prerequisite for early steps of the assembly, which are closely linked with the viral genome replication. This review presents the recent progress in understanding the mechanisms for replication and assembly of HCV through its interactions with organelles or distinct organelle-like structures.
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Affiliation(s)
- Tetsuro Suzuki
- Department of Virology and Parasitology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, 431-3192, Japan.
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13
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Detection of Hepatitis C core antibody by dual-affinity yeast chimera and smartphone-based electrochemical sensing. Biosens Bioelectron 2016; 86:690-696. [DOI: 10.1016/j.bios.2016.07.023] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/17/2016] [Accepted: 07/08/2016] [Indexed: 12/11/2022]
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de Souza TLF, de Lima SMB, Braga VLDA, Peabody DS, Ferreira DF, Bianconi ML, Gomes AMDO, Silva JL, de Oliveira AC. Charge neutralization as the major factor for the assembly of nucleocapsid-like particles from C-terminal truncated hepatitis C virus core protein. PeerJ 2016; 4:e2670. [PMID: 27867765 PMCID: PMC5111903 DOI: 10.7717/peerj.2670] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/08/2016] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Hepatitis C virus (HCV) core protein, in addition to its structural role to form the nucleocapsid assembly, plays a critical role in HCV pathogenesis by interfering in several cellular processes, including microRNA and mRNA homeostasis. The C-terminal truncated HCV core protein (C124) is intrinsically unstructured in solution and is able to interact with unspecific nucleic acids, in the micromolar range, and to assemble into nucleocapsid-like particles (NLPs) in vitro. The specificity and propensity of C124 to the assembly and its implications on HCV pathogenesis are not well understood. METHODS Spectroscopic techniques, transmission electron microscopy and calorimetry were used to better understand the propensity of C124 to fold or to multimerize into NLPs when subjected to different conditions or in the presence of unspecific nucleic acids of equivalent size to cellular microRNAs. RESULTS The structural analysis indicated that C124 has low propensity to self-folding. On the other hand, for the first time, we show that C124, in the absence of nucleic acids, multimerizes into empty NLPs when subjected to a pH close to its isoelectric point (pH ≈ 12), indicating that assembly is mainly driven by charge neutralization. Isothermal calorimetry data showed that the assembly of NLPs promoted by nucleic acids is enthalpy driven. Additionally, data obtained from fluorescence correlation spectroscopy show that C124, in nanomolar range, was able to interact and to sequester a large number of short unspecific nucleic acids into NLPs. DISCUSSION Together, our data showed that the charge neutralization is the major factor for the nucleocapsid-like particles assembly from C-terminal truncated HCV core protein. This finding suggests that HCV core protein may physically interact with unspecific cellular polyanions, which may correspond to microRNAs and mRNAs in a host cell infected by HCV, triggering their confinement into infectious particles.
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Affiliation(s)
- Theo Luiz Ferraz de Souza
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Vanessa L. de Azevedo Braga
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - David S. Peabody
- Department of Molecular Genetics and Microbiology and Cancer Research and Treatment Center, University of New Mexico, Albuquerque, United States
| | - Davis Fernandes Ferreira
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M. Lucia Bianconi
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Andre Marco de Oliveira Gomes
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jerson Lima Silva
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Andréa Cheble de Oliveira
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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15
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Stewart H, Bingham R, White SJ, Dykeman EC, Zothner C, Tuplin AK, Stockley PG, Twarock R, Harris M. Identification of novel RNA secondary structures within the hepatitis C virus genome reveals a cooperative involvement in genome packaging. Sci Rep 2016; 6:22952. [PMID: 26972799 PMCID: PMC4789732 DOI: 10.1038/srep22952] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 02/19/2016] [Indexed: 12/11/2022] Open
Abstract
The specific packaging of the hepatitis C virus (HCV) genome is hypothesised to be driven by Core-RNA interactions. To identify the regions of the viral genome involved in this process, we used SELEX (systematic evolution of ligands by exponential enrichment) to identify RNA aptamers which bind specifically to Core in vitro. Comparison of these aptamers to multiple HCV genomes revealed the presence of a conserved terminal loop motif within short RNA stem-loop structures. We postulated that interactions of these motifs, as well as sub-motifs which were present in HCV genomes at statistically significant levels, with the Core protein may drive virion assembly. We mutated 8 of these predicted motifs within the HCV infectious molecular clone JFH-1, thereby producing a range of mutant viruses predicted to possess altered RNA secondary structures. RNA replication and viral titre were unaltered in viruses possessing only one mutated structure. However, infectivity titres were decreased in viruses possessing a higher number of mutated regions. This work thus identified multiple novel RNA motifs which appear to contribute to genome packaging. We suggest that these structures act as cooperative packaging signals to drive specific RNA encapsidation during HCV assembly.
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MESH Headings
- Aptamers, Nucleotide/chemistry
- Aptamers, Nucleotide/genetics
- Aptamers, Nucleotide/metabolism
- Base Sequence
- Blotting, Western
- Cell Line, Tumor
- Gene Expression Regulation, Viral
- Genome, Viral/genetics
- Hepacivirus/genetics
- Hepacivirus/metabolism
- Humans
- Mutation
- Nucleic Acid Conformation
- Nucleotide Motifs/genetics
- Protein Binding
- RNA, Viral/chemistry
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- SELEX Aptamer Technique
- Viral Core Proteins/genetics
- Viral Core Proteins/metabolism
- Viral Proteins/genetics
- Viral Proteins/metabolism
- Virus Assembly/genetics
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Affiliation(s)
- H. Stewart
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - R.J. Bingham
- York Centre for Complex Systems Analysis, Departments of Mathematics and Biology, University of York, York, YO10 5DD, United Kingdom
| | - S. J. White
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - E. C. Dykeman
- York Centre for Complex Systems Analysis, Departments of Mathematics and Biology, University of York, York, YO10 5DD, United Kingdom
| | - C. Zothner
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - A. K. Tuplin
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - P. G. Stockley
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - R. Twarock
- York Centre for Complex Systems Analysis, Departments of Mathematics and Biology, University of York, York, YO10 5DD, United Kingdom
| | - M. Harris
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
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16
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Mirnurollahi SM, Bolhassani A, Irani S, Davoudi N. Expression and Purification of HCV Core and Core-E1E2 Proteins in Different Bacterial Strains. IRANIAN JOURNAL OF BIOTECHNOLOGY 2015; 13:57-62. [PMID: 28959300 DOI: 10.15171/ijb.1249] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Hepatitis C virus (HCV) is a main public health problem causing chronic liver infection and subsequently liver cirrhosis and lethal hepatocellular carcinoma (HCC). Vaccination based on HCV capsid proteins has attracted a special interest for prevention of viral infections. The core protein is a basic and evolutionary most conserved protein, which regulates the cellular processes related to viral replication and pathogenesis. The envelope E1 and E2 proteins involve in generation of the infectious particles, viral entry by binding to a host cell receptor, and modulation of the immune responses. OBJECTIVES In current study, the efficient generation of recombinant core and core-E1E2 proteins was developed in bacterial expression systems. MATERIALS AND METHODS The expression of HCV core and core-E1E2 proteins was performed using prokaryotic pET-28a and pQE-30 expression systems in BL21/ Rosetta, and M15 strains, respectively. The recombinant proteins were purified using affinity chromatography under native conditions and also reverse staining method. Finally, the levels of recombinant proteins were assessed by BCA kit and spectrophotometer. RESULTS The data showed a clear band of ~573 bp for HCV core and ~2238 bp for core-E1E2 genes in agarose gel. Moreover, a ~21 kDa band of core protein and a ~83 kDa band of core-E1E2 protein were revealed in SDS-PAGE. The affinity chromatography could not purify the core and core-E1E2 proteins completely, because of low affinity to Ni-NTA bead in comparison with reverse staining method. CONCLUSIONS This study is the first report for purification of HCV core and core-E1E2 proteins using the reverse staining procedure with no need of any chromatography columns. The BL21 strain was more potent than Rosetta strain for HCV core protein in pET 28a expression system. Furthermore, M15 strain was suitable for expression of coreE1E2 in pQE-30 bacterial system.
