2OJT: Structure And Mechanism Of Kainate Receptor Modulation By Anions

Citation:
Abstract
L-glutamate, the major excitatory neurotransmitter in the human brain, activates a family of ligand-gated ion channels, the major subtypes of which are named AMPA, kainate, and NMDA receptors. In common with many signal transduction proteins, glutamate receptors are modulated by ions and small molecules, including Ca(2+), Mg(2+), Zn(2+), protons, polyamines, and steroids. Strikingly, the activation of kainate receptors by glutamate requires the presence of both Na(+) and Cl(-) in the extracellular solution, and in the absence of these ions, receptor activity is abolished. Here, we identify the site and mechanism of action of anions. Surprisingly, we find that Cl(-) ions are essential structural components of kainate receptors. Cl(-) ions bind in a cavity formed at the interface between subunits in a dimer pair. In the absence of Cl(-), dimer stability is reduced, the rate of desensitization increases, and the fraction of receptors competent for activation by glutamate drops precipitously.
PDB ID: 2OJTDownload
MMDB ID: 45221
PDB Deposition Date: 2007/1/14
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 1.95  Å
Source Organism:
Similar Structures:
Biological Unit for 2OJT: dimeric; determined by author
Molecular Components in 2OJT
Label Count Molecule
Proteins (2 molecules)
2
Glutamate Receptor, Ionotropic Kainate 1(Gene symbol: Grik1)
Molecule annotation
Chemicals (6 molecules)
1
2
2
2
3
2
* Click molecule labels to explore molecular sequence information.

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