FIG. 2.

abc3⁺ transcript levels are downregulated by iron in a Fep1-dependent manner. (A) Logarithmic-phase cultures of the isogenic strains FY435 (wild type [WT]) and BPY10 (fep1Δ) were left untreated (−) or were treated with Dip (250 μM) or FeCl₃ (Fe) (100 μM) for 90 min. Total RNA was then prepared from each sample and analyzed by RNase protection assays. Steady-state levels of abc3⁺, abc1⁺, abc2⁺, abc4⁺, hmt1⁺, and act1⁺ mRNAs (indicated with dots and arrows) were analyzed in both the wild-type strain and a strain lacking the fep1⁺ allele. NS, nonspecific signal. (B) Graphic representation of the quantification of the results of three independent RNase protection assays, including the experiment shown in panel A. The values shown are the means of three replicates ± the standard deviations.