Identification of a PY motif in the epithelial Na channel subunits as a target sequence for mutations causing channel activation found in Liddle syndrome

Détails

ID Serval
serval:BIB_F99224DF3C2A
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Identification of a PY motif in the epithelial Na channel subunits as a target sequence for mutations causing channel activation found in Liddle syndrome
Périodique
EMBO Journal
Auteur(s)
Schild  L., Lu  Y., Gautschi  I., Schneeberger  E., Lifton  R. P., Rossier  B. C.
ISSN
0261-4189
Statut éditorial
Publié
Date de publication
05/1996
Peer-reviewed
Oui
Volume
15
Numéro
10
Pages
2381-7
Notes
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S. --- Old month value: May 15
Résumé
Liddle syndrome is an autosomal dominant form of hypertension, resulting from mutations in the cytoplasmic C-terminus of either the beta or gamma subunits of the amiloride-sensitive epithelial Na channel (ENaC) which lead to constitutively increased channel activity. Most mutations reported to date result in the elimination of 45-75 normal amino acids from these segments, leaving open the question of the identity of the precise amino acids in which mutation can lead to an enhanced channel activity. To address this question, we have performed a systematic mutagenesis study of the C-termini of the alpha, beta and gamma ENaC subunits of the rat channel and have analyzed their function by expression in Xenopus oocytes. The results demonstrate that a short proline-rich segment present in the cytoplasmic C-terminus of each subunit is required for the normal regulation of channel activity. Missense mutations altering a consensus PPPXY sequence of the alpha, beta or gamma subunits reproduced the increase in channel activity found in mutants in which the entire cytoplasmic C-termini are deleted. This proline-rich sequence, referred to as the PY motif, is known to be a site of binding by proteins bearing a WW domain. These findings show that the three PY motifs in the C-termini of ENaC are involved in the regulation of channel activity, probably via protein-protein interactions. This new regulatory mechanism of channel function is critical for the maintenance of normal Na reabsorption in the kidney and of Na+ balance and blood pressure.
Mots-clé
Amino Acid Sequence Animals Blood Pressure/physiology Consensus Sequence Epithelial Sodium Channel Humans Hypertension/*genetics/metabolism Kidney/metabolism Membrane Glycoproteins/chemistry/deficiency/*genetics Molecular Sequence Data Natriuresis/physiology Oocytes *Protein Structure, Tertiary Rats Recombinant Fusion Proteins/biosynthesis Sequence Deletion Sodium/*metabolism Sodium Channels/chemistry/deficiency/*genetics Xenopus
Pubmed
Web of science
Création de la notice
24/01/2008 14:01
Dernière modification de la notice
20/08/2019 17:25
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