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Affiliation(s)
| | - Azam Bolhassani
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
| | - Shiva Irani
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Noushin Davoudi
- Biotechnology Research Center, Department of Medical Biotechnology, Pasteur Institute of Iran, Tehran, Iran
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17
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Abstract
Chronic hepatitis C virus (HCV) infection results in a progressive disease that may end in cirrhosis and, eventually, in hepatocellular carcinoma. In the last several years, tremendous progress has been made in understanding the HCV life cycle and in the development of small molecule compounds for the treatment of chronic hepatitis C. Nevertheless, the complete understanding of HCV assembly and particle release as well as the detailed characterization and structure of HCV particles is still missing. One of the most important events in the HCV assembly is the nucleocapsid formation which is driven by the core protein, that can oligomerize upon interaction with viral RNA, and is orchestrated by viral and host proteins. Despite a growing number of new factors involved in HCV assembly process, we do not know the three-dimensional structure of the core protein or its topology in the nucleocapsid. Since the core protein contains a hydrophobic C-terminal domain responsible for the binding to cellular membranes, the assembly pathway of HCV virions might proceed via coassembly at endoplasmic reticulum membranes. Recently, new mechanisms involving viral proteins and host factors in HCV particle formation and egress have been described. The present review aims to summarize the advances in our understanding of HCV assembly with an emphasis on the core protein as a structural component of virus particles that possesses the ability to interact with a variety of cellular components and is potentially an attractive target for the development of a novel class of anti-HCV agents.
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Affiliation(s)
- Katarzyna Gawlik
- Department of Immunology and Microbial Science, IMM-9, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA, 92037, USA
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18
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Afzal MS, Alsaleh K, Farhat R, Belouzard S, Danneels A, Descamps V, Duverlie G, Wychowski C, Zaidi NUSS, Dubuisson J, Rouillé Y. Regulation of core expression during the hepatitis C virus life cycle. J Gen Virol 2015; 96:311-321. [DOI: 10.1099/vir.0.070433-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Affiliation(s)
- Muhammad Sohail Afzal
- Atta ur Rahman School of Applied Biosciences (ASAB), National University of Science and Technology (NUST), Islamabad, Pakistan
- Center for Infection & Immunity of Lille (CIIL), Inserm U1019, CNRS UMR8204, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
| | - Khaled Alsaleh
- Center for Infection & Immunity of Lille (CIIL), Inserm U1019, CNRS UMR8204, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
| | - Rayan Farhat
- Center for Infection & Immunity of Lille (CIIL), Inserm U1019, CNRS UMR8204, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
| | - Sandrine Belouzard
- Center for Infection & Immunity of Lille (CIIL), Inserm U1019, CNRS UMR8204, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
| | - Adeline Danneels
- Center for Infection & Immunity of Lille (CIIL), Inserm U1019, CNRS UMR8204, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
| | - Véronique Descamps
- EA4294, Unité de Virologie Clinique et Fondamentale, CHU d’Amiens, University of Picardie Jules Verne, Amiens, France
| | - Gilles Duverlie
- EA4294, Unité de Virologie Clinique et Fondamentale, CHU d’Amiens, University of Picardie Jules Verne, Amiens, France
| | - Czeslaw Wychowski
- Center for Infection & Immunity of Lille (CIIL), Inserm U1019, CNRS UMR8204, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
| | - Najam us Sahar Sadaf Zaidi
- Atta ur Rahman School of Applied Biosciences (ASAB), National University of Science and Technology (NUST), Islamabad, Pakistan
| | - Jean Dubuisson
- Center for Infection & Immunity of Lille (CIIL), Inserm U1019, CNRS UMR8204, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
| | - Yves Rouillé
- Center for Infection & Immunity of Lille (CIIL), Inserm U1019, CNRS UMR8204, Institut Pasteur de Lille, Université Lille Nord de France, Lille, France
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19
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Ahour F, Pournaghi-Azar MH, Alipour E, Hejazi MS. Detection and discrimination of recombinant plasmid encoding hepatitis C virus core/E1 gene based on PNA and double-stranded DNA hybridization. Biosens Bioelectron 2013; 45:287-91. [PMID: 23500377 DOI: 10.1016/j.bios.2013.01.063] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 01/29/2013] [Accepted: 01/30/2013] [Indexed: 12/15/2022]
Abstract
Development of an electrochemical DNA biosensor for direct detection and discrimination of double-stranded plasmid (ds-Pl) without the need for denaturation of the target plasmid sample using a peptide nucleic acid (PNA) oligomer as the probe is described. This goal was achieved by modification of gold electrode with 6-mercapto-1-hexanol following monolayer self-assembly of cysteine conjugated 20-mer PNA oligomer probe, complementary to the HCV core/E1 region, which binds to ds-Pl and forms PNA/ds-Pl structure. The significant variation in differential pulse voltammetric response of methylene blue on the probe modified electrode upon contacting with complementary double-strand plasmid to form PNA/ds-Pl triplex structure is the principle of target plasmid detection. The results indicated that the reduction peak current was linear with the concentration of complementary strand in the range of 10-300 pg/μl with a detection limit of 9.5 pg/μl.
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Affiliation(s)
- Fatemeh Ahour
- Electroanalytical Chemistry Laboratory, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
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20
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Tsirulnikov K, Abuladze N, Vahi R, Hasnain H, Phillips M, Ryan CM, Atanasov I, Faull KF, Kurtz I, Pushkin A. Aminoacylase 3 binds to and cleaves the N-terminus of the hepatitis C virus core protein. FEBS Lett 2012; 586:3799-804. [PMID: 23010594 DOI: 10.1016/j.febslet.2012.09.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 08/30/2012] [Accepted: 09/06/2012] [Indexed: 01/13/2023]
Abstract
Aminoacylase 3 (AA3) mediates deacetylation of N-acetyl aromatic amino acids and mercapturic acids. Deacetylation of mercapturic acids of exo- and endobiotics are likely involved in their toxicity. AA3 is predominantly expressed in kidney, and to a lesser extent in liver, brain, and blood. AA3 has been recently reported to interact with the hepatitis C virus core protein (HCVCP) in the yeast two-hybrid system. Here we demonstrate that AA3 directly binds to HCVCP (K(d) ~10 μM) that may by implicated in HCV pathogenesis. AA3 also revealed a weak endopeptidase activity towards the N-terminus of HCVCP.
