FIGURE 2.
The amount and stability of Kre6 protein in various mutant cells and the colony-forming activity of these mutants. A, the strains were grown overnight at 25 °C until A600 nm = 0.5 and then shifted to the semi-permissive temperature, 30 °C, and grown for 90 min. Kre6 protein in the total cell lysate was detected by immunoblotting using anti-Kre6 antiserum. The immunoblotting bands of Scs2 are shown as the loading control. B, stability of Kre6 protein at the permissive 25 °C was examined by immunoblotting after protein synthesis was blocked by adding 10 μg/ml cycloheximide at A600 nm = 0.5. Degradation in the keg1-1 mutant was retarded by ubc7Δ. Scs2 was used as the loading control. C, Colony formation of keg1-1 at 37 °C was not rescued by pep4Δ or ubc7Δ mutation that reduced degradation of Kre6.