1
|
Zhou C, Tajima N. Structural insights into NMDA receptor pharmacology. Biochem Soc Trans 2023; 51:1713-1731. [PMID: 37431773 PMCID: PMC10586783 DOI: 10.1042/bst20230122] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/12/2023] [Accepted: 06/16/2023] [Indexed: 07/12/2023]
Abstract
N-methyl-d-aspartate receptors (NMDARs) comprise a subfamily of ionotropic glutamate receptors that form heterotetrameric ligand-gated ion channels and play fundamental roles in neuronal processes such as synaptic signaling and plasticity. Given their critical roles in brain function and their therapeutic importance, enormous research efforts have been devoted to elucidating the structure and function of these receptors and developing novel therapeutics. Recent studies have resolved the structures of NMDARs in multiple functional states, and have revealed the detailed gating mechanism, which was found to be distinct from that of other ionotropic glutamate receptors. This review provides a brief overview of the recent progress in understanding the structures of NMDARs and the mechanisms underlying their function, focusing on subtype-specific, ligand-induced conformational dynamics.
Collapse
Affiliation(s)
- Changping Zhou
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, U.S.A
| | - Nami Tajima
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, U.S.A
| |
Collapse
|
2
|
Sawchuk SD, Reid HMO, Neale KJ, Shin J, Christie BR. Effects of Ethanol on Synaptic Plasticity and NMDA Currents in the Juvenile Rat Dentate Gyrus. Brain Plast 2020; 6:123-136. [PMID: 33680851 PMCID: PMC7903019 DOI: 10.3233/bpl-200110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background and Objectives: We examined how acute ethanol (EtOH) exposure affects long term depression (LTD) in the dentate gyrus (DG) of the hippocampus in juvenile rats. EtOH is thought to directly modulate n-methyl-D-aspartate receptor (NMDAr) currents, which are believed important for LTD induction. LTD in turn is believed to play an important developmental role in the hippocampus by facilitating synaptic pruning. Methods: Hippocampal slices (350μm) were obtained at post-natal day (PND) 14, 21, or 28. Field EPSPs (excitatory post-synaptic potential) or whole-cell EPSCs (excitatory post-synaptic conductance) were recorded from the DG (dentate gyrus) in response to medial perforant path activation. Low-frequency stimulation (LFS; 900 pulses; 120 s pulse) was used to induce LTD. Results: Whole-cell recordings indicated that EtOH exposure at 50mM did not significantly impact ensemble NMDAr EPSCs in slices obtained from animals in the PND14 or 21 groups, but it reliably produced a modest inhibition in the PND28 group. Increasing the concentration to 100 mM resulted in a modest inhibition of NMDAr EPSCs in all three groups. LTD induction and maintenance was equivalent in magnitude in all three age groups in control conditions, however, and surprisingly, NMDA antagonist AP5 only reliably blocked LTD in the PND21 and 28 age groups. The application of 50 mM EtOH attenuated LTD in all three age groups, however increasing the concentration to 100 mM did not reliably inhibit LTD. Conclusions: These results indicate that the effect of EtOH on NMDAr-EPSCs recorded from DGCs is both age and concentration dependent in juveniles. Low concentrations of EtOH can attenuate, but did not block LTD in the DG. The effects of EtOH on LTD do not align well with it’s effects on NNMDA receptors.
