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Park EH, Kao HY, Jourdi H, van Dijk MT, Carrillo-Segura S, Tunnell KW, Gutierrez J, Wallace EJ, Troy-Regier M, Radwan B, Lesburguères E, Alarcon JM, Fenton AA. Phencyclidine Disrupts Neural Coordination and Cognitive Control by Dysregulating Translation. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2024; 4:252-263. [PMID: 38298788 PMCID: PMC10829677 DOI: 10.1016/j.bpsgos.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 02/02/2024] Open
Abstract
Background Phencyclidine (PCP) causes psychosis, is abused with increasing frequency, and was extensively used in antipsychotic drug discovery. PCP discoordinates hippocampal ensemble action potential discharge and impairs cognitive control in rats, but how this uncompetitive NMDA receptor (NMDAR) antagonist impairs cognition remains unknown. Methods The effects of PCP were investigated on hippocampal CA1 ensemble action potential discharge in vivo in urethane-anesthetized rats and during awake behavior in mice, on synaptic responses in ex vivo mouse hippocampus slices, in mice on a hippocampus-dependent active place avoidance task that requires cognitive control, and on activating the molecular machinery of translation in acute hippocampus slices. Mechanistic causality was assessed by comparing the PCP effects with the effects of inhibitors of protein synthesis, group I metabotropic glutamate receptors (mGluR1/5), and subunit-selective NMDARs. Results Consistent with ionotropic actions, PCP discoordinated CA1 ensemble action potential discharge. PCP caused hyperactivity and impaired active place avoidance, despite the rodents having learned the task before PCP administration. Consistent with metabotropic actions, PCP exaggerated protein synthesis-dependent DHPG-induced mGluR1/5-stimulated long-term synaptic depression. Pretreatment with anisomycin or the mGluR1/5 antagonist MPEP, both of which repress translation, prevented PCP-induced discoordination and the cognitive and sensorimotor impairments. PCP as well as the NR2A-containing NMDAR antagonist NVP-AAM077 unbalanced translation that engages the Akt, mTOR (mechanistic target of rapamycin), and 4EBP1 translation machinery and increased protein synthesis, whereas the NR2B-containing antagonist Ro25-6981 did not. Conclusions PCP dysregulates translation, acting through NR2A-containing NMDAR subtypes, recruiting mGluR1/5 signaling pathways, and leading to neural discoordination that is central to the cognitive and sensorimotor impairments.
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Affiliation(s)
- Eun Hye Park
- Center for Neural Science, New York University, New York, New York
| | - Hsin-Yi Kao
- Center for Neural Science, New York University, New York, New York
| | - Hussam Jourdi
- Center for Neural Science, New York University, New York, New York
| | - Milenna T. van Dijk
- Center for Neural Science, New York University, New York, New York
- Graduate Program in Neuroscience and Physiology, New York University Langone Medical Center, New York, New York
| | - Simón Carrillo-Segura
- Center for Neural Science, New York University, New York, New York
- Graduate Program in Mechanical and Aerospace Engineering, New York University Tandon School of Engineering, New York, New York
| | - Kayla W. Tunnell
- Center for Neural Science, New York University, New York, New York
| | | | - Emma J. Wallace
- Graduate Program in Neural and Behavioral Science, State University of New York, Downstate Health Sciences University, Brooklyn, New York
- Department of Physiology and Pharmacology, State University of New York, Downstate Health Sciences University, Brooklyn, New York
| | - Matthew Troy-Regier
- Graduate Program in Neural and Behavioral Science, State University of New York, Downstate Health Sciences University, Brooklyn, New York
- Department of Physiology and Pharmacology, State University of New York, Downstate Health Sciences University, Brooklyn, New York
| | - Basma Radwan
- Graduate Program in Neural Science, Center for Neural Science, New York University, New York, New York
| | | | - Juan Marcos Alarcon
- Department of Pathology, State University of New York, Downstate Health Sciences University, Brooklyn, New York
- Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York, Downstate Health Sciences University, Brooklyn, New York
| | - André A. Fenton
- Center for Neural Science, New York University, New York, New York
- Department of Physiology and Pharmacology, State University of New York, Downstate Health Sciences University, Brooklyn, New York
- Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York, Downstate Health Sciences University, Brooklyn, New York
- Neuroscience Institute, NYU Langone Health, New York, New York
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2
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Tikhonov DB. Channel Blockers of Ionotropic Glutamate
Receptors. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021020149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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3
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Morris PJ, Moaddel R, Zanos P, Moore CE, Gould TD, Zarate CA, Thomas CJ. Synthesis and N-Methyl-d-aspartate (NMDA) Receptor Activity of Ketamine Metabolites. Org Lett 2017; 19:4572-4575. [PMID: 28829612 DOI: 10.1021/acs.orglett.7b02177] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ketamine is rapidly metabolized in the human body to a variety of metabolites, including the hydroxynorketamines. At least two hydroxynorketamines have significant antidepressant action in rodent models, with limited action against the N-methyl-d-aspartate (NMDA) receptor. The synthesis of 12 hydroxynorketamines and their binding affinity to the NMDA receptor is presented here.
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Affiliation(s)
- Patrick J Morris
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health , Rockville, Maryland 20850, United States
| | - Ruin Moaddel
- Biomedical Research Center, National Institute on Aging, National Institutes of Health , Baltimore, Maryland 21224, United States
| | - Panos Zanos
- Department of Psychiatry, University of Maryland School of Medicine , Baltimore, Maryland 21201, United States
| | - Curtis E Moore
- Department of Chemistry and Biochemistry, University of California, San Diego , La Jolla, California 92093, United States
| | - Todd D Gould
- Departments of Psychiatry, Pharmacology, and Anatomy & Neurobiology, University of Maryland School of Medicine , Baltimore, Maryland 21201, United States
| | - Carlos A Zarate
- Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Craig J Thomas
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health , Rockville, Maryland 20850, United States
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Tabuena DR, Solis A, Geraldi K, Moffatt CA, Fuse M. Central neural alterations predominate in an insect model of nociceptive sensitization. J Comp Neurol 2017; 525:1176-1191. [PMID: 27650422 PMCID: PMC5258852 DOI: 10.1002/cne.24124] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 05/20/2016] [Accepted: 09/11/2016] [Indexed: 12/12/2022]
Abstract
Many organisms respond to noxious stimuli with defensive maneuvers. This is noted in the hornworm, Manduca sexta, as a defensive strike response. After tissue damage, organisms typically display sensitized responses to both noxious or normally innocuous stimuli. To further understand this phenomenon, we used novel in situ and in vitro preparations based on paired extracellular nerve recordings and videography to identify central and peripheral nerves responsible for nociception and sensitization of the defensive behavior in M. sexta. In addition, we used the in vivo defensive strike response threshold assayed with von Frey filaments to examine the roles that N-methyl-D-aspartate receptor (NMDAR) and hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels play in this nociceptive sensitization using the inhibitors MK-801 and AP5 (NMDAR), and ivabradine and ZD7288 (HCN). Using our new preparations, we found that afferent activity evoked by noxious pinch in these preparations was conveyed to central ganglia by axons in the anterior- and lateral-dorsal nerve branches, and that sensitization induced by tissue damage was mediated centrally. Furthermore, sensitization was blocked by all inhibitors tested except the inactive isomer L-AP5, and reversed by ivabradine both in vivo and in vitro. Our findings suggest that M. sexta's sensitization occurs through central signal amplification. Due to the relatively natural sensitization method and conserved molecular actions, we suggest that M. sexta may be a valuable model for studying the electrophysiological properties of nociceptive sensitization and potentially related conditions such as allodynia and hyperalgesia in a comparative setting that offers unique experimental advantages. J. Comp. Neurol. 525:1176-1191, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Dennis R Tabuena
- San Francisco State University, Dept. Biology. 1600 Holloway Avenue, San Francisco, CA 94132
| | - Allan Solis
