The ATP-induced K(+)-transport pathway of yeast mitochondria may function as an uncoupling pathway.

The effect of the presence of K+ during oxidative phosphorylation measured on isolated yeast mitochondria was dependent on phosphate concentration. At 0.5 mM phosphate, K+ did promote an uncoupling of oxidative phosphorylation, which was prevented by decavanadate, a potent inhibitor of the ATP-induced K(+)-transport pathway. AT 5 mM phosphate, no uncoupling effect of K+ could be evidenced. These data suggest that the ATP-induced K(+)-transport pathway may, under certain conditions, function as an uncoupling pathway of oxidative phosphorylation.