Association with {beta}-COP regulates the trafficking of the newly synthesized Na,K-ATPase.

Détails

ID Serval
serval:BIB_88940B8EB5CC
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Association with {beta}-COP regulates the trafficking of the newly synthesized Na,K-ATPase.
Périodique
Journal of Biological Chemistry
Auteur⸱e⸱s
Morton M.J., Farr G.A., Hull M., Capendeguy O., Horisberger J.D., Caplan M.J.
ISSN
1083-351X[electronic], 0021-9258[linking]
Statut éditorial
Publié
Date de publication
2010
Volume
285
Numéro
44
Pages
33737-33746
Langue
anglais
Résumé
Plasma membrane expression of the Na,K-ATPase requires assembly of its α- and β-subunits. Using a novel labeling technique to identify Na,K-ATPase partner proteins, we detected an interaction between the Na,K-ATPase α-subunit and the coat protein, β-COP, a component of the COP-I complex. When expressed in the absence of the Na,K-ATPase β-subunit, the Na,K-ATPase α-subunit interacts with β-COP, is retained in the endoplasmic reticulum, and is targeted for degradation. In the presence of the Na,K-ATPase β-subunit, the α-subunit does not interact with β-COP and traffics to the plasma membrane. Pulse-chase experiments demonstrate that in cells expressing both the Na,K-ATPase α- and β-subunits, newly synthesized α-subunit associates with β-COP immediately after its synthesis but that this interaction does not constitute an obligate intermediate in the assembly of the α- and β-subunits to form the pump holoenzyme. The interaction with β-COP was reduced by mutating a dibasic motif at Lys(54) in the Na,K-ATPase α-subunit. This mutant α-subunit is not retained in the endoplasmic reticulum and reaches the plasma membrane, even in the absence of Na,K-ATPase β-subunit expression. Although the Lys(54) α-subunit reaches the cell surface without need for β-subunit assembly, it is only functional as an ion-transporting ATPase in the presence of the β-subunit.
Mots-clé
endoplasmic-reticulum retention, sodium-potassium pump, na-k-atpase, alpha-subunit, cell-surface, crystal-structure, xenopus oocytes, proteins, rat, transcription
Pubmed
Web of science
Open Access
Oui
Création de la notice
10/11/2010 16:34
Dernière modification de la notice
20/08/2019 14:47
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