Yeast Trk1 Potassium Transporter Gradually Changes Its Affinity in Response to Both External and Internal Signals.

ABSTRACT: Yeasts need a high intracellular concentration of potassium to grow. The main K⁺ uptake system in Saccharomyces cerevisiae is the Trk1 transporter, a complex protein with four MPM helical membrane motifs. Trk1 has been shown to exist in low- or high-affinity modes, which reflect the availability of potassium in the environment. However, when and how the affinity changes, and whether the potassium availability is the only signal for the affinity switch, remains unknown. Here, we characterize the Trk1 kinetic parameters under various conditions and find that Trk1's K_T and V_max change gradually. This gliding adjustment is rapid and precisely reflects the changes in the intracellular potassium content and membrane potential. A detailed characterization o

SUBMITTER: Masaryk J 

PROVIDER: S-EPMC9144525 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature