8FPC

Conformation 1 of the ligand binding domain (LBDconf1) 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 100mM glutamate (Open-CaNaMg)

8FPC の概要

• エントリーDOI: 10.2210/pdb8fpc/pdb
• EMDBエントリー: 29360 29361 29363 29364 29367 29368
• 分子名称: Glutamate receptor 2, GLUTAMIC ACID, CYCLOTHIAZIDE, ... (4 entities in total)
• 機能のキーワード: ionotropic glutamate receptors, ampa receptors, ion channel, ligand-gated ion channel, auxiliary subunit, stargazing, tarp gamma2, transport protein
• 由来する生物種: Rattus norvegicus (Norway rat)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 400385.87

構造登録者

Nakagawa, T. (登録日: 2023-01-04, 公開日: 2024-02-28, 最終更新日: 2024-11-06)

主引用文献

Nakagawa, T.,Wang, X.T.,Miguez-Cabello, F.J.,Bowie, D.
The open gate of the AMPA receptor forms a Ca 2+ binding site critical in regulating ion transport.
Nat.Struct.Mol.Biol., 31:688-700, 2024

PubMed Abstract: 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-permeable AMPARs (rat GRIA2 flip-Q isoform) at 2.3-2.6 Å resolution. We show that the ion permeation pathway attains an extracellular Ca binding site (site-G) when the channel gate moves into the open configuration. Site-G is highly selective for Ca over Na, favoring the movement of Ca into the selectivity filter of the pore. Seizure-related N619K mutation, adjacent to site-G, promotes channel opening but attenuates Ca binding and thus diminishes Ca 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 through the channel pore.

PubMed: 38409505
DOI: 10.1038/s41594-024-01228-3

実験手法

ELECTRON MICROSCOPY (2.78 Å)