FIG. 7.

Ste6p is partially stabilized in a pre1-1 pre2-1 mutant, defective in the chymotrypsin-like activity of the proteasome. Metabolic pulse-chase labeling and immunoprecipitation of Ste6p and Cpy were carried out as described in the legend to Fig. 3B. Cells were shifted to 38°C for 40 min prior to metabolic labeling to impose the pre1 pre2 block. Strains used were SM3288 (PRE, pSM683) and SM3290 (pre1-1 pre2-1, pSM683). For abbreviations, see the legend to Fig. 5.