FIG. 11.
A functional proteasome is required for rapid degradation of ΔF670 Yor1p. A yor1-1::hisG mutant cell lacking normal proteasome function (pre1-1 pre2-2) was transformed with low-copy-number plasmids bearing the gene for either the wild-type or ΔF670 form of Yor1p. Low-copy-number plasmids carrying PRE1 and PRE2 (pPRE1/pPRE2) or the vector plasmids alone (pRS313/pRS315) were introduced into these transformants to examine the consequence of varying the activity of the proteasome on turnover of these two forms of Yor1p. Appropriate transformants were analyzed for stability of wild-type or ΔF670 Yor1p by pulse-chase analysis as described above. The calculated half-lives (T1/2; in minutes) are on the right.