beta-subunit assembly is essential for the correct packing and the stable membrane insertion of the H,K-ATPase alpha-subunit

Détails

ID Serval
serval:BIB_A883DEEAB0EC
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
beta-subunit assembly is essential for the correct packing and the stable membrane insertion of the H,K-ATPase alpha-subunit
Périodique
Journal of Biological Chemistry
Auteur(s)
Beggah  A. T., Beguin  P., Bamberg  K., Sachs  G., Geering  K.
ISSN
0021-9258 (Print)
Statut éditorial
Publié
Date de publication
03/1999
Volume
274
Numéro
12
Pages
8217-23
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Mar 19
Résumé
The alpha-subunits of H,K-ATPase (HKAalpha) and Na,K-ATPase require a beta-subunit for maturation. We investigated the role of the beta-subunit in the membrane insertion and stability of the HKAalpha expressed in Xenopus oocytes. Individual membrane segments M1, M2, M3, M4, and M9 linked to a glycosylation reporter act as signal anchor (SA) motifs, and M10 acts as a partial stop transfer motif. In combined HKAalpha constructs, M2 acts as an efficient stop transfer sequence, and M3 acts as a SA sequence. However, M5 and M9 have only partial SA function, and M7 has no SA function. Consistent with the membrane insertion properties of segments in combined alpha constructs, M1-3 alpha-proteins are resistant to cellular degradation, and M1-5 up to M1-10 alpha-proteins are not resistant to cellular degradation. However, co-expression with beta-subunits increases the membrane insertion of M9 in a M1-9 alpha-protein and completely protects M1-10 alpha-proteins against cellular degradation. Our results indicate that HKAalpha N-terminal (M1-M4) membrane insertion and stabilization are mediated by intrinsic molecular characteristics; however, the C-terminal (M5-M10) membrane insertion and thus the stabilization of the entire alpha-subunit depend on intramolecular and intermolecular beta-subunit interactions that are similar but not identical to data obtained for the Na,K-ATPase alpha-subunit.
Mots-clé
Animals Cell Membrane/enzymology Cells, Cultured Female H(+)-K(+)-Exchanging ATPase/chemistry/*ultrastructure Oocytes/enzymology Protein Conformation Rabbits Stomach/enzymology Structure-Activity Relationship Xenopus laevis
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 13:28
Dernière modification de la notice
20/08/2019 16:13
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