A mutation in the epithelial sodium channel causing Liddle disease increases channel activity in the Xenopus laevis oocyte expression system

Détails

ID Serval
serval:BIB_952FDB9D07F7
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
A mutation in the epithelial sodium channel causing Liddle disease increases channel activity in the Xenopus laevis oocyte expression system
Périodique
Proceedings of the National Academy of Sciences of the United States of America
Auteur(s)
Schild  L., Canessa  C. M., Shimkets  R. A., Gautschi  I., Lifton  R. P., Rossier  B. C.
ISSN
0027-8424
Statut éditorial
Publié
Date de publication
06/1995
Peer-reviewed
Oui
Volume
92
Numéro
12
Pages
5699-703
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Jun 6
Résumé
We have studied the functional consequences of a mutation in the epithelial Na+ channel that causes a heritable form of salt-sensitive hypertension, Liddle disease. This mutation, identified in the original kindred described by Liddle, introduces a premature stop codon in the channel beta subunit, resulting in a deletion of almost all of the C terminus of the encoded protein. Coexpression of the mutant beta subunit with wild-type alpha and gamma subunits in Xenopus laevis oocytes resulted in an approximately 3-fold increase in the macroscopic amiloride-sensitive Na+ current (INa) compared with the wild-type channel. This change in INa reflected an increase in the overall channel activity characterized by a higher number of active channels in membrane patches. The truncation mutation in the beta subunit of epithelial Na+ channel did not alter the biophysical and pharmacological properties of the channel--including unitary conductance, ion selectivity, or sensitivity to amiloride block. These results provide direct physiological evidence that Liddle disease is related to constitutive channel hyperactivity in the cell membrane. Deletions of the C-terminal end of the beta and gamma subunits of rat epithelial Na+ channel were functionally equivalent in increasing INa, suggesting that the cytoplasmic domain of the gamma subunit might be another molecular target for mutations responsible for salt-sensitive forms of hypertension.
Mots-clé
Amiloride/pharmacology Animals Epithelium/metabolism Hypertension/*genetics Mutation Oocytes/*metabolism Sequence Deletion Sodium Channels/drug effects/*genetics/physiology Xenopus laevis/*genetics
Pubmed
Web of science
Création de la notice
24/01/2008 14:00
Dernière modification de la notice
03/03/2018 19:39
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