title: Glutathione peroxidases as redox sensor proteins in plant cells.
abstract: Glutathione peroxidases are thiol-based enzymes that catalyze the reduction of H2O2 and hydroperoxides to H2O or alcohols, they mitigate the toxicity of these compounds to the cell mainly using thioredoxin as an electron donor. Additionally, certain redox sensor and signaling functions are being ascribed to these enzymes in prokaryotes, fungi, and plants. We review the evolutionary history, enzymatic and biochemical evidence that make GPX proteins, in addition to being peroxiredoxins, important candidates for acting as redox sensor proteins in plants: (i) the lower peroxidase activity of Cys-GPX; (ii) the thiol catalytic center; (iii) the capacity to interact with regulatory proteins. All these characteristics suggest that at the basal level, plant GPXs have an important role in redox signal transduction in addition to their peroxidase activity.
authors: Department of Genetics, Federal University of Rio Grande do Sul, RS, Brazil.
authors: Gisele
authors: G
authors: Passaia
authors: Department of Genetics, Federal University of Rio Grande do Sul, RS, Brazil. Electronic address: marcia.margis@ufrgs.br.
authors: Márcia
authors: M
authors: Margis-Pinheiro
mesh_terms: D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D054464:Peroxiredoxins / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D013879:Thioredoxins / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D013879:Thioredoxins; D006861:Hydrogen Peroxide; D054464:Peroxiredoxins; D005979:Glutathione Peroxidase; D005978:Glutathione
keywords: Glutathione peroxidases; Oxidative stress; Reactive oxygen species; Redox regulation; Redox signaling