- City College of San Francisco, 50 Phelan Ave, San Francisco, CA 94112
| | - Ken Geraldi
- San Francisco State University, Dept. Biology. 1600 Holloway Avenue, San Francisco, CA 94132
| | - Christopher A Moffatt
- San Francisco State University, Dept. Biology. 1600 Holloway Avenue, San Francisco, CA 94132
| | - Megumi Fuse
- San Francisco State University, Dept. Biology. 1600 Holloway Avenue, San Francisco, CA 94132
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Tachibana SI, Touhara K, Ejima A. Modification of Male Courtship Motivation by Olfactory Habituation via the GABAA Receptor in Drosophila melanogaster. PLoS One 2015; 10:e0135186. [PMID: 26252206 PMCID: PMC4529276 DOI: 10.1371/journal.pone.0135186] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 07/18/2015] [Indexed: 11/29/2022] Open
Abstract
A male-specific component, 11-cis-vaccenyl acetate (cVA) works as an anti-aphrodisiac pheromone in Drosophila melanogaster. The presence of cVA on a male suppresses the courtship motivation of other males and contributes to suppression of male-male homosexual courtship, while the absence of cVA on a female stimulates the sexual motivation of nearby males and enhances the male-female interaction. However, little is known how a male distinguishes the presence or absence of cVA on a target fly from either self-produced cVA or secondhand cVA from other males in the vicinity. In this study, we demonstrate that male flies have keen sensitivity to cVA; therefore, the presence of another male in the area reduces courtship toward a female. This reduced level of sexual motivation, however, could be overcome by pretest odor exposure via olfactory habituation to cVA. Real-time imaging of cVA-responsive sensory neurons using the neural activity sensor revealed that prolonged exposure to cVA decreased the levels of cVA responses in the primary olfactory center. Pharmacological and genetic screening revealed that signal transduction via GABAA receptors contributed to this olfactory habituation. We also found that the habituation experience increased the copulation success of wild-type males in a group. In contrast, transgenic males, in which GABA input in a small subset of local neurons was blocked by RNAi, failed to acquire the sexual advantage conferred by habituation. Thus, we illustrate a novel phenomenon in which olfactory habituation positively affects sexual capability in a competitive environment.
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Affiliation(s)
- Shin-Ichiro Tachibana
- Career-Path Promotion Unit for Young Life Scientists, Kyoto University, Kyoto, 606–8501, Japan
- Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka, 558–8585, Japan
| | - Kazushige Touhara
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113–8657, Japan
- ERATO Touhara Chemosensory Signal Project, JST, The University of Tokyo, Tokyo, 113–8657, Japan
| | - Aki Ejima
- Career-Path Promotion Unit for Young Life Scientists, Kyoto University, Kyoto, 606–8501, Japan
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113–8657, Japan
- ERATO Touhara Chemosensory Signal Project, JST, The University of Tokyo, Tokyo, 113–8657, Japan
- * E-mail:
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Metaxa V, Lagoudaki R, Meditskou S, Thomareis O, Oikonomou L, Sakadamis A. Delayed post-ischaemic administration of xenon reduces brain damage in a rat model of global ischaemia. Brain Inj 2013; 28:364-9. [DOI: 10.3109/02699052.2013.865273] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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7
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Berger ML, Schweifer A, Rebernik P, Hammerschmidt F. NMDA receptor affinities of 1,2-diphenylethylamine and 1-(1,2-diphenylethyl)piperidine enantiomers and of related compounds. Bioorg Med Chem 2009; 17:3456-62. [DOI: 10.1016/j.bmc.2009.03.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Accepted: 03/13/2009] [Indexed: 12/22/2022]
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Grey KB, Moss BL, Burrell BD. Molecular identification and expression of the NMDA receptor NR1 subunit in the leech. INVERTEBRATE NEUROSCIENCE 2009; 9:11-20. [PMID: 19142676 DOI: 10.1007/s10158-008-0085-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Accepted: 12/17/2008] [Indexed: 12/31/2022]
Abstract
The N-methyl-D-aspartate receptor (NMDAR) is involved in a number of physiological and pathophysiological processes in vertebrates, but there have been few studies examining the role of invertebrate NMDA receptors. In the leech, pharmacological evidence suggests that NMDARs contribute to synaptic plasticity, but there has been no molecular identification of NMDA receptors. In this report, a partial cDNA encoding the leech NR1 subunit of the NMDA receptor (HirNR1) is presented. Reverse transcriptase-polymerase chain reaction from single neurons of the leech central nervous system confirms HirNR1 expression in the Retzius (R), Anterior Pagoda (AP), Pressure (P), and Touch (T) neurons. Immunoblotting with an anti-NR1 antibody yielded a approximately 110 kDa protein, similar to the expected weight of the NR1 subunit (approximately 116 kDa). Finally, pairing pre- and postsynaptic activity elicited long-term potentiation in synapses between neurons expressing NR1 mRNA (P-to-AP synapse) and this potentiation was blocked by the NMDAR antagonist AP5.
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Affiliation(s)
- Kathryn B Grey
- Division of Basic Biomedical Sciences, Neuroscience Group, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA
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Valente P, García‐Sanz N, Gomis A, Fernández‐Carvajal A, Fernández‐Ballester G, Viana F, Belmonte C, Ferrer‐Montiel A. Identification of molecular determinants of channel gating in the transient receptor potential box of vanilloid receptor I. FASEB J 2008; 22:3298-309. [DOI: 10.1096/fj.08-107425] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Pierluigi Valente
- Instituto de Biología Molecular y CelularUniversidad Miguel Hernández Elche Alicante Spain
| | - Nuria García‐Sanz
- Instituto de Biología Molecular y CelularUniversidad Miguel Hernández Elche Alicante Spain
| | - Ana Gomis
- Instituto de Neurociencias de AlicanteUniversidad Miguel Hernández‐Consejo Superior de Investigaciones Científicas San Juan de Alicante Alicante Spain
| | | | | | - Félix Viana
- Instituto de Neurociencias de AlicanteUniversidad Miguel Hernández‐Consejo Superior de Investigaciones Científicas San Juan de Alicante Alicante Spain
| | - Carlos Belmonte
- Instituto de Neurociencias de AlicanteUniversidad Miguel Hernández‐Consejo Superior de Investigaciones Científicas San Juan de Alicante Alicante Spain
| | - Antonio Ferrer‐Montiel
- Instituto de Biología Molecular y CelularUniversidad Miguel Hernández Elche Alicante Spain
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10
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Xia S, Miyashita T, Fu TF, Lin WY, Wu CL, Pyzocha L, Lin IR, Saitoe M, Tully T, Chiang AS. NMDA receptors mediate olfactory learning and memory in Drosophila. Curr Biol 2005; 15:603-15. [PMID: 15823532 PMCID: PMC3045563 DOI: 10.1016/j.cub.2005.02.059] [Citation(s) in RCA: 173] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Revised: 02/13/2005] [Accepted: 02/14/2005] [Indexed: 01/15/2023]
Abstract
BACKGROUND Molecular and electrophysiological properties of NMDARs suggest that they may be the Hebbian "coincidence detectors" hypothesized to underlie associative learning. Because of the nonspecificity of drugs that modulate NMDAR function or the relatively chronic genetic manipulations of various NMDAR subunits from mammalian studies, conclusive evidence for such an acute role for NMDARs in adult behavioral plasticity, however, is lacking. Moreover, a role for NMDARs in memory consolidation remains controversial. RESULTS The Drosophila genome encodes two NMDAR homologs, dNR1 and dNR2. When coexpressed in Xenopus oocytes or Drosophila S2 cells, dNR1 and dNR2 form functional NMDARs with several of the distinguishing molecular properties observed for vertebrate NMDARs, including voltage/Mg(2+)-dependent activation by glutamate. Both proteins are weakly expressed throughout the entire brain but show preferential expression in several neurons surrounding the dendritic region of the mushroom bodies. Hypomorphic mutations of the essential dNR1 gene disrupt olfactory learning, and this learning defect is rescued with wild-type transgenes. Importantly, we show that Pavlovian learning is disrupted in adults within 15 hr after transient induction of a dNR1 antisense RNA transgene. Extended training is sufficient to overcome this initial learning defect, but long-term memory (LTM) specifically is abolished under these training conditions. CONCLUSIONS Our study uses a combination of molecular-genetic tools to (1) generate genomic mutations of the dNR1 gene, (2) rescue the accompanying learning deficit with a dNR1+ transgene, and (3) rapidly and transiently knockdown dNR1+ expression in adults, thereby demonstrating an evolutionarily conserved role for the acute involvement of NMDARs in associative learning and memory.
