Figure 4.—
Ubc4/5-dependent ubiquitin ligases are necessary for the rapid degradation of α1. (A) Cycloheximide-chase analysis of α13HA turnover in wild-type, ufd4Δ, and rsp5-2 cells. In experiments with the rsp5-2 mutant, the temperature-sensitive strain and a congenic wild-type strain were shifted to 37° for 1 hr prior to the cycloheximide-chase assay and maintained at this temperature throughout the assay. A representative experiment is shown at the top, and the quantitative results of multiple experiments are shown below. (B) Measurement of the α13HA degradation rate at 30° in wild-type, slx5Δ, slx8Δ, and slx5Δ slx8Δ cells. A representative experiment is shown at the top, and the quantitative results of multiple experiments are shown below.