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Affiliation(s)
- Kirill Tsirulnikov
- Division of Nephrology, Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, CA 90095, USA.
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21
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The disordered N-terminal region of dengue virus capsid protein contains a lipid-droplet-binding motif. Biochem J 2012; 444:405-15. [PMID: 22428600 DOI: 10.1042/bj20112219] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dengue is the major arthropod-borne human viral disease, for which no vaccine or specific treatment is available. We used NMR, zeta potential measurements and atomic force microscopy to study the structural features of the interaction between dengue virus C (capsid) protein and LDs (lipid droplets), organelles crucial for infectious particle formation. C protein-binding sites to LD were mapped, revealing a new function for a conserved segment in the N-terminal disordered region and indicating that conformational selection is involved in recognition. The results suggest that the positively charged N-terminal region of C protein prompts the interaction with negatively charged LDs, after which a conformational rearrangement enables the access of the central hydrophobic patch to the LD surface. Taken together, the results allowed the design of a peptide with inhibitory activity of C protein-LD binding, paving the way for new drug development approaches against dengue.
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22
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Duvignaud JB, Majeau N, Delisle P, Voyer N, Gagné SM, Leclerc D. Interfering with hepatitis C virus assembly in vitro using affinity peptides directed towards core protein. Can J Microbiol 2012; 58:475-82. [DOI: 10.1139/w2012-009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Viral assembly is a crucial key step in the life cycle of every virus. In the case of Hepatitis C virus (HCV), the core protein is the only structural protein to interact directly with the viral genomic RNA. Purified recombinant core protein is able to self-assemble in vitro into nucleocapsid-like particles upon addition of a structured RNA, providing a robust assay with which to study HCV assembly. Inhibition of self-assembly of the C170 core protein (first 170 amino acids) was tested using short peptides derived from the HCV core, from HCV NS5A protein, and from diverse proteins (p21 and p73) known to interact with HCV core protein. Interestingly, peptides derived from the core were the best inhibitors. These peptides are derived from regions of the core predicted to be involved in the interaction between core subunits during viral assembly. We also demonstrated that a peptide derived from the C-terminal end of NS5A protein moderately inhibits the assembly process.
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Affiliation(s)
- Jean-Baptiste Duvignaud
- PROTEO, IBIS and Department of Biochemistry and Microbiology, Université Laval, Québec, QC G1V 0A6, Canada
- Infectious Diseases Research Centre, CHUL, Université Laval, 2705 boulevard Laurier, Québec, QC G1V 4G2, Canada
| | - Nathalie Majeau
- Infectious Diseases Research Centre, CHUL, Université Laval, 2705 boulevard Laurier, Québec, QC G1V 4G2, Canada
| | - Priscilla Delisle
- PROTEO and Department of Chemistry, Université Laval, Québec, QC G1V 0A6, Canada
| | - Normand Voyer
- PROTEO and Department of Chemistry, Université Laval, Québec, QC G1V 0A6, Canada
| | - Stéphane M. Gagné
- PROTEO, IBIS and Department of Biochemistry and Microbiology, Université Laval, Québec, QC G1V 0A6, Canada
| | - Denis Leclerc
- Infectious Diseases Research Centre, CHUL, Université Laval, 2705 boulevard Laurier, Québec, QC G1V 4G2, Canada
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23
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Suzuki T. Morphogenesis of infectious hepatitis C virus particles. Front Microbiol 2012; 3:38. [PMID: 22347224 PMCID: PMC3273859 DOI: 10.3389/fmicb.2012.00038] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 01/23/2012] [Indexed: 12/17/2022] Open
Abstract
More than 170 million individuals are currently infected with hepatitis C virus (HCV) worldwide and are at continuous risk of developing chronic liver disease. Since a cell culture system enabling relatively efficient propagation of HCV has become available, an increasing number of viral and host factors involved in HCV particle formation have been identified. Association of the viral Core, which forms the capsid with lipid droplets appears to be prerequisite for early HCV morphogenesis. Maturation and release of HCV particles is tightly linked to very-low-density lipoprotein biogenesis. Although expression of Core as well as E1 and E2 envelope proteins produces virus-like particles in heterologous expression systems, there is increasing evidence that non-structural viral proteins and p7 are also required for the production of infectious particles, suggesting that HCV genome replication and virion assembly are closely linked. Advances in our understanding of the various molecular mechanisms by which infectious HCV particles are formed are summarized.
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Affiliation(s)
- Tetsuro Suzuki
- Department of Infectious Diseases, Hamamatsu University School of Medicine Hamamatsu, Japan
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24
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Ivanyi-Nagy R, Darlix JL. Fuzziness in the Core of the Human Pathogenic Viruses HCV and HIV. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 725:142-58. [DOI: 10.1007/978-1-4614-0659-4_9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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25
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Weiser BM, Tellinghuisen TL. Structural biology of the hepatitis C virus proteins. DRUG DISCOVERY TODAY. TECHNOLOGIES 2012; 9:e175-e226. [PMID: 24064309 DOI: 10.1016/j.ddtec.2011.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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26
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Lee JW, Liao PC, Young KC, Chang CL, Chen SSL, Chang TT, Lai MD, Wang SW. Identification of hnRNPH1, NF45, and C14orf166 as Novel Host Interacting Partners of the Mature Hepatitis C Virus Core Protein. J Proteome Res 2011; 10:4522-34. [DOI: 10.1021/pr200338d] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Jun-Wei Lee
- Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
| | - Pao-Chi Liao
- Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
| | - Kung-Chia Young
- Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
- Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
| | - Christina L. Chang
- Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
- Institute of Molecular Medicine, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
| | - Steve S. L. Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan, Republic of China
| | - Ting-Tsung Chang
- Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
- Department of Medicine, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
- Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
| | - Ming-Derg Lai
- Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
- Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
| | - Shainn-Wei Wang
- Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
- Institute of Molecular Medicine, College of Medicine, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
- Division of Clinical Research, National Health Research Institutes, Tainan 70401, Taiwan, Republic of China
- Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan 70401, Taiwan, Republic of China
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27
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Abstract
Infection with hepatitis C virus (HCV) is a major risk factor for chronic hepatitis, cirrhosis and hepatocellular carcinoma. Once robust cell culture systems for production of recombinant infectious HCV became available, evidence on molecular mechanisms underlying assembly and release of the virus particles began to accumulate. Recent studies have demonstrated that lipid droplets and viral nonstructural proteins play key roles in HCV morphogenesis. This review considers the current knowledge about maturation of HCV structural proteins and production of viral infectious particles.
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Affiliation(s)
- Tetsuro Suzuki
- Department of Infectious Diseases, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan.