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Affiliation(s)
- Shouzhen Xia
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724
| | - Tomoyuki Miyashita
- Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan
| | - Tsai-Feng Fu
- Institute of Biotechnology and Department of Life Science, National Tsing Hua University, Hsinchu 30043, Taiwan
| | - Wei-Yong Lin
- Institute of Biotechnology and Department of Life Science, National Tsing Hua University, Hsinchu 30043, Taiwan
| | - Chia-Lin Wu
- Institute of Biotechnology and Department of Life Science, National Tsing Hua University, Hsinchu 30043, Taiwan
| | - Lori Pyzocha
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724
| | - Inn-Ray Lin
- Institute of Biotechnology and Department of Life Science, National Tsing Hua University, Hsinchu 30043, Taiwan
| | - Minoru Saitoe
- Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Tim Tully
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724
| | - Ann-Shyn Chiang
- Institute of Biotechnology and Department of Life Science, National Tsing Hua University, Hsinchu 30043, Taiwan
- Brain Research Center, National Tsing Hua University, University System of Taiwan, Hsinchu 30043, Taiwan
- Correspondence:
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LePage KT, Ishmael JE, Low CM, Traynelis SF, Murray TF. Differential binding properties of [3H]dextrorphan and [3H]MK-801 in heterologously expressed NMDA receptors. Neuropharmacology 2005; 49:1-16. [PMID: 15992576 PMCID: PMC4654417 DOI: 10.1016/j.neuropharm.2005.01.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2003] [Revised: 11/29/2004] [Accepted: 01/26/2005] [Indexed: 11/30/2022]
Abstract
The N-methyl-D-aspartate receptor (NMDAR) antagonists: MK-801, phencyclidine and ketamine are open-channel blockers with limited clinical value due to psychotomimetic effects. Similarly, the psychotomimetic effects of the dextrorotatory opioids, dextromethorphan and its metabolite dextrorphan, derive from their NMDAR antagonist actions. Differences in the use dependency of blockade, however, suggest that the binding sites for MK-801 and dextrorphan are distinct. In the absence of exogenous glutamate and glycine, the rate of association of [3H]MK-801 with wild-type NR1-1a/NR2A receptors was considerably slower than that for [3H]dextrorphan. Glutamate individually, and in the presence of the co-agonist glycine, had substantial effects on the specific binding of [3H]MK-801, while the binding of [3H]dextrorphan was not affected. Mutation of residues N616 and A627 in the NR1 subunit had a profound effect on [3H]MK-801 binding affinity, while that of [3H]dextrorphan was unaltered. In contrast, NR1 residues, W611 and N812, were critical for specific binding of [3H]dextrorphan to NR1-1a/NR2A complexes with no corresponding influence on that of [3H]MK-801. Thus, [3H]dextrorphan and [3H]MK-801 have distinct molecular determinants for high-affinity binding. The ability of [3H]dextrorphan to bind to a closed channel, moreover, indicates that its recognition site is shallower in the ion channel domain than that of MK-801 and may be associated with the extracellular vestibule of the NMDAR.
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Affiliation(s)
- K T LePage
- Department of Physiology and Pharmacology, The University of Georgia, College of Veterinary Medicine, Athens, GA 30602, USA.
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12
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Osteen CL, Giza CC, Hovda DA. Injury-induced alterations in N-methyl-D-aspartate receptor subunit composition contribute to prolonged 45calcium accumulation following lateral fluid percussion. Neuroscience 2004; 128:305-22. [PMID: 15350643 DOI: 10.1016/j.neuroscience.2004.06.034] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2004] [Indexed: 10/26/2022]
Abstract
Cells that survive traumatic brain injury are exposed to changes in their neurochemical environment. One of these changes is a prolonged (48 h) uptake of calcium which, by itself, is not lethal. The N-methyl-D-aspartate receptor (NMDAR) is responsible for the acute membrane flux of calcium following trauma; however, it is unclear if it is involved in a flux lasting 2 days. We proposed that traumatic brain injury induced a molecular change in the NMDAR by modifying the concentrations of its corresponding subunits (NR1 and NR2). Changing these subunits could result in a receptor being more sensitive to glutamate and prolong its opening, thereby exposing cells to a sustained flux of calcium. To test this hypothesis, adult rats were subjected to a lateral fluid percussion brain injury and the NR1, NR2A and NR2B subunits measured within different regions. Although little change was seen in NR1, both NR2 subunits decreased nearly 50% compared with controls, particularly within the ipsilateral cerebral cortex. This decrease was sustained for 4 days with levels returning to control values by 2 weeks. However, this decrease was not the same for both subunits, resulting in a decrease (over 30%) in the NR2A:NR2B ratio indicating that the NMDAR had temporarily become more sensitive to glutamate and would remain open longer once activated. Combining these regional and temporal findings with 45calcium autoradiographic studies revealed that the degree of change in the subunit ratio corresponded to the extent of calcium accumulation. Finally, utilizing a combination of NMDAR and NR2B-specific antagonists it was determined that as much at 85% of the long term NMDAR-mediated calcium flux occurs through receptors whose subunits favor the NR2B subunit. These data indicate that TBI induces molecular changes within the NMDAR, contributing to the cells' post-injury vulnerability to glutamatergic stimulation.
