FIGURE 5.

Proteasome core particles and regulatory particles depend differently on Ubp3 for vacuolar targeting. A and B, wild type or ubp3Δ strains with gene fusions encoding Rpn1-GFP (A) or β5-GFP (B) were analyzed for vacuolar targeting of RP and CP, respectively, upon nitrogen starvation. Samples were resolved on SDS-PAGE and immunoblotted for GFP and the loading control Pgk1. Lower panel shows quantifications as in Fig. 2. Shown are the averages from 3 to 5 experiments, and error bars indicate S.E. C and D, microscope images and quantification (n > 100) of cells from A and B before and after 24 h of starvation. c + v, little nuclear staining and clear vacuolar localization; n + c, nuclear and cytosolic staining with stronger signals in nucleus, except for β5-GFP ubp3Δ cells where there was clearly stronger signal in the cytosol. Irrespectively, all n + c all have little to no vacuolar staining.