TY - JOUR
AU1 - Kluck, Ruth M.
AU2 - Esposti, Mauro Degli
AU3 - Perkins, Guy
AU4 - Renken, Christian
AU5 - Kuwana, Tomomi
AU6 - Bossy-Wetzel, Ella
AU7 - Goldberg, Martin
AU8 - Allen, Terry
AU9 - Barber, Michael J.
AU1 - Green, Douglas R.
AU1 - Newmeyer, Donald D.
AB - During apoptosis, an important pathway leading to caspase activation involves the release of cytochrome c from the intermembrane space of mitochondria. Using a cell-free system based on Xenopus egg extracts, we examined changes in the outer mitochondrial membrane accompanying cytochrome c efflux. The pro-apoptotic proteins, Bid and Bax, as well as factors present in Xenopus egg cytosol, each induced cytochrome c release when incubated with isolated mitochondria. These factors caused a permeabilization of the outer membrane that allowed the corelease of multiple intermembrane space proteins: cytochrome c, adenylate kinase and sulfite oxidase. The efflux process is thus nonspecific. None of the cytochrome c- releasing factors caused detectable mitochondrial swelling, arguing that matrix swelling is not required for outer membrane permeability in this system. Bid and Bax caused complete release of cytochrome c but only a limited permeabilization of the outer membrane, as measured by the accessibility of inner membrane-associated respiratory complexes III and IV to exogenously added cytochrome c . However, outer membrane permeability was strikingly increased by a macromolecular cytosolic factor, termed PEF (permeability enhancing factor). We hypothesize that PEF activity could help determine whether cells can recover from mitochondrial cytochrome c release. apoptosis Bid Bax cytochrome c mitochondrial outer membrane Footnotes Dr. Degli Esposti is on leave from the Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Vic 3169, Australia. . Abbreviations used in this paper: AK, adenylate kinase; FEISEM, field emission in-lens scanning electron microscopy; PEF, permeability enhancing factor; SOx, sulfite oxidase; tBid, truncated Bid; VDAC, voltage-dependent anion channel. Submitted: 5 August 1999 Revision requested 28 September 1999 Accepted: 12 October 1999
TI - The Pro-Apoptotic Proteins, Bid and Bax, Cause a Limited Permeabilization of the Mitochondrial Outer Membrane That Is Enhanced by Cytosol
JF - The Journal of Cell Biology
DO - 10.1083/jcb.147.4.809
DA - 1999-11-15
UR - https://www.deepdyve.com/lp/rockefeller-university-press/the-pro-apoptotic-proteins-bid-and-bax-cause-a-limited-vK36Si0QNx
SP - 809
VL - 147
IS - 4
DP - DeepDyve