Collapse
Affiliation(s)
- Scott D Sawchuk
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Hannah M O Reid
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Katie J Neale
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - James Shin
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Brian R Christie
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Psychology, University of British Columbia, Vancouver, BC, Canada.,Island Medical Program and Department of Cellular and Physiological Sciences, University of British Columbia, Victoria, BC, Canada
| |
Collapse
|
3
|
GluN2 Subunit-Dependent Redox Modulation of NMDA Receptor Activation by Homocysteine. Biomolecules 2020; 10:biom10101441. [PMID: 33066432 PMCID: PMC7602226 DOI: 10.3390/biom10101441] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/07/2020] [Accepted: 10/12/2020] [Indexed: 12/25/2022] Open
Abstract
Homocysteine (HCY) molecule combines distinct pharmacological properties as an agonist of N-methyl-d-aspartate receptors (NMDARs) and a reducing agent. Whereas NMDAR activation by HCY was elucidated, whether the redox modulation contributes to its action is unclear. Here, using patch-clamp recording and imaging of intracellular Ca2+, we study dithiothreitol (DTT) effects on currents and Ca2+ responses activated by HCY through native NMDARs and recombinant diheteromeric GluN1/2A, GluN1/2B, and GluN1/2C receptors. Within a wide range (1–800 μM) of [HCY]s, the concentration–activation relationships for recombinant NMDARs revealed a biphasicness. The high-affinity component obtained between 1 and 100 µM [HCY]s corresponding to the NMDAR activation was not affected by 1 mM DTT. The low-affinity phase observed at [HCY]s above 200 μM probably originated from thiol-dependent redox modulation of NMDARs. The reduction of NMDAR disulfide bonds by either 1 mM DTT or 1 mM HCY decreased GluN1/2A currents activated by HCY. In contrast, HCY-elicited GluN1/2B currents were enhanced due to the remarkable weakening of GluN1/2B desensitization. In fact, cleaving NMDAR disulfide bonds in neurons reversed the HCY-induced Ca2+ accumulation, making it dependent on GluN2B- rather than GluN2A-containing NMDARs. Thus, estimated concentrations for the HCY redox effects exceed those in the plasma during intermediate hyperhomocysteinemia but may occur during severe hyperhomocysteinemia.
Collapse
|
4
|
Perkins DO, Jeffries CD, Do KQ. Potential Roles of Redox Dysregulation in the Development of Schizophrenia. Biol Psychiatry 2020; 88:326-336. [PMID: 32560962 PMCID: PMC7395886 DOI: 10.1016/j.biopsych.2020.03.016] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 03/03/2020] [Accepted: 03/22/2020] [Indexed: 12/20/2022]
Abstract
Converging evidence implicates redox dysregulation as a pathological mechanism driving the emergence of psychosis. Increased oxidative damage and decreased capacity of intracellular redox modulatory systems are consistent findings in persons with schizophrenia as well as in persons at clinical high risk who subsequently developed frank psychosis. Levels of glutathione, a key regulator of cellular redox status, are reduced in the medial prefrontal cortex, striatum, and thalamus in schizophrenia. In humans with schizophrenia and in rodent models recapitulating various features of schizophrenia, redox dysregulation is linked to reductions of parvalbumin containing gamma-aminobutyric acid (GABA) interneurons and volumes of their perineuronal nets, white matter abnormalities, and microglia activation. Importantly, the activity of transcription factors, kinases, and phosphatases regulating diverse aspects of neurodevelopment and synaptic plasticity varies according to cellular redox state. Molecules regulating interneuron function under redox control include NMDA receptor subunits GluN1 and GluN2A as well as KEAP1 (regulator of transcription factor NRF2). In a rodent schizophrenia model characterized by impaired glutathione synthesis, the Gclm knockout mouse, oxidative stress activated MMP9 (matrix metalloprotease 9) via its redox-responsive regulatory sites, causing a cascade of molecular events leading to microglia activation, perineural net degradation, and impaired NMDA receptor function. Molecular pathways under redox control are implicated in the etiopathology of schizophrenia and are attractive drug targets for individualized drug therapy trials in the contexts of prevention and treatment of psychosis.
Collapse
Affiliation(s)
- Diana O. Perkins
- corresponding author: CB 7160, Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, Office: 919-962-1401, Cell: 919-360-1602,
| | - Clark D. Jeffries
- Renaissance Computing Institute, University of North Carolina, Chapel Hill NC
| | - Kim Q. Do
- Center for Psychiatric Neuroscience, Department of Psychiatry, Lausanne University Hospital-CHUV, Prilly-Lausanne, Switzerland
| |
Collapse
|
5
|
Shi EY, Yuan CL, Sipple MT, Srinivasan J, Ptak CP, Oswald RE, Nowak LM. Noncompetitive antagonists induce cooperative AMPA receptor channel gating. J Gen Physiol 2019; 151:156-173. [PMID: 30622133 PMCID: PMC6363417 DOI: 10.1085/jgp.201812209] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 11/05/2018] [Accepted: 12/11/2018] [Indexed: 12/24/2022] Open
Abstract
Glutamate activates individual subunits of AMPA receptors in a stepwise manner. Shi et al. reveal that two noncompetitive antagonists disrupt this gating pattern and that their binding sites at the boundary between the transmembrane and extracellular linker domains is a tunable locus for gating. Glutamate is released from presynaptic nerve terminals in the central nervous system (CNS) and spreads excitation by binding to and activating postsynaptic iGluRs. Of the potential glutamate targets, tetrameric AMPA receptors mediate fast, transient CNS signaling. Each of the four AMPA subunits in the receptor channel complex is capable of binding glutamate at its ligand-binding domains and transmitting the energy of activation to the pore domain. Homotetrameric AMPA receptor channels open in a stepwise manner, consistent with independent activation of individual subunits, and they exhibit complex kinetic behavior that manifests as temporal shifts between four different conductance levels. Here, we investigate how two AMPA receptor-selective noncompetitive antagonists, GYKI-52466 and GYKI-53655, disrupt the intrinsic step-like gating patterns of maximally activated homotetrameric GluA3 receptors using single-channel recordings from cell-attached patches. Interactions of these 2,3-benzodiazepines with residues in the boundary between the extracellular linkers and transmembrane helical domains reorganize the gating behavior of channels. Low concentrations of modulators stabilize open and closed states to different degrees and coordinate the activation of subunits so that channels open directly from closed to higher conductance levels. Using kinetic and structural models, we provide insight into how the altered gating patterns might arise from molecular contacts within the extracellular linker-channel boundary. Our results suggest that this region may be a tunable locus for AMPA receptor channel gating.
