Effect of RNAi-mediated ablation of subunits α, Tb7760 or Tb2930 on mitochondrial ATP production.
Crude mitochondrial preparations from uninduced and 3-day RNAi-silenced RNA_sub α (A), RNAi_Tb2930 (B) and RNAi_Tb7760 (C) cells were obtained by digitonin extraction and ATP production in the three mitochondrial pathways was measured individually. ATP-production was triggered by the addition of ADP plus one of the following substrates, succinate, α-ketoglutarate and pyruvate/succinate. Uninduced cells (−tet) are shown in grey, induced (+tet) are shown in black. The tested substrate is indicated at the top. Malonate (Mal.), a specific inhibitor of succinate dehydrogenase, was used to inhibit ATP production by oxidative phosphorylation and atractyloside (Atrac.) was used to inhibit import of ADP into mitochondria. Addition of these compounds to the sample is indicated at the bottom of each panel. ATP production in mitochondria isolated from uninduced cells and tested without additions of malonate or atractyloside (None) was set to 100%. The bars represent means expressed as percentages from three independent RNAi inductions. Standard deviations are indicated.