Role of lipid composition on human plasma membrane interactions with the Ebola virus matrix protein VP40.

Abstract

The Ebola virus is a very dangerous zoonotic virus and its infection can cause hemorrhagic fever with high fatality rates. The Ebola virus matrix protein VP40 is the major protein responsible for the formation of the viral matrix by localizing and assembling it at the inner leaflet of the human plasma membrane (PM). This assembly leads to the formation of virus-like-particles (VLP) and eventual budding. Anionic lipids PI(4,5)P2 (PIP2) and Phosphatidylserine (PS) have been shown to facilitate VP40-membrane binding through electrostatic interactions with cationic VP40 residues. It has been determined that Phosphatidic Acid (PA), resulting from the enzyme Phospholipase-D (PLD), may also play an active role in this process. We performed coarse-grained molecular dynamics (CGMD) simulations to investigate the effects various lipids have on VP40-lipid interactions. We used a triple-dimer structure of VP40 and a PM composed of various lipid types. Contact analyses show interactions with specific cationic VP40 residues that facilitate most of the lipid interactions. Interaction strengths between VP40 residues and lipid headgroups are found to vary when PA was included in the PM compared to when it was not. The radial distribution functions also show differences in local lipid clustering between the two systems. These simulations provide new insights on VP40 interactions with the human PM and how different lipids may influence the overall membrane association and assembly of the VP40 dimers.