Reduction of N-acetyl methionine sulfoxide in plants.

Differential regulation of plastidial and cytosolic isoforms of peptide methionine sulfoxide reductase in Arabidopsis.

We report the characterization of two members of a gene family from Arabidopsis that encode, respectively, cytosolic (cPMSR) and plastid-targeted (pPMSR) isoforms of the oxidative-stress-repair enzyme peptide methionine sulfoxide reductase. Overexpression of these proteins in Escherichia coli confirmed that each had PMSR enzyme activity with a synthetic substrate, N-acetyl-[(3)H]-methionine sul...

Diversity of Plant Methionine Sulfoxide Reductases B and Evolution of a Form Specific for Free Methionine Sulfoxide

Methionine can be reversibly oxidized to methionine sulfoxide (MetO) under physiological conditions. Organisms evolved two distinct methionine sulfoxide reductase families (MSRA & MSRB) to repair oxidized methionine residues. We found that 5 MSRB genes exist in the soybean genome, including GmMSRB1 and two segmentally duplicated gene pairs (GmMSRB2 and GmMSRB5, GmMSRB3 and GmMSRB4). GmMSRB2 and...

Methionine-r-sulfoxide Reductases and Biological Importance of Free Methionine Sulfoxide Reduction

Investigations into the role of the plastidial peptide methionine sulfoxide reductase in response to oxidative stress in Arabidopsis.

Peptidyl Met residues are readily oxidized by reactive oxygen species to form Met sulfoxide. The enzyme peptide Met sulfoxide reductase (PMSR) catalyzes the reduction of Met sulfoxides back to Met. In doing so, PMSR is proposed to act as a last-chance antioxidant, repairing proteins damaged from oxidative stress. To assess the role of this enzyme in plants, we generated multiple transgenic line...

Methionine sulfoxide reduction in mammals: characterization of methionine-R-sulfoxide reductases.

Methionine residues in proteins are susceptible to oxidation by reactive oxygen species, but can be repaired via reduction of the resulting methionine sulfoxides by methionine-S-sulfoxide reductase (MsrA) and methionine-R-sulfoxide reductase (MsrB). However, the identity of all methionine sulfoxide reductases involved, their cellular locations and relative contributions to the overall pathway a...