Loss of function of cytochrome c in Jurkat cells undergoing fas-mediated apoptosis.
Mitochondrial function was examined in Jurkat cells undergoing Fas-mediated apoptosis. With succinate or ascorbate/tetramethylphenylenediamine as substrate, oxygen uptake by digitonin-permeabilized apoptotic mitochondria was greatly decreased as compared with control. Assessment of the function of the cytochrome c-cytochrome oxidase segment of the electron transport chain of apoptotic mitochondria showed that the activity of cytochrome oxidase appeared to be normal, but that of cytochrome c was greatly diminished. A death protease was found to participate in the events leading to the loss of cytochrome c activity, but the cytochrome did not seem to be extensively degraded during the course of apoptosis. Our results suggest that a rapid loss in mitochondrial function due at least in part to the inhibition or inactivation of cytochrome c is a potentially fatal component of the apoptosis program of Jurkat cells.
Krippner
A
A
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA.
Matsuno-Yagi
A
A
Gottlieb
R A
RA
Babior
B M
BM
D017209:Apoptosis / Q000276:immunology*; D002460:Cell Line; D003574:Cytochrome c Group / Q000037:antagonists & inhibitors*; D004579:Electron Transport; D010450:Endopeptidases / Q000378:metabolism; D004789:Enzyme Activation; D006801:Humans; D008564:Membrane Potentials / Q000276:immunology; D008928:Mitochondria / Q000201:enzymology / Q000502:physiology; D019014:fas Receptor / Q000502:physiology*
D003574:Cytochrome c Group; D019014:fas Receptor; D010450:Endopeptidases