Structure and pharmacological properties of a molluscan glutamate-gated cation channel and its likely role in feeding behavior.

Stühmer, T., Amar, M., Harvey, R.J., Bermudez, I., Van Minnen, J. and Darlison, M.G. (1996) Structure and pharmacological properties of a molluscan glutamate-gated cation channel and its likely role in feeding behavior. Journal of Neuroscience, 16 (9). pp. 2869-80.

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Abstract

We describe the isolation of a molluscan (Lymnaea stagnalis) full-length complementary DNA that encodes a mature polypeptide (which we have named Lym-eGluR2) with a predicted molecular weight of 105 kDa that exhibits 44-48% identity to the mammalian kainate-selective glutamate receptor GluR5, GluR6, and GluR7 subunits. Injection of in vitro-transcribed RNA from this clone into Xenopus laevis oocytes results in the robust expression of homo-oligomeric cation channels that can be gated by L-glutamate (EC50 = 1.2 +/- 0.3 micron) and several other glutamate receptor agonists; rank order of potency: glutamate >> kainate > ibotenate > AMPA. These currents can be blocked by the mammalian non-NMDA receptor antagonists 6,7-dinitroquinoxaline-2,3-dione, 6-cyano-7-nitroquinoxaline-2,3-dione, and 1-(4-chlorobenzoyl)piperazine-2,3-dicarboxylic acid. Ionic-replacement experiments have shown that the agonist-induced current is carried entirely by sodium and potassium ions. In situ hybridization has revealed that the Lym-eGluR2 transcript is present in all 11 ganglia of the Lymnaea CNS, including the 4-cluster motorneurons within the paired buccal ganglia. The pharmacological properties and deduced location of Lym-eGluR2 are entirely consistent with it being (a component of) the receptor, which has been identified previously on buccal motorneurons, that mediates the excitatory effects of glutamate released from neurons within the feeding central pattern generator.

Item Type:Article
Departments, units and centres:Department of Pharmacology > Department of Pharmacology
ID Code:1990
Journal or Publication Title:Journal of Neuroscience
Deposited By:Library Staff
Deposited On:01 Apr 2011 10:07
Last Modified:16 Jun 2011 11:11

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