Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
J Cell Biol 1999 Nov 15;1474:809-22. doi: 10.1083/jcb.147.4.809.
Show Gene links Show Anatomy links

The pro-apoptotic proteins, Bid and Bax, cause a limited permeabilization of the mitochondrial outer membrane that is enhanced by cytosol.

Kluck RM , Esposti MD , Perkins G , Renken C , Kuwana T , Bossy-Wetzel E , Goldberg M , Allen T , Barber MJ , Green DR , Newmeyer DD .

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.

PubMed ID: 10562282
PMC ID: PMC2156156
Article link: J Cell Biol
Grant support: [+]

Species referenced: Xenopus laevis
Genes referenced: bax bcl2 bid tbx2

Article Images: [+] show captions
References [+] :
Allen, Accessing nuclear structure for field emission, in lens, scanning electron microscopy (FEISEM). 1998, Pubmed, Xenbase