title: Phosphate transporters of the SLC20 and SLC34 families.
abstract: Transport of inorganic phosphate (Pi) across the plasma membrane is essential for normal cellular function. Members of two families of SLC proteins (SLC20 and SLC34) act as Na(+)-dependent, secondary-active cotransporters to transport Pi across cell membranes. The SLC34 proteins are expressed in specific organs important for Pi homeostasis: NaPi-IIa (SLC34A1) and NaPi-IIc (SLC34A3) fulfill essential roles in Pi reabsorption in the kidney proximal tubule and NaPi-IIb (SLC34A2) mediates Pi absorption in the gut. The SLC20 proteins, PiT-1 (SLC20A1), PiT-2 (SLC20A2) are expressed ubiquitously in all tissues and although generally considered as "housekeeping" transport proteins, the discovery of tissue-specific activity, regulatory pathways and gene-related pathophysiologies, is redefining their importance. This review summarizes our current knowledge of SLC20 and SLC34 proteins in terms of their basic molecular characteristics, physiological roles, known pathophysiology and pharmacology.
authors.affiliation: Institute of Physiology and Zurich Center for Integrated Human Physiology, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland. iforster@access.uzh.ch
authors.forename: Ian C
authors.initials: IC
authors.lastname: Forster
authors.forename: Nati
authors.initials: N
authors.lastname: Hernando
authors.forename: Jürg
authors.initials: J
authors.lastname: Biber
authors.forename: Heini
authors.initials: H
authors.lastname: Murer
mesh_terms: D017245:Foscarnet / Q000494:pharmacology; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D008958:Models, Molecular; D005810:Multigene Family / Q000235:genetics*; D011487:Protein Conformation; D050608:Sodium-Phosphate Cotransporter Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*
chemical_list: D050608:Sodium-Phosphate Cotransporter Proteins; D017245:Foscarnet