1. Pyruvate-sensitive AOX exists as a non-covalently associated dimer in the homeothermic spadix of the skunk cabbage, Symplocarpus renifolius
- Author
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Yukie Abe, Yoshihiko Onda, Hiroyuki Koiwa, Kazushige Matsukawa, Yasuko Ito-Inaba, Minoru Otsuka, Takanori Ito, Miyuki Morohashi, Yoshiaki Kato, Kikukatsu Ito, Megumi Ichikawa, and Yuka Ito
- Subjects
Thermogenic plants ,Pyruvate ,Alternative oxidase ,Dimer ,Blotting, Western ,Cell Respiration ,Molecular Sequence Data ,Submitochondrial Particles ,Biophysics ,Carboxylic Acids ,Flowers ,Mitochondrion ,Biochemistry ,Dithiothreitol ,Mitochondrial Proteins ,chemistry.chemical_compound ,Structural Biology ,Gene Expression Regulation, Plant ,biology.animal ,Pyruvic Acid ,Genetics ,Homeothermy ,Araceae ,Amino Acid Sequence ,RNA, Messenger ,Molecular Biology ,Gene ,Plant Proteins ,Diamide ,Skunk cabbage ,biology ,Respiration ,Temperature ,Cell Biology ,NAD ,humanities ,Mitochondria ,chemistry ,Ketoglutaric Acids ,Spadix (botany) ,Skunk ,Oxidoreductases ,Dimerization ,Oxidation-Reduction - Abstract
The cyanide-resistant alternative oxidase (AOX) is a homodimeric protein whose activity can be regulated by the oxidation/reduction state and by α-keto acids. To further clarify the role of AOX in the skunk cabbage, Symplocarpus renifolius, we have performed expression and functional analyses of the encoding gene. Among the various tissues in the skunk cabbage, SrAOX transcripts were found to be specifically expressed in the thermogenic spadix. Moreover, our data demonstrate that the SrAOX protein exists as a non-covalently associated dimer in the thermogenic spadix, and is more sensitive to pyruvate than to other carboxylic acids. Our results suggest that the pyruvate-mediated modification of SrAOX activity plays a significant role in thermoregulation in the skunk cabbage.
- Published
- 2007