In baker's yeast (Saccharomyces cerevisiae), Trk1, a member of the superfamily of K-transporters (SKT), is the main K+ uptake system under conditions when its concentration in the environment is low. Structurally, Trk1 is made up of four domains, each similar and homologous to a K-channel α subunit. Because most K-channels are proteins containing four channel-building α subunits, Trk1 could be functional as a monomer. However, related SKT proteins TrkH and KtrB were crystallised as dimers, and for Trk1, a tetrameric arrangement has been proposed based on molecular modelling. Here, based on Bimolecular Fluorescence Complementation experiments and single-molecule fluorescence microscopy combined with molecular modelling; we provide evidence that Trk1 can exist in the yeast plasma membrane as a monomer as well as a dimer. The association of monomers to dimers is regulated by the K+ concentration.
- MeSH
- Biological Transport MeSH
- Cell Membrane metabolism MeSH
- Potassium metabolism MeSH
- Fungal Proteins metabolism MeSH
- Cation Transport Proteins * genetics metabolism MeSH
- Saccharomyces cerevisiae Proteins * genetics metabolism MeSH
- Saccharomyces cerevisiae metabolism MeSH
- Translocation, Genetic MeSH
- Carrier Proteins metabolism MeSH
- Publication type
- Journal Article MeSH
