Mechanisms of urinary K+ and H+ excretion: primary structure and functional expression of a novel H,K-ATPase

Détails

ID Serval
serval:BIB_473E499CA107
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Mechanisms of urinary K+ and H+ excretion: primary structure and functional expression of a novel H,K-ATPase
Périodique
Journal of Cell Biology
Auteur(s)
Jaisser  F., Horisberger  J. D., Geering  K., Rossier  B. C.
ISSN
0021-9525 (Print)
Statut éditorial
Publié
Date de publication
12/1993
Volume
123
Numéro
6 Pt 1
Pages
1421-9
Notes
Comparative Study
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Dec
Résumé
The kidney plays an essential role in regulating potassium and acid balance. A major site for these regulations is in the collecting tubule. In the present study, we report the primary sequence of a novel alpha subunit of the P-ATPase gene family, which we isolated from the urinary bladder epithelium of the toad Bufo marinus, the amphibian equivalent of the mammalian collecting tubule. The cDNA encodes a protein of 1,042 amino acids which shares approximately 67% identity with the alpha 1 subunit of the ouabain-inhibitable Na,K-ATPase and approximately 69% identity with the alpha subunit of the SCH28080-inhibitable gastric H,K-ATPase. When coexpressed in Xenopus oocytes with a beta subunit isolated from the same cDNA library, the ATPase is able to transport rubidium (a potassium surrogate) inward, and hydrogen outward, leading to alkalization of the intracellular compartment and acidification of the external medium. The novel ATPase has a unique pharmacological profile showing intermediate sensitivity to both ouabain and SCH28080. Our findings indicate that the bladder ATPase is a member of a new ion motive P-ATPase subfamily. The bladder ATPase is expressed in the urinary tract but not in the stomach or the colon. This H,K-ATPase may be one of the molecules involved in H+ and K+ homeostasis, mediating the transport of these ions across urinary epithelia and therefore regulating their urinary excretion.
Mots-clé
Amino Acid Sequence Animals Base Sequence Bufo marinus Cloning, Molecular DNA Primers/chemistry Gene Expression H(+)-K(+)-Exchanging ATPase/chemistry/*metabolism Hydrogen-Ion Concentration Imidazoles/metabolism Kidney/enzymology Molecular Sequence Data Multigene Family Ouabain/metabolism Potassium/*urine Protein Binding RNA, Messenger/genetics Rats Sequence Alignment Sequence Homology, Amino Acid Tissue Distribution Urinary Bladder/enzymology
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 13:28
Dernière modification de la notice
08/05/2019 18:00
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