(A–B) Wild-type (WT) and the ssa1,2, ssa1,3, ssa1,4 mutants were labeled with 35S-methionine for 10 min and the breakdown of pulse-labeled proteins were measured at 28°C (A) or 38°C (B). (C) The plasmid carrying SSA1 gene (pGAL-SSA1) was introduced into ssa1,2 mutant and the rate of degradation of short-lived proteins was compared with those of WT and ssa1,2 mutant. (D) Degradation of short-lived proteins in WT, ssa2,3,4 triple mutant and ssa1-45 ts mutant at 38°C. (E) Degradation of long-lived proteins in WT, ssa1,2 and ssa1-45 ts mutants at 28°C. Data represent means ± S. D. from three independent experiments.