Adaptive changes of the yeast mitochondrial proteome in response to salt stress

Abstract Mitochondria are dynamic organelles with the capacity to adapt to environmental stimuli and stress. Here we use yeast (Saccharomyces cerevisiae) in combination with proteomic approaches to quantify the changes in the protein composition of mitochondria in the presence of salt stress provoked by NaCl. We identified 15 proteins that were more than twofold overrepresented in salt adapted mitochondria. These proteins are mainly involved in the oxidative stress defense, the biosynthesis of amino acids and ubiquinone or in the metabolism of pyruvate and acetate. Loss of function of most of the upregulated proteins did not result in a significant growth phenotype under high salt conditions. However, all identified proteins were necessary to sustain efficient growth under oxidative stress caused by hydrogen peroxide. Additionally, a subset of outer mitochondrial membrane proteins was shown to be upregulated upon salt stress. We furthermore identified nine proteins that were more than threefold underrepre...