title: Simultaneous determination of in vivo plastoquinone and ubiquinone redox states by HPLC-based analysis.
abstract: For a better understanding of the metabolic interaction between chloroplasts and mitochondria, it is important to analyze the in vivo redox states of the electron transport chains in both organelles at the same time. For this purpose, we devised an HPLC-based measurement system simultaneously analyzing plastoquinone (PQ) and ubiquinone (UQ) contents and redox states. Using this system, we discovered that, in addition to PQ, the reduction levels of UQ were elevated under high-light conditions. We also provide direct evidence that mitochondrial alternative oxidase contributes to alleviate UQ over-reduction under such conditions.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan. yoshida.k.ao@m.titech.ac.jp
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yoshida
authors.forename: Masaru
authors.initials: M
authors.lastname: Shibata
authors.forename: Ichiro
authors.initials: I
authors.lastname: Terashima
authors.forename: Ko
authors.initials: K
authors.lastname: Noguchi
mesh_terms: D017360:Arabidopsis / Q000737:chemistry* / Q000201:enzymology; D002736:Chloroplasts / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D008027:Light; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism; D010940:Plant Proteins; D010971:Plastoquinone / Q000032:analysis*; D014451:Ubiquinone / Q000032:analysis*; D000099188:Alternative Oxidase
chemical_list: D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010940:Plant Proteins; D010971:Plastoquinone; D014451:Ubiquinone; D000099188:Alternative Oxidase