Differential efflux of mitochondrial endonuclease G by hNoxa and tBid.
The Bcl-2 family of proteins regulates mitochondrial functions during cell death by modulating the efflux of death-promoting proteins such as cytochrome c and endonuclease G. Upon the binding of death ligands to their receptors, caspase-8 cleaves Bid, a BH3-only protein, into tBid that causes the mitochondrial damages resulting in the release of cytochrome c and endonuclease G. Also, another BH3-only protein, hNoxa, has been shown to induce the efflux of cytochrome c from the mitochondria. Whether the efflux proteins from the mitochondria in response to tBid or hNoxa are the same or different, however, has not been addressed. We have demonstrated that endonuclease G activities are not detectable among the proteins released from isolated mitochondria by hNoxa but are detectable in that by tBid. These results suggest that the efflux of proteins from the mitochondria are differentially modulated by tBid and hNoxa.
Seo
Young Woo
YW
Department of Biochemistry and Molecular Biology, Chosun University School of Medicine, Dong-Gu, Gwangju, 501-759, Korea.
Park
Sun Young
SY
Yun
Cheol-Won
CW
Kim
Tae-Hyoung
TH
D000818:Animals; D051023:BH3 Interacting Domain Death Agonist Protein / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D015153:Blotting, Western; D045304:Cytochromes c / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000166:cytology; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism
D051023:BH3 Interacting Domain Death Agonist Protein; D024101:Mitochondrial Proteins; C498702:PMAIP1 protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D045304:Cytochromes c; D004706:Endodeoxyribonucleases; C052391:endonuclease G