Filoviruses for which there is no cure or treatment cause fatal hemorrhagic fevers in primates. The life cycle of these viruses is a complex process requiring production of infectious virions from the host cell membrane to sustain the infection. The process of generating a new virion involves an array of protein interactions but there is a paucity of mechanistic information on this process. Because inhibition of new virion formation from the plasma membrane of the host cell is an avenue of curing and preventing these infections, identifying the key interactions and modes of inhibition are of utmost importance. For an infectious virion to form, newly synthesized viral proteins and genomic RNA in the form of nucleocapsids are transported to the cell membrane to form a bud site. Generation of the bud site is a prime target for therapy and has been speculated to require any array of membrane-protein interactions. We demonstrate two proteins from Ebola termed matrix proteins;VP40 and VP24 associate with specific lipid membranes and induce changes in membrane curvature to generate virus like particles (VLPs) (a model of new virions). This discovery and subsequent investigation will create a new paradigm in the life cycle of a virus. Moreover, from studying the viral matrix proteins much new information can be obtained on mechanisms of peripheral protein assembly impacting more than one scientific community. The primary objective of this proposed research is to fully elucidate the mechanistic basis of lipid-interactions by filoviridae matrix proteins and their mechanism of generating VLPs from host cells.
The specific aims for the proposed research are as follows: 1) Determination of the membrane targeting and curvature inducing mechanism of the matrix protein VP40;2) Determination of the interplay of cellular membranes and F-actin in targeting VP24 and its ability to curve membranes;3) Determination of the lipid-dependent interaction properties of VP40 and human Nedd4-1 in the generation of VLPs. The principal methodologies to be used include: (1) the biophysical analysis of interactions of viral proteins (VP40 and VP24) with various model membranes by monolayer, surface plasmon resonance, sedimentation, and stop-flow analysis;(2) the cellular membrane targeting properties of VP40 and VP24 using fluorescent proteins;(3) the qualitative and quantitative membrane curvature inducing properties of these proteins in vitro and in mammalian cells;(4) the structural investigation of the membrane curvature process with X-ray and an array of fluorescence methodologies;(5) the hijacking of the human protein Nedd4-1 by VP40 on lipid membranes both in vitro and in mammalian cells;(6) the interaction properties of VP24 with F-actin. Collectively, these aims will provide a comprehensive view of the plasma membrane based viral assembly and generation of new virions.

Public Health Relevance

There is a paucity of therapeutics for treatment or prevention of many viral infections and there is increasing concern countries or terrorist groups may have weaponized viruses for dissemination. The proposed studies will provide the first mechanistic insight into how viral proteins interact with mammalian cell membranes to generate new infectious virions serving as a prerequisite to the development of therapeutic protocols for generation of small-molecule inhibitors, vaccines, or therapeutic antibodies.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
3R01AI081077-02S1
Application #
8118645
Study Section
Biochemistry and Biophysics of Membranes Study Section (BBM)
Program Officer
Repik, Patricia M
Project Start
2010-08-09
Project End
2011-08-08
Budget Start
2010-08-09
Budget End
2011-08-08
Support Year
2
Fiscal Year
2010
Total Cost
$137,475
Indirect Cost
Name
Indiana University-Purdue University at Indianapolis
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
603007902
City
Indianapolis
State
IN
Country
United States
Zip Code
46202
Del Vecchio, Kathryn; Stahelin, Robert V (2018) Investigation of the phosphatidylserine binding properties of the lipid biosensor, Lactadherin C2 (LactC2), in different membrane environments. J Bioenerg Biomembr 50:1-10
Del Vecchio, Kathryn; Frick, Cary T; Gc, Jeevan B et al. (2018) A cationic, C-terminal patch and structural rearrangements in Ebola virus matrix VP40 protein control its interactions with phosphatidylserine. J Biol Chem 293:3335-3349
Bhattarai, Nisha; Gc, Jeevan B; Gerstman, Bernard S et al. (2017) Plasma membrane association facilitates conformational changes in the Marburg virus protein VP40 dimer. RSC Adv 7:22741-22748
Wijesinghe, Kaveesha J; Urata, Sarah; Bhattarai, Nisha et al. (2017) Detection of lipid-induced structural changes of the Marburg virus matrix protein VP40 using hydrogen/deuterium exchange-mass spectrometry. J Biol Chem 292:6108-6122
Shirey, Carolyn M; Scott, Jordan L; Stahelin, Robert V (2017) Notes and tips for improving quality of lipid-protein overlay assays. Anal Biochem 516:9-12
Gc, Jeevan B; Pokhrel, Rudramani; Bhattarai, Nisha et al. (2017) Graphene-VP40 interactions and potential disruption of the Ebola virus matrix filaments. Biochem Biophys Res Commun 493:176-181
Gc, Jeevan B; Gerstman, Bernard S; Stahelin, Robert V et al. (2016) The Ebola virus protein VP40 hexamer enhances the clustering of PI(4,5)P2 lipids in the plasma membrane. Phys Chem Chem Phys 18:28409-28417
Johnson, Kristen A; Taghon, Geoffrey J F; Scott, Jordan L et al. (2016) The Ebola Virus matrix protein, VP40, requires phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) for extensive oligomerization at the plasma membrane and viral egress. Sci Rep 6:19125
Oda, Shun-Ichiro; Noda, Takeshi; Wijesinghe, Kaveesha J et al. (2016) Crystal Structure of Marburg Virus VP40 Reveals a Broad, Basic Patch for Matrix Assembly and a Requirement of the N-Terminal Domain for Immunosuppression. J Virol 90:1839-48
Gc, Jeevan B; Johnson, Kristen A; Husby, Monica L et al. (2016) Interdomain salt-bridges in the Ebola virus protein VP40 and their role in domain association and plasma membrane localization. Protein Sci 25:1648-58

Showing the most recent 10 out of 33 publications