Fusion of Semliki Forest virus with cholesterol-containing liposomes at low pH: a specific requirement for sphingolipids
- 1 January 1995
- journal article
- research article
- Published by Taylor & Francis in Molecular Membrane Biology
- Vol. 12 (1), 143-149
- https://doi.org/10.3109/09687689509038510
Abstract
Semliki Forest virus (SFV) utilizes a membrane fusion strategy to introduce its genome into the host cell. After binding to cell-surface receptors, virus particles are internalized through receptor-mediated endocytosis and directed to the endosomal cell compartment. Subsequently, triggered by the acid pH in the lumen of the endosomes, the viral envelope fuses with the endosomal membrane. As a result of this fusion reaction the viral RNA gains access to the cell cytosol. Low-pH-induced fusion of SFV, in model systems as well as in cells, has been demonstrated previously to be strictly dependent on the presence of cholesterol in the target membrane. In this paper, we show that fusion of SFV with cholesterol-containing liposomes depends on sphingomyelin (SM) or other sphingolipids in the target membrane, ceramide representing the sphingolipid minimally required for mediating the process. The action of the sphingolipid is confined to the actual fusion event, cholesterol being necessary and sufficient tor low-pH-dependent binding of the virus to target membranes. The 3-hydroxyl group on the sphingosine backbone plays a key role in the SFV fusion reaction, since 3-deoxy-sphingomyelin does not support the process. This, and the remarkably low levels of sphingolipid required for half-maximal fusion (1–2 mol%), suggest that the sphingolipid does not play a structural role in SFV fusion, but rather acts as a co-factor, possibly through activation of the viral fusion protein. Domain formation between cholesterol and sphingolipid, although it may facilitate SFV fusion, is unlikely to play a crucial role in the process.Keywords
This publication has 39 references indexed in Scilit:
- Interaction of cholesterol with synthetic sphingomyelin derivatives in mixed monolayersBiochemistry, 1991
- Interaction of cholesterol with sphingomyelin in bilayer membranes: evidence that the hydroxy group of sphingomyelin does not modulate the rate of cholesterol exchange between vesiclesBiochemistry, 1991
- Static and dynamic lipid asymmetry in cell membranesBiochemistry, 1991
- Cholesterol oxidase catalyzed oxidation of cholesterol in mixed lipid monolayers: effects of surface pressure and phospholipid composition on catalytic activityBiochemistry, 1990
- Membrane phospholipid asymmetry in Semliki Forest virus grown in BHK cellsBiochimica et Biophysica Acta (BBA) - Biomembranes, 1989
- Biomembrane fusion: a new concept derived from model studies using two interacting planar lipid bilayersBiochimica et Biophysica Acta (BBA) - Reviews on Biomembranes, 1987
- Nucleotide sequence of cDNA coding for Semliki Forest virus membrane glycoproteinsNature, 1980
- Excimer-forming lipids in membrane researchChemistry and Physics of Lipids, 1980
- On the entry of semliki forest virus into BHK-21 cellsThe Journal of cell biology, 1980
- A rapid and sensitive sub-micro phosphorus determinationAnalytica Chimica Acta, 1961