Redox-regulation of the expression of the peroxide-detoxifying chloroplast 2-cys peroxiredoxin in the liverwort Riccia fluitans.
2-Cys peroxiredoxins (2-CPs) are H2O2- and alkyl hydroperoxide-detoxifying enzymes, and occur in animals, fungi, bacteria and higher plants. Here, the cDNA encoding a peroxiredoxin of a multicellular cryptogamic plant was first cloned from the liverwort Riccia fluitans L., and the dependence of its expression on the cellular redox state was analysed. The presence of an N-terminal targeting signal indicates that, like 2-CPs from higher plants, Riccia 2-CP is posttranslationally imported into chloroplasts. Addition of ascorbate and other reductants suppressed 2-CP gene expression and decreased 2-CP protein levels. With ascorbate, the decrease in 2-CP transcript level was fast, concentration dependent, and correlated with the amounts of ascorbate taken up by the tissue. In an approach to identify signaling components, staurosporine was proved to be a highly potent inhibitor of ascorbate-dependent repression of 2-CP-expression. The staurosporine effect indicates that a serine/threonine-kinase is involved in ascorbate-modulated redox regulation of 2-CP expression.
Horling
F
F
Department of Physiology and Biochemistry of Plants, Universität Bielefeld, Germany.
Baier
M
M
Dietz
K J
KJ
D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins; D001205:Ascorbic Acid / Q000494:pharmacology; D015153:Blotting, Western; D002736:Chloroplasts / Q000378:metabolism; D003001:Cloning, Molecular; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005978:Glutathione / Q000494:pharmacology; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D054464:Peroxiredoxins; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D010944:Plants / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D029681:Arabidopsis Proteins; D010940:Plant Proteins; D010544:Peroxidases; C108214:BAS1 protein, Arabidopsis; D054464:Peroxiredoxins; D005978:Glutathione; D001205:Ascorbic Acid