Khatri, A., Burger, P. B., Swanger, S. A., Hansen, K. B., Zimmerman, S., Karakas, E., Liotta, D. C., Furukawa, H., Snyder, J. P., Traynelis, S. F. (September 2014) Structural Determinants and Mechanism of Action of a GluN2C-selective NMDA Receptor Positive Allosteric Modulator. Mol Pharmacol, 86 (5). pp. 548-560. ISSN 0026-895x
Abstract
NMDA receptors are tetrameric complexes of GluN1, GluN2A-D, and GluN3A-B subunits and are involved in normal brain function and neurological disorders. We have identified a novel class of stereo-selective pyrrolidinone (PYD) positive allosteric modulators for GluN2C-containing NMDA receptors, exemplified by methyl 4-(3-acetyl-4-hydroxy-1-(2-(2-methyl-1H-indol-3-yl)ethyl)-5-oxo-2,5-dihydro-1H-py rrol-2-yl)benzoate. Here we explore the site and mechanism of action of a prototypical analogue PYD-106, which at 30 muM does not alter responses of NMDA receptors containing GluN2A, GluN2B, and GluN2D, and has no effect on AMPA and kainate receptors. Co-application of 50 muM PYD-106 with a maximally effective concentration of glutamate and glycine increases the response of GluN1/GluN2C NMDA receptors in HEK-293 cells to 221% of that obtained in the absence of PYD (taken as 100%). Evaluation of the concentration-dependence of this enhancement revealed an EC50 value for PYD of 13 muM. PYD-106 increased opening frequency and open time of single channel currents activated by maximally effective concentrations of agonist, but only had modest effects on glutamate and glycine EC50. PYD-106 selectively enhanced the responses of diheteromeric GluN1/GluN2C receptors, but not triheteromeric GluN1/GluN2A/GluN2C receptors. Inclusion of residues encoded by GluN1-exon5 attenuated the effects of PYD. Three GluN2C residues (Arg194, Ser470, Lys470), at which mutagenesis virtually eliminated PYD function, line a cavity at the interface of the ligand binding and the amino terminal domains in a homology model of GluN1/GluN2C built from crystallographic data on GluN1/GluN2B. We propose that this domain interface constitutes a new allosteric modulatory site on the NMDA receptor.
| Item Type: | Paper |
|---|---|
| Subjects: | bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > NMDA receptor structural biology |
| CSHL Authors: | |
| Communities: | CSHL labs > Furukawa lab |
| Depositing User: | Matt Covey |
| Date: | 9 September 2014 |
| Date Deposited: | 24 Sep 2014 14:33 |
| Last Modified: | 30 Aug 2017 14:45 |
| PMCID: | PMC4201136 |
| Related URLs: | |
| URI: | https://repository.cshl.edu/id/eprint/30813 |
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