Collapse
Affiliation(s)
- Edward Y Shi
- Department of Molecular Medicine, Cornell University, Ithaca, NY
| | - Christine L Yuan
- Department of Molecular Medicine, Cornell University, Ithaca, NY
| | - Matthew T Sipple
- Department of Molecular Medicine, Cornell University, Ithaca, NY
| | | | | | - Robert E Oswald
- Department of Molecular Medicine, Cornell University, Ithaca, NY
| | - Linda M Nowak
- Department of Molecular Medicine, Cornell University, Ithaca, NY
| |
Collapse
|
6
|
Hansen KB, Yi F, Perszyk RE, Furukawa H, Wollmuth LP, Gibb AJ, Traynelis SF. Structure, function, and allosteric modulation of NMDA receptors. J Gen Physiol 2018; 150:1081-1105. [PMID: 30037851 PMCID: PMC6080888 DOI: 10.1085/jgp.201812032] [Citation(s) in RCA: 342] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 07/03/2018] [Indexed: 12/22/2022] Open
Abstract
Hansen et al. review recent structural data that have provided insight into the function and allosteric modulation of NMDA receptors. NMDA-type glutamate receptors are ligand-gated ion channels that mediate a Ca2+-permeable component of excitatory neurotransmission in the central nervous system (CNS). They are expressed throughout the CNS and play key physiological roles in synaptic function, such as synaptic plasticity, learning, and memory. NMDA receptors are also implicated in the pathophysiology of several CNS disorders and more recently have been identified as a locus for disease-associated genomic variation. NMDA receptors exist as a diverse array of subtypes formed by variation in assembly of seven subunits (GluN1, GluN2A-D, and GluN3A-B) into tetrameric receptor complexes. These NMDA receptor subtypes show unique structural features that account for their distinct functional and pharmacological properties allowing precise tuning of their physiological roles. Here, we review the relationship between NMDA receptor structure and function with an emphasis on emerging atomic resolution structures, which begin to explain unique features of this receptor.
