Fatty acid-mediated uncoupling of potato tuber mitochondria.
The present work examined whether the ATP/ADP carrier, other than the plant uncoupling mitochondrial protein, participates in free fatty acid-mediated uncoupling of potato tuber mitochondria. The basal respiration rate of succinate-energized mitochondria was stimulated by a low concentration of palmitate (20 microM). This uncoupling was reversed by 10 microM carboxyatractyloside and by the subsequent addition of 0.1% bovine serum albumin. The decrease in membrane potential caused by palmitate was suppressed by carboxyatractyloside (1 microM) and, to a lesser degree, by bongkrekate (20 microM). GTP could also reversed this decrease via a carboxyatractyloside-independent mechanism. These results indicate that the ATP/ADP carrier, along with the plant uncoupling mitochondrial protein, participates in the protonophoric action of palmitate in potato tuber mitochondria.
Saviani
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Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, SP, CEP, Brazil.
Martins
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D001278:Atractyloside / Q000031:analogs & derivatives / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism / Q000502:physiology; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D007425:Intracellular Membranes / Q000187:drug effects / Q000502:physiology; D007473:Ion Channels; D008564:Membrane Potentials / Q000187:drug effects; D008565:Membrane Proteins / Q000378:metabolism / Q000502:physiology; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D024101:Mitochondrial Proteins; D010101:Oxygen Consumption / Q000187:drug effects; D010168:Palmitates / Q000494:pharmacology; D010940:Plant Proteins / Q000378:metabolism / Q000502:physiology; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D011198:Solanum tuberosum / Q000187:drug effects / Q000378:metabolism*; D013386:Succinates / Q000494:pharmacology; D000071256:Uncoupling Protein 1
C037688:ADP-ATP carrier receptor; D002352:Carrier Proteins; D005230:Fatty Acids, Nonesterified; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D010168:Palmitates; D010940:Plant Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D013386:Succinates; D000071256:Uncoupling Protein 1; D001278:Atractyloside; D012710:Serum Albumin, Bovine; C003853:carboxyatractyloside