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The Arabidopsis thaliana sulfiredoxin is a plastidic cysteine‐sulfinic acid reductase involved in the photooxidative stress response
Author(s) -
Rey Pascal,
Bécuwe Noëlle,
Barrault MarieBénédicte,
Rumeau Dominique,
Havaux Michel,
Biteau Benoît,
Toledano Michel B.
Publication year - 2007
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2006.02969.x
Subject(s) - arabidopsis thaliana , biochemistry , cysteine , arabidopsis , sulfinic acid , mutant , enzyme , chemistry , chloroplast , yeast , biology , gene , organic chemistry
Summary The 2‐cysteine peroxiredoxins (2‐Cys‐Prxs) are antioxidants that reduce peroxides through a thiol‐based mechanism. During catalysis, these ubiquitous enzymes are occasionally inactivated by the substrate‐dependent oxidation of the catalytic cysteine to the sulfinic acid (‐SO 2 H) form, and are reactivated by reduction by sulfiredoxin (Srx), an enzyme recently identified in yeast and in mammal cells. In plants, 2‐Cys‐Prxs constitute the most abundant Prxs and are located in chloroplasts. Here we have characterized the unique Srx gene in Arabidopsis thaliana ( AtSrx ) from a functional point of view, and analyzed the phenotype of two AtSrx knockout ( AtSrx –) mutant lines. AtSrx is a chloroplastic enzyme displaying sulfinic acid reductase activity, as shown by the ability of the recombinant AtSrx to reduce the overoxidized 2‐Cys‐Prx form in vitro , and by the accumulation of the overoxidized Prx in mutant lines lacking Srx in vivo . Furthermore, AtSrx mutants exhibit an increased tolerance to photooxidative stress generated by high light combined with low temperature. These data establish that, as in yeast and in mammals, plant 2‐Cys‐Prxs are subject to substrate‐mediated inactivation reversed by Srx, and suggest that the 2‐Cys‐Prx redox status and sulfiredoxin are parts of a signaling mechanism participating in plant responses to oxidative stress.