title: The properties of the mitochondrial megachannel in mitoplasts from human colon carcinoma cells are not influenced by Bax.
abstract: This paper explores the relationship between Bax and the mitochondrial permeability transition pore (PTP). Isolated human colon tumor (HCT116) Bax- mitochondria exposed to recombinant Bax exhibited a slow, cyclosporin A-sensitive swelling, but only at [Bax]>200 nM. The amount of Bax incorporated was much higher than that found in organelles isolated from HCT116 Bax+ staurosporine- or etoposide-treated apoptotic cells, casting doubts on the significance of the putative PT induction for apoptosis. Bax did not influence the electrophysiological properties of an approximately 1 nS channel ascribed to the Ca2+-dependent mitochondrial permeability transition pore. These observations indicate that the PTP is independent of Bax.
authors.affiliation: CNR Institute of Neuroscience, Biomembranes Section, Department of Biomedical Sciences, University of Padova, Viale Giuseppe Colombo 3, 35121 Padova, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Campello
authors.forename: Umberto
authors.initials: U
authors.lastname: De Marchi
authors.forename: Ildikò
authors.initials: I
authors.lastname: Szabò
authors.forename: Francesco
authors.initials: F
authors.lastname: Tombola
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Martinou
authors.forename: Mario
authors.initials: M
authors.lastname: Zoratti
mesh_terms: D002118:Calcium / Q000494:pharmacology; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism*; D002413:Cations, Divalent / Q000494:pharmacology; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007473:Ion Channels / Q000502:physiology*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D008933:Mitochondrial Swelling; D009154:Mutation; D018408:Patch-Clamp Techniques; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D051028:bcl-2-Associated X Protein
chemical_list: C494826:BAX protein, human; D002413:Cations, Divalent; D007473:Ion Channels; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D002118:Calcium