A novel cell entry pathway for a DAF-using human enterovirus is dependent on lipid rafts.
The glycosylphosphatidylinositol (GPI)-anchored complement regulatory protein decay-accelerating factor (DAF) is used by a number of enteroviruses as a receptor during infection. DAF and other GPI-anchored proteins can be found in cholesterol-rich ordered domains within the plasma membrane that are known as "lipid rafts." We have shown, by using drugs to specifically inhibit various endocytosis routes, that infection by a DAF-using strain of echovirus 11 (EV11) is dependent upon cholesterol and an intact cytoskeleton, whereas a non-DAF-using mutant derived from it was unaffected by these drugs. Using RNA transfection and virus-binding assays, we have shown that this requirement for cholesterol, the actin cytoskeleton, and the microtubule network occurs postbinding of the virus but prior to uncoating of the RNA, indicating a role during virus entry. Confocal microscopy of virus infection supported the role of cholesterol and the cytoskeleton during entry. In addition, [(35)S]methionine-labeled DAF-using EV11, but not the non-DAF-using EV11, could be copurified with lipid raft components during infection after Triton X-100 extraction. These data indicate that DAF usage by EV11 enables the virus to associate with lipid rafts and enter cells through this novel route.
Stuart
Amanda D
AD
Division of Virology, Department of Pathology, University of Cambridge, CB2 1QP Cambridge, United Kingdom. ads35@mole.bio.cam.ac.uk
Eustace
Hannah E
HE
McKee
Thomas A
TA
Brown
T D K
TD
D018958:CD55 Antigens / Q000378:metabolism*; D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism*; D002460:Cell Line; D002746:Chlorpromazine / Q000494:pharmacology; D002784:Cholesterol / Q000378:metabolism; D015638:Cytochalasin D / Q000494:pharmacology; D003599:Cytoskeleton / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects; D029822:Enterovirus B, Human / Q000187:drug effects / Q000472:pathogenicity*; D004769:Enterovirus Infections / Q000821:virology; D006801:Humans; D021962:Membrane Microdomains / Q000378:metabolism*; D015739:Nocodazole / Q000494:pharmacology; D009761:Nystatin / Q000494:pharmacology
D018958:CD55 Antigens; D051242:Caveolin 1; D022461:Caveolins; D009761:Nystatin; D015638:Cytochalasin D; D002784:Cholesterol; D015739:Nocodazole; D002746:Chlorpromazine