Collapse
Affiliation(s)
- Kasper B Hansen
- Department of Biomedical and Pharmaceutical Sciences and Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT
| | - Feng Yi
- Department of Biomedical and Pharmaceutical Sciences and Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT
| | - Riley E Perszyk
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA
| | - Hiro Furukawa
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
| | - Lonnie P Wollmuth
- Departments of Neurobiology & Behavior and Biochemistry & Cell Biology, Stony Brook University, Stony Brook, NY
| | - Alasdair J Gibb
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA
| |
Collapse
|
7
|
Domith I, Socodato R, Portugal CC, Munis AF, Duarte-Silva AT, Paes-de-Carvalho R. Vitamin C modulates glutamate transport and NMDA receptor function in the retina. J Neurochem 2017; 144:408-420. [PMID: 29164598 DOI: 10.1111/jnc.14260] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 11/09/2017] [Accepted: 11/11/2017] [Indexed: 12/27/2022]
Abstract
Vitamin C (in the reduced form ascorbate or in the oxidized form dehydroascorbate) is implicated in signaling events throughout the central nervous system (CNS). In the retina, a high-affinity transport system for ascorbate has been described and glutamatergic signaling has been reported to control ascorbate release. Here, we investigated the modulatory role played by vitamin C upon glutamate uptake and N-methyl-d-aspartate (NMDA) receptor activation in cultured retinal cells or in intact retinal tissue using biochemical and imaging techniques. We show that both forms of vitamin C, ascorbate or dehydroascorbate, promote an accumulation of extracellular glutamate by a mechanism involving the inhibition of glutamate uptake. This inhibition correlates with the finding that ascorbate promotes a decrease in cell surface levels of the neuronal glutamate transporter excitatory amino acid transporter 3 in retinal neuronal cultures. Interestingly, vitamin C is prone to increase the activity of NMDA receptors but also promotes a decrease in glutamate-stimulated [3 H] MK801 binding and decreases cell membrane content of NMDA receptor glutamate ionotropic receptor subunit 1 (GluN1) subunits. Both compounds were also able to increase cAMP response element-binding protein phosphorylation in neuronal nuclei in a glutamate receptor and calcium/calmodulin kinase-dependent manner. Moreover, the effect of ascorbate is not blocked by sulfinpyrazone and then does not depend on its uptake by retinal cells. Overall, these data indicate a novel molecular and functional target for vitamin C impacting on glutamate signaling in retinal neurons.
Collapse
Affiliation(s)
- Ivan Domith
- Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil
| | - Renato Socodato
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Camila C Portugal
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Andressa F Munis
- Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil
| | - Aline T Duarte-Silva
- Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil
| | - Roberto Paes-de-Carvalho
- Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil.,Department of Neurobiology, Institute of Biology, Fluminense Federal University, Niterói, RJ, Brazil
| |
Collapse
|
8
|
Yakovlev AV, Kurmasheva ED, Ishchenko Y, Giniatullin R, Sitdikova GF. Age-Dependent, Subunit Specific Action of Hydrogen Sulfide on GluN1/2A and GluN1/2B NMDA Receptors. Front Cell Neurosci 2017; 11:375. [PMID: 29225568 PMCID: PMC5705612 DOI: 10.3389/fncel.2017.00375] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 11/10/2017] [Indexed: 11/13/2022] Open
Abstract
Hydrogen sulfide (H2S) is an endogenously produced neuroactive gas implicated in many key processes in the peripheral and central nervous system. Whereas the neuroprotective role of H2S has been shown in adult brain, the action of this messenger in newborns remains unclear. One of the known targets of H2S in the nervous system is the N-methyl-D-aspartate (NMDA) glutamate receptor which can be composed of different subunits with distinct functional properties. In the present study, using patch clamp technique, we compared the effects of the H2S donor sodium hydrosulfide (NaHS, 100 μM) on hippocampal NMDA receptor mediated currents in rats of the first and third postnatal weeks. This was supplemented by testing effects of NaHS on recombinant GluN1/2A and GluN1/2B NMDA receptors expressed in HEK293T cells. The main finding is that NaHS action on NMDA currents is age-dependent. Currents were reduced in newborns but increased in older juvenile rats. Consistent with an age-dependent switch in NMDA receptor composition, in HEK239T cells expressing GluN1/2A receptors, NaHS increased NMDA activated currents associated with acceleration of desensitization and decrease of the deactivation rate. In contrast, in GluN1/2B NMDA receptors, which are prevalent in newborns, NaHS decreased currents and reduced receptor deactivation without effect on the desensitization rate. Adenylate cyclase inhibitor MDL-12330A (10 μM) did not prevent the age-dependent effects of NaHS on NMDA evoked currents in pyramidal neurons of hippocampus. The reducing agent dithiothreitol (DTT, 2 mM) applied on HEK293T cells prevented facilitation induced by NaHS on GluN1/2A NMDA receptors, however in GluN1/2B NMDA receptors the inhibitory effect of NaHS was still observed. Our data indicate age-dependent effect of H2S on NMDA receptor mediated currents determined by glutamate receptor subunit composition. While the inhibitory action of H2 on GluN1/2B receptors could limit the excessive activation in early age, the enhanced functionality of GluN1/2A receptor in the presence of this gasotransmitter can enlarge synaptic efficacy and promote synaptic plasticity in adults.
