Role of the intracellular domain of the beta subunit in Na,K pump function.

Détails

ID Serval
serval:BIB_C60677B58132
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Role of the intracellular domain of the beta subunit in Na,K pump function.
Périodique
Biochimica et Biophysica Acta-Bioenergetics
Auteur(s)
Abriel H., Hasler U., Geering K., Horisberger J.D.
ISSN
0005-2736
ISSN-L
1879-2642
Statut éditorial
Publié
Date de publication
1999
Peer-reviewed
Oui
Volume
1418
Numéro
1
Pages
85-96
Langue
anglais
Notes
Journal Article Research Support, Non-U.S. Gov't --- Old month value: Apr 14
Résumé
The catalytic alpha subunit of the (Na,K)- and (H,K)-ATPases needs to be coexpressed with a beta subunit in order to produce cation transport activity. Although the isoform of the beta subunit is known to influence the functional characteristics of the Na,K pump, the role of the different domains of the beta subunit is not fully understood. We have studied the function of a Na,K pump resulting from the expression of a wild-type alpha subunit with a N-terminally truncated mutant of the beta subunit using the two-electrode voltage clamp and the cut-open oocyte techniques. While the maximal activity, measured as the K+-activated outward current, was not significantly altered, the beta N-terminal truncation induced an ouabain-sensitive conductance in the absence of extracellular K+. The voltage dependence of the ouabain-sensitive charge distribution indicated that in the Na/Na exchange conditions, the E1-E2 conformation equilibrium was shifted towards the E2 conformation, a change resulting from alteration of both the forward and the backward reaction rate. Removal of the intracellular domain of the beta subunit modifies several aspects of the whole enzyme function by a mechanism that must imply the state of the extracellular and/or transmembrane parts of the alpha/beta subunit complex.
Mots-clé
Animals, Cell Membrane, Membrane Potentials, Oocytes, Ouabain, Patch-Clamp Techniques, Sodium-Potassium-Exchanging ATPase, Xenopus
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 11:56
Dernière modification de la notice
09/05/2019 1:01
Données d'usage