Electrophysiological and pharmacological properties of GluR1, a subunit of a glutamate receptor-channel expressed in Xenopus oocytes.
A cDNA clone encoding an excitatory amino acid receptor was isolated from a rat brain cDNA library by Hollmann et al. (Nature, 342 (1989) 643-648). In Xenopus oocytes, this clone, GluR1, expressed a functional receptor-channel activated by kainate (KA), domoate (D), glutamate and quisqualate (QA). The apparent affinity (EC50) for QA (0.1 microM) was higher than that for KA (50 microM). The maximal response to QA was about 1/10 of that to KA. QA inhibited the KA induced current. The N-methyl-D-aspartate (non-NMDA) receptor antagonist 6,7-dinitroquinoxaline-2,3 dione (DNQX) competitively blocked the effects of both agonists. Currents induced by KA, QA and D in oocytes expressing GluR1 showed identical voltage sensitivities. GluR1 and KA receptor-channels expressed from rat striatum poly(A)+ RNA showed the same ionic selectivity, being permeable mostly to Na+ and K+. The current-voltage relationships of GluR1 showed a strong inward rectification, whereas those of KA receptor-channels expressed from poly(A)+ RNA from various rat brain regions were more linear.
Lambolez
B
B
Laboratoire de Physiologie Nerveuse, CNRS, Gif sur Yvette, France.
Curutchet
P
P
Stinnakre
J
J
Bregestovski
P
P
Rossier
J
J
Prado de Carvalho
L
L
D000818:Animals; D001921:Brain / Q000502:physiology*; D003001:Cloning, Molecular; D005260:Female; D015723:Gene Library; D005971:Glutamates / Q000378:metabolism / Q000494:pharmacology*; D007608:Kainic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*; D046911:Macromolecular Substances; D008564:Membrane Potentials / Q000187:drug effects; D009467:Neuromuscular Depolarizing Agents / Q000494:pharmacology; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D016318:Quisqualic Acid / Q000494:pharmacology; D051381:Rats; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D014981:Xenopus
D005971:Glutamates; D046911:Macromolecular Substances; D009467:Neuromuscular Depolarizing Agents; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter; D016318:Quisqualic Acid; C012301:domoic acid; D007608:Kainic Acid