FIG. 5.
Stimulation of 3×GFP-NLS efflux from nuclei of permeabilized uninfected cells by extracts from poliovirus-infected cells. Monolayers of HeLa-3E cells were permeabilized with digitonin and incubated with 10-fold-diluted S100 extracts from mock-infected (a and d) or poliovirus-infected (b and e) HeLa cells for 1 h at 37°C. In panels c and f, the permeabilized cells were incubated with a 10-fold-diluted mixture of 1 and 9 μl of lysates from infected and mock-infected cells, respectively (the protein concentrations in all probes being equal). The effects of protease inhibitors (g to o) were assayed on permeabilized uninfected HeLa-3E cells by using the extract prepared as described for panels c and f. The extracts were preincubated with the inhibitors for 20 min at 4°C and then applied to the cells for 1 h at 37°C.