Structural Features of the Glutamate Binding Site in Recombinant NR1/NR2A N-Methyl-d-aspartate Receptors Determined by Site-Directed Mutagenesis and Molecular Modeling

  title={Structural Features of the Glutamate Binding Site in Recombinant NR1/NR2A N-Methyl-d-aspartate Receptors Determined by Site-Directed Mutagenesis and Molecular Modeling},
  author={Philip E. Chen and Matthew T. Geballe and Phillip J. Stansfeld and Alexander R. Johnston and Hongjie Yuan and Amanda L. Jacob and James P. Snyder and Stephen F. Traynelis and David J. A. Wyllie},
  journal={Molecular Pharmacology},
  pages={1470 - 1484}
We have used site-directed mutagenesis of amino acids located within the S1 and S2 ligand binding domains of the NR2A N-methyl-d-aspartate (NMDA) receptor subunit to explore the nature of ligand binding. Wild-type or mutated NR1/NR2A NMDA receptors were expressed in Xenopus laevis oocytes and studied using two electrode voltage clamp. We investigated the effects of mutations in the S1 and S2 regions on the potencies of the agonists l-glutamate, l-aspartate, (R,S)-tetrazol-5yl-glycine, and NMDA… 

Tweaking Agonist Efficacy at N-Methyl-d-aspartate Receptors by Site-Directed Mutagenesis

The data indicate that agonist efficacy at the NR2B subunit can be controlled by the extent of steric clashes between the agonist and the ligand binding domains and by ligand-dependent arrangements of residues within the binding pocket.

The Integrity of the Glycine Co-agonist Binding Site of N-Methyl-d-aspartate Receptors Is a Functional Quality Control Checkpoint for Cell Surface Delivery*

Findings demonstrate that integrity of the glycine co-agonist binding site is a functional checkpoint requisite for efficient cell surface trafficking of assembled NMDA receptors.

Structural Determinants of Agonist Efficacy at the Glutamate Binding Site of N-Methyl-d-Aspartate Receptors

Variation in the overall receptor conformation, which is strongly influenced by the nature of interdomain interactions in resting and active states, mediates differences in agonist efficacy and partial agonism at the GluN2 subunits are proposed.

The NR1 M3 Domain Mediates Allosteric Coupling in the N-Methyl-D-aspartate Receptor

The data demonstrate that theNR1 M3 segment is functionally coupled to key structural domains in both the NR1 and NR2 subunits, and suggests that perturbation of M3 can stabilize the ligand binding domain in a closed cleft conformation, even in the absence of agonist.

The NR 1 M 3 Domain Mediates Allosteric Coupling in the N-Methyl-D-aspartate Receptor

To further explore the mechanism of receptor activation, two gain-of-function mutations within the NR1 M3 segment, a transmembrane domain proposed to couple ligand binding and channel opening are characterized, demonstrating that the NR2 M3 domain is functionally coupled to key structural domains in both theNR1 and NR2 subunits.

Single-channel properties of N-methyl-D-aspartate receptors containing chimaeric GluN2A/GluN2D subunits.

The results show that the identity of the GluN2 LBD not only controls glutamate potency, but also influences the potency of the NMDAR co-agonist glycine, whereas the single-channel conductance and the duration of single activations of ion channels can be predicted by the identities of the M1-M3 regions and the LBD.

Single‐channel analysis of a point mutation of a conserved serine residue in the S2 ligand‐binding domain of the NR2A NMDA receptor subunit

The authors' single‐channel data, together with modelling using a kinetic scheme to describe channel activations, support the hypothesis that the S670G point mutation reduces the dwell time of glutamate in its binding site.

Subunit-Specific Agonist Activity at NR2A-, NR2B-, NR2C-, and NR2D-Containing N-Methyl-d-aspartate Glutamate Receptors

Despite high homology and conserved atomic contact residues within the agonist binding pocket of NR2A and NR2D, glutamate adopts a different binding orientation that could be exploited for the development of subunit selective agonists and competitive antagonists.

Modulation of glycine potency in rat recombinant NMDA receptors containing chimeric NR2A/2D subunits expressed in Xenopus laevis oocytes

It is concluded that the variation in glycine potency is caused by interactions between the NR1 and NR2 ligand‐binding domains that occur following agonist binding and which may be involved in the initial conformation changes that determine channel gating.

Evaluation of natural and nitramine binding energies to 3-D models of the S1S2 domains in the N-methyl-D-aspartate receptor

The results predict that these nitramines are not efficacious and thus do not produce excitoxicity when they bind to the S1S2 domain of the NMDAR.



Identification of Amino Acid Residues of the NR2A Subunit That Control Glutamate Potency in Recombinant NR1/NR2A NMDA Receptors

It is shown that residues on the NR2A subunit control glutamate potency in recombinant NR1/NR2A receptors, without affecting glycine potency, and proposed that the glutamate binding site is located on NR2 subunits and (taking the data together with previous work) implies that each NMDA receptor subunit possesses a binding site for an agonist.

Activation of N-methyl-D-aspartate receptors by glycine: role of an aspartate residue in the M3-M4 loop of the NR1 subunit.

Glutamate and glycine are coagonists that act at distinct sites to activate N-methyl-D-aspartate (NMDA) receptors. In the NR1 subunit of the NMDA receptor, mutation of D732 to glutamate (D732E),

Influence of a threonine residue in the S2 ligand binding domain in determining agonist potency and deactivation rate of recombinant NR1a/NR2D NMDA receptors

The results suggest that this conserved threonine residue plays a crucial role in ligand binding to NMDA NR2 receptor subunits and supports the idea that the slow decay kinetics associated with NR1a/NR2D NMDA receptors can be explained by the slow dissociation of glutamate from this NMDA receptor subtype.

Cysteine Mutagenesis and Homology Modeling of the Ligand-binding Site of a Kainate-binding Protein*

The results are consistent with the proposal that the energy driving kainate binding is contributed both from residues within the binding site and from interactions between two regions of the protein that are brought into contact upon ligand binding in a manner analogous to that seen in bacterial amino acid-binding proteins.

Heteromeric NMDA Receptors: Molecular and Functional Distinction of Subtypes

Molecular cloning identified three complementary DNA species of rat brain, encoding NMDA receptor subunits NMDAR2A (NR2A), NR2B, and NR2C, which are 55 to 70% ientical in sequence, and these are structurally related, with less than 20% sequence identity, to other excitatory amino acid receptor sub Units.

Functional and pharmacological differences between recombinant N-methyl-D-aspartate receptors.

Channel deactivation was fast and comparable among receptors obtained by cotransfecting five distinct spliced variants of the NR1 subunit, each with the NR2A subunits, and recovery from desensitization was slower for NR1/NR2B than for NR2/NR3 channels, suggesting mechanisms additional to subunit composition may also regulate deactivation time course.