title: Quinones in long-lived clk-1 mutants of Caenorhabditis elegans.
abstract: Ubiquinone (UQ) (coenzyme Q) is a lipophilic redox-active molecule that functions as an electron carrier in the mitochondrial electron transport chain. Electron transfer via UQ involves the formation of semiubiquinone radicals, which causes the generation of superoxide radicals upon reaction with oxygen. In the reduced form, UQ functions as a lipid-soluble antioxidant, and protects cells from lipid peroxidation. Thus, UQ is also important as a lipophilic regulator of oxidative stress. Recently, a study on long-lived clk-1 mutants of Caenorhabditis elegans demonstrated that biosynthesis of UQ is dramatically altered in mutant mitochondria. Demethoxy ubiquinone (DMQ), that accumulates in clk-1 mutants in place of UQ, may contribute to the extension of life span. Here we elucidate the possible mechanisms of life span extension in clk-1 mutants, with particular emphasis on the electrochemical property of DMQ. Recent findings on the biochemical function of CLK-1 are also discussed.
authors.affiliation: Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-0033, Tokyo, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Miyadera
authors.forename: Kenji
authors.initials: K
authors.lastname: Kano
authors.forename: Hideto
authors.initials: H
authors.lastname: Miyoshi
authors.forename: Naoaki
authors.initials: N
authors.lastname: Ishii
authors.forename: Siegfried
authors.initials: S
authors.lastname: Hekimi
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kita
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins / Q000235:genetics*; D008954:Models, Biological; D009154:Mutation; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000378:metabolism*
chemical_list: C104339:CLK-1 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; D014451:Ubiquinone; C000866:5-demethoxyubiquinone-9