The Mitochondrial Permeability Transition in Saccharomyces Cerevisiae is Controlled by Hexose Phosphates from the Glycolytic Pathway

Abstract

S. cerevisiae is a "Crabtree positive yeast" The "Crabtree effect" is the decrease in oxygen consumption in response to glucose and involves competition between glycolysis and oxidative phosphorylation for ADP and/or Pi. Mitochondrial activity modification by glucose-6-phosphate (G6P), fructose-6-phosphate (F6P) and fructose-1,6-bisphosphate (F1,6BP) appears to be important for the induction of this effect. F1,6BP inhibits the activity of mitochondrial complex III and IV, while is activated by F6P and G6P (Diaz-Ruiz et al. (2008) J Biol Chem, 283, 40, 26948-55). Mitochondrial activity in S. cerevisiae may also be affected by the permeability transition which might be a reversible physiological response mediated by a permeability transition pore (PTP) regulated by cations, ADP, ATP and Pi. In isolated mitochondria from S. cerevisiae we studied the effect of hexoses phosphate on the permeability transition. It was observed that F1,6BP acted as an oxidative phosphorylation coupling agent, while G6P was an uncoupler. It is suggested that the glycolytic intermediaries G6P and F1, 6BP are signals for the communication between glycolysis and oxidative phosphorylation promoting the Crabtree effect.