| Structural highlightsFunction[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.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14]
Publication Abstract from PubMed
AMPA-subtype ionotropic glutamate receptors (AMPARs) mediate fast excitatory neurotransmission and contribute to high cognitive processes such as learning and memory. In the brain, AMPAR trafficking, gating, and pharmacology is tightly controlled by transmembrane AMPAR regulatory proteins (TARPs). Here, we used cryo-electron microscopy to elucidate the structural basis of AMPAR regulation by one of these auxiliary proteins, TARP gamma2, or stargazin (STZ). Our structures illuminate the variable interaction stoichiometry of the AMPAR-TARP complex, with one or two TARP molecules binding one tetrameric AMPAR. Analysis of the AMPAR-STZ binding interfaces suggests that electrostatic interactions between the extracellular domains of AMPAR and STZ play an important role in modulating AMPAR function through contact surfaces that are conserved across AMPARs and TARPs. We propose a model explaining how TARPs stabilize the activated state of AMPARs and how the interactions between AMPARs and their auxiliary proteins control fast excitatory synaptic transmission.
Elucidation of AMPA receptor-stargazin complexes by cryo-electron microscopy.,Twomey EC, Yelshanskaya MV, Grassucci RA, Frank J, Sobolevsky AI Science. 2016 Jul 1;353(6294):83-6. doi: 10.1126/science.aaf8411. PMID:27365450[15]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
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- ↑ Twomey EC, Yelshanskaya MV, Grassucci RA, Frank J, Sobolevsky AI. Elucidation of AMPA receptor-stargazin complexes by cryo-electron microscopy. Science. 2016 Jul 1;353(6294):83-6. doi: 10.1126/science.aaf8411. PMID:27365450 doi:http://dx.doi.org/10.1126/science.aaf8411
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