Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Proc Natl Acad Sci U S A
1996 Dec 24;9326:15370-5. doi: 10.1073/pnas.93.26.15370.
Show Gene links
Show Anatomy links
Cell surface expression of the epithelial Na channel and a mutant causing Liddle syndrome: a quantitative approach.
Firsov D
,
Schild L
,
Gautschi I
,
Mérillat AM
,
Schneeberger E
,
Rossier BC
.
???displayArticle.abstract???
The epithelial amiloride-sensitive sodium channel (ENaC) controls transepithelial Na+ movement in Na(+)-transporting epithelia and is associated with Liddle syndrome, an autosomal dominant form of salt-sensitive hypertension. Detailed analysis of ENaC channel properties and the functional consequences of mutations causing Liddle syndrome has been, so far, limited by lack of a method allowing specific and quantitative detection of cell-surface-expressed ENaC. We have developed a quantitative assay based on the binding of 125I-labeled M2 anti-FLAG monoclonal antibody (M2Ab*) directed against a FLAG reporter epitope introduced in the extracellular loop of each of the alpha, beta, and gamma ENaC subunits. Insertion of the FLAG epitope into ENaC sequences did not change its functional and pharmacological properties. The binding specificity and affinity (Kd = 3 nM) allowed us to correlate in individual Xenopus oocytes the macroscopic amiloride-sensitive sodium current (INa) with the number of ENaC wild-type and mutant subunits expressed at the cell surface. These experiments demonstrate that: (i) only heteromultimeric channels made of alpha, beta, and gamma ENaC subunits are maximally and efficiently expressed at the cell surface; (ii) the overall ENaC open probability is one order of magnitude lower than previously observed in single-channel recordings; (iii) the mutation causing Liddle syndrome (beta R564stop) enhances channel activity by two mechanisms, i.e., by increasing ENaC cell surface expression and by changing channel open probability. This quantitative approach provides new insights on the molecular mechanisms underlying one form of salt-sensitive hypertension.
Buchegger,
Radiolabeled fragments of monoclonal antibodies against carcinoembryonic antigen for localization of human colon carcinoma grafted into nude mice.
1983, Pubmed
Buchegger,
Radiolabeled fragments of monoclonal antibodies against carcinoembryonic antigen for localization of human colon carcinoma grafted into nude mice.
1983,
Pubmed
Canessa,
Amiloride-sensitive epithelial Na+ channel is made of three homologous subunits.
1994,
Pubmed
,
Xenbase
Canessa,
Membrane topology of the epithelial sodium channel in intact cells.
1994,
Pubmed
,
Xenbase
Chang,
Mutations in subunits of the epithelial sodium channel cause salt wasting with hyperkalaemic acidosis, pseudohypoaldosteronism type 1.
1996,
Pubmed
Frindt,
Feedback regulation of Na channels in rat CCT. III. Response to cAMP.
1995,
Pubmed
Geering,
A role for the beta-subunit in the expression of functional Na+-K+-ATPase in Xenopus oocytes.
1989,
Pubmed
,
Xenbase
Hamilton,
Single-channel recordings from amiloride-sensitive epithelial sodium channel.
1985,
Pubmed
,
Xenbase
Helman,
Blocker-related changes of channel density. Analysis of a three-state model for apical Na channels of frog skin.
1990,
Pubmed
Lifton,
Molecular genetics of human blood pressure variation.
1996,
Pubmed
Lingueglia,
Molecular cloning and functional expression of different molecular forms of rat amiloride-binding proteins.
1993,
Pubmed
McDonald,
Cloning and expression of the beta- and gamma-subunits of the human epithelial sodium channel.
1995,
Pubmed
,
Xenbase
Palmer,
Gating of Na channels in the rat cortical collecting tubule: effects of voltage and membrane stretch.
1996,
Pubmed
Palmer,
Amiloride-sensitive Na channels from the apical membrane of the rat cortical collecting tubule.
1986,
Pubmed
Palmer,
Epithelial sodium channels: characterization by using the patch-clamp technique.
1986,
Pubmed
Palmer,
Effects of cell Ca and pH on Na channels from rat cortical collecting tubule.
1987,
Pubmed
Puoti,
The highly selective low-conductance epithelial Na channel of Xenopus laevis A6 kidney cells.
1995,
Pubmed
,
Xenbase
Renard,
Biochemical analysis of the membrane topology of the amiloride-sensitive Na+ channel.
1994,
Pubmed
,
Xenbase
Rossier,
Epithelial sodium channels.
1994,
Pubmed
Schild,
A mutation in the epithelial sodium channel causing Liddle disease increases channel activity in the Xenopus laevis oocyte expression system.
1995,
Pubmed
,
Xenbase
Schild,
Identification of a PY motif in the epithelial Na channel subunits as a target sequence for mutations causing channel activation found in Liddle syndrome.
1996,
Pubmed
,
Xenbase
Shimkets,
Liddle's syndrome: heritable human hypertension caused by mutations in the beta subunit of the epithelial sodium channel.
1994,
Pubmed
Snyder,
Membrane topology of the amiloride-sensitive epithelial sodium channel.
1994,
Pubmed
,
Xenbase
Snyder,
Mechanism by which Liddle's syndrome mutations increase activity of a human epithelial Na+ channel.
1995,
Pubmed
,
Xenbase
Staub,
WW domains of Nedd4 bind to the proline-rich PY motifs in the epithelial Na+ channel deleted in Liddle's syndrome.
1996,
Pubmed
Voilley,
The lung amiloride-sensitive Na+ channel: biophysical properties, pharmacology, ontogenesis, and molecular cloning.
1994,
Pubmed