Collapse
Affiliation(s)
- Aleksey V Yakovlev
- Department of Human and Animal Physiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Evgeniya D Kurmasheva
- Department of Human and Animal Physiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Yevheniia Ishchenko
- Laboratory of Molecular Pain Research, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Rashid Giniatullin
- Laboratory of Molecular Pain Research, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.,Laboratory of Neurobiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Guzel F Sitdikova
- Department of Human and Animal Physiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| |
Collapse
|
9
|
Iglesias A, Cimadevila M, la Fuente RAD, Martí-Solano M, Cadavid MI, Castro M, Selent J, Loza MI, Brea J. Serotonin 2A receptor disulfide bridge integrity is crucial for ligand binding to different signalling states but not for its homodimerization. Eur J Pharmacol 2017; 815:138-146. [PMID: 28899696 DOI: 10.1016/j.ejphar.2017.09.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 08/28/2017] [Accepted: 09/08/2017] [Indexed: 02/06/2023]
Abstract
The serotonin 2A (5-HT2A) receptor is a G-protein coupled receptor (GPCR) with a conserved disulfide bridge formed by Cys148 (transmembrane helix 3, TM3) and Cys227 (extracellular loop 2, ECL-2). We hypothesized that disulfide bridges may determine serotonin 5-HT2A receptor functions such as receptor activation, functional selectivity and ligand recognition. We used the reducing agent dithiothreitol (DTT) to determine how the reduction of disulfide bridges affects radioligand binding, second messenger mobilization and receptor dimerization. A DTT-induced decrease in the number of binding sites (1190 ± 63.55 fmol/mg protein for control cells compared with 921.2 ± 60.84 fmol/mg protein for DTT-treated cells) as well as in the efficacy of both signalling pathways characterized was observed, although the affinity and potency were unchanged. Bioluminiscence resonance energy transfer (BRET) assays revealed the DTT treatment did not modify the homodimeric nature of serotonin 5-HT2A receptors. In molecular dynamic simulations, the ECL-2 of the receptor with a broken cysteine bond adopts a wider variety of conformations, some of which protrude deeper into the receptor orthosteric binding pocket leading to collapse of the pocket. A shrunken binding pocket would be incapable of accommodating lysergic acid diethylamide (LSD). Our findings suggest that the decrease of efficacy may be due to disruption of disulfide bridge between TM3 and ECL-2. This reveals the integrity of the ECL-2 epitope, which should be explored in the development of novel ligands acting as allosteric modulators of serotonin 5-HT2A receptors.
Collapse
Affiliation(s)
- Alba Iglesias
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain
| | - Marta Cimadevila
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain
| | - Rocío Ailim de la Fuente
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain; Molecular Pharmacology of G Protein-coupled Receptors Laboratory, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain
| | - María Martí-Solano
- GPCR Drug Discovery Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM) - Department of Experimental and Health Sciences of Pompeu Fabra University (UPF), Barcelona, Spain
| | - María Isabel Cadavid
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain
| | - Marián Castro
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain; Molecular Pharmacology of G Protein-coupled Receptors Laboratory, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain
| | - Jana Selent
- GPCR Drug Discovery Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM) - Department of Experimental and Health Sciences of Pompeu Fabra University (UPF), Barcelona, Spain
| | - María Isabel Loza
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain.
| | - José Brea
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain.
| |
Collapse
|
10
|
Chopra DA, Sapkota K, Irvine MW, Fang G, Jane DE, Monaghan DT, Dravid SM. A single-channel mechanism for pharmacological potentiation of GluN1/GluN2A NMDA receptors. Sci Rep 2017; 7:6933. [PMID: 28761055 PMCID: PMC5537304 DOI: 10.1038/s41598-017-07292-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 06/16/2017] [Indexed: 11/09/2022] Open
Abstract
NMDA receptors (NMDARs) contribute to several neuropathological processes. Novel positive allosteric modulators (PAMs) of NMDARs have recently been identified but their effects on NMDAR gating remain largely unknown. To this end, we tested the effect of a newly developed molecule UBP684 on GluN1/GluN2A receptors. We found that UBP684 potentiated the whole-cell currents observed under perforated-patch conditions and slowed receptor deactivation. At the single channel level, UBP684 produced a dramatic reduction in long shut times and a robust increase in mean open time. These changes were similar to those produced by NMDAR mutants in which the ligand-binding domains (LBDs) are locked in the closed clamshell conformation by incorporating a disulfide bridge. Since the locked glutamate-binding clefts primarily contributes to receptor efficacy these results suggests that UBP684 binding may induce switch in conformation similar to glutamate LBD locked state. Consistent with this prediction UBP684 displayed greater potentiation of NMDARs with only the GluN1 LBD locked compared to NMDARs with only the GluN2 LBD locked. Docking studies suggest that UBP684 binds to the GluN1 and GluN2 LBD interface supporting its potential ability in stabilizing the LBD closed conformation. Together these studies identify a novel pharmacological mechanism of facilitating the function of NMDARs.
