Fusion of Semliki Forest virus with cholesterol-containing liposomes at low pH: A specific requirement for sphingolipids
| Autor: | Jan Wilschut, Kasireddy Chandraprakash Reddy, Jeroen Corver, Robert Bittman, Lise Moesby, José Luis Nieva, Romke Bron |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1995 |
| Předmět: |
Ceramide
Endosome viruses MEMBRANE-FUSION Ceramides Semliki Forest virus Endocytosis Fluorescence Mice Structure-Activity Relationship chemistry.chemical_compound Viral envelope BILAYER-MEMBRANES Sphingosine Animals SEMLIKI FOREST VIRUS SPHINGOLIPID EXCHANGE Molecular Biology Sphingolipids SPHINGOMYELIN Pyrenes biology MEMBRANE FUSION CHOLESTEROL Cell Membrane Lipid bilayer fusion Cell Biology Hydrogen-Ion Concentration ENVELOPE GLYCOPROTEIN biology.organism_classification Egg Yolk Sphingolipid Sphingomyelins Cell biology SPIKE PROTEIN Kinetics Biochemistry chemistry MIXED MONOLAYERS Liposomes CELLS lipids (amino acids peptides and proteins) PENETRATION Sphingomyelin CATALYZED OXIDATION |
| Zdroj: | Molecular Membrane Biology, 12(1), 143-149 |
| ISSN: | 0968-7688 |
| Popis: | 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 for low-pH-dependent binding of the virus to target membranes. The 9-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 cofactor, 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. |
| Databáze: | OpenAIRE |
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