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Updated: Jun 17, 2026
08:21
Visualization of HIV-1 Gag Binding to Giant Unilamellar Vesicle (GUV) Membranes
Published on: July 28, 2016
GM1 structure determines SV40-induced membrane invagination and infection
Helge Ewers1, Winfried Römer, Alicia E Smith
1ETH Zurich, Institute of Biochemistry, HPM E, Schafmattstrasse 18, 8093 Zurich, Switzerland.
Nature Cell Biology
|December 22, 2009
Summary
Simian virus 40 (SV40) uses its VP1 protein to bind GM1 gangliosides, inducing membrane curvature for cell entry. Short-chain GM1 prevents this, blocking SV40 infection and endocytosis.
Area of Science:
- Virology
- Cell Biology
- Biophysics
Background:
- Simian virus 40 (SV40) enters host cells via plasma membrane invaginations.
- Viral entry involves binding to GM1 gangliosides by pentameric VP1 capsid proteins.
Purpose of the Study:
- To investigate the role of GM1 gangliosides and VP1 in SV40-induced membrane curvature.
- To elucidate the mechanism of SV40 endocytosis and infection.
Main Methods:
- Experiments using SV40, isolated VP1, and giant unilamellar vesicles (GUVs) with varying GM1 acyl chain lengths.
- Development of a physical model based on energetic considerations.
Main Results:
- SV40 and VP1 binding to GM1 induce significant membrane curvature, forming invaginations and tubules.
- GM1 species with short acyl chains failed to support membrane invagination, inhibiting endocytosis and infection.
- A physical model supported the experimental observations.
Conclusions:
- SV40 utilizes GM1 gangliosides and its VP1 protein to directly induce plasma membrane curvature, facilitating endocytic uptake.
- This mechanism, involving glycosphingolipids and pentameric protein scaffolds, is shared by other viruses and bacterial toxins.
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