Journal of Biological Chemistry
Medical Sciences | Medicine and Health Sciences | Pharmacy and Pharmaceutical Sciences
GAT-1, a gamma-aminobutyric acid (GABA) transporter cloned from rat brain, was expressed in Xenopus oocytes. Voltage-clamp measurements showed concentration-dependent, inward currents in response to GABA (K0.5 4.7 microM). The transport current required extracellular sodium and chloride ions; the Hill coefficient for chloride was 0.7, and that for sodium was 1.7. Correlation of current and [3H]GABA uptake measurements indicate that flux of one positive charge occurs per molecule of GABA transported. Membrane hyperpolarization from -40 to -100 mV increased the transport current approximately 3-fold. The results indicate that the transport of one molecule of GABA involves the co-transport of two sodium ions and one chloride ion.
© 1992 The American Society for Biochemistry and Molecular Biology, Inc.
Kavanaugh, Michael; Arriza, Jeffrey L.; North, R. Alan; and Amara, Susan G., "Electrogenic uptake of gamma-aminobutyric acid by a cloned transporter expressed in Xenopus oocytes" (1992). Biomedical and Pharmaceutical Sciences Faculty Publications. 62.