Bufo marinus bladder H-K-ATPase carries out electroneutral ion transport

Détails

ID Serval
serval:BIB_DAAF2C60C5E0
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Bufo marinus bladder H-K-ATPase carries out electroneutral ion transport
Périodique
American Journal of Physiology. Renal Physiology
Auteur(s)
Burnay  M., Crambert  G., Kharoubi-Hess  S., Geering  K., Horisberger  J. D.
ISSN
0363-6127 (Print)
Statut éditorial
Publié
Date de publication
11/2001
Volume
281
Numéro
5
Pages
F869-74
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Nov
Résumé
Bufo marinus bladder H-K-ATPase belongs to the Na-K-ATPase and H-K-ATPase subfamily of oligomeric P-type ATPases and is closely related to rat and human nongastric H-K-ATPases. It has been demonstrated that this ATPase transports K(+) into the cell in exchange for protons and sodium ions, but the stoichiometry of this cation exchange is not yet known. We studied the electrogenic properties of B. marinus bladder H-K-ATPase expressed in Xenopus laevis oocytes. In a HEPES-buffered solution, K(+) activation of the H-K-ATPase induced a slow-onset inward current that reached an amplitude of approximately 20 nA after 1-2 min. When measurements were performed in a solution containing 25 mM HCO at a PCO(2) of 40 Torr, the negative current activated by K(+) was reduced. In noninjected oocytes, intracellular alkalization activated an inward current similar to that due to B. marinus H-K-ATPase. We conclude that the transport activity of the nongastric B. marinus H-K-ATPase is not intrinsically electrogenic but that the inward current observed in oocytes expressing this ion pump is secondary to intracellular alkalization induced by proton transport.
Mots-clé
4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid/pharmacology Animals Bicarbonates/pharmacology Biological Transport *Bufo marinus Carbon Dioxide/pharmacology Electric Conductivity Female Gene Expression H(+)-K(+)-Exchanging ATPase/genetics/*metabolism Hydrogen-Ion Concentration Membrane Potentials Na(+)-K(+)-Exchanging ATPase/metabolism Oocytes/metabolism Rubidium Radioisotopes/metabolism Transfection Urinary Bladder/*enzymology Xenopus laevis
Pubmed
Web of science
Création de la notice
24/01/2008 13:28
Dernière modification de la notice
03/03/2018 21:55
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