Phosphate permeases of Saccharomyces cerevisiae

AbstractThe PHO 84 and PHO 89 genes of Saccharomyces cerevisiae encode two high-affinity phosphate contransporters of the plasma membrane. Hydropathy analysis suggests a secondary structure arrangement of the proteins in 12 transmembrane domains. The derepressible Pho84 and Pho89 transporters appear to have characteristic similarities with the phosphate transporters of Neurospora crassa. The Pho84 protein catalyzes a proton-coupled phosphate transport at acidic pH, while the Pho89 protein catalyzes a sodium-dependent phosphate uptake at alkaline pH. The Pho84 transporter can be stably overproduced in the cytoplasmic membrane of Escherichia coli, purified and reconstituted in a functional state into proteoliposomes