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28
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Duvignaud JB, Leclerc D, Gagné SM. Structure and dynamics changes induced by 2,2,2-trifluoro-ethanol (TFE) on the N-terminal half of hepatitis C virus core protein. Biochem Cell Biol 2010; 88:315-23. [PMID: 20453932 DOI: 10.1139/o09-155] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022] Open
Abstract
The Core protein of hepatitis C virus is involved in several interactions other than the encapsidation of viral RNA. We recently proposed that this is related to the fact that the N-terminal half of this protein (C82) is an intrinsically unstructured protein (IUP) domain. IUP domains can adopt a secondary structure when they are interacting with another molecule, such as a nucleic acid or a protein. It is also possible to mimic these conditions by modifying the environment of the protein. We investigated the propensity of this protein to fold as a function of salt concentration, detergent, pH, and 2,2,2-trifluoro-ethanol (TFE); only the addition of TFE resulted in a structural change. The effect of TFE addition was studied by circular dichroism, structural, and dynamic data obtained by NMR. The data indicate that C82 can adopt an alpha-helical structure; this conformation is likely relevant to one of the functional roles of the HCV Core protein.
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Affiliation(s)
- Jean-Baptiste Duvignaud
- PROTEO and Department of Biochemistry and Microbiology, Pavillon C-E MARCHAND, Universite Laval, 1030 avenue de Medecine, Local 3255, Quebec, QC G1V 0A6, Canada.
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29
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Strosberg AD, Kota S, Takahashi V, Snyder JK, Mousseau G. Core as a novel viral target for hepatitis C drugs. Viruses 2010; 2:1734-1751. [PMID: 21994704 PMCID: PMC3185734 DOI: 10.3390/v2081734] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/06/2010] [Accepted: 08/16/2010] [Indexed: 02/07/2023] Open
Abstract
Hepatitis C virus (HCV) infects over 130 million people worldwide and is a major cause of liver disease. No vaccine is available. Novel specific drugs for HCV are urgently required, since the standard-of-care treatment of pegylated interferon combined with ribavirin is poorly tolerated and cures less than half of the treated patients. Promising, effective direct-acting drugs currently in the clinic have been described for three of the ten potential HCV target proteins: NS3/NS4A protease, NS5B polymerase and NS5A, a regulatory phosphoprotein. We here present core, the viral capsid protein, as another attractive, non-enzymatic target, against which a new class of anti-HCV drugs can be raised. Core plays a major role in the virion's formation, and interacts with several cellular proteins, some of which are involved in host defense mechanisms against the virus. This most conserved of all HCV proteins requires oligomerization to function as the organizer of viral particle assembly. Using core dimerization as the basis of transfer-of-energy screening assays, peptides and small molecules were identified which not only inhibit core-core interaction, but also block viral production in cell culture. Initial chemical optimization resulted in compounds active in single digit micromolar concentrations. Core inhibitors could be used in combination with other HCV drugs in order to provide novel treatments of Hepatitis C.
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Affiliation(s)
- Arthur Donny Strosberg
- Department of Infectology, The Scripps Research Institute-Scripps Florida, 130 Scripps Way, Jupiter, FL-33458, USA; E-Mails: (S.K.); (V.T.); (G.M.)
| | - Smitha Kota
- Department of Infectology, The Scripps Research Institute-Scripps Florida, 130 Scripps Way, Jupiter, FL-33458, USA; E-Mails: (S.K.); (V.T.); (G.M.)
| | - Virginia Takahashi
- Department of Infectology, The Scripps Research Institute-Scripps Florida, 130 Scripps Way, Jupiter, FL-33458, USA; E-Mails: (S.K.); (V.T.); (G.M.)
| | - John K. Snyder
- Department of Chemistry, The Center for Chemical Methodology and Library Development, Boston University, Boston, MA 02215, USA; E-Mail:
| | - Guillaume Mousseau
- Department of Infectology, The Scripps Research Institute-Scripps Florida, 130 Scripps Way, Jupiter, FL-33458, USA; E-Mails: (S.K.); (V.T.); (G.M.)
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30
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Carmona P, Molina M. Interactions of Protein and Nucleic Acid Components of Hepatitis C Virus As Revealed by Fourier Transform Infrared Spectroscopy. Biochemistry 2010; 49:4724-31. [DOI: 10.1021/bi100535k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pedro Carmona
- Instituto de Estructura de la Materia (CSIC), Serrano 121, 28006 Madrid, Spain
| | - Marina Molina
- Departamento de Química Orgánica, Escuela Universitaria de Optica, Arcos de Jalón, s/n, 28037 Madrid, Spain
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31
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Madesis P, Osathanunkul M, Georgopoulou U, Gisby MF, Mudd EA, Nianiou I, Tsitoura P, Mavromara P, Tsaftaris A, Day A. A hepatitis C virus core polypeptide expressed in chloroplasts detects anti-core antibodies in infected human sera. J Biotechnol 2010; 145:377-86. [PMID: 19969031 DOI: 10.1016/j.jbiotec.2009.12.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 11/27/2009] [Accepted: 12/01/2009] [Indexed: 01/19/2023]
Abstract
Hepatitis C virus (HCV) is a major disease agent affecting approximately 3% of the world's population. Expression in plant chloroplasts enables low-cost production of the conserved HCV core protein used in diagnostic tests to combat virus spread in developing countries with high infection rates. The bactericidal activity of the 21 kDa precore protein hinders cloning the core gene in plastid expression cassettes, which are active in bacteria due to the similarities between bacterial and plastid promoters and ribosome binding sites. This was overcome by using a topology-dependent expression cassette containing tandem rrn and psbA plastid promoters, whose activity was shown to be dependent on temperature. The viral core gene and a codon-optimised gene encoding a C-terminal truncated 16 kDa core polypeptide were expressed in tobacco chloroplasts. The codon-optimised gene increased monocistronic core mRNA levels by at least 2-fold and core polypeptides by over 5-fold, relative to the native viral gene. Expression of the 16 kDa core polypeptide was stable in leaves of different ages. Anti-core antibodies in HCV-infected human sera were detected by the 16 kDa core polypeptide in total leaf protein fractionated on Western blots providing a first step towards developing a chloroplast-based HCV diagnostic method.
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Affiliation(s)
- P Madesis
- Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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32
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Majeau N, Fromentin R, Savard C, Duval M, Tremblay MJ, Leclerc D. Palmitoylation of hepatitis C virus core protein is important for virion production. J Biol Chem 2009; 284:33915-25. [PMID: 19783655 DOI: 10.1074/jbc.m109.018549] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hepatitis C virus core protein is the viral nucleocapsid of hepatitis C virus. Interaction of core with cellular membranes like endoplasmic reticulum (ER) and lipid droplets (LD) appears to be involved in viral assembly. However, how these interactions with different cellular membranes are regulated is not well understood. In this study, we investigated how palmitoylation, a post-translational protein modification, can modulate the targeting of core to cellular membranes. We show that core is palmitoylated at cysteine 172, which is adjacent to the transmembrane domain at the C-terminal end of core. Site-specific mutagenesis of residue Cys(172) showed that palmitoylation is not involved in the maturation process carried out by the signal peptide peptidase or in the targeting of core to LD. However, palmitoylation was shown to be important for core association with smooth ER membranes and ER closely surrounding LDs. Finally, we demonstrate that mutation of residue Cys(172) in the J6/JFH1 virus genome clearly impairs virion production.
