Journalartikel

Jahr der Veröffentlichung: 1994

Seiten: 1132-1136

Zeitschrift: Molecular Pharmacology

Bandnummer: 45

Heftnummer: 6

ISSN: 0026-895X

eISSN: 1521-0111

Verlag: American Society for Pharmacology and Experimental Therapeutics (ASPET)

Abstract: 
Palytoxin causes potassium efflux and sodium influx in all investigated animal cells. Much evidence points to the sodium pump (Na+/K+-ATPase) as the target of the toxin. A heterologous expression system for mammalian Na+/K+-ATPase in the brewers yeast Saccharomyces cerevisiae has been used to test this hypothesis. Yeast cells do not contain endogenous sodium pumps but can be transformed with vectors coding for the a: and p subunits of the mammalian sodium pump. We now show that transformed yeast cells expressing both alpha and beta subunits of Na+/K+-ATPase are highly sensitive to the toxin, as measured by the loss of intracellular potassium. Palytoxin-induced potassium efflux is completely inhibited by 500 mu M ouabain. In contrast, nontransformed yeast cells or cells expressing either the alpha or beta subunits are insensitive to palytoxin. Thus, the alpha/beta heterodimer of the sodium pump is required for the release of potassium induced by palytoxin. The results suggest that palytoxin converts the sodium pump into an open channel, allowing the passage of alkali ions.

Harvard-Zitierstil: SCHEINERBOBIS, G., HERINGDORF, D., CHRIST, M. and HABERMANN, E. (1994) PALYTOXIN INDUCES K+ EFFLUX FROM YEAST-CELLS EXPRESSING THE MAMMALIAN SODIUM-PUMP, Molecular Pharmacology, 45(6), pp. 1132-1136

APA-Zitierstil: SCHEINERBOBIS, G., HERINGDORF, D., CHRIST, M., & HABERMANN, E. (1994). PALYTOXIN INDUCES K+ EFFLUX FROM YEAST-CELLS EXPRESSING THE MAMMALIAN SODIUM-PUMP. Molecular Pharmacology. 45(6), 1132-1136.