2i0c
From Proteopedia
Crystal structure of the GluR6 ligand binding core dimer crosslinked by disulfide bonds between Y490C and L752C at 2.25 Angstroms Resolution
Structural highlights
Function[GRIK2_RAT] Ionotropic glutamate receptor. 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. May be involved in the transmission of light information from the retina to the hypothalamus. Modulates cell surface expression of NETO2 (By similarity).[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedDesensitization is a universal feature of ligand-gated ion channels. Using the crystal structure of the GluR2 L483Y mutant channel as a guide, we attempted to build non-desensitizing kainate-subtype glutamate receptors. Success was achieved for GluR5, GluR6 and GluR7 with intermolecular disulfide cross-links but not by engineering the dimer interface. Crystallographic analysis of the GluR6 Y490C L752C dimer revealed relaxation from the active conformation, which functional studies reveal is not sufficient to trigger desensitization. The equivalent non-desensitizing cross-linked GluR2 mutant retained weak sensitivity to a positive allosteric modulator, which had no effect on GluR2 L483Y. These results establish that the active conformation of AMPA and kainate receptors is conserved and further show that their desensitization requires dimer rearrangements, that subtle structural differences account for their diverse functional properties and that the ligand-binding core dimer is a powerful regulator of ion-channel activity. Conformational restriction blocks glutamate receptor desensitization.,Weston MC, Schuck P, Ghosal A, Rosenmund C, Mayer ML Nat Struct Mol Biol. 2006 Dec;13(12):1120-7. Epub 2006 Nov 19. PMID:17115050[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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