The role of hexokinase as a possible modulator of Ca2+ movements in isolated rat brain mitochondria.
The present study shows that in brain mitochondria the active calcium uptake and the sodium-dependent calcium efflux are modulated by the porin-bound enzyme hexokinase. The release of the enzyme, promoted by glucose-6-phosphate (G-6-P), under conditions which do not affect mitochondrial functions, is accompanied by a decrease of the rates of fluxes of the cation. This phenomenon is discussed and correlated with the formation of microcompartments between the inner and outer mitochondrial membranes, where the hexokinase-porin complex may constitute a regulating gate system for calcium.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001921:Brain / Q000201:enzymology*; D002118:Calcium / Q000378:metabolism*; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000494:pharmacology; D006593:Hexokinase / Q000502:physiology*; D007700:Kinetics; D008297:Male; D008565:Membrane Proteins / Q000502:physiology; D008928:Mitochondria / Q000201:enzymology; D018272:Porins; D051381:Rats; D012964:Sodium / Q000494:pharmacology; D050994:Voltage-Dependent Anion Channels
D005958:Glucosephosphates; D008565:Membrane Proteins; D018272:Porins; D050994:Voltage-Dependent Anion Channels; D019298:Glucose-6-Phosphate; D012964:Sodium; D006593:Hexokinase; D002118:Calcium