FIGURE 6.

FZ exposure decreases the turnover of the destabilized EGFP, a model substrate of proteasome. A, H1299 cells were transiently transfected with pd1EGFP plasmid as described under “Experimental Procedures.” 24 h post-transfection, cells were treated with cycloheximide (50 μg/ml) and chased in the presence or absence of 5 μm FZ for different time periods. GFP fluorescence was observed under a Nikon fluorescence microscope. B, following treatment, the cells were processed for Western blotting using GFP and β-actin antibodies. C, H1299 cells were transiently transfected as described in A and treated with different doses of FZ. Cell lysates were subjected to immunoprecipitation (IP) using anti-GFP antibody followed by Western blot analysis (WB) using GFP and ubiquitin antibodies.