Ubc7p-dependent degradation of unphosphorylated Ssk1p. Ubc7p is involved in the degradation of Ssk1p. Tagged Ssk1p was expressed from pNS114 in the YPD1+ ssk1Δ hog1Δ UBC7+ (NS318), YPD1+ ssk1Δ hog1Δ ubc7Δ (NS329), ypd1Δ ssk1Δ hog1Δ UBC7+ (NS320), and ypd1Δ ssk1Δ hog1Δ ubc7Δ (NS333) strains, and the Ssk1p content was monitored as described in the legend to Fig. 3. +, present; Δ, deleted.