title: Type 1 sodium-dependent phosphate transporter acts as a membrane potential-driven urate exporter.
abstract: SLC17A1 protein (NPT1) was the first identified member of the SLC17 phosphate transporter family, and is known to mediate Na(+)/inorganic phosphate (Pi) co-transport when expressed in Xenopus oocytes. Although this protein was suggested to be a renal polyspecific anion exporter, its transport properties were not well characterized. The clean biochemical approach revealed that proteoliposomes comprising purified NPT1 as the only protein source transport various organic anions such as urate, p-aminohippuric acid (PAH), and acetylsalicylic acid (aspirin) in a membrane potential (Δψ)-driven and Cl(-) -dependent manner. Human NPT1 carrying an SNP mutation, Thr269Ile, known to increase the risk of gout, exhibited 32% lower urate transport activity compared to the wild type protein, leading to the conclusion that NPT1 is the long searched for transporter responsible for renal urate excretion. In the present article, we summarized the history of identification of the urate exporter and its possible involvement in the dynamism of urate under physiological and pathological conditions.
authors.affiliation: Advanced Science Research Center, Okayama University, Okayama 700-8530, Japan. tmiyaji@pharm.okayama-u.ac.jp
authors.forename: Takaaki
authors.initials: T
authors.lastname: Miyaji
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Natsuko
authors.initials: N
authors.lastname: Togawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Omote
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Moriyama
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006073:Gout / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008564:Membrane Potentials; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide; D050609:Sodium-Phosphate Cotransporter Proteins, Type I / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D014527:Uric Acid / Q000378:metabolism*
chemical_list: C493546:SLC17A1 protein, human; D050609:Sodium-Phosphate Cotransporter Proteins, Type I; D014527:Uric Acid