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Affiliation(s)
- Nathalie Majeau
- Infectious Disease Research Centre, CHUL, Université Laval, 2705 boulevard Laurier, Québec G1V 4G2, Canada
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33
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Kota S, Coito C, Mousseau G, Lavergne JP, Strosberg AD. Peptide inhibitors of hepatitis C virus core oligomerization and virus production. J Gen Virol 2009; 90:1319-1328. [DOI: 10.1099/vir.0.008565-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Hepatitis C virus (HCV) nucleocapsid assembly requires dimerization of the core protein, an essential step in the formation of the virus particle. We developed a novel quantitative assay for monitoring this protein–protein interaction, with the goal of identifying inhibitors of core dimerization that might block HCV production in infected Huh-7.5 hepatoma cells. Two core-derived, 18-residue peptides were found that inhibited the dimerization of a fragment of core comprising residues 1–106 (core106) by 68 and 63 %, respectively. A third, related 15-residue peptide displayed 50 % inhibition, with an IC50 of 21.9 μM. This peptide was shown, by fluorescence polarization, to bind directly to core106 with a K
d of 1.9 μM and was displaced by the unlabelled peptide with an IC50 of 18.7 μM. When measured by surface plasmon resonance, the same peptide bound core169 with a K
d of 7.2 μM. When added to HCV-infected cells, each of the three peptides blocked release, but not replication, of infectious virus. When measured by real-time RT-PCR, the RNA levels were reduced by 7-fold. The 15-residue peptide had no effect on HIV propagation. Such inhibitors may constitute useful tools to investigate the role of core dimerization in the virus cycle.
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Affiliation(s)
- S. Kota
- The Scripps Research Institute – Florida, Department of Infectology, 130 Scripps Way, #3C1 Jupiter, FL 33458, USA
| | - C. Coito
- The Scripps Research Institute – Florida, Department of Infectology, 130 Scripps Way, #3C1 Jupiter, FL 33458, USA
| | - G. Mousseau
- The Scripps Research Institute – Florida, Department of Infectology, 130 Scripps Way, #3C1 Jupiter, FL 33458, USA
| | - J.-P. Lavergne
- Institut de Biologie et Chimie des Protéines, UMR5086, CNRS-Université Lyon I, IFR128, 7 Passage du Vercors, 69367 Lyon Cedex 07, France
| | - A. D. Strosberg
- The Scripps Research Institute – Florida, Department of Infectology, 130 Scripps Way, #3C1 Jupiter, FL 33458, USA
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34
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Structure and dynamics of the N-terminal half of hepatitis C virus core protein: an intrinsically unstructured protein. Biochem Biophys Res Commun 2008; 378:27-31. [PMID: 18992225 DOI: 10.1016/j.bbrc.2008.10.141] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Accepted: 10/22/2008] [Indexed: 12/22/2022]
Abstract
Hepatitis C virus core protein plays an important role in the assembly and packaging of the viral genome. We have studied the structure of the N-terminal half of the core protein (C82) which was shown to be sufficient for the formation of nucleocapsid-like particle (NLP) in vitro and in yeast. Structural bioinformatics analysis of C82 suggests that it is mostly unstructured. Circular dichroism and structural NMR data indicate that C82 lacks secondary structure. Moreover, NMR relaxation data shows that C82 is highly disordered. These results indicate that the N-terminal half of the HCV core protein belongs to the growing family of intrinsically unstructured proteins (IUP). This explains the tendency of the hepatitis C virus core protein to interact with several host proteins, a well-documented characteristic of IUPs.
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35
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Pérez‐Berná AJ, Veiga AS, Castanho MARB, Villalaín J. Hepatitis C virus core protein binding to lipid membranes: the role of domains 1 and 2. J Viral Hepat 2008; 15:346-56. [PMID: 18179451 PMCID: PMC7166730 DOI: 10.1111/j.1365-2893.2007.00948.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have analysed and identified different membrane-active regions of the Hepatitis C virus (HCV) core protein by observing the effect of 18-mer core-derived peptide libraries from two HCV strains on the integrity of different membrane model systems. In addition, we have studied the secondary structure of specific membrane-interacting peptides from the HCV core protein, both in aqueous solution and in the presence of model membrane systems. Our results show that the HCV core protein region comprising the C-terminus of domain 1 and the N-terminus of domain 2 seems to be the most active in membrane interaction, although a role in protein-protein interaction cannot be excluded. Significantly, the secondary structure of nearly all the assayed peptides changes in the presence of model membranes. These sequences most probably play a relevant part in the biological action of HCV in lipid interaction. Furthermore, these membranotropic regions could be envisaged as new possible targets, as inhibition of its interaction with the membrane could potentially lead to new vaccine strategies.
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Affiliation(s)
- A. J. Pérez‐Berná
- Instituto de Biología Molecular y Celular, Universidad “Miguel Hernández”, Elche‐Alicante, Spain
| | - A. S. Veiga
- Centro de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, Lisboa, Portugal
| | - M. A. R. B. Castanho
- Centro de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, Lisboa, Portugal
| | - J. Villalaín
- Instituto de Biología Molecular y Celular, Universidad “Miguel Hernández”, Elche‐Alicante, Spain
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36
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Wang JM, Zhang HJ, Shi ZL. Expression and assembly mechanism of the capsid proteins of a satellite virus (XSV) associated with Macrobrachium rosenbergii nodavirus. Virol Sin 2008. [DOI: 10.1007/s12250-008-2926-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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37
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Ivanyi-Nagy R, Lavergne JP, Gabus C, Ficheux D, Darlix JL. RNA chaperoning and intrinsic disorder in the core proteins of Flaviviridae. Nucleic Acids Res 2007; 36:712-25. [PMID: 18033802 PMCID: PMC2241907 DOI: 10.1093/nar/gkm1051] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
RNA chaperone proteins are essential partners of RNA in living organisms and viruses. They are thought to assist in the correct folding and structural rearrangements of RNA molecules by resolving misfolded RNA species in an ATP-independent manner. RNA chaperoning is probably an entropy-driven process, mediated by the coupled binding and folding of intrinsically disordered protein regions and the kinetically trapped RNA. Previously, we have shown that the core protein of hepatitis C virus (HCV) is a potent RNA chaperone that can drive profound structural modifications of HCV RNA in vitro. We now examined the RNA chaperone activity and the disordered nature of core proteins from different Flaviviridae genera, namely that of HCV, GBV-B (GB virus B), WNV (West Nile virus) and BVDV (bovine viral diarrhoea virus). Despite low-sequence similarities, all four proteins demonstrated general nucleic acid annealing and RNA chaperone activities. Furthermore, heat resistance of core proteins, as well as far-UV circular dichroism spectroscopy suggested that a well-defined 3D protein structure is not necessary for core-induced RNA structural rearrangements. These data provide evidence that RNA chaperoning-possibly mediated by intrinsically disordered protein segments-is conserved in Flaviviridae core proteins. Thus, besides nucleocapsid formation, core proteins may function in RNA structural rearrangements taking place during virus replication.
