Assembly of Taurine Transporter (Slc6a6) with Na⁺-H⁺ Exchanger Regulatory Factor 1 (Slc9a3r1) Improves GABA Transport Activity by Increasing the Maximum Transport Velocity Assembly of Taurine Transporter (Slc6a6) with Na<sup>+</sup>–H<sup>+</sup> Exchanger Regulatory Factor 1 (Slc9a3r1) Improves GABA Transport Activity by Increasing the Maximum Transport Velocity

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Author(s)

Abstract

<p>Regulating γ-aminobutyric acid (GABA) uptake transport on the plasma membranes is required for its efficient clearance from the brain interstitial fluid. The purpose of this study was to clarify the assembly of taurine transporter (TauT/Slc6a6) and PSD-95/Disc-large/Zo-1 (PDZ) domain of Na<sup>+</sup>–H<sup>+</sup> exchanger regulatory factor 1 (NHERF1) as a regulatory mechanism of TauT-mediated GABA transport activity. <i>In vitro</i> glutathione <i>S</i>-transferase (GST)-pull down assay and immunoblotting with anti-NHERF1 antibody revealed that NHERF1 protein was present in rat brain lysates as the binding protein of the GST-fusion TauT C-terminal protein with the PDZ-binding ETMM motif but not its corresponding deletion mutant lacking the motif. [<sup>3</sup>H]GABA uptake by TauT-NHERF1-coexpressing oocytes and TauT-singly expressing oocytes exhibited saturable kinetics with Michaelis–Menten constant values of 0.835±0.288 and 0.982±0.569 mM and a maximal transport velocity of 206±37 and 283±28 pmol/(h·oocyte), respectively. These results suggest that the assembly of TauT PDZ-binding motif and NHERF1 increases the maximal transport velocity of GABA rather than changes the affinity.</p>

Journal

  • Biological and Pharmaceutical Bulletin

    Biological and Pharmaceutical Bulletin 41(3), 338-341, 2018

    The Pharmaceutical Society of Japan

Codes

  • NII Article ID (NAID)
    130006407354
  • NII NACSIS-CAT ID (NCID)
    AA10885497
  • Text Lang
    ENG
  • ISSN
    0918-6158
  • NDL Article ID
    028854288
  • NDL Call No.
    Z53-V41
  • Data Source
    NDL  J-STAGE 
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