Differential effect of pH on sodium binding by the various GABA transporters expressed in Xenopus oocytes

Tamar R. Grossman, Nathan Nelson*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

Mouse GABA transporters belong to the family of Na+- and Cl--dependent neurotransmitter transporters. The four GABA transporters exhibit unique presteady-state currents when expressed in Xenopus oocytes. The properties of the presteady-state currents correspond to their different affinities to Na+. In the presence of 20 μM GABA and at pH 7.5, the half-maximal uptake activity was 47, 120, 25 and 35 mM Na+ for GAT1, GAT2, GAT3 and GAT4, respectively. The appearance of presteady-state currents at positive or negative imposed potentials was in correlation with the affinity to Na+. Changing the external pH differentially affected the GABA uptake and the presteady-state activities of the various GABA transporters. It is suggested that protons compete with Na+ on its binding site; however, the proton binding is not productive and is unable to drive GABA uptake.

Original languageEnglish
Pages (from-to)125-132
Number of pages8
JournalFEBS Letters
Volume527
Issue number1-3
DOIs
StatePublished - 11 Sep 2002

Funding

FundersFunder number
United States-Israel Binational Science Foundation

    Keywords

    • Neurotransmitter
    • Proton
    • Sodium
    • Transport
    • Transporter
    • γ-Aminobutyric acid

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