The physiological role of CPR1 in Saccharomyces cerevisiae KNU5377 against menadione stress by proteomics.

In order to understand the functional role of CPR1 in Saccharomyces cerevisiae KNU5377 with regard to its multi-tolerance characteristics against high temperatures, inorganic acids, and oxidative stress conditions, whole cellular proteins were analyzed via liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). This procedure was followed by two-dimensional (2-D) gel electrophoresis. Under menadione stress conditions, the 23 upregulated proteins were clearly identified only in the wildtype strain of KNU5377. Among the proteins, Sod1p, Tsa1p, Ahp1, Cpr1p, Cpr3, Ssb2p, and Hsp12p were identified as components of antioxidant systems or protein-folding related systems. The CPR1 protein could not be completely detected in the cpr1Delta mutant of KNU5377 and the other upregulated proteins in the wild-type strain evidenced a clear correlation with the results of immunoblot analysis. Moreover, a reduction in growth patterns (about 50%) could be observed in the cpr1Delta mutant, as compared with that of the wild-type strain under mild MD stress conditions. These results indicate that the upregulation of CPR1 may contribute to tolerance against MD as an inducer of oxidative stress.