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

Figure 1

AA-RCD resistance due to acid stress depends on HOG1 and RTG2. (a) Cells were treated with acetic acid (AcOH) after acid stress adaptation, except for WT where indicated. Viability was analyzed at indicated times by measuring colony-forming units (CFU). Cell survival (100%) corresponds to the CFU at time zero. Values are shown as the deviations from four independent experiments. (b, c) DNA fragmentation and intracellular ROS levels were detected by using the TUNEL assay and H₂DCF-DA probe, respectively. The percentage of TUNEL- and DCF-positive cells is reported at 150 min and 30 min, respectively, with (AcOH) and without (CTRL) acetic acid treatment. In both cases, at least 400 cells were analyzed in three samples from each of the three independent experiments. Paired Student’s -test: statistically significantly different with when comparing Δrtg2 versus WT, with or without acid stress adaptation, Δhog1, and Δhog1rtg2. (d) The index of respiratory competence (IRC) was measured at the indicated times by plating the same cell number on YPD (2% dextrose) and YPG (3% glycerol). The IRC was calculated from three independent experiments as the percentage of cells able to grow in both YPD and YPG and reported as % of acid-stressed WT-adapted cells.

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