Mitochondria, oxidative stress and the petite phenotype in Saccharomyces cerevisiae

Abstract

Oxidative stress has long been recognised as biologically important and is increasingly implicated in a variety of phenomena, such as mutation, carcinogenesis, degenerative and other diseases, inflammation, ageing, and development. The role of the mitochondrion in oxidative stress and the production of reactive oxygen species (ROS) and other radical species is well-established, with mitochondria providing a fascinating area of study within the oxidative stress field. Mitochondria are essential organelles for the viability of all eukaryotic organisms. While mitochondria perform important processes associated with oxidative phosphorylation and energy production, and numerous other metabolic processes, such as iron sulfur cluster biogenesis, lipid and amino acid synthesis, they also appear to be the largest intracellular source of ROS in aerobic cells. The steady state concentration of O2 in the mitochondrial matrix is five- to tenfold higher than in the cytosol or nuclear space according to one estimation. Therefore, mitochondrial macromolecules such as mitochondrial DNA are particularly susceptible to oxidative damage.