Figure 1.—
The α1 protein is short-lived and degraded by the ubiquitin–proteasome pathway. (A) A representative cycloheximide-chase assay of α13HA turnover in wild-type, cim3-1, and cim5-1 strains is shown at the top, and the quantitative results of multiple experiments are shown below. In these experiments, the strains were shifted to 37° for 1 hr prior to the cycloheximide-chase assay and maintained at this temperature throughout the assay. The amount of α13HA present at the given chase time was expressed relative to that observed at time zero and replicates of multiple experiments were averaged. (B) A representative cycloheximide-chase assay of α13HA turnover in a pdr5Δ strain treated with 25 μg/ml of MG-132 or the solvent DMSO is shown at the top, and the quantitative results of multiple experiments are shown below. These experiments were performed at 30°.