Research Paper Volume 5, Issue 4 pp 234—269

Figure 7. Under CR conditions, the atg32Δ mutation reduces capacity of the mitochondrial ETC, lowers the efficacy of coupling between ADP phosphorylation and electron transport, compromises the integrity of the IMM, and disproportionally decreases activities of all OXPHOS enzymes.

WT and atg32Δ strains were cultured in the nutrient-rich YP medium initially containing 0.2% glucose. Mitochondria were purified from WT and atg32Δ cells recovered on day 4 of culturing. The rates of state III (A and B), state IV (D and E) and UC (G and H) respiration were measured using NADH (A, D and G) or succinate (B, E and H) as a respiratory substrate. The ratios of state III rate/state IV rate (RCR; J and K), state III rate/UC rate (M and N) and ADP/O (P and Q) were determined using NADH (J, M and P) or succinate (K, N and Q) as a respiratory substrate. Enzymatic activities of the OXPHOS enzymes NADH:decylubiquinone oxidoreductase (NQR; C), succinate:decylubiquinone-2,6-dichlorophenolindo-phenol oxidoreductase (complex II) (F), ubiquinol:cytochrome c oxidoreductase (complex III) (I), cytochrome c oxidase (complex IV) (L) and F₁F₀-ATP synthase (complex V) (O) were assessed. For each of these OXPHOS enzymes, the ratio “activity in mitochondria of atg32Δ strain/activity in mitochondria of WT strain” was calculated (R).