| Structural highlights
4o3c is a 1 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , , , , , |
| Related: | 1fto, 1ftj, 4o3a, 4o3b |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
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
In purification of the ionotropic glutamate receptor A2 (GluA2) ligand-binding domain (LBD), l-Glu-supplemented buffers have previously been used for protein stabilization during the procedure. This sometimes hampers structural studies of low-affinity ligands, because l-Glu is difficult to displace, despite extensive dialysis. Here, we show that l-Asp binds to full-length GluA2 with low affinity (Ki = 0.63 mm) and to the GluA2 LBD with even lower affinity (Ki = 2.6 mm), and we use differential scanning fluorimetry to show that l-Asp is able to stabilize the isolated GluA2 LBD. We also show that l-Asp can replace l-Glu during purification, providing both equal yields and purity of the resulting protein sample. Furthermore, we solved three structures of the GluA2 LBD in the presence of 7.5, 50 and 250 mm l-Asp. Surprisingly, with 7.5 mm l-Asp, the GluA2 LBD crystallized as a mixed dimer, with l-Glu being present in one subunit, and neither l-Asp nor l-Glu being present in the other subunit. Thus, residual l-Glu is retained from the expression medium. On the other hand, only l-Asp was found at the binding site when 50 or 250 mm l-Asp was used for crystallization. The binding mode observed for l-Asp at the GluA2 LBD is very similar to that described for l-Glu. Taking our findings together, we have shown that l-Asp can be used instead of l-Glu for ligand-dependent stabilization of the GluA2 LBD during purification. This will enable structural studies of low-affinity ligands for lead optimization in structure-based drug design. DATABASE: Structural data are available in the Protein Data Bank under accession numbers 4O3B (7.5 mm l-Asp), 4O3C (50 mm l-Asp), and 4O3A (250 mm l-Asp) STRUCTURED DIGITAL ABSTRACT: GluA2 and GluA2 bind by x-ray crystallography (View interaction).
L-Asp is a useful tool in the purification of the ionotropic glutamate receptor A2 ligand-binding domain.,Krintel C, Frydenvang K, Ceravalls de Rabassa A, Kaern AM, Gajhede M, Pickering DS, Kastrup JS FEBS J. 2014 May;281(10):2422-30. doi: 10.1111/febs.12795. Epub 2014 Apr 17. PMID:24673938[15]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
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- ↑ Kato AS, Gill MB, Ho MT, Yu H, Tu Y, Siuda ER, Wang H, Qian YW, Nisenbaum ES, Tomita S, Bredt DS. Hippocampal AMPA receptor gating controlled by both TARP and cornichon proteins. Neuron. 2010 Dec 22;68(6):1082-96. doi: 10.1016/j.neuron.2010.11.026. PMID:21172611 doi:10.1016/j.neuron.2010.11.026
- ↑ Jin R, Horning M, Mayer ML, Gouaux E. Mechanism of activation and selectivity in a ligand-gated ion channel: structural and functional studies of GluR2 and quisqualate. Biochemistry. 2002 Dec 31;41(52):15635-43. PMID:12501192
- ↑ Sun Y, Olson R, Horning M, Armstrong N, Mayer M, Gouaux E. Mechanism of glutamate receptor desensitization. Nature. 2002 May 16;417(6886):245-53. PMID:12015593 doi:10.1038/417245a
- ↑ Jin R, Banke TG, Mayer ML, Traynelis SF, Gouaux E. Structural basis for partial agonist action at ionotropic glutamate receptors. Nat Neurosci. 2003 Aug;6(8):803-10. PMID:12872125 doi:10.1038/nn1091
- ↑ Armstrong N, Mayer M, Gouaux E. Tuning activation of the AMPA-sensitive GluR2 ion channel by genetic adjustment of agonist-induced conformational changes. Proc Natl Acad Sci U S A. 2003 May 13;100(10):5736-41. Epub 2003 May 2. PMID:12730367 doi:http://dx.doi.org/10.1073/pnas.1037393100
- ↑ Jin R, Clark S, Weeks AM, Dudman JT, Gouaux E, Partin KM. Mechanism of positive allosteric modulators acting on AMPA receptors. J Neurosci. 2005 Sep 28;25(39):9027-36. PMID:16192394 doi:25/39/9027
- ↑ Frandsen A, Pickering DS, Vestergaard B, Kasper C, Nielsen BB, Greenwood JR, Campiani G, Fattorusso C, Gajhede M, Schousboe A, Kastrup JS. Tyr702 is an important determinant of agonist binding and domain closure of the ligand-binding core of GluR2. Mol Pharmacol. 2005 Mar;67(3):703-13. Epub 2004 Dec 9. PMID:15591246 doi:10.1124/mol.104.002931
- ↑ Armstrong N, Jasti J, Beich-Frandsen M, Gouaux E. Measurement of conformational changes accompanying desensitization in an ionotropic glutamate receptor. Cell. 2006 Oct 6;127(1):85-97. PMID:17018279 doi:10.1016/j.cell.2006.08.037
- ↑ 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
- ↑ Rossmann M, Sukumaran M, Penn AC, Veprintsev DB, Babu MM, Greger IH. Subunit-selective N-terminal domain associations organize the formation of AMPA receptor heteromers. EMBO J. 2011 Mar 2;30(5):959-71. Epub 2011 Feb 11. PMID:21317873 doi:10.1038/emboj.2011.16
- ↑ 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
- ↑ Krintel C, Frydenvang K, Ceravalls de Rabassa A, Kaern AM, Gajhede M, Pickering DS, Kastrup JS. L-Asp is a useful tool in the purification of the ionotropic glutamate receptor A2 ligand-binding domain. FEBS J. 2014 May;281(10):2422-30. doi: 10.1111/febs.12795. Epub 2014 Apr 17. PMID:24673938 doi:http://dx.doi.org/10.1111/febs.12795
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