Coordinated decrease of the expression of the mitochondrial and nuclear complex I genes in a mitochondrial mutant of Drosophila.
We have studied a mutant strain of Drosophila in which 80% of the mitochondrial DNA molecules have lost over 30% of their coding region through deletion. This deletion affects genes encoding five subunits of complex I of the respiratory chain (NADH:ubiquinone oxidoreductase). The enzymatic activity of complex I in the mutant strain is half that in the wild strain, but ATP synthesis is unaffected. The drop in enzymatic activity of complex I in the mutant strain is associated with a 50% decrease in the quantity of constitutive proteins of the complex. Moreover, in the mutant strain there is a 50% decrease in the steady-state concentration of the transcripts of the mitochondrial genes affected by the deletion. This decrease is also observed for the transcripts of the nuclear genes coding for the subunits of complex I. These results suggest a coordination of the expression of the mitochondrial and nuclear genes coding for mitochondrial proteins.
Farge
Géraldine
G
Equipe Génome Mitochondrial, UMR CNRS 6547, Université Blaise-Pascal, Clermont II, Aubière, France.
Touraille
Sylvie
S
Lachaume
Philippe
P
Debise
Roger
R
Procaccio
Vincent
V
Alziari
Serge
S
D000818:Animals; D030801:Animals, Genetically Modified / Q000378:metabolism; D002478:Cells, Cultured; D004272:DNA, Mitochondrial / Q000235:genetics; D015536:Down-Regulation / Q000502:physiology; D004330:Drosophila / Q000201:enzymology* / Q000235:genetics*; D042967:Electron Transport Complex I / Q000235:genetics* / Q000378:metabolism*; D003576:Electron Transport Complex IV / Q000378:metabolism*; D004789:Enzyme Activation; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism
D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; D003576:Electron Transport Complex IV; D042967:Electron Transport Complex I