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Affiliation(s)
- C L Osteen
- Brain Injury Research Center, Division of Neurosurgery/Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-7039, USA
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Maruo K, Nagata T, Yamamoto S, Nagai K, Yajima Y, Maruo S, Nishizaki T. Tunicamycin inhibits NMDA and AMPA receptor responses independently of N-glycosylation. Brain Res 2003; 977:294-7. [PMID: 12834891 DOI: 10.1016/s0006-8993(03)02838-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In a whole-cell patch-clamp configuration, currents through N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor channels were monitored in cultured rat hippocampal neurons, and those currents were depressed to 25 and 28% of basal levels, respectively, by 3-min treatment with tunicamycin (10 microM), an inhibitor of protein N-glycosylation. Tunicamycin (10 microM) reduced amplitude of population spikes elicited in the dentate gyrus of rat hippocampal slices, reaching 78% of basal levels 60 min after the beginning of treatment, and long-term potentiation (LTP) of the perforant path was never induced in the presence of tunicamycin. Tunicamycin, thus, appears to serve as a modulator for NMDA and AMPA receptors, regardless of N-glycosylation, thereby inhibiting neurotransmission and LTP in the dentate gyrus.
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Affiliation(s)
- Keishi Maruo
- Department of Physiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya 663-8501, Japan
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Klopman G, Sedykh A. An MCASE approach to the search of a cure for Parkinson's Disease. BMC Pharmacol 2002; 2:8. [PMID: 11926966 PMCID: PMC107836 DOI: 10.1186/1471-2210-2-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2001] [Accepted: 04/02/2002] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Parkinson's disease is caused by a dopamine deficiency state in the fore brain area. Dopamine receptor agonists, MAO-B inhibitors, and N-Methyl-D-Aspartate (NMDA) receptor antagonists are known to have antiparkinson effect. Levodopa, a dopamine structural analog, is the best currently available medication for the treatment of Parkinsons disease. Unfortunately, it also induces side effects upon long administration time. Thus, multidrug therapy is often used, in which various adjuvants alleviate side effects of levodopa and enhance its antiparkinsonian action. RESULTS Computer models have been created for three known antiparkinson mechanisms using the MCASE methodology. New drugs for Parkinsons disease can be designed on the basis of these models. We also speculate that the presence of biophores belonging to different groups can be beneficial and designed some potential drugs along this line. The proposed compounds bear pharmacophores of MAO-B inhibitors, dopamine agonists and NMDA antagonists, which could synergistically enhance their antiparkinson effect. CONCLUSIONS The methodology could readily be expanded to other endpoints where drugs with multiple activity mechanisms would be desirable.
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Affiliation(s)
- Gilles Klopman
- Chemistry Department, Case Western Reserve University, 10700, Euclid Avenue, Cleveland, OH 44106, USA
- KCI, 22 Hyde Park, Beachwood, OH 44106, USA
| | - Aleksandr Sedykh
- Chemistry Department, Case Western Reserve University, 10700, Euclid Avenue, Cleveland, OH 44106, USA
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Brockie PJ, Mellem JE, Hills T, Madsen DM, Maricq AV. The C. elegans glutamate receptor subunit NMR-1 is required for slow NMDA-activated currents that regulate reversal frequency during locomotion. Neuron 2001; 31:617-30. [PMID: 11545720 DOI: 10.1016/s0896-6273(01)00394-4] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The N-methyl-D-aspartate (NMDA) subtype of glutamate receptor is important for synaptic plasticity and nervous system development and function. We have used genetic and electrophysiological methods to demonstrate that NMR-1, a Caenorhabditis elegans NMDA-type ionotropic glutamate receptor subunit, plays a role in the control of movement and foraging behavior. nmr-1 mutants show a lower probability of switching from forward to backward movement and a reduced ability to navigate a complex environment. Electrical recordings from the interneuron AVA show that NMDA-dependent currents are selectively disrupted in nmr-1 mutants. We also show that a slowly desensitizing variant of a non-NMDA receptor can rescue the nmr-1 mutant phenotype. We propose that NMDA receptors in C. elegans provide long-lived currents that modulate the frequency of movement reversals during foraging behavior.
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Affiliation(s)
- P J Brockie
- Department of Biology, University of Utah, Salt Lake City 84112, USA
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16
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Bachurin S, Tkachenko S, Baskin I, Lermontova N, Mukhina T, Petrova L, Ustinov A, Proshin A, Grigoriev V, Lukoyanov N, Palyulin V, Zefirov N. Neuroprotective and cognition-enhancing properties of MK-801 flexible analogs. Structure-activity relationships. Ann N Y Acad Sci 2001; 939:219-36. [PMID: 11462774 DOI: 10.1111/j.1749-6632.2001.tb03629.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Neuroprotective and biobehavioral properties of a series of novel open chain MK-801 analogs, as well as their structure-activity relationships have been investigated. Three groups of compounds were synthesized: monobenzylamino, benzhydrylamino, and dibenzylamino (DBA) analogs of MK-801. It was revealed that DBA analogs exhibit pronounced glutamate-induced calcium uptake blocking properties and anti-NMDA activity. The hit compound of DBA series, NT-1505, was investigated for its ability to improve cognition functions in animal model of Alzheimer's disease type dementia, simulated by treating animals with cholinotoxin AF64A. The results from an active avoidance test and a Morris water maze test showed that experimental animals, treated additionally with NT-1505, exhibited much better learning ability and memory than the control group (AF64A treated) and close to that of the vehicle group of animals (treated with physiological solution). Study of NT-1505 influence on locomotor activity revealed that it is characterized by a spectrum of behavioral activity radically different from that of MK-801, and in contrast to the latter one does not produce any psychotomimetic side effects in the therapeutically significant dose interval. The computed docking of MK-801 and its flexible analogs on the NMDA receptor elucidated the crucial role of the hydrogen bond formed between these compounds and the asparagine residue for magnesium binding in the NMDA receptor. It was suggested that strong hydrophobic interaction between MK-801 and the hydrophobic pocket in the NMDA receptor-channel complex determines much higher irreversibility of this adduct compared to the intermediates formed between this site and Mg ions or flexible DBA derivatives, which might explain the absence of PCP-like side effects of the latter compounds.
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Affiliation(s)
- S Bachurin
- Institute of Physiologically Active Compounds RAS, 142432, Chernogolovka, Russia.
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17
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García-Martínez C, Morenilla-Palao C, Planells-Cases R, Merino JM, Ferrer-Montiel A. Identification of an aspartic residue in the P-loop of the vanilloid receptor that modulates pore properties. J Biol Chem 2000; 275:32552-8. [PMID: 10931826 DOI: 10.1074/jbc.m002391200] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vanilloid receptor subunit 1 (VR1) is a nonselective cation channel that integrates multiple pain-producing stimuli. VR1 channels are blocked with high efficacy by the well established noncompetitive antagonist ruthenium red and exhibit high permeability to divalent cations. The molecular determinants that define these functional properties remain elusive. We have addressed this question and evaluated by site-specific neutralization the contribution on pore properties of acidic residues located in the putative VR1 pore region. Mutant receptors expressed in Xenopus oocytes exhibited capsaicin-operated ionic currents akin to those of wild type channels. Incorporation of glutamine residues at Glu(648) and Glu(651) rendered minor effects on VR1 pore attributes, while Glu(636) slightly modulated pore blockade. In contrast, replacement of Asp(646) by asparagine decreased 10-fold ruthenium red blockade efficacy and reduced 4-fold the relative permeability of the divalent cation Mg(2+) with respect to Na(+) without changing the selectivity of monovalent cations. At variance with wild type channels and E636Q, E648Q, and E651Q mutant receptors, ruthenium red blockade of D646N mutants was weakly sensitive to extracellular pH acidification. Collectively, our results suggest that Asp(646) is a molecular determinant of VR1 pore properties and imply that this residue may form a ring of negative charges that structures a high affinity binding site for cationic molecules at the extracellular entryway.
