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RESEARCH PRODUCT
Echovirus 1 Endocytosis into Caveosomes Requires Lipid Rafts, Dynamin II, and Signaling EventsV⃞
Ari HeleniusTimo HyypiäTimo HyypiäLucas PelkmansLucas PelkmansVarpu MarjomäkiVilja PietiäinenPaula Uplasubject
SucroseTime FactorsvirusesEndocytic cycleDynamin IIchemistry.chemical_compoundDynamin IIPhosphorylationInternalizationCytoskeletonIn Situ HybridizationIn Situ Hybridization Fluorescencemedia_commonGenes Dominant0303 health sciencesMicroscopy Videobiology030302 biochemistry & molecular biologyArticlesBrefeldin AEndocytosisCell biologyEnterovirus B HumanCholesterolRNA ViralElectrophoresis Polyacrylamide GelProtein BindingSignal TransductionCholera Toxinmedia_common.quotation_subjectIntegrinGreen Fluorescent ProteinsImmunoblottingEndocytosisTransfectionCell Line03 medical and health sciencesCapsidMembrane MicrodomainsViral entryCentrifugation Density GradientAnimalsMolecular Biology030304 developmental biologyBinding SitesBrefeldin ACell MembraneCell BiologyKineticschemistryViral replicationMicroscopy Fluorescencebiology.proteindescription
Binding of echovirus 1 (EV1, a nonenveloped RNA virus) to the α2β1 integrin on the cell surface is followed by endocytic internalization of the virus together with the receptor. Here, video-enhanced live microscopy revealed the rapid uptake of fluorescently labeled EV1 into mobile, intracellular structures, positive for green fluorescent protein-tagged caveolin-1. Partial colocalization of EV1 with SV40 (SV40) and cholera toxin, known to traffic via caveosomes, demonstrated that the vesicles were caveosomes. The initiation of EV1 infection was dependent on dynamin II, cholesterol, and protein phosphorylation events. Brefeldin A, a drug that prevents SV40 transport, blocked the EV1 infection cycle, whereas drugs that disrupt the cellular cytoskeleton had no effect. In situ hybridization revealed the localization of viral RNA with endocytosed viral capsid proteins in caveosomes before initiation of viral replication. Thus, both the internalization of EV1 to caveosomes and subsequent events differ clearly from caveolar endocytosis of SV40 because EV1 uptake is fast and independent of actin and EV1 is not sorted further to sER from caveosomes. These results shed further light on the cell entry of nonenveloped viral pathogens and illustrate the use of viruses as probes to dissect caveolin-associated endocytic pathways.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2004-11-01 |