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Affiliation(s)
- Roland Ivanyi-Nagy
- LaboRetro INSERM #758, Ecole Normale Supérieure de Lyon, IFR 128 Biosciences Lyon-Gerland, 69364 Lyon Cedex 07, France
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38
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Rodríguez-Casado A, Molina M, Carmona P. Core protein-nucleic acid interactions in hepatitis C virus as revealed by Raman and circular dichroism spectroscopy. APPLIED SPECTROSCOPY 2007; 61:1219-1224. [PMID: 18028701 DOI: 10.1366/000370207782597139] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Molecular interactions required for hepatitis C virus (HCV) assembly are not well known and are poorly understood. The 5' untranslated region (5'UTR) of the RNA genome is highly conserved and has extensive secondary structure, and the highly basic core protein is rich in arginine residues. Using Raman and circular dichroism (CD) spectroscopies, specific interactions have been demonstrated here between the 5'UTR sequence and the core protein that may be important for the specific encapsidation of the viral genome during HCV replication. These interactions can be described as follows: (1) hydrogen bonding of arginine with unpaired guanine and/or with wobble GU base pairs, and arginine-phosphate electrostatic contacts; (2) although the percentage of base pairs in the A-form is maintained in 5'UTR, the HCVc-120 protein is beta-sheet and beta-helix enriched upon formation of protein-5'UTR macromolecular assemblies; (3) protein-5'UTR interactions resulting in protein alpha-helix formation involve guanine bases in duplex segments. The mentioned interactions may represent novel targets for antiviral strategies against this important virus.
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39
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Suzuki T, Ishii K, Aizaki H, Wakita T. Hepatitis C viral life cycle. Adv Drug Deliv Rev 2007; 59:1200-12. [PMID: 17825945 DOI: 10.1016/j.addr.2007.04.014] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Accepted: 04/11/2007] [Indexed: 12/16/2022]
Abstract
Hepatitis C virus (HCV) has been recognized as a major cause of chronic liver diseases worldwide. Molecular studies of the virus became possible with the successful cloning of its genome in 1989. Although much work remains to be done regarding early and late stages of the HCV life cycle, significant progress has been made with respect to the molecular biology of HCV, especially the viral protein processing and the genome replication. This review summarizes our current understanding of genomic organization of HCV, features of the viral protein characteristics, and the viral life cycle.
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Affiliation(s)
- Tetsuro Suzuki
- Department of Virology II, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
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40
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Majeau N, Bolduc M, Duvignaud JB, Fromentin R, Leclerc D. Effect of cAMP-dependent protein kinase A (PKA) on HCV nucleocapsid assembly and degradation. Biochem Cell Biol 2007; 85:78-87. [PMID: 17464347 DOI: 10.1139/o06-195] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The primary function of the hepatitis C virus (HCV) core protein is genome encapsidation. Core protein is also subject to post-translational modifications that can impact on the assembly process. In this report, we have studied the effect of cAMP-dependent protein kinase A (PKA) phosphorylation on its assembly and stability in a yeast Pichia pastoris expression system. We have recently shown that co-expression of the human signal peptide peptidase and core protein (amino acids 1-191) in yeast leads to the formation of nucleocapsid-like particles (NLPs) that are morphologically similar to the wild-type HCV capsid. In this system, we expressed mutants S53A and S116A and mutants S53D and S116D to abolish or mimic PKA phosphorylation, respectively. None of these mutations affected HCV assembly, but S116D led to the degradation of core protein. We also showed that nonenveloped NLPs were labelled in vitro by PKA, suggesting that the phosphorylation sites are available at the surface of the NLPs. The co-expression of human PKA with core and human signal peptide peptidase in yeast did not produce phosphorylated NLPs and led to a decreased accumulation of nonenveloped particles. Mutation S116A restored the core protein content. These results suggest that PKA phosphorylation can modulate HCV core levels in infected cells.
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Affiliation(s)
- Nathalie Majeau
- Centre de Recherche en Infectiologie, Pav. CHUL, Université Laval, 2705 boul. Laurier, QC G1V 4G2, Canada
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41
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Tsitoura P, Georgopoulou U, Pêtres S, Varaklioti A, Karafoulidou A, Vagena D, Politis C, Mavromara P. Evidence for cellular uptake of recombinant hepatitis C virus non-enveloped capsid-like particles. FEBS Lett 2007; 581:4049-57. [PMID: 17678898 DOI: 10.1016/j.febslet.2007.07.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Accepted: 07/16/2007] [Indexed: 12/17/2022]
Abstract
Although the hepatitis C virus (HCV) is an enveloped virus, naked nucleocapsids have been reported in the serum of infected patients, and most recently novel HCV subgenomes with deletions of the envelope proteins have been identified. However the significance of these findings remains unclear. In this study, we used the baculovirus expression system to generate recombinant HCV capsid-like particles, and investigated their possible interactions with cells. We show that expression of HCV core in insect cells can sufficiently direct the formation of capsid-like particles in the absence of the HCV envelope glycoproteins and of the 5' untranslated region. By confocal microscopy analysis, we provide evidence that the naked capsid-like particles could be uptaken by human hepatoma cells. Moreover, our findings suggest that they have the potential to produce cell-signaling effects.
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Affiliation(s)
- Panagiota Tsitoura
- Molecular Virology Laboratory, Hellenic Pasteur Institute, 127, Vas. Sofias Ave, Athens 11521, Greece
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42
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Patkar CG, Jones CT, Chang YH, Warrier R, Kuhn RJ. Functional requirements of the yellow fever virus capsid protein. J Virol 2007; 81:6471-81. [PMID: 17526891 PMCID: PMC1900127 DOI: 10.1128/jvi.02120-06] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Accepted: 03/23/2007] [Indexed: 11/20/2022] Open
Abstract
Although it is known that the flavivirus capsid protein is essential for genome packaging and formation of infectious particles, the minimal requirements of the dimeric capsid protein for virus assembly/disassembly have not been characterized. By use of a trans-packaging system that involved packaging a yellow fever virus (YFV) replicon into pseudo-infectious particles by supplying the YFV structural proteins using a Sindbis virus helper construct, the functional elements within the YFV capsid protein (YFC) were characterized. Various N- and C-terminal truncations, internal deletions, and point mutations of YFC were analyzed for their ability to package the YFV replicon. Consistent with previous reports on the tick-borne encephalitis virus capsid protein, YFC demonstrates remarkable functional flexibility. Nearly 40 residues of YFC could be removed from the N terminus while the ability to package replicon RNA was retained. Additionally, YFC containing a deletion of approximately 27 residues of the C terminus, including a complete deletion of C-terminal helix 4, was functional. Internal deletions encompassing the internal hydrophobic sequence in YFC were, in general, tolerated to a lesser extent. Site-directed mutagenesis of helix 4 residues predicted to be involved in intermonomeric interactions were also analyzed, and although single mutations did not affect packaging, a YFC with the double mutation of leucine 81 and valine 88 was nonfunctional. The effects of mutations in YFC on the viability of YFV infection were also analyzed, and these results were similar to those obtained using the replicon packaging system, thus underscoring the flexibility of YFC with respect to the requirements for its functioning.
