FIG. 2.

Ssk1p is stabilized in proteasome mutants. HA-tagged Ssk1p was expressed from the high-copy-number plasmid pNS252 in the wild-type (WT) (W303-1A), rpn9Δ (J43), and rpn12-1 (YK109) strains cultured in SGal medium at 30°C. Transcription and translation were shut off in SD medium containing cycloheximide at 37°C. Cells were collected at the indicated times, the proteins were extracted, and the Ssk1p content was monitored by Western blotting with anti-HA antibody. Actin was detected as the loading control.