title: Expression of uncoupling protein and alternative oxidase depends on lipid or carbohydrate substrates in thermogenic plants.
abstract: Thermogenesis, in which cellular respiratory activity is considerably stimulated, requires mitochondrial uncoupling protein (UCP) in mammals and an alternative oxidase (AOX) in plants. Here, we show that the genes for both proteins are expressed in thermogenic plants, but the type correlates with the respiratory substrate. A novel gene termed PsUCPa encoding a variant of UCP was specifically expressed in thermogenic flowers of Philodendron selloum, which uses lipids as substrates. However, a gene termed DvAOX encoding for AOX protein was expressed in thermogenic flowers of Dracunculus vulgaris, which presumably uses carbohydrates as substrates. These findings suggest that cellular metabolism is a major determinant in selective expression of appropriate thermogenic genes in plants.
authors.affiliation: Faculty of Agriculture, Iwate University Cryobiosystem Research Centre Ueda 3-18-8, Morioka, Iwate 020-8550, Japan. kikuito@iwate-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Ito
authors.forename: R S
authors.initials: RS
authors.lastname: Seymour
mesh_terms: D029064:Araceae / Q000235:genetics / Q000378:metabolism*; D002151:Calorimetry; D050260:Carbohydrate Metabolism; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism*; D050356:Lipid Metabolism; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D031062:Philodendron / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins; D013696:Temperature; D000071256:Uncoupling Protein 1; D000099188:Alternative Oxidase
chemical_list: D007473:Ion Channels; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010940:Plant Proteins; D000071256:Uncoupling Protein 1; D000099188:Alternative Oxidase