Abstract
Stable and inducible expression of human metabotropic glutamate receptor types 2, 5, and 8 was achieved in HEK293 cells using the ecdysone inducible system. Treatment of the respective cell lines with ponasterone A resulted in time and concentration-dependent induction of receptor expression. In all cases, the functional activation of receptorswas determined bymeasuring increases in intracellular calcium. The physiologically G• i-coupled receptors mGluR2 andm GluR8 were successfully coupled to phospholipase Cactivation using the chimeric Gprotein G• q/o. The pharmacological properties of recombinant receptors were characterized and proved to be similar to native receptors. Our data suggest that the ecdysone system has a number of characteristics thatmake itwell suited for expressing mGluRs and that the combined use of this systemand chimeric G proteins allows receptors to be characterized using a rapid and straightforward Ca 2+assay.
