Release of cytochrome c and decrease of cytochrome c oxidase in Bax-expressing yeast cells, and prevention of these effects by coexpression of Bcl-xL.
The characteristics of mitochondria of yeast cells expressing the pro-apoptotic gene Bax or coexpressing Bax and the anti-apoptotic gene Bcl-xL have been investigated in whole cells, isolated mitochondria and permeabilized spheroplasts. It is found that Bax-induced growth arrest of yeast cells is related to two defects in the respiratory chain: (i) a decrease in the amount of cytochrome c oxidase, the terminal enzyme of the respiratory chain, and (ii) a dramatic increase in the release of cytochrome c to the cytosol. Other components of the inner mitochondrial membrane (bc1 complex and F0F1-ATPase) are unaffected. Coexpression of Bcl-xL almost fully prevented the effect of Bax. Surprisingly, these results obtained in yeast parallel similar observations reported in mammalian cells.
Manon
S
S
Institut de Biochimie et de Génétique Cellulaire du Centre National de la Recherche Scientifique, Université Victor Ségalen-Bordeaux II, France. stephen.manon@ibgc.u-bordeaux2.fr
Chaudhuri
B
B
Guérin
M
M
D017209:Apoptosis; D017936:Cytochrome a Group / Q000378:metabolism; D003574:Cytochrome c Group / Q000378:metabolism*; D003576:Electron Transport Complex IV / Q000378:metabolism*; D004734:Energy Metabolism; D005690:Galactose / Q000378:metabolism; D015870:Gene Expression; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D006180:Proton-Translocating ATPases / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*; D013053:Spectrophotometry; D013104:Spheroplasts / Q000378:metabolism; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein
D017936:Cytochrome a Group; D003574:Cytochrome c Group; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; D003576:Electron Transport Complex IV; D006180:Proton-Translocating ATPases; D005690:Galactose