Abstract
The Pho84 high-affinity phosphate permease is the primary phosphate transporter in the yeast Saccharomyces cerevisiae under phosphate-limiting conditions. The soluble G protein, Gtr1, has previously been suggested to be involved in the derepressible Pho84 phosphate uptake function. This idea was based on a displayed deletion phenotype of Deltagtr1 similar to the Deltapho84 phenotype. As of yet, the mode of interaction has not been described. The consequences of a deletion of gtr1 on in vivo Pho84 expression, trafficking and activity, and extracellular phosphatase activity were analyzed in strains synthesizing either Pho84-green fluorescent protein or Pho84-myc chimeras. The studies revealed a delayed response in Pho84-mediated phosphate uptake and extracellular phosphatase activity under phosphate-limiting conditions. EPR spectroscopic studies verified that the N-terminal G binding domain (residues 1-185) harbors the nucleotide responsive elements. In contrast, the spectra obtained for the C-terminal part (residues 186-310) displayed no evidence of conformational changes upon GTP addition.
Original language | English |
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Pages (from-to) | 511-7 |
Journal | Biochemistry |
Volume | 44 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2005 Jan 18 |
Externally published | Yes |
Free keywords
- Electron Spin Resonance Spectroscopy
- Gene Deletion
- Green Fluorescent Proteins
- Models, Molecular
- Monomeric GTP-Binding Proteins
- Phosphates
- Protein Binding
- Protein Conformation
- Protein Transport
- Proton-Phosphate Symporters
- Recombinant Fusion Proteins
- Saccharomyces cerevisiae Proteins
- Structure-Activity Relationship
- Thermodynamics
- Journal Article
- Research Support, Non-U.S. Gov't