Fig 5. Sensitivity of CTH2 and Δcth2 mutant cells to oxidative stress under iron limitation conditions.
(A) Intracellular Fe levels in the following strains: MML1082 (Δcth1 Δcth2 / CTH2) and MML1081 (Δcth1 Δcth2) growing in liquid YPD medium without or with t-BOOH (0.3 mM, indicated times), and without or with BPS (75 μM, 16 hours); or MML1116 (Δcth1 Δcth2 / CTH2 tetO2-FTR1) and MML1114 (Δcth1 Δcth2 tetO2-FTR1) growing in liquid YPD medium with doxycycline (5 μg/ml, 40 hours). Bars represent the mean of three experiments (± s.d.), and are normalized with respect to Δcth1 Δcth2 / CTH2 cells without additions, which are given the unit value. These are also employed as reference to analyze the statistical significance of the value differences (Tukey-Kramer test, *: p<0.05). (B) Percentage of budded cells in cultures of Δcth1 Δcth2 / CTH2 and Δcth1 Δcth2 strains grown during 16 hours in YPD medium plus 75 μM BPS, arrested with α-factor in this same medium and then synchronously released at time 0 in BPS-containing YPD medium without (control, continuous lines) or with 0.2 or 0.3 mM t-BOOH (dashed lines). (C) Percentage of budded cells in cultures of Δcth1 Δcth2 / CTH2 tetO2-FTR1 and Δcth1 Δcth2 tetO2-FTR1 strains grown during 40 hours in YPD medium plus 5 μg/ml doxycycline, arrested with α-factor in this same medium and then synchronously released at time 0 in doxycycline-containing YPD medium without (control, continuous lines) or with 0.3 mM t-BOOH (dashed lines). In both (B) and (C) the mean (± s.d.) of three independent experiments is shown.