On-line measurements of oscillating mitochondrial membrane potential in glucose-fermenting Saccharomyces cerevisiae.
We employed the fluorescent cyanine dye DiOC(2)(3) to measure membrane potential in semi-anaerobic yeast cells under conditions where glycolysis was oscillating. Oscillations in glycolysis were studied by means of the naturally abundant nicotinamide adenine dinucleotide (NADH). We found that the mitochondrial membrane potential was oscillating, and that these oscillations displayed the same frequency and duration as the NADH oscillations. It was confirmed that DiOC(2)(3) localizes itself in the mitochondrial membrane and thus reports qualitative changes solely in mitochondrial membrane potential. Our studies showed that glycolytic oscillations perturb the mitochondrial membrane potential and that the mitochondria do not have any controlling effect on the dynamics of glycolysis under these conditions. Depolarization of the mitochondrial membrane by addition of FCCP quenched mitochondrial membrane potential oscillations and delocalized DiOC(2)(3), while glycolysis continued to oscillate unaffected.
Andersen
Ann Zahle
AZ
University of Southern Denmark, Department of Biochemistry and Molecular Biology, CelCom, Campusvej 55, 5230 Odense M, Denmark. zahle@bmb.sdu.dk
Poulsen
Allan K
AK
Brasen
Jens Christian
JC
Olsen
Lars Folke
LF
D001683:Biological Clocks / Q000187:drug effects / Q000502:physiology; D002232:Carbocyanines / Q000737:chemistry; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000737:chemistry; D006019:Glycolysis; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects / Q000502:physiology*; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D009243:NAD / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D014475:Uncoupling Agents / Q000494:pharmacology
D002232:Carbocyanines; D005456:Fluorescent Dyes; D014475:Uncoupling Agents; D009243:NAD; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; C081554:3,3'-diethyloxacarbocyanine