Collapse
Affiliation(s)
- Divyan A Chopra
- Department of Pharmacology, Creighton University, Omaha, NE, 68178, United States
| | - Kiran Sapkota
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Mark W Irvine
- School of Physiology & Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - Guangyu Fang
- School of Physiology & Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - David E Jane
- School of Physiology & Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - Daniel T Monaghan
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Shashank M Dravid
- Department of Pharmacology, Creighton University, Omaha, NE, 68178, United States.
| |
Collapse
|
11
|
Molecular Mechanism of Disease-Associated Mutations in the Pre-M1 Helix of NMDA Receptors and Potential Rescue Pharmacology. PLoS Genet 2017; 13:e1006536. [PMID: 28095420 PMCID: PMC5240934 DOI: 10.1371/journal.pgen.1006536] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/13/2016] [Indexed: 12/31/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs), ligand-gated ionotropic glutamate receptors, play key roles in normal brain development and various neurological disorders. Here we use standing variation data from the human population to assess which protein domains within NMDAR GluN1, GluN2A and GluN2B subunits show the strongest signal for being depleted of missense variants. We find that this includes the GluN2 pre-M1 helix and linker between the agonist-binding domain (ABD) and first transmembrane domain (M1). We then evaluate the functional changes of multiple missense mutations in the NMDAR pre-M1 helix found in children with epilepsy and developmental delay. We find mutant GluN1/GluN2A receptors exhibit prolonged glutamate response time course for channels containing 1 or 2 GluN2A-P552R subunits, and a slow rise time only for receptors with 2 mutant subunits, suggesting rearrangement of one GluN2A pre-M1 helix is sufficient for rapid activation. GluN2A-P552R and analogous mutations in other GluN subunits increased the agonist potency and slowed response time course, suggesting a functionally conserved role for this residue. Although there is no detectable change in surface expression or open probability for GluN2A-P552R, the prolonged response time course for receptors that contained GluN2A-P552R increased charge transfer for synaptic-like activation, which should promote excitotoxic damage. Transfection of cultured neurons with GluN2A-P552R prolonged EPSPs, and triggered pronounced dendritic swelling in addition to excitotoxicity, which were both attenuated by memantine. These data implicate the pre-M1 region in gating, provide insight into how different subunits contribute to gating, and suggest that mutations in the pre-M1 helix can compromise neuronal health. Evaluation of FDA-approved NMDAR inhibitors on the mutant NMDAR-mediated current response and neuronal damage provides a potential clinical path to treat individuals harboring similar mutations in NMDARs.
Collapse
|
12
|
Hansen KB, Yi F, Perszyk RE, Menniti FS, Traynelis SF. NMDA Receptors in the Central Nervous System. Methods Mol Biol 2017; 1677:1-80. [PMID: 28986865 DOI: 10.1007/978-1-4939-7321-7_1] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
NMDA-type glutamate receptors are ligand-gated ion channels that mediate a major component of excitatory neurotransmission in the central nervous system (CNS). They are widely distributed at all stages of development and are critically involved in normal brain functions, including neuronal development and synaptic plasticity. NMDA receptors are also implicated in the pathophysiology of numerous neurological and psychiatric disorders, such as ischemic stroke, traumatic brain injury, Alzheimer's disease, epilepsy, mood disorders, and schizophrenia. For these reasons, NMDA receptors have been intensively studied in the past several decades to elucidate their physiological roles and to advance them as therapeutic targets. Seven NMDA receptor subunits exist that assemble into a diverse array of tetrameric receptor complexes, which are differently regulated, have distinct regional and developmental expression, and possess a wide range of functional and pharmacological properties. The diversity in subunit composition creates NMDA receptor subtypes with distinct physiological roles across neuronal cell types and brain regions, and enables precise tuning of synaptic transmission. Here, we will review the relationship between NMDA receptor structure and function, the diversity and significance of NMDA receptor subtypes in the CNS, as well as principles and rules by which NMDA receptors operate in the CNS under normal and pathological conditions.
