View source for 8fpk


==LBD conformation 1 of GluA2 flip Q isoform of AMPA receptor in complex with gain-of-function TARP gamma-2, with 10mM CaCl2, 150mM NaCl, 1mM MgCl2, 330uM CTZ, and 100uM CNQX (Closed-CaNaMg)==
<StructureSection load='8fpk' size='340' side='right'caption='[[8fpk]], [[Resolution|resolution]] 2.76&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8fpk]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8FPK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8FPK FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.76&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CYZ:CYCLOTHIAZIDE'>CYZ</scene>, <scene name='pdbligand=Y4Y:6-(aminomethyl)-7-nitro-1,4-dihydroquinoxaline-2,3-dione'>Y4Y</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8fpk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8fpk OCA], [https://pdbe.org/8fpk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8fpk RCSB], [https://www.ebi.ac.uk/pdbsum/8fpk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8fpk ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GRIA2_RAT GRIA2_RAT] Receptor for glutamate that functions as ligand-gated ion channel in the central nervous system and plays an important role in excitatory synaptic transmission. L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. Binding of the excitatory neurotransmitter L-glutamate induces a conformation change, leading to the opening of the cation channel, and thereby converts the chemical signal to an electrical impulse. The receptor then desensitizes rapidly and enters a transient inactive state, characterized by the presence of bound agonist. In the presence of CACNG4 or CACNG7 or CACNG8, shows resensitization which is characterized by a delayed accumulation of current flux upon continued application of glutamate.<ref>PMID:9351977</ref> <ref>PMID:19265014</ref> <ref>PMID:21172611</ref> <ref>PMID:12501192</ref> <ref>PMID:12015593</ref> <ref>PMID:12872125</ref> <ref>PMID:12730367</ref> <ref>PMID:16192394</ref> <ref>PMID:15591246</ref> <ref>PMID:17018279</ref> <ref>PMID:16483599</ref> <ref>PMID:19946266</ref> <ref>PMID:21317873</ref> <ref>PMID:21846932</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionic acid receptors (AMPARs) are cation-selective ion channels that mediate most fast excitatory neurotransmission in the brain. Although their gating mechanism has been studied extensively, understanding how cations traverse the pore has remained elusive. Here we investigated putative ion and water densities in the open pore of Ca(2+)-permeable AMPARs (rat GRIA2 flip-Q isoform) at 2.3-2.6 A resolution. We show that the ion permeation pathway attains an extracellular Ca(2+) binding site (site-G) when the channel gate moves into the open configuration. Site-G is highly selective for Ca(2+) over Na(+), favoring the movement of Ca(2+) into the selectivity filter of the pore. Seizure-related N619K mutation, adjacent to site-G, promotes channel opening but attenuates Ca(2+) binding and thus diminishes Ca(2+) permeability. Our work identifies the importance of site-G, which coordinates with the Q/R site of the selectivity filter to ensure the preferential transport of Ca(2+) through the channel pore.

The open gate of the AMPA receptor forms a Ca(2+) binding site critical in regulating ion transport.,Nakagawa T, Wang XT, Miguez-Cabello FJ, Bowie D Nat Struct Mol Biol. 2024 Apr;31(4):688-700. doi: 10.1038/s41594-024-01228-3. , Epub 2024 Feb 26. PMID:38409505<ref>PMID:38409505</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8fpk" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Rattus norvegicus]]
[[Category: Nakagawa T]]