Unusual degradation of alpha-beta complexes in Xenopus oocytes by beta-subunits of Xenopus gastric H-K-ATPase

Détails

ID Serval
serval:BIB_47E77620C908
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Unusual degradation of alpha-beta complexes in Xenopus oocytes by beta-subunits of Xenopus gastric H-K-ATPase
Périodique
American Journal of Physiology
Auteur(s)
Chen  P. X., Mathews  P. M., Good  P. J., Rossier  B. C., Geering  K.
ISSN
0363-6143
Statut éditorial
Publié
Date de publication
07/1998
Volume
275
Numéro
1 Pt 1
Pages
C139-45
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Jul
Résumé
The catalytic alpha-subunit of oligomeric P-type ATPases such as Na-K-ATPase and H-K-ATPase requires association with a beta-subunit after synthesis in the endoplasmic reticulum (ER) to become stably expressed and functionally active. In this study, we have expressed the beta-subunit of Xenopus gastric H-K-ATPase (betaHK) in Xenopus oocytes together with alpha-subunits of H-K-ATPase (alphaHK) or Na-K-ATPase (alphaNK) and have followed the biosynthesis, assembly, and cell surface expression of functional pumps. Immunoprecipitations of Xenopus betaHK from metabolically labeled oocytes show that it is well expressed and, when synthesized without alpha-subunits, can leave the ER and become fully glycosylated. Xenopus betaHK can associate with both coexpressed alphaHK and alphaNK, but the alpha-beta complexes formed are degraded rapidly in or close to the ER and do not produce functional pumps at the cell surface as assessed by 86Rb uptake. A possible explanation of these results is that Xenopus betaHK may contain a tissue-specific signal that is important in the formation or correct targeting of functional alpha-beta complexes in the stomach but that cannot be recognized in Xenopus oocytes and in consequence leads to cellular degradation of the alpha-beta complexes in this experimental system.
Mots-clé
Amino Acid Sequence Animals Cell Membrane/enzymology Cloning, Organism DNA, Complementary Female Gastric Mucosa/*enzymology Glycosylation H(+)-K(+)-Exchanging ATPase/biosynthesis/chemistry/*metabolism Macromolecular Substances Molecular Sequence Data Na(+)-K(+)-Exchanging ATPase/biosynthesis/chemistry/*metabolism Oocytes/*physiology Polymerase Chain Reaction RNA, Complementary Rabbits Recombinant Proteins/biosynthesis/metabolism Sequence Alignment Sequence Homology, Amino Acid Xenopus laevis
Pubmed
Web of science
Création de la notice
24/01/2008 13:28
Dernière modification de la notice
03/03/2018 16:51
Données d'usage