The poliovirus empty capsid specifically recognizes the poliovirus receptor and undergoes some, but not all, of the transitions associated with cell entry.
Experimental results presented here demonstrate that the poliovirus empty capsid binds with saturable character to poliovirus-susceptible cells, binds preferentially to susceptible cells, and competes with mature virus for binding sites on cells. Hence, induced changes in the structure and/or stability of the particle by RNA encapsidation and virus maturation are not necessary for recognition by receptor. In mature virus, heat-induced rearrangements mimic those induced by receptor at physiological temperatures in several important respects, namely, expulsion of VP4 and externalization of the VP1 N-terminal arm. It is shown here that in the empty capsid the VP1 N-terminal arm is externalized but the VP4 portion of VP0 is not. Thus, these two hallmark rearrangements associated with cell entry can be uncoupled.
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA. ravi_basavappa@urmc.rochester.edu
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Basavappa
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Gómez-Yafal
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Hogle
D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002213:Capsid / Q000378:metabolism* / Q000502:physiology; D002460:Cell Line; D006367:HeLa Cells; D006361:Heating; D006801:Humans; D008565:Membrane Proteins; D051379:Mice; D017955:Poliovirus / Q000378:metabolism* / Q000502:physiology; D011233:Precipitin Tests; D011991:Receptors, Virus / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000378:metabolism; D014771:Virion
D008565:Membrane Proteins; D011991:Receptors, Virus; C066100:poliovirus receptor; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase