Kinetics of a human glutamate transporter

Abstract

Currents mediated by a glutamate transporter cloned from human motor cortex were measured in Xenopus oocytes. In the absence of glutamate, voltage jumps induced Na(+)-dependent capacitive currents that were blocked by kainate, a competitive transport antagonist. The pre-steady-state currents can be described by an ordered binding model in which a voltage-dependent Na+ binding is followed by a voltage-independent kainate binding. At -80 mV, two charges are translocated per molecule of glutamate, with a cycling time of approximately 70 ms, which is significantly slower than the predicted time course of synaptically released glutamate. The results suggest that glutamate diffusion and binding to transporters, rather than uptake, are likely to dominate the synaptic concentration decay kinetics.

Keywords

Kainate receptorGlutamate receptorBiophysicsChemistryExcitatory amino-acid transporterKineticsTransporterIonotropic effectHippocampal formationMetabotropic glutamate receptorNeuroscienceBiochemistryBiologyAMPA receptorReceptorPhysics

MeSH Terms

ATP-Binding Cassette TransportersAmino Acid Transport System X-AGAnimalsBrain ChemistryCloningMolecularElectric ConductivityFemaleGene ExpressionGene Transfer TechniquesHumansKainic AcidKineticsMembrane PotentialsMotor CortexOocytesXenopus

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Publication Info

Year: 1995
Type: article
Volume: 14
Issue: 5
Pages: 1019-1027
Citations: 405
Access: Closed

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APA Style

                            
                                
                                    Jacques I. Wadiche, 
                                
                                    Jeffrey L. Arriza, 
                                
                                    Susan Amara
                                
                                et al.
                            
                            (1995). 
                            Kinetics of a human glutamate transporter. 
                            Neuron
                            , 14
                            (5)
                            , 1019-1027.
                            https://doi.org/10.1016/0896-6273(95)90340-2
                        

Identifiers

DOI: 10.1016/0896-6273(95)90340-2
PMID: 7748550

Data Quality

Data completeness: 90%