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Affiliation(s)
- C García-Martínez
- Centro de Biologia Molecular y Celular, Universidad Miguel Hernández, Elche (Alicante) 03202, Spain
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18
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Planells-Cases R, Aracil A, Merino JM, Gallar J, Pérez-Payá E, Belmonte C, González-Ros JM, Ferrer-Montiel AV. Arginine-rich peptides are blockers of VR-1 channels with analgesic activity. FEBS Lett 2000; 481:131-6. [PMID: 10996311 DOI: 10.1016/s0014-5793(00)01982-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Vanilloid receptors (VRs) play a fundamental role in the transduction of peripheral tissue injury and/or inflammation responses. Molecules that antagonize VR channel activity may act as selective and potent analgesics. We report that synthetic arginine-rich hexapeptides block heterologously expressed VR-1 channels with submicromolar efficacy in a weak voltage-dependent manner, consistent with a binding site located near/at the entryway of the aqueous pore. Dynorphins, natural arginine-rich peptides, also blocked VR-1 activity with micromolar affinity. Notably, synthetic and natural arginine-rich peptides attenuated the ocular irritation produced by topical capsaicin application onto the eyes of experimental animals. Taken together, our results imply that arginine-rich peptides are VR-1 channel blockers with analgesic activity. These findings may expand the development of novel analgesics by targeting receptor sites distinct from the capsaicin binding site.
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Affiliation(s)
- R Planells-Cases
- Centro de Biologia Molecular y Celular, Universidad Miguel Hernandez, Edf. Torregaitan, Avda, Ferrocarril sln, 03202 Elche, Spain
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19
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Tikhonov DB, Zhorov BS, Magazanik LG. Intersegment hydrogen bonds as possible structural determinants of the N/Q/R site in glutamate receptors. Biophys J 1999; 77:1914-26. [PMID: 10512812 PMCID: PMC1300473 DOI: 10.1016/s0006-3495(99)77033-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Specific electrophysiological and pharmacological properties of ionic channels in NMDA, AMPA, and kainate subtypes of ionotropic glutamate receptors (GluRs) are determined by the Asn (N), Gln (Q), and Arg (R) residues located at homologous positions of the pore-lining M2 segments (the N/Q/R site). Presumably, the N/Q/R site is located at the apex of the reentrant membrane loop and forms the narrowest constriction of the pore. Although the shorter Asn residues are expected to protrude in the pore to a lesser extent than the longer Gln residues, the effective dimension of the NMDA channel (corresponding to the size of the largest permeant organic cation) is, surprisingly, smaller than that of the AMPA channel. To explain this paradox, we propose that the N/Q/R residues form macrocyclic structures (rings) stabilized by H-bonds between a NH(2) group in the side chain of a given M2 segment and a C==O group of the main chain in the adjacent M2 segment. Using Monte Carlo minimization, we have explored conformational properties of the rings. In the Asn, but not in the Gln ring, the side-chain oxygens protruding into the pore may facilitate ion permeation and accept H-bonds from the blocking drugs. In this way, the model explains different electrophysiological and pharmacological properties of NMDA and non-NMDA GluR channels. The ring of H-bonded polar residues at the pore narrowing resembles the ring of four Thr(75) residues observed in the crystallographic structure of the KcsA K(+) channel.
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Affiliation(s)
- D B Tikhonov
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, St. Petersburg 194223, Russia.
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20
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Abstract
N-Methyl-D-aspartate (NMDA) receptor channels play important roles in various physiological functions such as synaptic plasticity and synapse formation underlying memory, learning and formation of neural networks during development. They are also important for a variety of pathological states including acute and chronic neurological disorders, psychiatric disorders, and neuropathic pain syndromes. cDNA cloning has revealed the molecular diversity of NMDA receptor channels. The identification of multiple subunits with distinct distributions, properties and regulation, implies that NMDA receptor channels are heterogeneous in their pharmacological properties, depending on the brain region and the developmental stage. Furthermore, mutation studies have revealed a critical role for specific amino acid residues in certain subunits in determining the pharmacological properties of NMDA receptor channels. The molecular heterogeneity of NMDA receptor channels as well as their dual role in physiological and pathological functions makes it necessary to develop subunit- and site-specific drugs for precise and selective therapeutic intervention. This review summarizes from a molecular perspective the recent advances in our understanding of the pharmacological properties of NMDA receptor channels with specific references to agonists binding sites, channel pore regions, allosteric modulation sites for protons, polyamines, redox agents, Zn2+ and protein kinases, phosphatases.
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Affiliation(s)
- T Yamakura
- Department of Anesthesiology, Niigata University School of Medicine, Japan
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21
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Villmann C, Strutz N, Morth T, Hollmann M. Investigation by ion channel domain transplantation of rat glutamate receptor subunits, orphan receptors and a putative NMDA receptor subunit. Eur J Neurosci 1999; 11:1765-78. [PMID: 10215929 DOI: 10.1046/j.1460-9568.1999.00594.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Among the 18 ionotropic glutamate receptor subunits identified in the mammalian central nervous system, five (delta1, delta2, GluR7, chi2 and NR3A, formerly called NMDAR-L or chi1) reportedly fail to form functional ion channels in heterologous expression systems. Four of these subunits, delta1, delta2, chi2 and NR3A, have not even been shown to bind glutamatergic ligands, relegating them to the status of 'orphan' receptors. We used a domain transplantation approach to investigate potential functional properties of the putative ion channel domains of four of these subunits. By exchanging ion pore domains between functional glutamate receptors (GluR1, GluR6 and NMDAR1) with known pore properties we first tested the feasibility of the domain swapping method. We demonstrate that ion channel domains can be transplanted between all three functional subfamilies of ionotropic glutamate receptors. Furthermore, exchange of ion pore domains allows identification of those channel properties determined exclusively by the ion pore. We then show that transplanting the pore domain of GluR7 into either GluR1 or GluR6 generates perfectly functional ligand-gated ion channels that allow characterization of electrophysiological and pharmacological properties of the GluR7 pore domain. In contrast, delta1, delta2 and NR3A do not produce functional receptors when their pore domains are transplanted into either the AMPA receptor, GluR1, the kainate receptor, GluR6, or the NMDA receptor, NMDAR1. We speculate that the orphan receptors delta1 and delta2, and the NMDA receptor-like subunit NR3A may serve some modulatory function, rather than contributing to the formation of ion channels.
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Affiliation(s)
- C Villmann
- Glutamate Receptor Laboratory, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany
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22
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Beck C, Wollmuth LP, Seeburg PH, Sakmann B, Kuner T. NMDAR channel segments forming the extracellular vestibule inferred from the accessibility of substituted cysteines. Neuron 1999; 22:559-70. [PMID: 10197535 DOI: 10.1016/s0896-6273(00)80710-2] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In NMDA receptor channels, the M2 loop forms the narrow constriction and the cytoplasmic vestibule. The identity of an extracellular vestibule leading toward the constriction remained unresolved. Using the substituted cysteine accessibility method (SCAM), we identified channel-lining residues of the NR1 subunit in the region preceding M1 (preM1), the C-terminal part of M3 (M3C), and the N-terminal part of M4 (M4N). These residues are located on the extracellular side of the constriction and, with one exception, are exposed to the pore independently of channel activation, suggesting that the gate is at the constriction or further cytoplasmic to it. Permeation of Ca2+ ions was decreased by mutations in M3C and M4N, but not by mutations in preM1, suggesting a functionally distinct contribution of the segments to the extracellular vestibule of the NMDA receptor channel.
