Apoptosis repressor with caspase recruitment domain protects against cell death by interfering with Bax activation.
Myocardial ischemia/reperfusion (I/R) is associated with an extensive loss of myocardial cells. The apoptosis repressor with caspase recruitment domain (ARC) is a protein that is highly expressed in heart and skeletal muscle and has been demonstrated to protect the heart against I/R injury (Gustafsson, A. B., Sayen, M. R., Williams, S. D., Crow, M. T., and Gottlieb, R. A. (2002) Circulation 106, 735-739). In this study, we have shown that transduction of TAT-ARCL31F, a mutant of ARC in the caspase recruitment domain, did not reduce creatine kinase release and infarct size after I/R. TAT-ARCL31F also failed to protect against hydrogen peroxide-mediated cell death in H9c2 cells, suggesting that the caspase recruitment domain is important in mediating ARC's protective effects. In addition, we report that ARC co-immunoprecipitated with the pro-apoptotic protein Bax, which causes cytochrome c release when activated. TAT-ARC, but not TAT-ARCL31F, prevented Bax activation and cytochrome c release in hydrogen peroxide-treated H9c2 cells. TAT-ARC was also effective in blocking cytochrome c release after ischemia and reperfusion, whereas TAT-ARCL31F had no effect on cytochrome c release. In addition, recombinant ARC protein abrogated Bax-induced cytochrome c release from isolated mitochondria. This suggests that ARC can protect against cell death by interfering with activation of the mitochondrial death pathway through the interaction with Bax, preventing mitochondrial dysfunction and release of pro-apoptotic factors.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.
Asa B
AB
Gustafsson
Joseph G
JG
Tsai
Susan E
SE
Logue
Michael T
MT
Crow
Roberta A
RA
Gottlieb
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins; D061945:Caspase Inhibitors; D016923:Cell Death / Q000502:physiology*; D002460:Cell Line; D003402:Creatine Kinase / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism*; D009203:Myocardial Infarction / Q000201:enzymology / Q000517:prevention & control; D009206:Myocardium / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D051028:bcl-2-Associated X Protein
D051017:Apoptosis Regulatory Proteins; C494828:Bax protein, rat; D061945:Caspase Inhibitors; D009124:Muscle Proteins; C491788:Nol3 protein, rat; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011993:Recombinant Fusion Proteins; D051028:bcl-2-Associated X Protein; D045304:Cytochromes c; D003402:Creatine Kinase