TRK1 encodes a plasma membrane protein required for high-affinity potassium transport in Saccharomyces cerevisiae

Autor: Gaber, R F, Styles, C A, Fink, G R
Zdroj: Molecular and Cellular Biology; July 1988, Vol. 8 Issue: 7 p2848-2859, 12p
Abstrakt: We identified a 180-kilodalton plasma membrane protein in Saccharomyces cerevisiae required for high-affinity transport (uptake) of potassium. The gene that encodes this putative potassium transporter (TRK1) was cloned by its ability to relieve the potassium transport defect in trk1 cells. TRK1 encodes a protein 1,235 amino acids long that contains 12 potential membrane-spanning domains. Our results demonstrate the physical and functional independence of the yeast potassium and proton transport systems. TRK1 is nonessential in S. cerevisiae and maps to a locus unlinked to PMA1, the gene that encodes the plasma membrane ATPase. Haploid cells that contain a null allele of TRK1 (trk1 delta) rely on a low-affinity transporter for potassium uptake and, under certain conditions, exhibit energy-dependent loss of potassium, directly exposing the activity of a transporter responsible for the efflux of this ion.
Databáze: Supplemental Index