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Affiliation(s)
- C Beck
- Abteilung Molekulare Neurobiologie, Max-Planck-Institut für medizinische Forschung, Heidelbeg, Germany
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23
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Monaghan DT, Andaloro VJ, Skifter DA. Molecular determinants of NMDA receptor pharmacological diversity. PROGRESS IN BRAIN RESEARCH 1999; 116:171-90. [PMID: 9932377 DOI: 10.1016/s0079-6123(08)60437-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Affiliation(s)
- D T Monaghan
- Department of Pharmacology, University of Nebraska Medical Center, Omaha 68198-6260, USA.
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24
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Kreimeyer A, Laube B, Sturgess M, Goeldner M, Foucaud B. Reactive affinity probes for the mapping of the glycine-binding site of the NMDA receptor NR1 subunit. J Recept Signal Transduct Res 1999; 19:547-57. [PMID: 10071784 DOI: 10.3109/10799899909036671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The glycine co-agonist binding site of the NMDA receptor is a target for the prevention and treatment of neurotoxic and neurodegenerative conditions. Until now, the interactions taking place at this site, and its structure, have been investigated by ligand structure-activity relationships and by site-directed mutagenesis. On the basis of a structural model which is currently proposed for this site, we have designed and synthesized six affinity markers by substituting electrophilic reactive groups in the 4, the 7 and the 3' positions of L 701,324, a high-affinity glycine site antagonist. These compounds compete with 3H-DCKA binding to rat brain membranes at equilibrium with nanomolar to low-micromolar affinities, and antagonize glycine-evoked currents in oocytes transfected with wild-type NR1-NR2B. However, they do not induce a time-shift in binding equilibria, and do not inactivate irreversibly the glycine evoked currents. Since they react only with cysteine at physiological pH, we conclude that there is no such residue in the site, in agreement with the model. Our affinity markers therefore represent potential topological probes for NMDA receptors with sequence positions related to the glycine-binding site mutated into cysteine.
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Affiliation(s)
- A Kreimeyer
- Laboratoire de Chimie Bioorganique, CNRS-UMR 7514, ULP-Faculté de Pharmacie, Illkirch, France
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25
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Lim K, Owens SM, Arnold L, Sacchettini JC, Linthicum DS. Crystal structure of monoclonal 6B5 Fab complexed with phencyclidine. J Biol Chem 1998; 273:28576-82. [PMID: 9786848 DOI: 10.1074/jbc.273.44.28576] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The crystal structure of monoclonal antibody (mAb) 6B5 Fab fragment complexed with 1-(1-phenylcyclohexyl)piperidine (PCP or phencyclidine) was determined at 2.2-A resolution. 6B5 was originally produced from a mouse immunized with a phencyclidine analogue hapten 5-[N-(1'phenylcyclohexyl)amino]pentanoic acid conjugated to bovine serum albumin. This mAb was selected for further study because of its high affinity (Kd = 2 x 10(-9) M/liter) for PCP and usefulness in reversing PCP-induced central nervous system toxicity in laboratory animals. The dominant feature of the 6B5 Fab.PCP complex is the deep binding site and hydrophobic nature of the interaction. The ligand binding pocket of 6B5 Fab has numerous aromatic side chains, as compared with other known Fab structures. The most notable feature of the binding site is a Trp at position 97H (H-chain), and the side chain of this residue appears to act as a hydrophobic umbrella on the ligand in the antigen binding pocket. There are only two other known Fabs found with a Trp at the 97H position in complementarity determining region (CDR) H3, but they do not play a major role in the interaction with their respective antigens; in both Fab TE33 and R6.5 the Trp 97H side chain is positioned away from the bound antigen. Comparison of the CDR residues of 6B5 with other Fab structures with similar CDR sizes and amino acid compositions reveals a number of important patterns of residue substitutions that appear to be critical for specific PCP ligand interactions.
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Affiliation(s)
- K Lim
- Center for Structural Biology, Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, 77843, USA
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26
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Ferrer-Montiel AV, Merino JM, Planells-Cases R, Sun W, Montal M. Structural determinants of the blocker binding site in glutamate and NMDA receptor channels. Neuropharmacology 1998; 37:139-47. [PMID: 9680238 DOI: 10.1016/s0028-3908(98)00007-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Glutamate receptor channels of the NMDA-type (N-methyl-D-aspartate) and non-NMDA-type (GluR) differ in their pore properties. The N-site in the M2 transmembrane segment of NMDA receptors (NMDAR), or the corresponding Q/R-site in GluRs, is a pivotal structural determinant of their permeation and blockade characteristics. Substitutions at a second site in M2, the L-site (L577) in GluR1, drastically alter the receptor selectivity to divalent cations. Here we report that M2 mutants carrying an asparagine or a threonine residue at the Q-site of GluR1, along with a tryptophan residue at the L-site, form homomeric GluR1 channels that are highly sensitive to structurally diverse, uncompetitive NMDA antagonists such as arylcyclohexylamines, dibenzocycloheptenimines, and to morphinian and adamantane derivatives. Analysis of the voltage dependence of channel blockade locates the blocker binding site approximately 0.65 partway into the transmembrane electric field in both GluR1 mutants and NMDAR channels. Our results suggest that the homomeric GluR1 double mutants, L577W/Q582N and L577W/Q582T, fairly approximate the pore properties of the heteromeric NMDA receptor and support the structural kinship of their permeation pathways.
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Affiliation(s)
- A V Ferrer-Montiel
- Department of Biology, University of California San Diego, La Jolla 92093-0366, USA
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27
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Ferrer-Montiel AV, Merino JM, Blondelle SE, Perez-Payà E, Houghten RA, Montal M. Selected peptides targeted to the NMDA receptor channel protect neurons from excitotoxic death. Nat Biotechnol 1998; 16:286-91. [PMID: 9528011 DOI: 10.1038/nbt0398-286] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Excitotoxic neuronal death, associated with neurodegeneration and stroke, is triggered primarily by massive Ca2+ influx arising from overactivation of glutamate receptor channels of the N-methyl-D-aspartate (NMDA) subtype. To search for channel blockers, synthetic combinatorial libraries were assayed for block of agonist-evoked currents by the human NR1-NR2A NMDA receptor subunits expressed in amphibian oocytes. A set of arginine-rich hexapeptides selectively blocked the NMDA receptor channel with IC50 approximately 100 nM, a potency similar to clinically tolerated blockers such as memantine, and only marginally blocked on non-NMDA glutamate receptors. These peptides prevent neuronal cell death elicited by an excitotoxic insult on hippocampal cultures.
