Journal article
Cell surface expression and biosynthesis of epithelial Na+ channels
Biochemical journal, Vol.336(3), pp.705-710
12/15/1998
DOI: 10.1042/bj3360705
PMCID: PMC1219923
PMID: 9841884
Abstract
The epithelial Na+ channel (ENaC) complex is composed of three homologous subunits: α, β and γ. Mutations in ENaC subunits can increase the number of channels on the cell surface, causing a hereditary form of hypertension called Liddle's syndrome, or can decrease channel activity, causing pseudohypoaldosteronism type I, a salt-wasting disease of infancy. To investigate surface expression, we studied ENaC subunits expressed in COS-7 and HEK293 cells. Using surface biotinylation and protease sensitivity, we found that when individual ENaC subunits are expressed alone, they traffic to the cell surface. The subunits are glycosylated with high-mannose oligosaccharides, but seem to have the carbohydrate removed before they reach the cell surface. Moreover, subunits form a complex that cannot be disrupted by several non-ionic detergents. The pattern of glycosylation and detergent solubility/insolubility persists when the N-teminal and C-terminal cytoplasmic regions of ENaC are removed. With co-expression of all three ENaC subunits, the insoluble complex is the predominant species. These results show that ENaC and its family members are unique in their trafficking, biochemical characteristics and post-translational modifications.
Details
- Title: Subtitle
- Cell surface expression and biosynthesis of epithelial Na+ channels
- Creators
- Lawrence S PRINCE - Howard Hughes Medical Institute, Departments of Pediatrics, Internal Medicine, and Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA 52242, U.S.AMichael J WELSH - Howard Hughes Medical Institute, Departments of Pediatrics, Internal Medicine, and Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, IA 52242, U.S.A
- Resource Type
- Journal article
- Publication Details
- Biochemical journal, Vol.336(3), pp.705-710
- DOI
- 10.1042/bj3360705
- PMID
- 9841884
- PMCID
- PMC1219923
- ISSN
- 0264-6021
- eISSN
- 1470-8728
- Language
- English
- Date published
- 12/15/1998
- Academic Unit
- Neurology; Molecular Physiology and Biophysics; Pulmonary, Critical Care, and Occupational Medicine; Neurosurgery; Internal Medicine
- Record Identifier
- 9984020628002771
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