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Motsa BB, Sharma T, Cioffi MD, Chapagain PP, Stahelin RV. Minor electrostatic changes robustly increase VP40 membrane binding, assembly, and budding of Ebola virus matrix protein derived virus-like particles. J Biol Chem 2024; 300:107213. [PMID: 38522519 PMCID: PMC11061732 DOI: 10.1016/j.jbc.2024.107213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/05/2024] [Accepted: 03/15/2024] [Indexed: 03/26/2024] Open
Abstract
Ebola virus (EBOV) is a filamentous negative-sense RNA virus, which causes severe hemorrhagic fever. There are limited vaccines or therapeutics for prevention and treatment of EBOV, so it is important to get a detailed understanding of the virus lifecycle to illuminate new drug targets. EBOV encodes for the matrix protein, VP40, which regulates assembly and budding of new virions from the inner leaflet of the host cell plasma membrane (PM). In this work, we determine the effects of VP40 mutations altering electrostatics on PM interactions and subsequent budding. VP40 mutations that modify surface electrostatics affect viral assembly and budding by altering VP40 membrane-binding capabilities. Mutations that increase VP40 net positive charge by one (e.g., Gly to Arg or Asp to Ala) increase VP40 affinity for phosphatidylserine and phosphatidylinositol 4,5-bisphosphate in the host cell PM. This increased affinity enhances PM association and budding efficiency leading to more effective formation of virus-like particles. In contrast, mutations that decrease net positive charge by one (e.g., Gly to Asp) lead to a decrease in assembly and budding because of decreased interactions with the anionic PM. Taken together, our results highlight the sensitivity of slight electrostatic changes on the VP40 surface for assembly and budding. Understanding the effects of single amino acid substitutions on viral budding and assembly will be useful for explaining changes in the infectivity and virulence of different EBOV strains, VP40 variants that occur in nature, and for long-term drug discovery endeavors aimed at EBOV assembly and budding.
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Affiliation(s)
- Balindile B Motsa
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, Indiana, USA
| | - Tej Sharma
- Department of Physics, Florida International University, Miami, Florida, USA
| | - Michael D Cioffi
- Department of Physics, Florida International University, Miami, Florida, USA
| | - Prem P Chapagain
- Department of Physics, Florida International University, Miami, Florida, USA; Biomolecular Sciences Institute, Florida International University, Miami, Florida, USA
| | - Robert V Stahelin
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, Indiana, USA.
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Johnson KA, Budicini MR, Bhattarai N, Sharma T, Urata S, Gerstman BS, Chapagain PP, Li S, Stahelin RV. PI(4,5)P 2 binding sites in the Ebola virus matrix protein VP40 modulate assembly and budding. J Lipid Res 2024; 65:100512. [PMID: 38295986 PMCID: PMC10909612 DOI: 10.1016/j.jlr.2024.100512] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 01/12/2024] [Accepted: 01/17/2024] [Indexed: 03/02/2024] Open
Abstract
Ebola virus (EBOV) causes severe hemorrhagic fever in humans and is lethal in a large percentage of those infected. The EBOV matrix protein viral protein 40 kDa (VP40) is a peripheral binding protein that forms a shell beneath the lipid bilayer in virions and virus-like particles (VLPs). VP40 is required for virus assembly and budding from the host cell plasma membrane. VP40 is a dimer that can rearrange into oligomers at the plasma membrane interface, but it is unclear how these structures form and how they are stabilized. We therefore investigated the ability of VP40 to form stable oligomers using in vitro and cellular assays. We characterized two lysine-rich regions in the VP40 C-terminal domain (CTD) that bind phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) and play distinct roles in lipid binding and the assembly of the EBOV matrix layer. The extensive analysis of VP40 with and without lipids by hydrogen deuterium exchange mass spectrometry revealed that VP40 oligomers become extremely stable when VP40 binds PI(4,5)P2. The PI(4,5)P2-induced stability of VP40 dimers and oligomers is a critical factor in VP40 oligomerization and release of VLPs from the plasma membrane. The two lysine-rich regions of the VP40 CTD have different roles with respect to interactions with plasma membrane phosphatidylserine (PS) and PI(4,5)P2. CTD region 1 (Lys221, Lys224, and Lys225) interacts with PI(4,5)P2 more favorably than PS and is important for VP40 extent of oligomerization. In contrast, region 2 (Lys270, Lys274, Lys275, and Lys279) mediates VP40 oligomer stability via lipid interactions and has a more prominent role in release of VLPs.
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Affiliation(s)
- Kristen A Johnson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Melissa R Budicini
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA
| | - Nisha Bhattarai
- Department of Physics, Florida International University, Miami, FL, USA
| | - Tej Sharma
- Department of Physics, Florida International University, Miami, FL, USA
| | - Sarah Urata
- Department of Medicine, University of California San Diego, San Diego, CA, USA
| | - Bernard S Gerstman
- Department of Physics, Florida International University, Miami, FL, USA; Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| | - Prem P Chapagain
- Department of Physics, Florida International University, Miami, FL, USA; Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| | - Sheng Li
- Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
| | - Robert V Stahelin
- Department of Medicinal Chemistry and Molecular Pharmacology and the Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN, USA.
