Figure 7.

Lack of Q in the tRNAs leads to reduction in mitochondrial protein synthesis. Autoradiographs of 2D gel electrophoresis of total mitochondrial ³⁵S methionine–cysteine labeled proteins used to assess de novo mitochondrial translation. For this experiment, WT (A), TbTGT1 RNAi uninduced (−TET) (B) and induced (+TET) (C) cells were labeled with ³⁵S for mitochondrial translation and resolved on 2D gels (insets: Coomassie staining for loading control). (D) Semi-quantitative densitometric analysis of de novo synthesis of COXI from three independent experiments. Values were normalized to WT signals. (* P <0.05). (E) Spectrophotometric assay for cIV for WT, TbTGT1 RNAi uninduced (−TET) and induced (+TET) cells. Activity was measured in mitochondrial lysates prepared from three independent experiments. One unit (U) of activity catalyzes the oxidation of 1 mmol of cytochrome c per min. Specific activity is calculated as U per mg of mitochondrial protein. Mean ± SD values are shown. (F) Codon usage analysis for NAU and NAC codons in mitochondrially v/s nuclearly encoded subunits of respiratory complex IV. COX: Cytochrome c oxidase (The roman numeral after COX indicates the number of subunit).