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Affiliation(s)
- A V Ferrer-Montiel
- Department of Biology, University of California, San Diego, La Jolla 92093-0366, USA
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28
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Nishimura M, Sato K, Okada T, Schloss P, Shimada S, Tohyama M. MK-801 blocks monoamine transporters expressed in HEK cells. FEBS Lett 1998; 423:376-80. [PMID: 9515743 DOI: 10.1016/s0014-5793(98)00126-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
(+)-MK-801 is known to be a specific non-competitive antagonist of N-methyl-D-aspartate (NMDA) receptors. However, besides having an anticonvulsant effect, this compound possesses a central sympathomimetic effect and an anxiolytic-like action, raising the possibility that (+)-MK-801 might affect monoamine uptake systems. To elucidate this possibility, we investigated the effects of (+)-MK-801 on monoamine transporters expressed in HEK cells. (+)-MK-801 significantly inhibited the uptake of all three monoamine transporters in a dose-dependent manner and the inhibitions were competitive with respect to monoamines. The Ki values of (+)-MK-801 on the norepinephrine, dopamine and serotonin transporters were 3.2 microM, 40 microM and 43 microM, respectively. In addition, (-)-MK-801, a less potent antagonist of NMDA receptors, also inhibited monoamine transporters with a similar potency as that of (+)-MK-801. These results clearly indicate that MK-801, a non-competitive antagonist of NMDA receptors, competitively inhibits monoamine transporters without stereoselectivity.
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Affiliation(s)
- M Nishimura
- Department of Anatomy and Neuroscience, Osaka University Medical School, Suita, Japan.
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29
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Deutsch SI, Mastropaolo J, Riggs RL, Rosse RB. The antiseizure efficacies of MK-801, phencyclidine, ketamine, and memantine are altered selectively by stress. Pharmacol Biochem Behav 1997; 58:709-12. [PMID: 9329063 DOI: 10.1016/s0091-3057(97)90014-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Adaptive changes in the NMDA receptor complex occur in response to exposure to stress. We have previously shown that the ability of MK-801, an uncompetitive NMDA receptor antagonist, to antagonize electrically precipitated tonic hind-limb extension is reduced 24 h after mice are forced to swim for up to 10 min in cold water. The stress-induced reduction of the antiseizure efficacy of MK-801 stimulated the proposal that mice exposed to swim stress may serve as "an intact animal model" of altered or diminished NMDA-mediated neural transmission. In the current investigation, the dose-dependent abilities for the antagonism of electrically precipitated seizures in mice were determined for MK-801, phencyclidine, ketamine, and memantine. Interestingly, a single session of cold water swim stress reduced the antiseizure efficacies of MK-801 and memantine without affecting phencyclidine and ketamine when tested 24 h later. The data do not suggest that stress results in a simple reduction in the number of activated or open channels, but rather alters their size or charge characteristics.
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Affiliation(s)
- S I Deutsch
- Psychiatry Service, Department of Veterans Affairs Medical Center, Washington, DC 20422, USA
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30
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Gallagher MJ, Huang H, Grant ER, Lynch DR. The NR2B-specific interactions of polyamines and protons with the N-methyl-D-aspartate receptor. J Biol Chem 1997; 272:24971-9. [PMID: 9312102 DOI: 10.1074/jbc.272.40.24971] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Many compounds exhibit NR2B-specific modulation of the N-methyl-D-aspartate receptor, although their mechanism(s) of action are largely unknown. Using chimeric NR2A/NR2B subunits, we have located a region of NR2B (amino acids 138-238) which regulated glycine-independent polyamine stimulation. Mutation of glutamate 201 in this region affected stimulation by polyamines in the order E201D < E201A < E201N < E201R. The relief of proton inhibition of the N-methyl-D-aspartate-induced currents mediated by these mutant receptors correlated with the reduction in glycine-independent polyamine stimulation. Electrophysiological evidence with a triple mutant of NR2A further supports the hypothesis that polyamine stimulation may be linked to the relief of tonic inhibition by protons and demonstrates the crucial role of amino acids 200 and 201 in polyamine stimulation. Polyamines and protons, therefore, share common NR2B determinants.
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Affiliation(s)
- M J Gallagher
- Department of Pharmacology, University of Pennsylvania School of Medicine, Children's Seashore House, Philadelphia, Pennsylvania 19104, USA
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31
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Ferrer-Montiel AV, Canaves JM, DasGupta BR, Wilson MC, Montal M. Tyrosine phosphorylation modulates the activity of clostridial neurotoxins. J Biol Chem 1996; 271:18322-5. [PMID: 8702470 DOI: 10.1074/jbc.271.31.18322] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Clostridial neurotoxins' metalloprotease domain selectively cleaves proteins implicated in the process of synaptic vesicle fusion with the plasma membrane and, accordingly, blocks neurotransmitter release into the synaptic cleft. Here we investigate the potential modulation of these neurotoxins by intracellular cascades triggered by environmental signals, which in turn may alter its activity on target substrates. We report that the nonreceptor tyrosine kinase Src phosphorylates botulinum neurotoxins A, B, and E and tetanus neurotoxin. Protein tyrosine phosphorylation of serotypes A and E dramatically increases both their catalytic activity and thermal stability, while dephosphorylation reverses the effect. This suggests that the biologically significant form of the neurotoxins inside neurons is phosphorylated. Indeed, in PC12 cells in which tyrosine kinases such as Src and PYK2 are highly abundant, stimulation by membrane depolarization in presence of extracellular calcium induces rapid and selective tyrosine phosphorylation of internalized light chain, the metalloprotease domain, of botulinum toxin A. These findings provide a conceptual framework to connect intracellular signaling pathways involving tyrosine kinases, G-proteins, phosphoinositides, and calcium with the action of botulinum neurotoxins in abrogating vesicle fusion and neurosecretion.
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Affiliation(s)
- A V Ferrer-Montiel
- Department of Biology, University of California San Diego, La Jolla, California 92093-0366, USA
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32
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Ferrer-Montiel AV, Sun W, Montal M. A single tryptophan on M2 of glutamate receptor channels confers high permeability to divalent cations. Biophys J 1996; 71:749-58. [PMID: 8842213 PMCID: PMC1233531 DOI: 10.1016/s0006-3495(96)79274-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Ionotropic glutamate receptors (iGluRs) of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate/kainate subtype display lower permeability to Ca2+ than the N-methyl-D-aspartate (NMDA) subtype. The well-documented N/Q/R site on the M2 transmembrane segment (M2) is an important determinant of the distinct Ca2+ permeability exhibited by members of the non-NMDA receptor subfamily. This site, however, does not completely account for the different permeation properties displayed by non-NMDA and NMDA receptors, suggesting the involvement of other molecular determinants. We have identified additional molecular elements on M2 of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate/kainate receptor GluR1 that specify its permeation properties. Higher permeability to divalent over monovalent cations is conferred on GluR1 by a tryptophan at position 577, whereas blockade by external divalent cations is imparted by an asparagine at position 582. Hence, the permeation properties of ionotropic glutamate receptors appear to be primarily specified by two distinct determinants on M2, the well-known N/Q/R site and the newly identified L/W site. These findings substantiate the notion that M2 is a structural component of the pore lining.
