Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-17561
Nature October 17, 1996; 383 (6601): 634-7.

Flux coupling in a neuronal glutamate transporter.

Zerangue N , Kavanaugh MP .


Abstract
Synaptic transmission is commonly terminated by diffusion and reuptake of neurotransmitter from the synaptic cleft. Glutamate reuptake prevents neurotoxicity and sets the lower limit for the concentration of extracellular glutamate, so it is important to understand the thermodynamics of this process. Here we use voltage clamping with a pH-sensitive fluorescent dye to monitor electrical currents and pH changes associated with flux of glutamate mediated by the human neuronal glutamate transporter EAAT3. In contrast to a previous model, we find that three sodium ions and one proton are cotransported with each glutamate ion into the cell, while one potassium ion is transported out of the cell. This coupling can support a transmembrane glutamate concentration gradient ([Glu]in/[Glu]out) exceeding 10(6) under equilibrium conditions, and would allow the transporter to continue removing glutamate over a wide range of ionic conditions.

PubMed ID: 8857541
Article link: Nature

Genes referenced: slc1a1



Xenbase: The Xenopus laevis and X. tropicalis resource.
Version: 4.13.1
Major funding for Xenbase is provided by grant P41 HD064556