Sulfhydryl modification of V449C in the glutamate transporter EAAT1 abolishes substrate transport but not the substrate-gated anion conductance

Sulfhydryl modification of V449C in the glutamate transporter EAAT1 abolishes substrate transport but not the substrate-gated anion conductance.

Excitatory amino acid transporters (EAATs) buffer and remove synaptically released L-glutamate and maintain its concentrations below neurotoxic levels. EAATs also mediate a thermodynamically uncoupled substrate-gated anion conductance that may modulate cell excitability. Here, we demonstrate that modification of a cysteine substituted within a C-terminal domain of EAAT1 abolishes transport in b...

Neutral amino acid transporter ASCT2 displays substrate-induced Na+ exchange and a substrate-gated anion conductance.

The neutral amino acid transporter ASCT2 mediates electroneutral obligatory antiport but at the same time requires Na(+) for its function. To elucidate the mechanism, ASCT2 was expressed in Xenopus laevis oocytes and transport was analysed by flux studies and two-electrode voltage clamp recordings. Flux studies with (22)NaCl indicated that the uptake of one molecule of glutamine or alanine is a...

Zn2+ Inhibits the Anion Conductance of the Glutamate Transporter EAAT4*

Transport direction determines the kinetics of substrate transport by the glutamate transporter EAAC1.

Glutamate transport by the excitatory amino acid carrier EAAC1 is known to be reversible. Thus, glutamate can either be taken up into cells, or it can be released from cells through reverse transport, depending on the electrochemical gradient of the co- and countertransported ions. However, it is unknown how fast and by which reverse transport mechanism glutamate can be released from cells. Her...

TM4 of the glutamate transporter GLT-1 experiences substrate-induced motion during the transport cycle

Excitatory amino acid transporter 2 (EAAT2), also known as glial glutamate transporter type 1 (GLT-1), plays an important role in maintaining the extracellular glutamate concentrations below neurotoxic levels. The highly conserved TM2 transmembrane domain of GLT-1 maintains a stable position during the transport cycle; however, the effect of the transport cycle on the topology of TM4 in not wel...