Inward and outward rectifying potassium currents in Saccharomyces cerevisiae mediated by endogenous and heterelogously expressed ion channels.
Disruption of genes encoding endogenous transport proteins in Saccharomyces cerevisiae has facilitated the recent cloning, by functional expression, of cDNAs encoding K+ channels and amino acid transporters from the plant Arabidopsis thaliana [1-4]. In the present study, we demonstrate in whole-cell patch clamp experiments that the inability of trk1deltatrk2delta mutants of S. cerevisiae to grow on submillimolar K+ correlates with the lack of K+ inward currents, which are present in wild-type cells, and that transformation of the trk1deltatrk2delta double-deletion mutant with KAT1 from Arabidopsis thaliana restores this phenotype by encoding a plasma membrane protein that allows large K+ inward currents. Similar K+ inward currents are induced by transformation of a trk1 mutant with AKT1 from A. thaliana.
Department of Cellular and Molecular Physiology, Yale University, New Haven, CT 06510, USA.
A
A
Bertl
J A
JA
Anderson
C L
CL
Slayman
H
H
Sentenac
R F
RF
Gaber
D017360:Arabidopsis; D029681:Arabidopsis Proteins; D002352:Carrier Proteins / Q000235:genetics; D027682:Cation Transport Proteins; D005656:Fungal Proteins / Q000235:genetics; D017343:Genes, Plant; D005816:Genetic Complementation Test; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology; D017136:Ion Transport; D016547:Kinesins; D008565:Membrane Proteins / Q000235:genetics; D018408:Patch-Clamp Techniques; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology*; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000235:genetics / Q000502:physiology*; D024661:Potassium Channels, Inwardly Rectifying; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D017384:Sequence Deletion; D015534:Trans-Activators / Q000235:genetics / Q000502:physiology
C095214:ATK1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D027682:Cation Transport Proteins; D005656:Fungal Proteins; D018398:Homeodomain Proteins; C501210:KAT1 protein, Arabidopsis; D008565:Membrane Proteins; D010940:Plant Proteins; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D029701:Saccharomyces cerevisiae Proteins; C085258:TRK2 protein, S cerevisiae; D015534:Trans-Activators; C068664:TRK1 protein, S cerevisiae; D016547:Kinesins; D011188:Potassium