Expression, subcellular localization, and antioxidant role of mammalian methionine sulfoxide reductases in saccharomyces cerevisiae

Despite the growing body of evidence suggesting a role for MsrA in antioxidant defense, little is currently known regarding the function of MA in cellular protection against oxidative stress. In this study, we overexpressed the mammalian MA and MsrA genes in Saccharomyces cerevisiae and assessed their subcellular localization and antioxidant functions. We found that the mitochondrial MsrB3 protein (MsrB3B) was localized to the cytosol, but not to the mitochondria, of the yeast cells. The mitochondrial Msr82 protein was detected in the mitochondria and, to a lesser extent, the cytosol of the yeast cells. In this study, we report the first evidence that Msr83 overexpression in yeast cells protected them against H2O2-mediated cell death. Additionally, MsrB2 overexpression also provided yeast cells with resistance to oxidative stress, as did MsrA overexpression. Our results show that mammalian MsrB and MsrA proteins perform crucial functions in protection against oxidative stress in lower eukaryofic yeast cells. [BMB reports 2009; 42(2): 113-118]