Degradation of temperature-sensitive Ura3 alleles.

<p>A. Cells expressing myc-tagged Ura3 proteins were treated with cycloheximide and incubated at 25 or 37°C for the times indicated. Total protein samples were immunoblotted, with phosphoglycerate kinase (PGK) serving as an internal control. Molecular weights (kDa) of the proteins are indicated on the left of the blot B. As A, but with wild-type and <i>cim3-1</i> (ts proteasome mutant) cells. Note that for this test cells were incubated at high temperature for one hour before cycloheximide addition (at time 0). C. GFP-tagged Ura3-2 in wild-type and the indicated mutant cells. D. GFP-tagged Ura3-3 in the indicated stains.