Ionotropic glutamate receptor

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Lig_chan
PDB 1s50 EBI.jpg
x-ray structure of the glur6 ligand binding core (s1s2a) in complex with glutamate at 1.65 a resolution
Identifiers
Symbol Lig_chan
Pfam PF00060
Pfam clan CL0030
InterPro IPR001320
SCOP 1gr2
SUPERFAMILY 1gr2
TCDB 1.A.10
OPM superfamily 231
OPM protein 3kg2

Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that are activated by the neurotransmitter glutamate.[1] They mediate the majority of excitatory synaptic transmission throughout the central nervous system and are key players in synaptic plasticity, which is important for learning and memory. iGluRs have been divided into four subtypes on the basis of their ligand binding properties (pharmacology) and sequence similarity: AMPA receptors, kainate receptors, NMDA receptors and delta receptors (see below).[2]

AMPA receptors are the main charge carriers during basal transmission, permitting influx of sodium ions to depolarise the postsynaptic membrane. NMDA receptors are blocked by magnesium ions and therefore only permit ion flux following prior depolarisation. This enables them to act as coincidence detectors for synaptic plasticity. Calcium influx through NMDA receptors leads to persistent modifications in the strength of synaptic transmission.[3][4]

iGluRs are tetramers (they are formed of four subunits). All subunits have a shared architecture with four domain layers: two extracellular clamshell domains called the N-terminal domain (NTD) and ligand-binding domain (LBD; which binds glutamate), the transmembrane domain (TMD) that forms the ion channel, and an intracellular C-terminal domain (CTD).[5]

Human proteins/genes encoding iGluR subunits[edit]

AMPA receptors: GluA1/GRIA1; GluA2/GRIA2; GluA3/GRIA3; GluA4/GRIA4;

delta receptors: GluD1/GRID1; GluD2/GRID2;

kainate receptors: GluK1/GRIK1; GluK2/GRIK2; GluK3/GRIK3; GluK4/GRIK4; GluK5/GRIK5;

NMDA receptors: GluN1/GRIN1; GluN2A/GRIN2A; GluN2B/GRIN2B; GluN2C/GRIN2C; GluN2D/GRIN2D; GluN3A/GRIN3A; GluN3B/GRIN3B;

References[edit]

  1. ^ Traynelis SF, Wollmuth LP, McBain CJ, Menniti FS, Vance KM, Ogden KK, Hansen KB, Yuan H, Myers SJ, Dingledine R (September 2010). "Glutamate receptor ion channels: structure, regulation, and function". Pharmacol. Rev. 62 (3): 405–496. PMC 2964903Freely accessible. PMID 20716669. doi:10.1124/pr.109.002451. 
  2. ^ Collingridge GL, Olsen RW, Peters J, Spedding M (January 2009). "A nomenclature for ligand-gated ion channels". Neuropharmacology. 56 (1): 2–5. PMC 2847504Freely accessible. PMID 18655795. doi:10.1016/j.neuropharm.2008.06.063. 
  3. ^ Bliss TV, Collingridge GL (January 1993). "A synaptic model of memory: long-term potentiation in the hippocampus". Nature. 361 (6407): 31–39. PMID 8421494. doi:10.1038/361031a0. 
  4. ^ Citri A, Malenka RC (January 2008). "Synaptic plasticity: multiple forms, functions, and mechanisms". Neuropsychopharmacology. 33 (1): 18–41. PMID 17728696. doi:10.1038/sj.npp.1301559. 
  5. ^ Traynelis SF, Wollmuth LP, McBain CJ, Menniti FS, Vance KM, Ogden KK, Hansen KB, Yuan H, Myers SJ, Dingledine R (September 2010). "Glutamate receptor ion channels: structure, regulation, and function". Pharmacol. Rev. 62 (3): 405–496. PMC 2964903Freely accessible. PMID 20716669. doi:10.1124/pr.109.002451. 

This article incorporates text from the public domain Pfam and InterPro IPR001320