Collapse
Affiliation(s)
- Kasper B Hansen
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, USA. .,Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT, USA.
| | - Feng Yi
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, USA
| | - Riley E Perszyk
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Frank S Menniti
- MindImmune Therapeutics, Inc., George & Anne Ryan Institute for Neuroscience, Kingston, RI, USA
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| |
Collapse
|
13
|
Monin A, Fournier M, Baumann PS, Cuénod M, Do KQ. Role of Redox Dysregulation in White Matter Anomalies Associated with Schizophrenia. HANDBOOK OF BEHAVIORAL NEUROSCIENCE 2016. [DOI: 10.1016/b978-0-12-800981-9.00028-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
14
|
Kazi R, Dai J, Sweeney C, Zhou HX, Wollmuth LP. Mechanical coupling maintains the fidelity of NMDA receptor-mediated currents. Nat Neurosci 2014; 17:914-22. [PMID: 24859202 PMCID: PMC4072853 DOI: 10.1038/nn.3724] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 04/23/2014] [Indexed: 12/13/2022]
Abstract
The fidelity of integration of pre- and postsynaptic activity by NMDA receptors (NMDARs) requires a match between agonist binding and ion channel opening. To address how agonist binding is transduced into pore opening in NMDARs, we manipulated the coupling between the ligand-binding domain (LBD) and the ion channel by inserting residues in a linker between them. We found that a single residue insertion markedly attenuated the ability of NMDARs to convert a glutamate transient into a functional response. This was largely a result of a decreased likelihood of the channel opening and remaining open. Computational and thermodynamic analyses suggest that insertions prevent the agonist-bound LBD from effectively pulling on pore lining elements, thereby destabilizing pore opening. Furthermore, this pulling energy was more prominent in the GluN2 subunit. We conclude that an efficient NMDAR-mediated synaptic response relies on a mechanical coupling between the LBD and the ion channel.
Collapse
Affiliation(s)
- Rashek Kazi
- Graduate Program in Neuroscience, Stony Brook University, Stony Brook, NY 11794-5230
- Medical Scientist Training Program (MSTP), Stony Brook University, Stony Brook, NY 11794-5230
| | - Jian Dai
- Department of Physics and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306
| | - Cameron Sweeney
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230
- Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY 11794-5230
| | - Huan-Xiang Zhou
- Department of Physics and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306
| | - Lonnie P. Wollmuth
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230
- Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY 11794-5230
| |
Collapse
|
15
|
Sobolevsky AI. Structure and gating of tetrameric glutamate receptors. J Physiol 2013; 593:29-38. [PMID: 25556785 DOI: 10.1113/jphysiol.2013.264911] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 10/25/2013] [Indexed: 11/08/2022] Open
Abstract
Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that open their ion-conducting pores in response to the binding of agonist glutamate. In recent years, significant progress has been achieved in studies of iGluRs by determining numerous structures of isolated water-soluble ligand-binding and amino-terminal domains, as well as solving the first crystal structure of the full-length AMPA receptor in the closed, antagonist-bound state. These structural data combined with electrophysiological and fluorescence recordings, biochemical experiments, mutagenesis and molecular dynamics simulations have greatly improved our understanding of iGluR assembly, activation and desensitization processes. This article reviews the recent structural and functional advances in the iGluR field and summarizes them in a simplified model of full-length iGluR gating.
Collapse
Affiliation(s)
- Alexander I Sobolevsky
- Department of Biochemistry & Molecular Biophysics, Columbia University, 650 West 168th Street, Black Bldg. 513, New York, NY, 10032, USA
| |
Collapse
|
16
|
Abstract
Glutamate-gated ion channels embedded within the neuronal membrane are the primary mediators of fast excitatory synaptic transmission in the CNS. The ion channel of these glutamate receptors contains a pore-lining transmembrane M3 helix surrounded by peripheral M1 and M4 helices. In the NMDA receptor subtype, opening of the ion channel pore, mediated by displacement of the M3 helices away from the central pore axis, occurs in a highly concerted fashion, but the associated temporal movements of the peripheral helices are unknown. To address the gating dynamics of the peripheral helices, we constrained the relative movements of the linkers that connect these helices to the ligand-binding domain using engineered cross-links, either within (intra-GluN1 or GluN2A) or between subunits. Constraining the peripheral linkers in any manner dramatically curtailed channel opening, highlighting the requirement for rearrangements of these peripheral structural elements for efficient gating to occur. However, the magnitude of this gating effect depended on the specific subunit being constrained, with the most dramatic effects occurring when the constraint was between subunits. Based on kinetic and thermodynamic analysis, our results suggest an asynchrony in the displacement of the peripheral linkers during the conformational and energetic changes leading to pore opening. Initially there are large-scale rearrangements occurring between the four subunits. Subsequently, rearrangements occur within individual subunits, mainly GluN2A, leading up to or in concert with pore opening. Thus, the conformational changes induced by agonist binding in NMDA receptors converge asynchronously to permit pore opening.
