Influence of compartmental localization on the function of yeast NADP +-specific isocitrate dehydrogenases

Veronica Contreras-Shannon, Lee McAlister-Henn

Research output: Contribution to journalArticlepeer-review

17 Scopus citations

Abstract

Three differentially compartmentalized isozymes of isocitrate dehydrogenase (mitochondrial IDP1, cytosolic IDP2, and peroxisomal IDP3) in the yeast Saccharomyces cerevisiae catalyze the NADP+-dependent oxidative decarboxylation of isocitrate to form α-ketoglutarate. These enzymes are highly homologous but exhibit some significant differences in physical and kinetic properties. To examine the impact of these differences on physiological function, we exchanged promoters and altered organellar targeting information to obtain expression of IDP2 and IDP3 in mitochondria and of IDP1 and IDP3 in the cytosol. Physiological function was assessed as complementation by mislocalized isozymes of defined growth defects of isocitrate dehydrogenase mutant strains. These studies revealed that the IDP isozymes are functionally interchangeable for glutamate synthesis, although mitochondrial localization has a positive impact on this function during fermentative growth. However, IDP2, whether located in mitochondria or in the cytosol, provided the highest level of defense against endogenous or exogenous oxidative stress.

Original languageEnglish (US)
Pages (from-to)235-246
Number of pages12
JournalArchives of Biochemistry and Biophysics
Volume423
Issue number2
DOIs
StatePublished - Mar 15 2004

Keywords

  • Compartmentation
  • Isocitrate dehydrogenase
  • Isozymes
  • Saccharomyces cerevisiae

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology

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