Protein synthesis by isolated pea mitochondria is dependent on the activity of respiratory complex II.
In isolated pea (Pisum sativum L.) mitochondria incorporation of 35S-methionine into newly synthesised proteins was influenced by the presence of site-specific inhibitors of the respiratory electron-transport chain. These effects were not produced by changes in the rate of respiratory electron transport itself nor by changes in ATP concentration. Protein synthesis was inhibited by inhibitors of ubiquinone reduction but not by inhibitors of ubiquinol oxidation. By the use of additional inhibitors at specific sites of the respiratory chain, different oxidation-reduction states were obtained for the different complexes in the electron-transport chain. It was found that electron transport through succinate:ubiquinone oxidoreductase (respiratory complex II) was specifically required for protein synthesis, even when all the other conditions for protein synthesis were satisfied. We suggest that a subunit of complex II, or a component closely associated with complex II, is involved in a regulatory system that couples electron transport to protein synthesis.
Escobar Galvis
M L
ML
Plant Cell Biology, Lund University, Box 7007, S-220 07 Lund, Sweden.
Allen
J F
JF
Hâkansson
G
G
D002952:Citric Acid Cycle; D042963:Electron Transport Complex II; D015966:Gene Expression Regulation, Fungal; D008928:Mitochondria / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism*; D010101:Oxygen Consumption; D018532:Pisum sativum / Q000378:metabolism*; D010940:Plant Proteins / Q000096:biosynthesis*; D014176:Protein Biosynthesis; D013385:Succinate Dehydrogenase / Q000378:metabolism*
D009097:Multienzyme Complexes; D010940:Plant Proteins; D010088:Oxidoreductases; D042963:Electron Transport Complex II; D013385:Succinate Dehydrogenase