Activation of the potato plant uncoupling mitochondrial protein inhibits reactive oxygen species generation by the respiratory chain.
A variety of plant tissues contain an uncoupling mitochondrial protein (PUMP), recently described and characterized by our group. In this study we show that the inhibition of PUMP activity in potato tuber mitochondria significantly increases mitochondrial H2O2 generation, while PUMP substrates, such as linoleic acid, reduce mitochondrial H2O2 generation. This H2O2 generation occurred mainly by the dismutation of superoxide radicals formed through monoelectronic reduction of O2 by semiquinone forms of coenzyme Q. The results presented suggest that protection against mitochondrial oxidative stress may be a physiological role of PUMP.
Kowaltowski
A J
AJ
Departamento de Patologia Clinica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, SP, Brazil.
Costa
A D
AD
Vercesi
A E
AE
D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism*; D004579:Electron Transport; D006861:Hydrogen Peroxide / Q000378:metabolism; D007473:Ion Channels; D019787:Linoleic Acid / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D008565:Membrane Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism; D024101:Mitochondrial Proteins; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism / Q000494:pharmacology; D011198:Solanum tuberosum / Q000378:metabolism; D000071256:Uncoupling Protein 1
D002352:Carrier Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; D000071256:Uncoupling Protein 1; D012710:Serum Albumin, Bovine; D000255:Adenosine Triphosphate; D019787:Linoleic Acid; D006861:Hydrogen Peroxide; D002118:Calcium