title: Effects of overexpression of mitochondrial transcription factor A on lifespan and oxidative stress response in Drosophila melanogaster.
abstract: Mitochondrial transcription factor A (TFAM) plays a role in the maintenance of mitochondrial DNA (mtDNA) by packaging mtDNA, forming the mitochondrial nucleoid. There have been many reports about a function of TFAM at the cellular level, but only a few studies have been done in individual organisms. Here we examined the effects of TFAM on the Drosophila lifespan and oxidative stress response, by overexpressing TFAM using the GAL4/UAS system. Under standard conditions, the lifespan of TFAM-overexpressing flies was shorter than that of the control flies. However, the lifespan of TFAM-overexpressing flies was longer when they were treated with 1% H(2)O(2). These results suggest that even though excess TFAM has a negative influence on lifespan, it has a defensive function under strong oxidative stress. In the TFAM-overexpressing flies, no significant changes in mtDNA copy number or mtDNA transcription were observed. However, the results of a total antioxidant activity assay suggest the possibility that TFAM is involved in the elimination of oxidative stress. The present results clearly show the effects of TFAM overexpression on the lifespan of Drosophila under both standard conditions and oxidative stress conditions, and our findings contribute to the understanding of the physiological mechanisms involving TFAM in mitochondria.
authors.affiliation: Department of Biological Sciences, Graduate School of Humanities and Sciences, Ochanomizu University, Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Matsuda
authors.forename: Tomotake
authors.initials: T
authors.lastname: Kanki
authors.forename: Teiichi
authors.initials: T
authors.lastname: Tanimura
authors.forename: Dongchon
authors.initials: D
authors.lastname: Kang
authors.forename: Etsuko T
authors.initials: ET
authors.lastname: Matsuura
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D029721:Drosophila Proteins / Q000096:biosynthesis* / Q000235:genetics; D004331:Drosophila melanogaster / Q000378:metabolism / Q000502:physiology*; D008136:Longevity; D008928:Mitochondria / Q000378:metabolism; D018384:Oxidative Stress; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D029721:Drosophila Proteins; C489029:TFAM protein, Drosophila; D014157:Transcription Factors