Collapse
|
17
|
Gyengesi E, Paxinos G, Andrews ZB. Oxidative Stress in the Hypothalamus: the Importance of Calcium Signaling and Mitochondrial ROS in Body Weight Regulation. Curr Neuropharmacol 2013; 10:344-53. [PMID: 23730258 PMCID: PMC3520044 DOI: 10.2174/157015912804143496] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 07/12/2012] [Accepted: 08/02/2012] [Indexed: 12/25/2022] Open
Abstract
A considerable amount of evidence shows that reactive oxygen species (ROS) in the mammalian brain are directly responsible for cell and tissue function and dysfunction. Excessive reactive oxygen species contribute to various conditions including inflammation, diabetes mellitus, neurodegenerative diseases, tumor formation, and mental disorders such as depression. Increased intracellular calcium levels have toxic roles leading to cell death. However, the exact connection between reactive oxygen production and high calcium stress is not yet fully understood. In this review, we focus on the role of reactive oxygen species and calcium stress in hypothalamic arcuate neurons controlling feeding. We revisit the role of NPY and POMC neurons in the regulation of appetite and energy homeostasis, and consider how ROS and intracellular calcium levels affect these neurons. These novel insights give a new direction to research on hypothalamic mechanisms regulating energy homeostasis and may offer novel treatment strategies for obesity and type-2 diabetes.
Collapse
Affiliation(s)
- Erika Gyengesi
- Neuroscience Research Australia, Barker Street, Randwick, New South Wales, Australia
| | | | | |
Collapse
|
18
|
Vance KM, Hansen KB, Traynelis SF. GluN1 splice variant control of GluN1/GluN2D NMDA receptors. J Physiol 2012; 590:3857-75. [PMID: 22641781 DOI: 10.1113/jphysiol.2012.234062] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
NMDA receptors are ionotropic glutamate receptors that mediate a slow, Ca2+-permeable component of excitatory synaptic transmission in the central nervous system. Recombinant GluN1-1a/GluN2D receptors are characterized by low channel open probability and prolonged deactivation time course following the removal of agonist. Here, we show that the deactivation time course, agonist potency, and single channel properties of GluN2D-containing NMDA receptors are modulated by alternative RNA splicing of GluN1. Our results demonstrate that GluN1 exon 5, which encodes a 21-amino-acid insert in the amino-terminal domain, is a key determinant of GluN1/GluN2D receptor function. GluN1-1b/GluN2D receptors, which contain the residues encoded by exon 5, deactivate with a dual exponential time course described by a τFAST of 410 ms and a τSLOW of 1100 ms. This time course is 3-fold more rapid than that for exon 5-lacking GluN1-1a/GluN2D, which deactivates with a τFAST of 1100 ms and a τSLOW of 3400 ms. Exon 5-containing NMDA receptors also have a two-fold higher open probability (0.037) than exon 5-lacking receptors (0.017). Furthermore, inclusion of exon 5-encoded residues within the GluN1-1b subunit decreases the potency for the endogenous agonist l-glutamate. Evaluation of receptor kinetics for NMDA receptors containing mutated GluN1-1b subunits and wild-type GluN2D identified residue Lys211 in GluN1-1b as a key determinant of exon 5 control of the deactivation time course and glutamate potency. Evaluation of a kinetic model of GluN1/GluN2D gating suggests that residues encoded by exon 5 influence several rate-limiting steps. These data demonstrate that the GluN1 subunit is a key determinant of the kinetic and pharmacological properties of GluN2D-containing NMDA receptors.
Collapse
Affiliation(s)
- Katie M Vance
- S. F. Traynelis: Department of Pharmacology, Rollins Research Center, 1510 Clifton Road, Atlanta, GA 30322-3090, USA
| | | | | |
Collapse
|