Carol Asher

Position: Research Associate

Contact Details:

E-mail: carol.asher@weizmann.ac.il

Telephone: 972-8-934-2716

Research Description

Regulation of Salt Transport in Epithelial Cells

The regulation of salt and water balance in cells is of vital importance to all vertebrates. Abnormalities in this are manifested in hypertension and kidney disease.  We are examining regulators of  sodium transport in epithelial cells. Aldosterone is one of the major corticosteroids
regulating sodium transport.  We have shown that it acts as a short term transient regulator as well as a chronic long term factor on the transport of sodium ions via the apical sodium channel ENaC and the basolateral Na/K ATPase pump.   FXYD proteins  are small single span transmembrane proteins that also regulate salt transport via the Na/K ATPase.  We are studying the effect of these proteins on salt transport as well as on other cell functions.

Many different techniques have been used in these studies.  Studies are made on cell cultures doing electrical measurements of ion conductance and resistance of epithelial cells grown on permeable filters.  Effects on cell growth rates are determined by time lapse microscopy.  Expression of factors are determined by injection of  RNA into Xenopus oocytes and analysis of the proteins that are translated. Diffusion studies are done with fluorescent molecules of different sizes. Membrane surface expression is determined by biotinlylation of whole cells and extraction of the labeled proteins on streptavidin beads, or by antibody binding to the surface of Xenopus oocytes.

Our studies have helped to elucidate the mechanisms of regulating salt transport by FXYD proteins and by aldosterone.

.

.