Role of the Na,K-ATPase beta-subunit in the cellular accumulation and maturation of the enzyme as assessed by glycosylation inhibitors

Détails

ID Serval
serval:BIB_05953B9DEB87
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Role of the Na,K-ATPase beta-subunit in the cellular accumulation and maturation of the enzyme as assessed by glycosylation inhibitors
Périodique
Journal of Membrane Biology
Auteur(s)
Zamofing  D., Rossier  B. C., Geering  K.
ISSN
0022-2631
Statut éditorial
Publié
Date de publication
08/1988
Peer-reviewed
Oui
Volume
104
Numéro
1
Pages
69-79
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Aug
Résumé
No functional role could yet be established for the glycosylated beta-subunit of the Na,K-ATPase. In this study, we describe the intracellular processing of the beta-subunit as a glycoprotein in toad bladder cells and the consequences of its structural perturbation with glycosylation inhibitors on the cellular expression of the alpha- and beta-subunits and on the structural and functional maturation of the enzyme. Controlled trypsinolysis of homogenates from pulse-labeled cells reveals that the beta-subunit is subjected to glycosylation-dependent structural rearrangements during its intracellular routing. Inhibition of correct terminal glycosylation of the beta-subunit with deoxynojirimycin or swainsonine has no effect on the trypsin sensitivity of the alpha-subunit, its ability to perform cation-dependent conformation changes or the cellular Na,K-ATPase activity. Acquisition of core-sugars is sufficient for the enzyme to assume its catalytic functions. On the other hand, complete inhibition of glycosylation with tunicamycin leads to a destabilization of both the beta- and the alpha-subunits as judged by their higher trypsin sensitivity. In addition, tunicamycin treatment results in a decrease of the amount of newly synthesized beta- and alpha-subunit indicating that a glycoprotein, possibly the beta-subunit itself, plays a role in the efficient accumulation of the alpha-subunit in the endoplasmic reticulum.
Mots-clé
1-Deoxynojirimycin Alkaloids/pharmacology Animals Cell Line Glucosamine/analogs & derivatives/pharmacology Glycoproteins/biosynthesis/metabolism/physiology Glycosylation Na(+)-K(+)-Exchanging ATPase/biosynthesis/metabolism/*physiology Precipitin Tests Protein Conformation/drug effects Protein Processing, Post-Translational Swainsonine Trypsin/pharmacology Tunicamycin/pharmacology
Pubmed
Web of science
Création de la notice
24/01/2008 13:01
Dernière modification de la notice
20/08/2019 12:27
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