MAC, The Mitochondrial Apoptosis-induced Channel

MAC, the mitochondrial apoptosis-induced channel, is an early marker of the onset of the form of programmed cell death in mammals called apoptosiscite journal | author= Evgeny V. Pavlov, Muriel Priault, Dawn Pietkiewicz, Emily H.-Y. Cheng, Bruno Antonsson, Stephen Manon, Stanley J. Korsmeyer, Carmen A. Mannella, and Kathleen W. Kinnally | title= A novel, high conductance channel of mitochondria linked to apoptosis in mammalian cells and Bax expression in yeast. | journal= J. Cell Biol. | year=2001| volume=155 | page=725-732| url=http://www.jcb.org/cgi/content/full/155/5/725] cite journal | author= Liang Guo, Dawn Pietkiewicz, Evgeny V. Pavlov, Sergey M. Grigoriev, John J. Kasianowicz, Laurent M. Dejean, Stanley J. Korsmeyer, Bruno Antonsson, and Kathleen W. Kinnally | title= Effects of cytochrome c on the mitochondrial apoptosis-induced channel MAC. | journal= Am. J. Physiol. Cell. Physiol. | year=2004| volume=286 | page= C1109-C1117| url= http://ajpcell.physiology.org/cgi/content/full/286/5/C1109] . This ion channel is formed on the outer mitochondrial membrane in response to certain apoptotic stimulicite journal | author=Laurent M. Dejean, Sonia Martinez-Caballero, Kathleen W. Kinnally| title=Is MAC the knife that cuts cytochrome c from mitochondria during apoptosis? | journal=Cell Death and Differentiation| year=2006| volume=13| page=1387–1395| url=http://www.nature.com/cdd/journal/v13/n8/full/4401949a.html] . MAC activity is detected by patch clamping mitochondria from apoptotic cells at the time of cytochrome c releasecite journal | author= Laurent M. Dejean, Sonia Martinez-Caballero, Liang Guo, Cynthia Hughes, Oscar Teijido, Thomas Ducret, François Ichas, Stanley J. Korsmeyer, Bruno Antonsson, Elizabeth A. Jonas, and Kathleen W. Kinnally | title= Oligomeric Bax Is a Component of the Putative Cytochrome c Release Channel MAC, Mitochondrial Apoptosis-induced Channel. | journal= Mol. Biol. Cell | year=2005| volume=16 | page= 2424-2432| url= http://www.molbiolcell.org/cgi/content/full/16/5/2424] .

Members of the Bcl-2 protein family regulate apoptosis by controlling the formation of MAC: the pro-apoptotic members Bax and/or Bak form MACcite journal | author= Laurent M. Dejean, Sonia Martinez-Caballero, Liang Guo, Cynthia Hughes, Oscar Teijido, Thomas Ducret, François Ichas, Stanley J. Korsmeyer, Bruno Antonsson, Elizabeth A. Jonas, and Kathleen W. Kinnally | title= Oligomeric Bax Is a Component of the Putative Cytochrome c Release Channel MAC, Mitochondrial Apoptosis-induced Channel. | journal= Mol. Biol. Cell | year=2005| volume=16 | page= 2424-2432| url= http://www.molbiolcell.org/cgi/content/full/16/5/2424] cite journal | author=Laurent M. Dejean, Sonia Martinez-Caballero, Stephen Manon, Kathleen W. Kinnally| title=Regulation of the mitochondrial apoptosis-induced channel, MAC, by BCL-2 family proteins. | journal=Biochim Biophys Acta| year=2006| volume=1762| issue=2| page=191-201| url=http://www.ncbi.nlm.nih.gov/pubmed/16055309] , whereas the anti-apoptotic members like Bcl-2 or Bcl-xL prevent MAC formation. Once formed, MAC mediates the release of cytochrome c to the cytosol, triggering the commitment step of the mitochondrial apoptotic cascade.

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