3g3h
Crystal structure of the GluR6 ligand binding domain dimer K665R I749L Q753K mutant with glutamate and NaCl at 1.5 Angstrom resolution
Structural highlights
FunctionGRIK2_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 PubMedAMPA and kainate receptors mediate fast synaptic transmission. AMPA receptor ligand-binding domains form dimers, which are key functional units controlling ion-channel activation and desensitization. Dimer stability is inversely related to the rate and extent of desensitization. Kainate and AMPA receptors share common structural elements, but functional measurements suggest that subunit assembly and gating differs between these subtypes. To investigate this, we constructed a library of GluR6 kainate receptor mutants and directly measured changes in kainate receptor dimer stability by analytical ultracentrifugation, which, combined with electrophysiological experiments, revealed an inverse correlation between dimer stability and the rate of desensitization. We solved crystal structures for a series of five GluR6 mutants, to understand the molecular mechanisms for dimer stabilization. We demonstrate that the desensitized state of kainate receptors acts as a deep energy well offsetting the stabilizing effects of dimer interface mutants, and that the deactivation of kainate receptor responses is dominated by entry into desensitized states. Our results show how neurotransmitter receptors with similar structures and gating mechanisms can exhibit strikingly different functional properties. Stability of ligand-binding domain dimer assembly controls kainate receptor desensitization.,Chaudhry C, Weston MC, Schuck P, Rosenmund C, Mayer ML EMBO J. 2009 May 20;28(10):1518-30. Epub 2009 Apr 2. PMID:19339989[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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