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Affiliation(s)
- Chinmay G Patkar
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA
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43
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Suzuki T, Aizaki H, Murakami K, Shoji I, Wakita T. Molecular biology of hepatitis C virus. J Gastroenterol 2007; 42:411-23. [PMID: 17671755 DOI: 10.1007/s00535-007-2030-3] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Accepted: 02/10/2007] [Indexed: 02/04/2023]
Abstract
Infection with hepatitis C virus (HCV), which is distributed worldwide, often becomes persistent, causing chronic hepatitis, cirrhosis, and hepatocellular carcinoma. For many years, the characterization of the HCV genome and its products has been done by heterologous expression systems because of the lack of a productive cell culture system. The development of the HCV replicon system is a highlight of HCV research and has allowed examination of the viral RNA replication in cell culture. Recently, a robust system for production of recombinant infectious HCV has been established, and classical virological techniques are now able to be applied to HCV. This development of reverse genetics-based experimental tools in HCV research can bring a greater understanding of the viral life cycle and pathogenesis of HCV-induced diseases. This review summarizes the current knowledge of cell culture systems for HCV research and recent advances in the investigation of the molecular virology of HCV.
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Affiliation(s)
- Tetsuro Suzuki
- Department of Virology II, National Institute of Infectious Diseases, 1-23-1 Toyama, Tokyo, Japan
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44
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Fromentin R, Majeau N, Laliberté Gagné ME, Boivin A, Duvignaud JB, Leclerc D. A method for in vitro assembly of hepatitis C virus core protein and for screening of inhibitors. Anal Biochem 2007; 366:37-45. [PMID: 17493576 PMCID: PMC2023875 DOI: 10.1016/j.ab.2007.03.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 03/21/2007] [Accepted: 03/27/2007] [Indexed: 01/10/2023]
Abstract
The assembly of hepatitis C virus (HCV) is not well understood. We investigated HCV nucleocapsid assembly in vitro and the role of electrostatic/hydrophobic interactions in this process. We developed a simple and rapid in vitro assay in which the progress of assembly is monitored by measuring an increase in turbidity, thereby allowing the kinetics of assembly to be determined. Assembly is performed using a truncated HCV core (C1-82), containing the minimal assembly domain, purified from Escherichia coli. The increase in turbidity is linked to the formation of nucleocapsid-like particles (NLPs) in solution, and nucleic acids are essential to initiate nucleocapsid assembly under the experimental conditions used. The sensitivity of NLP formation to salt strongly suggests that electrostatic forces govern in vitro assembly. Mutational analysis of C1-82 demonstrated that it is the global positive charge of C1-82 rather than any specific basic residue that is important for the assembly process. Our in vitro assembly assay provides an easy and efficient means of screening for assembly inhibitors, and we have identified several inhibitory peptides that could represent a starting point for drug design.
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Affiliation(s)
- Rémi Fromentin
- Centre de Recherche en Infectiologie, Université Laval, Qué., Canada QC G1V 4G2
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45
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Rodríguez-Casado A, Molina M, Carmona P. Spectroscopic study of conformational changes accompanying self-assembly of HCV core protein. Proteins 2006; 66:110-7. [PMID: 17078073 DOI: 10.1002/prot.21192] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Electron microscopy and infrared and Raman spectroscopy have been used here to study the morphology, size distribution, secondary and tertiary structures of protein particles assembled from a truncated hepatitis C virus (HCV) core protein covering the first 120 aa. Particles of pure protein, having similar morphology and size distribution of those of nucleocapsids found in sera from HCV-infected patients, have been visualized for the first time. The secondary structure of these protein particles involve beta-sheet enrichment in relation to its protein monomer. Tertiary/quaternary structure has also been studied using the dynamics of H/D exchange. With this aim infrared spectra were measured as a function of H/D exchange time and subsequently analyzed by principal component analysis and two-dimensional correlation spectroscopy. Temporal dynamics of exchange for these protein particles were as follows: arginine residues exchanged first, followed by turn and unordered structures, followed by beta-sheets which may act as linkers of protein monomers.
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46
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Rodriguez-Casado A, Molina M, Carmona P. Conformational features of truncated hepatitis C virus core protein in virus-like particles. Biopolymers 2006; 82:334-8. [PMID: 16475155 DOI: 10.1002/bip.20474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
HCVc 120 is a truncated protein from the hepatitis C virus (HCV) core protein that interacts with itself to form nucleocapsid-like particles. We present here the infrared and Raman spectra of oligomeric HCVc 120 protein in order to obtain insights into its secondary structure as well as the environment surrounding some protein side chains. When compared with its monomer form, oligomeric HCVc 120 protein shows an increase in beta-sheet structure. Tryptophan residues have been found to be solvent exposed in the oligomeric form, and they likely do not significantly participate in the protein assembly. However, the beta-sheet content in oligomeric HCVc 120 protein suggests that this structural motif cannot be excluded in nucleocapsid formation, as shown recently in other viruses.
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Affiliation(s)
- A Rodriguez-Casado
- Instituto de Estructura de la Materia (CSIC), Serrano 121, 28006 Madrid, Spain
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47
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Acosta-Rivero N, Rodriguez A, Mussachio A, Poutou J, Falcon V, Torres D, Aguilar JC, Linares M, Alonso M, Perez A, Menendez I, Morales-Grillo J, Marquez G, Dueñas-Carrera S. A C-terminal truncated hepatitis C virus core protein variant assembles in vitro into virus-like particles in the absence of structured nucleic acids. Biochem Biophys Res Commun 2006; 334:901-6. [PMID: 16053919 DOI: 10.1016/j.bbrc.2005.06.185] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Accepted: 06/28/2005] [Indexed: 01/26/2023]
Abstract
Little is known about the assembly pathway or structure of the hepatitis C virus (HCV). In this work a truncated HCcAg variant covering the first 120 aa (HCcAg.120) with a 32 aa N-terminal fusion peptide (6x Histag-Xpress epitope) was purified as a monomer under strong denaturing conditions. In addition, minor HCcAg.120 peaks exhibiting little different molecular mass by SDS-PAGE which possibly represents alternative forms harboring the N-termini of HCcAg.120 were detected. Analysis using gel filtration chromatography showed that HCcAg.120 assembled into high molecular weight structures in vitro in the absence of structured nucleic acids. The negative-stain electron microscopy analysis revealed that these structures correspond with spherical VLPs of uniform morphology and size distribution. The diameters of these particles ranged from 20 to 43nm with an average diameter of approximately 30 nm and were specifically immunolabelled with a mouse monoclonal antibody against the residues 5-35 of HCcAg. Results presented in this work showed that HCcAg.120 assembled in vitro into VLPs in the absence of structured nucleic acids with similar morphology and size distribution to those found in sera and hepatocytes from HCV-infected patients. Therefore, these VLPs would be important to elucidate the mechanisms behind the ability of HCcAg to assemble into a nucleocapsid structure.
