Research Paper Volume 5, Issue 4 pp 234—269

Figure 8. Under CR conditions, the atg32Δ mutation increases the level of mitochondrially produced ROS, elevates the extent of oxidative damage to mitochondrial proteins and membrane lipids, and rises the frequencies of mutations in mtDNA.

WT and atg32Δ strains were cultured in the nutrient-rich YP medium initially containing 0.2% glucose. (A) The dynamics of age-dependent changes in the intracellular levels of ROS during chronological aging of yeast. ROS were visualized using dihydrorhodamine 123 (DHR). At least 1,000 cells were used for quantitation of DHR staining for each of 4 independent experiments. Data are presented as mean ± SEM. (B and C) Carbonylated proteins (B) and oxidatively damaged membrane lipids (C) in purified mitochondria were determined as described in Methods. Data are presented as mean ± SEM (n = 2-3). (D) The percentage of respiratory-deficient cells unable to grow in medium containing 3% glycerol because they carried large mtDNA deletions (rho⁻) or lacked mtDNA (rho°). Data are presented as mean ± SEM (n = 5). (E) The frequencies of rib2 and rib3 point mutations in mtDNA caused resistance to erythromycin. Data are presented as mean ± SEM (n = 4).