ATP Synthase Deficiency due to TMEM70 Mutation Leads to Ultrastructural Mitochondrial Degeneration and Is Amenable to Treatment

Figure 3

2D BN-PAGE reveals complex V deficiency. Analysis of muscle tissue in native gels revealing an almost complete deficiency of the mitochondrial ATP synthase (complex V) (a, b). I-V, mitochondrial complexes I-V; Co., control; 1, child I; 2, child II. (a) Mitochondrial complexes from homogenized skeletal muscle biopsies were solubilized by dodecylmaltoside, separated by hrCNE, and analyzed by ATP hydrolysis/lead phosphate precipitation assay. (b) Gel A was restained with Coomassie to display other complexes of the respiratory chain. Separation of the subunits of mitochondrial complexes by second-dimension SDS-PAGE showed drastically reduced but fully assembled ATP synthase (complex V) in the patients (c–e). I-V, mitochondrial complexes I-V. Mitochondrial complexes from patient skeletal muscle were solubilized by dodecylmaltoside and separated by hrCNE. The strip of the native gel was used for 2D SDS-PAGE to resolve the subunit composition of the mitochondrial complexes, as shown in silver stained gels for (c): control, (D): child I, and (e): child II. Yellow arrows mark and subunits of ATP synthase. Blue arrows indicate the SDHC and SDHD subunits of complex II.