title: A universal mechanism for transport and regulation of CPA sodium proton exchangers.
abstract: Recent studies performed on a series of Na+/H+ exchangers have led us to postulate a general mechanism for Na+/H+ exchange in the monovalent cation/proton antiporter superfamily. This simple mechanism employs a single binding site for which both substrates compete. The developed kinetic model is self-regulatory, ensuring down-regulation of transport activity at extreme pH, and elegantly explains the pH-dependent activity of Na+/H+ exchangers. The mechanism was experimentally verified and shown to describe both electrogenic and electroneutral exchangers. Using a small number of parameters, exchanger activity can be modeled under different conditions, providing insights into the physiological role of Na+/H+ exchangers.
authors.forename: Octavian
authors.initials: O
authors.lastname: Călinescu
authors.forename: Klaus
authors.initials: K
authors.lastname: Fendler
mesh_terms: D001692:Biological Transport; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008954:Models, Biological; D017923:Sodium-Hydrogen Exchangers / Q000737:chemistry / Q000378:metabolism*
chemical_list: D017923:Sodium-Hydrogen Exchangers