The uniqueness of the plant mitochondrial potassium channel

• Main Authors: Donato Pastore, Mario Soccio, Maura Nicoletta Laus, Daniela Trono
• Format: Article
• Language: English
• Published: Korean Society for Biochemistry and Molecular Biology 2013-08-01
• Series: BMB Reports
• Subjects: Chemiosmosis; Durum wheat; Mitochondrial potassium channel; Oxidative stress; Protonmotive force
• Online Access: http://bmbreports.org/jbmb/pdf.php?data=MTMxMDAyMTdAcGRmX3JhaW50cmFjZV9sZWV5c0AlNUI0Ni04JTVEMTMwOTEzMTUxMF8lMjgzOTEtMzk3JTI5Qk1CXzEzLTA3NSUyOCUyNiUyMzQ4MTIwJTNCJTI2JTIzNDU3NjglM0IlMjYlMjM0NzUzMiUzQiUyNiUyMzQ4NjI0JTNCJTI5LTEucGRm
• ISSN: 1976-6696; 1976-670X

The ATP-inhibited Plant Mitochondrial K+ Channel (PmitoKATP)was discovered about fifteen years ago in Durum WheatMitochondria (DWM). PmitoKATP catalyses the electrophoreticK+ uniport through the inner mitochondrial membrane;moreover, the co-operation between PmitoKATP and K+/H+antiporter allows such a great operation of a K+ cycle tocollapse mitochondrial membrane potential (ΔΨ) and ΔpH, thusimpairing protonmotive force (Δp). A possible physiological roleof such ΔΨ control is the restriction of harmful reactive oxygenspecies (ROS) production under environmental/oxidative stressconditions. Interestingly, DWM lacking Δp were found to benevertheless fully coupled and able to regularly accomplish ATPsynthesis; this unexpected behaviour makes necessary to recastin some way the classical chemiosmotic model. In the whole,PmitoKATP may oppose to large scale ROS production bylowering ΔΨ under environmental/oxidative stress, but, whenstress is moderate, this occurs without impairing ATP synthesisin a crucial moment for cell and mitochondrial bioenergetics.[BMB Reports 2013; 46(8): 391-397]