Acid Stress Triggers Resistance to Acetic Acid-Induced Regulated Cell Death through Hog1 Activation Which Requires RTG2 in Yeast

Figure 2

CTT1 mRNA upregulation triggered by acid stress is impaired in ∆rtg2 mutants. Cells were grown up to exponential phase (U), incubated at low pH (acid stress), and treated with acetic acid (AcOH) at the indicated times, respectively. (a) Catalase activities were determined on cell extracts at 30 min of acid stress and after 30 min of acetic acid exposure as described in Materials and Methods. Values are shown as the deviations from three independent experiments. Paired Student’s -test: statistically significantly different with when comparing WT versus Δrtg2, Δhog1, and Δhog1rtg2 and comparing Δrtg2 versus Δhog1 and Δhog1rtg2 at low pH and with acetic acid and with when comparing Δrtg2 versus Δhog1 and Δhog1rtg2 at low pH. (b, c) CTT1 and CTA1 mRNA levels were measured by real-time PCR at the indicated times in WT and mutant cells. In both cases, mRNA levels were normalized to that of ACT1 mRNA and reported as means with standard deviation in fluorescence arbitrary units (a.u.). Paired Student’s -test: statistically significantly different with when comparing WT versus Δrtg2, Δhog1, and Δhog1rtg2; with when comparing Δrtg2 versus Δhog1 and Δhog1rtg2 at 10 min low pH; and with when comparing WT and Δrtg2 versus Δhog1 and Δhog1rtg2 at 30 min low pH and with acetic acid.

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