Anionic Lipids Are Required for Vesicular Stomatitis Virus G Protein-mediated Single Particle Fusion with Supported Lipid Bilayers

Viral glycoproteins mediate fusion between viral and cellular membranes upon binding to cognate receptors and/or experiencing low pH. Although activation of viral glycoproteins is thought to be necessary and sufficient for fusion, accumulating evidence suggests that additional cellular factors, incl...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 2013-05, Vol.288 (18), p.12416-12425
Main Authors: Matos, Pedro M., Marin, Mariana, Ahn, Byungwook, Lam, Wilbur, Santos, Nuno C., Melikyan, Gregory B.
Format: Article
Language:English
Subjects:
Endocytosis
Endosomes - genetics
Endosomes - metabolism
Endosomes - virology
Fluorescence
Fusion Pore
HEK293 Cells
Hemifusion
Humans
Hydrogen-Ion Concentration
Kinetics
Lipid Bilayers - metabolism
Membrane Bilayer
Membrane Fusion
Membrane Glycoproteins - genetics
Membrane Glycoproteins - metabolism
Microbiology
Microscopic Imaging
Phospholipids - metabolism
Single Virus Imaging
Vesiculovirus - physiology
Viral Envelope Proteins - genetics
Viral Envelope Proteins - metabolism
Virus Entry
Virus Internalization
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Viral glycoproteins mediate fusion between viral and cellular membranes upon binding to cognate receptors and/or experiencing low pH. Although activation of viral glycoproteins is thought to be necessary and sufficient for fusion, accumulating evidence suggests that additional cellular factors, including lipids, can modulate the fusion process. Understanding the role of lipids in virus entry via endocytosis is impeded by poor accessibility and the highly diverse nature of endosomes. Here we imaged fusion of single retroviral particles pseudotyped with the vesicular stomatitis virus (VSV) G protein with dextran-supported lipid bilayers. Incorporation of diffusible fluorescent labels into the viral membrane and the viral interior enabled detection of the lipid mixing (hemifusion) and content transfer (full fusion) steps of VSV G-mediated fusion at low pH. Although single virus fusion with supported bilayers made of zwitterionic lipids could not be detected, inclusion of anionic lipids, phosphatidylserine, and bis(monoacylglycero)phosphate (BMP), greatly enhanced the efficiency of hemifusion and permitted full fusion. Importantly, lipid mixing always preceded the opening of a fusion pore, demonstrating that VSV G-mediated fusion proceeds through a long-lived hemifusion intermediate. Kinetic analysis of lipid and content transfer showed that the lags between lipid and content mixing defining the lifetime of a hemifusion intermediate were significantly shorter for BMP-containing compared with PS-containing bilayers. The strong fusion-enhancing effect of BMP, a late endosome-resident lipid, is consistent with the model that VSV initiates fusion in early endosomes but releases its core into the cytosol after reaching late endosomal compartments. Background: Regulation of virus entry by host lipids is poorly understood. Results: Imaging of low pH-mediated fusion between single vesicular stomatitis pseudoviruses and lipid bilayers revealed a striking reliance on anionic lipids. Conclusion: The dependence of fusion on late endosome-resident anionic lipids suggests a new means for regulating the virus entry sites. Significance: Reliance on specific lipids for fusion may shed light on future antiviral strategies.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M113.462028