Glutathione permeability of CFTR.
The cystic fibrosis transmembrane conductance regulator (CFTR) forms an ion channel that is permeable both to Cl- and to larger organic anions. Here we show, using macroscopic current recording from excised membrane patches, that the anionic antioxidant tripeptide glutathione is permeant in the CFTR channel. This permeability may account for the high concentrations of glutathione that have been measured in the surface fluid that coats airway epithelial cells. Furthermore, loss of this pathway for glutathione transport may contribute to the reduced levels of glutathione observed in airway surface fluid of cystic fibrosis patients, which has been suggested to contribute to the oxidative stress observed in the lung in cystic fibrosis. We suggest that release of glutathione into airway surface fluid may be a novel function of CFTR.
Linsdell
P
P
Department of Physiology, McGill University, Montréal, Québec, Canada H3G 1Y6.
Hanrahan
J W
JW
D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D002463:Cell Membrane Permeability; D006224:Cricetinae; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000737:chemistry* / Q000502:physiology*; D005978:Glutathione / Q000378:metabolism*; D019803:Glutathione Disulfide / Q000378:metabolism; D007700:Kinetics; D008564:Membrane Potentials; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D014162:Transfection
D011994:Recombinant Proteins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D005978:Glutathione; D019803:Glutathione Disulfide