Functional characterization of the Aspergillus nidulans methionine sulfoxide reductases (msrA and msrB).
Proteins are subject to modification by reactive oxygen species (ROS), and oxidation of specific amino acid residues can impair their biological function, leading to an alteration in cellular homeostasis. Sulfur-containing amino acids as methionine are the most vulnerable to oxidation by ROS, resulting in the formation of methionine sulfoxide [Met(O)] residues. This modification can be repaired by methionine sulfoxide reductases (Msr). Two distinct classes of these enzymes, MsrA and MsrB, which selectively reduce the two methionine sulfoxide epimers, methionine-S-sulfoxide and methionine-R-sulfoxide, respectively, are found in virtually all organisms. Here, we describe the homologs of methionine sulfoxide reductases, msrA and msrB, in the filamentous fungus Aspergillus nidulans. Both single and double inactivation mutants were viable, but more sensitive to oxidative stress agents as hydrogen peroxide, paraquat, and ultraviolet light. These strains also accumulated more carbonylated proteins when exposed to hydrogen peroxide indicating that MsrA and MsrB are active players in the protection of the cellular proteins from oxidative stress damage.
Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Ribeirão Preto, Brazil.
Frederico Marianetti
FM
Soriani
Marcia Regina
MR
Kress
Paula
P
Fagundes de Gouvêa
Iran
I
Malavazi
Marcela
M
Savoldi
Andreas
A
Gallmetzer
Joseph
J
Strauss
Maria Helena S
MH
Goldman
Gustavo Henrique
GH
Goldman
D001233:Aspergillus nidulans / Q000187:drug effects / Q000201:enzymology* / Q000528:radiation effects; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D051150:Methionine Sulfoxide Reductases; D050296:Microbial Viability; D016877:Oxidants / Q000633:toxicity; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010269:Paraquat / Q000633:toxicity; D050050:Protein Carbonylation; D014466:Ultraviolet Rays
D005656:Fungal Proteins; D016877:Oxidants; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D051150:Methionine Sulfoxide Reductases; C027219:methionine sulfoxide reductase; D010269:Paraquat