Protective roles of methionine-R-sulfoxide reductase against t-butyl hydroperoxide and t-butylhydroquinone in the fission yeast

Various enzymes protect or repair oxidized residues, including methionine sulfoxide reductases which reduce methionine-S-sulfoxide (MsrA) and methionine-R-sulfoxide (MsrB) residues back to corresponding methionine. Methionine-R-sulfoxide reductase repair oxidatively damaged proteins, protect against oxidative stress, and regulate protein function. The Schizosaccharomyces pombe msrB⁺ gene encoding methionine-R-sulfoxide reductase (MsrB) was previously cloned into the shuttle vector pRS316 to generate the recombinant plasmid pFMetSO. In this study, we further investigated the role and function of MsrB from Schizosaccharomces pombe under stress. When shifted into fresh medium containg tert-butyl hydroperoxide (t-BOOH) and tert-butylhydroquinone (t-BHQ), the S. pombe cells harboring pFMetSO displayed better growth than the vector control cells. They contained the lower reactive oxygen species (ROS) in the presence of t-BOOH and t-BHQ than the vector control cells, However, the S. pombe cells harboring pFMetSO and the vector control cells showed the similar levels of nitrite, an index of nitric oxide in the absence or presence of t-BOOH and t-BHQ. In brief, the S. pombe MsrB plays a protective role t-BOOH and t-BHQ through he down-regulation of ROS.