Figure 6. Cells treated with the proteasome inhibitor MG132 have normal actin cytoskeleton organization.

(A) To facilitate drug permeability or accumulation, erg6Δ and pdr5Δ strains were grown to mid-log, treated with 100 µM MG132 for 2 hr, fixed, stained with rhodamine phalloidin and visualized by fluorescence microscopy. (B) Wild-type (BY4742), erg6Δ, and pdr5Δ cells were treated with 50 µM MG132 and protein samples were isolated 0, 30, 75, and 120 min after MG132 addition to the medium. Protein concentrations were determined by Bradford assays and ∼45 µg of protein were separated by SDS-PAGE and analyzed by Western blotting with an anti-ubiquitin antibody.