Phenotypic expression of mtDNA heteroplasmy in the skeletal muscle of patients with oculomyopathy: defect in mitochondrial protein synthesis.
The biochemical consequences of mtDNA heteroplasmy, observed in patients with a range of diseases associated with the mitochondrial respiratory enzymes deficiency is of particular interest, as they might provide information with regard to the regulatory interactions which govern the expression of the human mitochondrial genome. Three patients with chronic progressive external ophthalmoplegia (CPEO) were investigated to study the consequences of mtDNA heteroplasmy on mitochondrial protein synthesis. All 3 patients exhibited partially deleted mtDNA species (varying in size from 10.5 to 14 kb) in their skeletal muscle, which co-existed with the normal 16.5 kb mtDNA. The examination of mitochondrial translation products following the incorporation of [35S]methionine by isolated mitochondria, showed grossly abnormal patterns of mitochondrial translation products, suggesting a major disturbance in the regulation of mitochondrial protein synthesis.
Sudoyo
H
H
Department of Biochemistry, Monash University, Clayton, Vic., Australia.
Marzuki
S
S
Byrne
E
E
Mastaglia
F
F
D000328:Adult; D003573:Cytochrome b Group / Q000172:deficiency / Q000235:genetics; D030401:Cytochrome-c Oxidase Deficiency; D004272:DNA, Mitochondrial / Q000235:genetics*; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III / Q000172:deficiency / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D006801:Humans; D008875:Middle Aged; D009124:Muscle Proteins / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics; D009132:Muscles / Q000378:metabolism*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000172:deficiency / Q000235:genetics; D009247:NADH, NADPH Oxidoreductases / Q000172:deficiency / Q000235:genetics; D017246:Ophthalmoplegia, Chronic Progressive External / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D014176:Protein Biosynthesis; D006180:Proton-Translocating ATPases / Q000172:deficiency / Q000235:genetics; D017384:Sequence Deletion
D003573:Cytochrome b Group; D004272:DNA, Mitochondrial; D009124:Muscle Proteins; D009247:NADH, NADPH Oxidoreductases; D016660:NAD(P)H Dehydrogenase (Quinone); D003576:Electron Transport Complex IV; D006180:Proton-Translocating ATPases; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III