| Structural highlights
Function
[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
Glutamate receptors mediate the majority of excitatory synaptic transmission in the central nervous system and excessive stimulation of these receptors is involved in a variety of neurological disorders and neuronal damage from stroke. The development of new subtype specific antagonists would be of considerable therapeutic interest. Natural products can provide important new lead compounds for drug discovery. The only natural product known to inhibit glutamate receptors competitively is (-)-kaitocephalin, which was isolated from the fungus, Eupenicillium shearii and found to protect CNS neurons from excitotoxicity. Previous work has shown that it is a potent antagonist of some subtypes of glutamate receptors (AMPA and NMDA, but not kainate). The structure of kaitocephalin bound to the ligand-binding domain of the AMPA receptor subtype, GluA2, is reported here. The structure suggests how kaitocephalin can be used as a scaffold to develop more selective and high affinity antagonists for glutamate receptors.
The Structure of (-)-Kaitocephalin Bound to the Ligand Binding Domain of the AMPA/Glutamate Receptor, GluA2.,Ahmed AH, Hamada M, Shinada T, Ohfune Y, Weerasinghe L, Garner PP, Oswald RE J Biol Chem. 2012 Oct 17. PMID:23076153[15]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
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- ↑ Kasper C, Pickering DS, Mirza O, Olsen L, Kristensen AS, Greenwood JR, Liljefors T, Schousboe A, Watjen F, Gajhede M, Sigurskjold BW, Kastrup JS. The structure of a mixed GluR2 ligand-binding core dimer in complex with (S)-glutamate and the antagonist (S)-NS1209. J Mol Biol. 2006 Apr 7;357(4):1184-201. Epub 2006 Jan 31. PMID:16483599 doi:10.1016/j.jmb.2006.01.024
- ↑ Sobolevsky AI, Rosconi MP, Gouaux E. X-ray structure, symmetry and mechanism of an AMPA-subtype glutamate receptor. Nature. 2009 Dec 10;462(7274):745-56. Epub . PMID:19946266 doi:10.1038/nature08624
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- ↑ Ahmed AH, Wang S, Chuang HH, Oswald RE. Mechanism of AMPA receptor activation by partial agonists: disulfide trapping of closed lobe conformations. J Biol Chem. 2011 Aug 16. PMID:21846932 doi:10.1074/jbc.M111.269001
- ↑ Ahmed AH, Hamada M, Shinada T, Ohfune Y, Weerasinghe L, Garner PP, Oswald RE. The Structure of (-)-Kaitocephalin Bound to the Ligand Binding Domain of the AMPA/Glutamate Receptor, GluA2. J Biol Chem. 2012 Oct 17. PMID:23076153 doi:10.1074/jbc.M112.416362
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