| Although biological markers of oxidative stress have been described in many disorders, the molecular mechanism of stress propagation and the stage(s) at which it is most relevant for these disorders remains unclear. In Friedreich ataxia (FA), the function of frataxin which is a mitochondrial protein responsible for FA disease is still not completely understood. Due to its conservation across species, the yeast S. cerevisiae homologue YFH1 have contributed to the understanding of the function of frataxin. Morphological and Proteomics studies were performed with YFH1 deletion strain (Deltayfh1) under oxidative stress. The cell response to the oxidative stress was evaluated by an addition of H2O 2 to the S. cerevisiae wild type and Deltayfh1 strain known to accumulate iron in mitochondria. The physiological changes with oxidative stress were monitored by measurement of growth patterns and carbonyl contents as well as cell viability test and microscopy observation. While wild type strain has a short-term growth arrest at early stage, Deltayfh1 didn't show growth arrest for several hours and eventually cells died. Moreover, there were good correlations between cell viability, cellular reactive oxygen species (ROS) levels, and carbonyls levels. The impact of oxidative stress on protein function was evaluated by proteomic techniques by targeting protein carbonylation. Oxidized proteins were selected by affinity chromatography and 53 proteins were identified by digestion followed by RPLC-MS/MS in both wild type and Deltayfh1 strain, respectively. |
