Inducible Expression of the GLT-1 Glutamate Transporter in a CHO Cell Line Selected for Low Endogenous Glutamate Uptake

Inducible expression of the mammalian glial cell glutamate transporter GLT-1 has been established in a CHO cell line selected for low endogenous Na+-dependent glutamate uptake by [3H]aspartate suicide selection. Culturing the cells in doxycycline-containing medium, to activate GLT-1 expression via the Tet-On system, increased uptake of the GLT-1 substrate D-aspartate 280-fold, and increased cell size. Applying glutamate to whole-cell clamped, doxycycline-treated cells evoked a transporter-mediated current with characteristics appropriate for GLT-1. This cell line provides a useful tool for further examination of the electrical, biochemical and pharmacological properties of GLT-1, the most abundant glutamate transporter in the brain.