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 language | English |
---|---|
Pages (from-to) | 125-132 |
Number of pages | 8 |
Journal | FEBS Letters |
Volume | 527 |
Issue number | 1-3 |
DOIs | |
State | Published - 11 Sep 2002 |
Keywords
- Neurotransmitter
- Proton
- Sodium
- Transport
- Transporter
- γ-Aminobutyric acid