Identification of a mitochondrial alcohol dehydrogenase in Schizosaccharomyces pombe: new insights into energy metabolism

Paul G. Crichton, Charles Affourtit, Anthony L. Moore

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11 Citations (Scopus)


In the present study we have shown that mitochondria isolated from Schizosaccharomyces pombe exhibit antimycin A-sensitive oxygen uptake activity that is exclusively dependent on ethanol and is inhibited by trifluoroethanol, a potent inhibitor of ADH (alcohol dehydrogenase). Ethanol-dependent respiratory activity has, to our knowledge, not been reported in S. pombe mitochondria to date, which is surprising as it has been concluded previously that only one ADH gene, encoding a cytosolic enzyme, occurs in this yeast. Spectrophotometric enzyme assays reveal that ADH activity in isolated mitochondria is increased ∼16-fold by Triton X-100, which demonstrates that the enzyme is located in the matrix. Using genetic knockouts, we show conclusively that the novel mitochondrial ADH is encoded by adh4 and, as such, is unrelated to ADH isoenzymes found in mitochondria of other yeasts. By performing a modular-kinetic analysis of mitochondrial electron transfer, we furthermore show how ethanol-dependent respiratory activity (which involves oxidation of matrix-located NADH) compares with that observed when succinate or externally added NADH are used as substrates. This analysis reveals distinct kinetic differences between substrates which fully explain the lack of respiratory control generally observed during ethanol oxidation in yeast mitochondria.

Original languageEnglish
Pages (from-to)459-464
Number of pages6
JournalBiochemical Journal
Issue number2
Publication statusPublished - 15 Jan 2007


  • Alcohol dehydrogenase
  • Mitochondrion
  • Modular kinetics
  • NADH dehydrogenase
  • Respiration
  • Schizosaccharomyces pombe
  • Ubiquinone pool

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