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Motsa BB, Sharma T, Chapagain PP, Stahelin RV. Minor changes in electrostatics robustly increase VP40 membrane binding, assembly, and budding of Ebola virus matrix protein derived virus-like particles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.30.578092. [PMID: 38352396 PMCID: PMC10862912 DOI: 10.1101/2024.01.30.578092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Ebola virus (EBOV) is a filamentous negative-sense RNA virus which causes severe hemorrhagic fever. There are limited vaccines or therapeutics for prevention and treatment of EBOV, so it is important to get a detailed understanding of the virus lifecycle to illuminate new drug targets. EBOV encodes for the matrix protein, VP40, which regulates assembly and budding of new virions from the inner leaflet of the host cell plasma membrane (PM). In this work we determine the effects of VP40 mutations altering electrostatics on PM interactions and subsequent budding. VP40 mutations that modify surface electrostatics affect viral assembly and budding by altering VP40 membrane binding capabilities. Mutations that increase VP40 net positive charge by one (e.g., Gly to Arg or Asp to Ala) increase VP40 affinity for phosphatidylserine (PS) and PI(4,5)P2 in the host cell PM. This increased affinity enhances PM association and budding efficiency leading to more effective formation of virus-like particles (VLPs). In contrast, mutations that decrease net positive charge by one (e.g., Gly to Asp) lead to a decrease in assembly and budding because of decreased interactions with the anionic PM. Taken together our results highlight the sensitivity of slight electrostatic changes on the VP40 surface for assembly and budding. Understanding the effects of single amino acid substitutions on viral budding and assembly will be useful for explaining changes in the infectivity and virulence of different EBOV strains, VP40 variants that occur in nature, and for long-term drug discovery endeavors aimed at EBOV assembly and budding.
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Affiliation(s)
- Balindile B. Motsa
- Borch Department of Medicinal Chemistry and Molecular Pharmacology and the Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
| | - Tej Sharma
- Department of Physics, Florida International University, Miami, FL 33199, USA
| | - Prem P. Chapagain
- Department of Physics, Florida International University, Miami, FL 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA
| | - Robert V. Stahelin
- Borch Department of Medicinal Chemistry and Molecular Pharmacology and the Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
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Werner AD, Schauflinger M, Norris MJ, Klüver M, Trodler A, Herwig A, Brandstädter C, Dillenberger M, Klebe G, Heine A, Saphire EO, Becker K, Becker S. The C-terminus of Sudan ebolavirus VP40 contains a functionally important CX nC motif, a target for redox modifications. Structure 2023; 31:1038-1051.e7. [PMID: 37392738 DOI: 10.1016/j.str.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/10/2023] [Accepted: 06/06/2023] [Indexed: 07/03/2023]
Abstract
The Ebola virus matrix protein VP40 mediates viral budding and negatively regulates viral RNA synthesis. The mechanisms by which these two functions are exerted and regulated are unknown. Using a high-resolution crystal structure of Sudan ebolavirus (SUDV) VP40, we show here that two cysteines in the flexible C-terminal arm of VP40 form a stabilizing disulfide bridge. Notably, the two cysteines are targets of posttranslational redox modifications and interact directly with the host`s thioredoxin system. Mutation of the cysteines impaired the budding function of VP40 and relaxed its inhibitory role for viral RNA synthesis. In line with these results, the growth of recombinant Ebola viruses carrying cysteine mutations was impaired and the released viral particles were elongated. Our results revealed the exact positions of the cysteines in the C-terminal arm of SUDV VP40. The cysteines and/or their redox status are critically involved in the differential regulation of viral budding and viral RNA synthesis.
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Affiliation(s)
| | | | - Michael J Norris
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Michael Klüver
- Institute for Virology, Philipps-University of Marburg, Marburg, Germany
| | - Anna Trodler
- Institute for Virology, Philipps-University of Marburg, Marburg, Germany
| | - Astrid Herwig
- Institute for Virology, Philipps-University of Marburg, Marburg, Germany
| | - Christina Brandstädter
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Giessen, Germany
| | - Melissa Dillenberger
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Giessen, Germany
| | - Gerhard Klebe
- Institute for Pharmaceutical Chemistry, Philipps-University of Marburg, Marburg, Germany
| | - Andreas Heine
- Institute for Pharmaceutical Chemistry, Philipps-University of Marburg, Marburg, Germany
| | | | - Katja Becker
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Giessen, Germany
| | - Stephan Becker
- Institute for Virology, Philipps-University of Marburg, Marburg, Germany.
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