FIG 3.

Mec1 and Rad53 checkpoint kinases do not regulate Sml1 protein levels under low-Fe conditions. Wild-type DES460, dun1Δ (MHY307), rad53Δ (DES453), and mec1Δ (DES459) yeast strains overexpressing RNR1 were grown at 30°C for 6 h in SC medium minus tryptophan (SC−trp), SC−trp with 100 μM BPS, and SC−trp with 0.04% MMS added during the last hour. Sml1/Pgk1 and Sml1/Rnr1 protein levels were determined and analyzed as described in the legend to Fig. 1. An anti-Rnr1 antibody was used to determine Rnr1 protein levels. For each strain, Sml1/Pgk1 and Sml1/Rnr1 protein quantitation under BPS and MMS conditions is relative to the values obtained in SC medium. A representative experiment and the average and standard deviation of three independent biological replicates are shown for each strain.