A highly active ATP-insensitive K+ import pathway in plant mitochondria.
We describe here a regulated and highly active K+ uptake pathway in potato (Solanum tuberosum), tomato (Lycopersicon esculentum), and maize (Zea mays) mitochondria. K+ transport was not inhibited by ATP, NADH, or thiol reagents, which regulate ATP-sensitive K+ channels previously described in plant and mammalian mitochondria. However, K+ uptake was completely prevented by quinine, a broad spectrum K+ channel inhibitor. Increased K+ uptake in plants leads to mitochondrial swelling, respiratory stimulation, heat release, and the prevention of reactive oxygen species formation. This newly described ATP-insensitive K+ import pathway is potentially involved in metabolism regulation and prevention of oxidative stress.
Ruy
Fernando
F
Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brazil.
Vercesi
Anibal E
AE
Andrade
Paula B M
PB
Bianconi
M Lucia
ML
Chaimovich
Hernan
H
Kowaltowski
Alicia J
AJ
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D018551:Solanum lycopersicum / Q000187:drug effects / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010940:Plant Proteins / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D011803:Quinine / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D011198:Solanum tuberosum / Q000187:drug effects / Q000378:metabolism*; D003313:Zea mays / Q000187:drug effects / Q000378:metabolism*
D010940:Plant Proteins; D015221:Potassium Channels; D000255:Adenosine Triphosphate; D011803:Quinine; D011188:Potassium