Induction and functional analysis of two reduced nicotinamide adenine dinucleotide phosphate-dependent glutathione peroxidase-like proteins in Synechocystis PCC 6803 during the progression of oxidative stress.
Synechocystis PCC 6803 contains two types of glutathione peroxidase-like proteins (GPX-1 and GPX-2) that utilize NADPH but not reduced glutathione and unsaturated fatty acid hydroperoxides or alkyl hydroperoxides. The steady-state transcript level of gpx-1 gradually increased under oxidative stress conditions imposed by high light intensity, high salinity, or application of methylviologen or t-butyl hydroperoxide in the wild-type and GPX-2 knock-out mutant (gpx-2Delta) cells. To examine the ability of GPX-1, GPX-2, and thioredoxin peroxidase to scavenge lipid hydroperoxide in vivo, we measured the photosynthetic evolution of O(2) and the level of lipid peroxidation in the wild-type and each type of mutant cell after the application of t-butyl hydroperoxide or H(2)O(2). The data reported here indicate that GPX-1 and GPX-2 are essential for the removal of lipid hydroperoxides under normal and stress conditions, leading to the protection of membrane integrity.
Gaber
Ahmed
A
Department of Applied Biological Chemistry, Osaka Prefecture University, Sakai 599-8531, Japan.
Yoshimura
Kazuya
K
Tamoi
Masahiro
M
Takeda
Toru
T
Nakano
Yoshihisa
Y
Shigeoka
Shigeru
S
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D018390:Gene Targeting; D005798:Genes, Bacterial; D005979:Glutathione Peroxidase / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D015227:Lipid Peroxidation; D008969:Molecular Sequence Data; D009154:Mutation; D009249:NADP / Q000378:metabolism; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D046939:Synechocystis / Q000235:genetics / Q000378:metabolism*; D000094765:Glutathione Peroxidase GPX1
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D007527:Isoenzymes; D009249:NADP; D005979:Glutathione Peroxidase; D010100:Oxygen; D000094765:Glutathione Peroxidase GPX1