FIG 4.

Iron deficiency promotes the 26S proteasomal and vacuolar degradation of Sml1 protein. (A) Wild-type YWO0607 and pre1-1 (YWO0608) yeast strains were grown in SC medium for 3 h at 37°C. Then, 100 μM BPS was added, and the cells were incubated for 6 additional hours at 37°C. (B) Wild-type BY4743, rad6Δ (SPY485), and ubr2Δ (SPY487) yeast strains were grown at 30°C for 6 h in SC medium, SC medium with 100 μM BPS, and SC medium with 0.04% MMS added during the last hour. (C) Wild-type BY4743 and pep4Δ (SPY496) yeast strains were grown at 30°C for 8 h in SC medium, SC medium with 100 μM BPS, and SC medium with 0.04% MMS added during the last hour. In all cases Sml1/Pgk1 protein levels were determined and analyzed as described in the legend to Fig. 1. For each strain, Sml1/Pgk1 protein quantitation under BPS and MMS conditions is relative to the levels obtained in SC medium. A representative experiment and the average and standard deviation of three independent biological replicates are shown.