A NEW-TYPE OF INOTROPIC GLUTAMATE RECEPTORS

The possibility of the existence of a new type of ionotropic glutamate receptor differing from NMDA and non-NMDA receptors was confirmed by cloning cDNA for XenNR1, a channel-forming subunit of the glutamate re ceptor from the Xenopus laevis brain, Cotransfection of the HEK-293 ce lls with the cDNAs for XenNR1 and XenU1 (a non-NMDA receptor subunit f rom X. laevis brain) resulted in the biosynthesis of a functionally ac tive heterosubunit receptor composed of NMDA and non-NMDA subunits, Th e functional co-expression of the XenNR1 and XenU1 cDNAs is the first direct evidence for the existence of a new type of glutamate receptor.