title: Overexpression of glutamate-cysteine ligase extends life span in Drosophila melanogaster.
abstract: The hypothesis that overexpression of glutamate-cysteine ligase (GCL), which catalyzes the rate-limiting reaction in de novo glutathione biosynthesis, could extend life span was tested in the fruit fly, Drosophila melanogaster. The GAL4-UAS binary transgenic system was used to generate flies overexpressing either the catalytic (GCLc) or modulatory (GCLm) subunit of this enzyme, in a global or neuronally targeted pattern. The GCL protein content of the central nervous system was elevated dramatically in the presence of either global or neuronal drivers. GCL activity was increased in the whole body or in heads, respectively, of GCLc transgenic flies containing global or neuronal drivers. The glutathione content of fly homogenates was increased by overexpression of GCLc or GCLm, particularly in flies overexpressing either subunit globally, or in the heads of GCLc flies possessing neuronal drivers. Neuronal overexpression of GCLc in a long-lived background extended mean and maximum life spans up to 50%, without affecting the rate of oxygen consumption by the flies. In contrast, global overexpression of GCLm extended the mean life span only up to 24%. These results demonstrate that enhancement of the glutathione biosynthetic capability, particularly in neuronal tissues, can extend the life span of flies, and thus support the oxidative stress hypothesis of aging.
authors.affiliation: Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275, USA. borr@smu.edu
authors.forename: William C
authors.initials: WC
authors.lastname: Orr
authors.forename: Svetlana N
authors.initials: SN
authors.lastname: Radyuk
authors.forename: Leena
authors.initials: L
authors.lastname: Prabhudesai
authors.forename: Dikran
authors.initials: D
authors.lastname: Toroser
authors.forename: Judith J
authors.initials: JJ
authors.lastname: Benes
authors.forename: James M
authors.initials: JM
authors.lastname: Luchak
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Mockett
authors.forename: Igor
authors.initials: I
authors.lastname: Rebrin
authors.forename: J Gregory
authors.initials: JG
authors.lastname: Hubbard
authors.forename: Rajindar S
authors.initials: RS
authors.lastname: Sohal
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression; D005721:Glutamate-Cysteine Ligase / Q000235:genetics* / Q000378:metabolism*; D006861:Hydrogen Peroxide; D008136:Longevity / Q000235:genetics; D009474:Neurons / Q000201:enzymology; D030781:Organisms, Genetically Modified; D018384:Oxidative Stress; D010101:Oxygen Consumption; D010269:Paraquat; D021122:Protein Subunits / Q000235:genetics
chemical_list: D021122:Protein Subunits; D006861:Hydrogen Peroxide; D005721:Glutamate-Cysteine Ligase; D010269:Paraquat