Journal article
Mutations in CFTR associated with mild-disease-form CI- channels with altered pore properties
Nature (London), Vol.362(6416), pp.160-164
03/1993
DOI: 10.1038/362160a0
PMID: 7680769
Abstract
THE cystic fibrosis transmembrane conductance regulator (CFTR) is a phosphorylation-regulated Cl- channel located in the apical membrane of epithelia1–10. Although cystic fibrosis (CF) is caused by mutations in a single gene encoding CFTR11,12, the disease has a variable clinical phenotype13,14. The most common mutation associated with cystic fibrosis, deletion of a phenylalanine at position 508 (frequency, 67%), is associated with severe disease15–17. But some missense mutations, for example ones in which arginine is replaced by histidine at residue at 117 (R117H; 0.8%), tryptophan at 334 (0.4%), or proline at 347 (0.5%), are associated with milder disease15,17,18. These missense mutations affect basic residues located at the external end of the second (M2) and in the sixth (M6) putative membrane-spanning sequences. Here we report that, when expressed in heterologous epithelial cells, all three mutants were correctly processed and generated cyclic AMP-regulated apical Cl- currents. Although the macroscopic current properties were normal, the amount of current was reduced. Patch-clamp analysis revealed that all three mutants had reduced single-channel conductances. In addition, R117H showed altered sensitivity to external pH and had altered single-channel kinetics. These results explain the quantitative decrease in macroscopic Cl- current, and suggest that R117, R334 and R347 contribute to the pore of the CFTR Cl- channel. Our results also suggest why R117H, R334W and R347P produce less severe clinical disease and have implications for our understanding of cystic fibrosis.
Details
- Title: Subtitle
- Mutations in CFTR associated with mild-disease-form CI- channels with altered pore properties
- Creators
- David N SheppardDevra P RichLynda S OstedgaardRichard J GregoryAlan E SmithMichael J Welsh
- Resource Type
- Journal article
- Publication Details
- Nature (London), Vol.362(6416), pp.160-164
- DOI
- 10.1038/362160a0
- PMID
- 7680769
- ISSN
- 0028-0836
- eISSN
- 1476-4687
- Language
- English
- Date published
- 03/1993
- Academic Unit
- Neurology; Molecular Physiology and Biophysics; Pulmonary, Critical Care, and Occupational Medicine; Neurosurgery; Internal Medicine
- Record Identifier
- 9984020612402771
Metrics
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