Effects of cystic fibrosis and congenital bilateral absence of the vas deferens-associated mutations on cystic fibrosis transmembrane conductance regulator-mediated regulation of separate channels.
The protein defective in cystic fibrosis (CF), the CF transmembrane-conductance regulator (CFTR), functions as an epithelial chloride channel and as a regulator of separate ion channels. Although the consequences that disease-causing mutations have on the chloride-channel function have been studied extensively, little is known about the effects that mutations have on the regulatory function. To address this issue, we transiently expressed CFTR-bearing mutations associated with CF or its milder phenotype, congenital bilateral absence of the vas deferens, and determined whether mutant CFTR could regulate outwardly rectifying chloride channels (ORCCs). CFTR bearing a CF-associated mutation in the first nucleotide-binding domain (NBD1), DeltaF508, functioned as a chloride channel but did not regulate ORCCs. However, CFTR bearing disease-associated mutations in other domains retained both functions, regardless of the associated phenotype. Thus, a relationship between loss of CFTR regulatory function and disease severity is evident for NBD1, a region of CFTR that appears important for regulation of separate channels.
Mickle
J E
JE
Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
Milewski
M I
MI
Macek
M
M
Cutting
G R
GR
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D019943:Amino Acid Substitution / Q000235:genetics; D001665:Binding Sites; D002460:Cell Line; D018118:Chloride Channels / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D003550:Cystic Fibrosis / Q000235:genetics* / Q000503:physiopathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004553:Electric Conductivity; D005905:Glyburide / Q000494:pharmacology; D006031:Glycosylation; D006801:Humans; D008297:Male; D008970:Molecular Weight; D009154:Mutation / Q000235:genetics*; D020125:Mutation, Missense / Q000235:genetics; D010641:Phenotype; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014649:Vas Deferens / Q000002:abnormalities* / Q000378:metabolism
C505032:CFTR protein, human; D018118:Chloride Channels; D002712:Chlorides; D011994:Recombinant Proteins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D000242:Cyclic AMP; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D005905:Glyburide