EXPRESSION OF FUNCTIONAL METABOTROPIC AND IONOTROPIC GLUTAMATE RECEPTORS IN BACULOVIRUS-INFECTED INSECT CELLS

An ionotropic glutamate receptor of the kainate subtype (GluR6) and a G-protein coupled metabotropic glutamate receptor (mGluR1 alpha) were expressed and studied in two insect cell lines: sf9 cells from Spodopt era frugiperda lrgipernn and MG1 cells from Trichoplusia ni. Applicati on of kainate to GluR6-infected MG1 cells produced kainate-activated c urrents. Glutamate activation of mGluR1 alpha in MG1- and sf9-infected cells caused rapid, transient increases in intracellular calcium leve ls. This effect was more pronounced in MG1 cells compared to sf9 cells . These results indicate that functional glutamate receptors can be ex pressed in the baculovirus system, and that MG1 cells may have several advantages over the widely used sf9 cells for studying the functional properties of receptors and channels.