FIG. 6.

Nucleocytoplasmic shuttling of E1 is inhibited upon leptomycin B treatment. (A) The HeLa cell-BALB/c heterokaryon assay was performed as described in the Fig. 4 legend, with HeLa cells transfected with an expression vector for E1-TES (T126E) or E1-TTE (S283E). (B) The heterokaryon assay was performed with HeLa cells transfected with E1-TTE, and cells were treated with LMB (50 ng/ml) or left untreated. Cells were stained using antibodies against E1 and counterstained with Hoechst dye. The arrows indicate mouse nuclei fused to HeLa cell nuclei in heterokaryons in which E1-S283E has shuttled (H+) or mouse nuclei in heterokaryons in which E1-S283E shuttling was inhibited following LMB treatment.