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Affiliation(s)
- Nelson Acosta-Rivero
- Biomedical Research Division, Center for Genetic Engineering and Biotechnology, P.O. Box 6162, C.P. 10600, C. Habana, Cuba.
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48
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Mihailova M, Fiedler M, Boos M, Petrovskis I, Sominskaya I, Roggendorf M, Viazov S, Pumpens P. Preparation of hepatitis C virus structural and non-structural protein fragments and studies of their immunogenicity. Protein Expr Purif 2006; 50:43-8. [PMID: 16889980 DOI: 10.1016/j.pep.2006.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Revised: 06/15/2006] [Accepted: 06/15/2006] [Indexed: 02/05/2023]
Abstract
Plasmids pQE-60 and pQE-30 containing 6 x His-tag sequence were used for expression of fragments of HCV structural and non-structural proteins in Escherichia coli (E. coli). The following fragments were used: core (1-98 aa), NS3 (202-482 aa), and tetramer of hypervariable region 1 (HVR1) of E2 protein. The constructed plasmids directed high levels of expression of HCV proteins in E. coli JM109. After purification by the metal-affinity chromatography on nickel-nitrilotriacetic acid (Ni-NTA) agarose, the His-tagged HCV proteins were used for immunization of BALB/c mice. All three proteins were able to induce high levels of specific antibodies and, in the case of the NS3 and HVR1 tetramer, also to mount vigorous cell-proliferating responses. High immunogenicity of the tested fragments of HCV proteins shows them as good candidates for inclusion into the future HCV vaccine preparations.
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Affiliation(s)
- Marija Mihailova
- Institute of Virology, Essen University Hospital, Hufelandstr. 55, 45122 Essen, Germany.
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Ivanyi-Nagy R, Kanevsky I, Gabus C, Lavergne JP, Ficheux D, Penin F, Fossé P, Darlix JL. Analysis of hepatitis C virus RNA dimerization and core-RNA interactions. Nucleic Acids Res 2006; 34:2618-33. [PMID: 16707664 PMCID: PMC1463901 DOI: 10.1093/nar/gkl240] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The core protein of hepatitis C virus (HCV) has been shown previously to act as a potent nucleic acid chaperone in vitro, promoting the dimerization of the 3′-untranslated region (3′-UTR) of the HCV genomic RNA, a process probably mediated by a small, highly conserved palindromic RNA motif, named DLS (dimer linkage sequence) [G. Cristofari, R. Ivanyi-Nagy, C. Gabus, S. Boulant, J. P. Lavergne, F. Penin and J. L. Darlix (2004) Nucleic Acids Res., 32, 2623–2631]. To investigate in depth HCV RNA dimerization, we generated a series of point mutations in the DLS region. We find that both the plus-strand 3′-UTR and the complementary minus-strand RNA can dimerize in the presence of core protein, while mutations in the DLS (among them a single point mutation that abolished RNA replication in a HCV subgenomic replicon system) completely abrogate dimerization. Structural probing of plus- and minus-strand RNAs, in their monomeric and dimeric forms, indicate that the DLS is the major if not the sole determinant of UTR RNA dimerization. Furthermore, the N-terminal basic amino acid clusters of core protein were found to be sufficient to induce dimerization, suggesting that they retain full RNA chaperone activity. These findings may have important consequences for understanding the HCV replicative cycle and the genetic variability of the virus.
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Affiliation(s)
| | - Igor Kanevsky
- CNRS-UMR 8113, LBPA-Alembert, Ecole Normale Supérieure de Cachan94235 Cachan Cedex, France
| | | | - Jean-Pierre Lavergne
- Institut de Biologie et Chimie des Protéines, CNRS-UMR 5086, Université Claude Bernard Lyon IIFR 128 Biosciences Lyon-Gerland, 69367 Lyon Cedex 07, France
| | - Damien Ficheux
- Institut de Biologie et Chimie des Protéines, CNRS-UMR 5086, Université Claude Bernard Lyon IIFR 128 Biosciences Lyon-Gerland, 69367 Lyon Cedex 07, France
| | - François Penin
- Institut de Biologie et Chimie des Protéines, CNRS-UMR 5086, Université Claude Bernard Lyon IIFR 128 Biosciences Lyon-Gerland, 69367 Lyon Cedex 07, France
| | - Philippe Fossé
- CNRS-UMR 8113, LBPA-Alembert, Ecole Normale Supérieure de Cachan94235 Cachan Cedex, France
| | - Jean-Luc Darlix
- To whom correspondence should be addressed. Tel: +33 4 72 72 81 69; Fax: +33 4 72 72 87 77;
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Martinez-Donato G, Acosta-Rivero N, Morales-Grillo J, Musacchio A, Vina A, Alvarez C, Figueroa N, Guerra I, Garcia J, Varas L, Muzio V, Dueñas-Carrera S. Expression and processing of hepatitis C virus structural proteins in Pichia pastoris yeast. Biochem Biophys Res Commun 2006; 342:625-31. [PMID: 16488393 DOI: 10.1016/j.bbrc.2006.01.157] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2006] [Accepted: 01/31/2006] [Indexed: 12/27/2022]
Abstract
Development of heterologous systems to produce useful HCV vaccine candidates is an important part of HCV research. In this study different HCV structural region variants were designed to express the first 120 aa, 176 aa, 339 aa, and 650 aa of HCV polyprotein, and aa 384 to 521, or aa 384-605 or aa 384-746 of HCV E2 protein fused to the leader sequence of sucrose invertase 2 allowing the secretion of recombinant E2 proteins. Low expression levels were observed for HCV core protein (HCcAg) variants expressing the first 120 aa and 176 aa (HCcAg.120 and HCcAg.176, respectively). Higher expression levels were observed when HCcAg was expressed as a polypeptide with either E1 or E1 and E2 proteins. In addition, HCcAg was processed to produce two antigenic bands with 21 and 23kDa (P21 and P23, respectively) when expressed as a polypeptide with HCV E1 and E2 proteins. Results also suggest E1 processing in the context of HCcAg.E1.E2 polyprotein. On the other hand, E2.521, E2.605, and E2.680 were efficiently excreted to the culture medium. However, the entire E2.746 variant predominantly localized in the insoluble fraction of ruptured cells. Results suggest that the hydrophobic C-terminal E2 region from aa 681 to 746 is critical for intracellular retention of recombinant E2.746 protein in Pichia pastoris cells. Endo H or PNGase F treatment suggests that E2.746 was modified with high-mannose type oligosaccharides in P. pastoris. These data justify the usefulness of P. pastoris expression system to express HCV structural viral proteins which may be useful targets for HCV vaccine candidates.
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Affiliation(s)
- Gillian Martinez-Donato
- Division of Vaccines, Center for Genetic Engineering and Biotechnology, P.O. Box 6162, C.P. 10600, City of Havana, Cuba.
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