Polio-induced vesicles form in the presence of BFA, but fail to induce Arf1 relocalization.

A. Polio non-structural proteins were expressed from non-replicating RNA. The cells were incubated in the presence or absence of 2 µg/ml of BFA. An equivalent amount of DMSO solvent was added to the incubation medium in the sample without BFA. After 4.5 h incubation, cells were fixed and processed for electron microscopy. B. Poliovirus non-structural proteins were expressed from non-replicating RNA in HeLa cells expressing Arf1-EGFP fusion. The cells were incubated in the presence of 2 µg/ml of BFA where indicated (panels E–H). An equivalent amount of DMSO solvent was added to the incubation medium in samples without BFA (panels A–D). To observe the localization of Arf1-EGFP fusion protein in cells without expression of polio proteins, an empty plasmid was substituted for the polio cDNA-bearing plasmid (panels D and H).