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Bcl-x(L) forms an ion channel in synthetic lipid membranes.
- Source :
-
Nature [Nature] 1997 Jan 23; Vol. 385 (6614), pp. 353-7. - Publication Year :
- 1997
-
Abstract
- Bcl-2-related proteins are critical regulators of cell survival that are localized to the outer mitochondrial, outer nuclear and endoplasmic reticulum membranes. Despite their physiological importance, the biochemical function of Bcl-2-related proteins has remained elusive. The three-dimensional structure of Bcl-xL, an inhibitor of apoptosis, was recently shown to be similar to the structures of the pore-forming domains of bacterial toxins. A key feature of these pore-forming domains is the ability to form ion channels in biological membranes. Here we demonstrate that Bcl-xL shares this functional feature. Like the bacterial toxins, Bcl-xL can insert into either synthetic lipid vesicles or planar lipid bilayers and form an ion-conducting channel. This channel is pH-sensitive and becomes cation-selective at physiological pH. The ion-conducting channel(s) formed by Bcl-xL display multiple conductance states that have identical ion selectivity. Together, these data suggest that Bcl-xL may maintain cell survival by regulating the permeability of the intracellular membranes to which it is distributed.
- Subjects :
- Cations metabolism
Cell Membrane Permeability
Electrochemistry
Escherichia coli
Humans
Hydrogen-Ion Concentration
Ion Channel Gating
Ion Channels chemistry
Ion Channels genetics
Kinetics
Lipid Bilayers
Protein Conformation
Proto-Oncogene Proteins chemistry
Proto-Oncogene Proteins genetics
Recombinant Proteins chemistry
Recombinant Proteins genetics
Recombinant Proteins metabolism
bcl-X Protein
Ion Channels metabolism
Proto-Oncogene Proteins metabolism
Proto-Oncogene Proteins c-bcl-2
Subjects
Details
- Language :
- English
- ISSN :
- 0028-0836
- Volume :
- 385
- Issue :
- 6614
- Database :
- MEDLINE
- Journal :
- Nature
- Publication Type :
- Academic Journal
- Accession number :
- 9002522
- Full Text :
- https://doi.org/10.1038/385353a0