gamma-glutamyl transpeptidase in transgenic tobacco plants. Cellular localization, processing, and biochemical properties
Storozhenko, S × Belles-Boix, E Babiychuk, E Herouart, D Davey, Mark Slooten, L Van Montagu, M Inze, D Kushnir, S #
Amer soc plant biologists
Plant physiology vol:128 issue:3 pages:1109-1119
gamma-Glutamyl transpeptidase (gamma-GT) is a ubiquitous enzyme that catalyzes the first step of glutathione (GSH) degradation in the gamma-glutamyl cycle in mammals. A cDNA encoding an Arabidopsis homolog for gamma-GT was overexpressed in tobacco (Nicotiona tabacum) plants. A high level of the membrane-bound gamma-GT activity was localized outside the cell in transgenic plants. The overproduced enzyme was characterized by a high affinity to GSH and was cleaved post-translationally in two unequal subunits. Thus, Arabidopsis gamma-GT is similar to the mammalian enzymes in enzymatic properties, post-translational processing, and cellular localization, suggesting analogous biological functions as a key enzyme in the catabolism of GSH.