Publication Date:
2009-12-01
Description:
Ionotropic glutamate receptors mediate most excitatory neurotransmission in the central nervous system and function by opening a transmembrane ion channel upon binding of glutamate. Despite their crucial role in neurobiology, the architecture and atomic structure of an intact ionotropic glutamate receptor are unknown. Here we report the crystal structure of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-sensitive, homotetrameric, rat GluA2 receptor at 3.6 A resolution in complex with a competitive antagonist. The receptor harbours an overall axis of two-fold symmetry with the extracellular domains organized as pairs of local dimers and with the ion channel domain exhibiting four-fold symmetry. A symmetry mismatch between the extracellular and ion channel domains is mediated by two pairs of conformationally distinct subunits, A/C and B/D. Therefore, the stereochemical manner in which the A/C subunits are coupled to the ion channel gate is different from the B/D subunits. Guided by the GluA2 structure and site-directed cysteine mutagenesis, we suggest that GluN1 and GluN2A NMDA (N-methyl-d-aspartate) receptors have a similar architecture, with subunits arranged in a 1-2-1-2 pattern. We exploit the GluA2 structure to develop mechanisms of ion channel activation, desensitization and inhibition by non-competitive antagonists and pore blockers.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2861655/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2861655/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sobolevsky, Alexander I -- Rosconi, Michael P -- Gouaux, Eric -- F32 NS049767-05/NS/NINDS NIH HHS/ -- R01 NS038631/NS/NINDS NIH HHS/ -- R01 NS038631-06/NS/NINDS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2009 Dec 10;462(7274):745-56. doi: 10.1038/nature08624. Epub .〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Vollum Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19946266" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Cell Line
;
Crystallization
;
Crystallography, X-Ray
;
Ion Channel Gating
;
Models, Molecular
;
Potassium Channels/chemistry/metabolism
;
Protein Conformation
;
Protein Subunits/chemistry/metabolism
;
Rats
;
Receptors, AMPA/antagonists & inhibitors/*chemistry/*metabolism
;
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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