title: The cystic fibrosis mutation (delta F508) does not influence the chloride channel activity of CFTR.
abstract: The cystic fibrosis transmembrane conductance regulator (CFTR) is a phosphorylation-regulated Cl- channel. In most mammalian cells, the functional consequences of the most common CF mutation, delta F508-CFTR, cannot be assessed as the mutant protein undergoes biosynthetic arrest. However, function can be studied in the baculovirus-insect cell expression system where delta F508-CFTR does not appear to undergo such arrest. Our results show that phosphorylation-regulated Cl- channel activity of delta F508-CFTR is similar to that of wild-type CFTR. This observation was confirmed in comparative studies of purified delta F508-CFTR and CFTR reconstituted in planar lipid bilayers. Therefore, we suggest that this common mutation does not result in a significant alteration in CFTR function.
authors.affiliation: Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Ramjeesingh
authors.forename: E
authors.initials: E
authors.lastname: Reyes
authors.forename: T
authors.initials: T
authors.lastname: Jensen
authors.forename: X
authors.initials: X
authors.lastname: Chang
authors.forename: J M
authors.initials: JM
authors.lastname: Rommens
authors.forename: C E
authors.initials: CE
authors.lastname: Bear
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002460:Cell Line; D018118:Chloride Channels / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006224:Cricetinae; D000242:Cyclic AMP / Q000494:pharmacology; D003550:Cystic Fibrosis / Q000235:genetics*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D006801:Humans; D007700:Kinetics; D008051:Lipid Bilayers; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010649:Phenylalanine; D010766:Phosphorylation; D017510:Protein Folding; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D017384:Sequence Deletion; D018411:Spodoptera; D014162:Transfection
chemical_list: C505032:CFTR protein, human; D018118:Chloride Channels; D008051:Lipid Bilayers; D008565:Membrane Proteins; D011994:Recombinant Proteins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D010649:Phenylalanine; D000242:Cyclic AMP