The entry of reovirus into L cells is dependent on vacuolar proton-ATPase activity

Inhibitors of vacuolar proton-ATPase activity (5 microM bafilomycin A1 or 50 nM concanamycin A) prevented infection by reovirus particles but not by infectious subviral particles (ISVPs). Neither compound affected virus attachment or internalization. However, both compounds potently blocked cleavage of the viral protein mu 1C. Finally, both reovirus particles and ISVPs efficiently translocated the toxin alpha-sarcin to the cytosol during virus entry. Bafilomycin A1 blocked translocation of alpha-sarcin by reovirus particles but not by ISVPs.