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MESH Headings
- Amino Acid Sequence
- Animals
- Calcium/metabolism
- Cations, Divalent/metabolism
- Cell Membrane Permeability
- DNA, Complementary
- Female
- Kinetics
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Oocytes/physiology
- Point Mutation
- Receptors, AMPA/biosynthesis
- Receptors, AMPA/chemistry
- Receptors, AMPA/physiology
- Receptors, Glutamate/biosynthesis
- Receptors, Glutamate/chemistry
- Receptors, Glutamate/physiology
- Receptors, Kainic Acid/biosynthesis
- Receptors, Kainic Acid/chemistry
- Receptors, Kainic Acid/physiology
- Receptors, N-Methyl-D-Aspartate/chemistry
- Receptors, N-Methyl-D-Aspartate/physiology
- Recombinant Proteins/metabolism
- Sequence Homology, Amino Acid
- Tryptophan
- Xenopus
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Affiliation(s)
- A V Ferrer-Montiel
- Department of Biology, University of California San Diego, La Jolla 92093-0366, USA
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Multiple structural elements determine subunit specificity of Mg2+ block in NMDA receptor channels. J Neurosci 1996. [PMID: 8642401 DOI: 10.1523/jneurosci.16-11-03549.1996] [Citation(s) in RCA: 156] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In NMDA receptor channels, subtype-specific differences of Mg2+ block are determined by the NR2 subunits. Channels assembled from the NR1-NR2A or NR1-NR2B subunits are blocked more strongly than channels formed by the NR1-NR2C or NR1-NR2D subunits, predominantly reflecting a difference in voltage dependence. A determinant of Mg2+ block common to the NR2 subunits is located in the M2 domain (N-site or Q/R/N-site). However, subunit-specific differences of block suggested that additional structural elements exist. Chimeric NR2 subunits were constructed by replacing segments of the least sensitive NR2C subunit with homologous segments of the most sensitive NR2B subunit. Mutant NR2 subunits were coexpressed with wild-type NR1 in Xenopus oocytes, and Mg2+ block was quantified. Replacement of the entire M1-M4 region resulted in a chimera with a sensitivity of Mg2+ block similar to that of the NR2B wild type. Replacing smaller segments or introducing point mutations did not generate channels with Mg2+ block characteristic of NR2B wild type. However, combining in a single chimera three small segments (M1, M2-M3 linker, M4), each independently mediating an increase in Mg2+ block, produced channels close to NR2B wild type. Thus, differences in Mg2+ block as controlled by the NR2 subunits cannot be explained by a single structural determinant in addition to the N-site. Moreover, three elements of the NR2 subunit are the major determinants of subtype-specific differences of Mg2+ block in heteromeric NMDA receptor channels.
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Kuner T, Schoepfer R. Multiple structural elements determine subunit specificity of Mg2+ block in NMDA receptor channels. J Neurosci 1996; 16:3549-58. [PMID: 8642401 PMCID: PMC6578835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In NMDA receptor channels, subtype-specific differences of Mg2+ block are determined by the NR2 subunits. Channels assembled from the NR1-NR2A or NR1-NR2B subunits are blocked more strongly than channels formed by the NR1-NR2C or NR1-NR2D subunits, predominantly reflecting a difference in voltage dependence. A determinant of Mg2+ block common to the NR2 subunits is located in the M2 domain (N-site or Q/R/N-site). However, subunit-specific differences of block suggested that additional structural elements exist. Chimeric NR2 subunits were constructed by replacing segments of the least sensitive NR2C subunit with homologous segments of the most sensitive NR2B subunit. Mutant NR2 subunits were coexpressed with wild-type NR1 in Xenopus oocytes, and Mg2+ block was quantified. Replacement of the entire M1-M4 region resulted in a chimera with a sensitivity of Mg2+ block similar to that of the NR2B wild type. Replacing smaller segments or introducing point mutations did not generate channels with Mg2+ block characteristic of NR2B wild type. However, combining in a single chimera three small segments (M1, M2-M3 linker, M4), each independently mediating an increase in Mg2+ block, produced channels close to NR2B wild type. Thus, differences in Mg2+ block as controlled by the NR2 subunits cannot be explained by a single structural determinant in addition to the N-site. Moreover, three elements of the NR2 subunit are the major determinants of subtype-specific differences of Mg2+ block in heteromeric NMDA receptor channels.
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Affiliation(s)
- T Kuner
- Zentrum für Molekulare Biologie der Universität Heidelberg, Germany
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Gallagher MJ, Huang H, Pritchett DB, Lynch DR. Interactions between ifenprodil and the NR2B subunit of the N-methyl-D-aspartate receptor. J Biol Chem 1996; 271:9603-11. [PMID: 8621635 DOI: 10.1074/jbc.271.16.9603] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Ifenprodil is an atypical noncompetitive modulator of the N-methyl-D-aspartate (NMDA) receptor (NR) which demonstrates a 140-fold preference for NR2B over NR2A subunits, although the molecular basis for this subunit specificity is unknown. We have made chimeric receptors by fusing the murine forms of NR2A (epsilon 1) and NR2B (epsilon 2) to localize the high affinity determinants of ifenprodil inhibition on the 2B subunit. Binding experiments with 125I-MK-801 implicated the region between amino acids 198 and 356 of NR2B for high affinity ifenprodil interaction. Site-directed mutants at Arg-337 showed that this residue is absolutely required for high affinity ifenprodil inhibition. Polyamines also modulate the NMDA receptor with a preference for NR2B subunits, and the pharmacology of these agents overlaps with ifenprodil. Although the determinants of the polyamine enhancement of iodo-MK-801 binding also localize to the NH2 terminus of NR2B, the point mutants at Arg-337 form receptors that are polyamine-stimulated at wild type levels. In addition, polyamine stimulation depends on the expression of NR1 splice variants, whereas high affinity ifenprodil inhibition is independent of NR1 isoform expression. These studies provide evidence that ifenprodil and polyamines interact at discrete sites on the NR2B subunit.
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Affiliation(s)
- M J Gallagher
- Department of Neurology, University of Pennsylvania, School of Medicine, Philadelphia, Pennsylvania 19104, USA
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Ferrer-Montiel AV, Montal M. Pentameric subunit stoichiometry of a neuronal glutamate receptor. Proc Natl Acad Sci U S A 1996; 93:2741-4. [PMID: 8610111 PMCID: PMC39701 DOI: 10.1073/pnas.93.7.2741] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Ionotropic glutamate receptors, neurotransmitter-activated ion channels that mediate excitatory synaptic transmission in the central nervous system, are oligomeric membrane proteins of unknown subunit stoichiometry. To determine the subunit stoichiometry we have used a functional assay based on the blockade of two alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate/kainate receptor subunit 1 (GluR1) mutant subunits selectively engineered to exhibit differential sensitivity to the open channel blockers phencyclidine and dizolcipine (MK-801). Coinjection into amphibian oocytes of weakly sensitive with highly sensitive subunit complementary RNAs produces functional heteromeric channels with mixed blocker sensitivities. Increasing the fraction of the highly sensitive subunit augmented the proportion of drug-sensitive receptors. Analysis of the data using a model based on random aggregation of receptor subunits allowed us to determine a pentameric stoichiometry for GluR1. This finding supports the view that a pentameric subunit organization underlies the structure of the neuronal ionotropic glutamate receptor gene family.
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Affiliation(s)
- A V Ferrer-Montiel
- Department of Biology, University of California at San Diego, La Jolla 92093-0366, USA
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37
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Abstract
Structural models have been produced for three types of non-NMDA inotropic glutamate receptors: an AMPA receptor, GluR1, a kainate receptor, GluR6; and a low-molecular-weight kainate receptor from goldfish, GFKAR alpha. Modeling was restricted to the domains of the proteins that bind the neurotransmitter glutamate and that form the ion channel. Model building combined homology modeling, distance geometry, molecular mechanics, interactive modeling, and known constraints. The models indicate new potential interactions in the extracellular domain between protein and agonists, and suggest that the transition from the "closed" to the "open" state involves the movement of a conserved positive residue away from, and two conserved negative residues into, the extracellular entrance to the pore upon binding. As a first approximation, the ion channel domain was modeled with a structure comprising a central antiparallel beta-barrel that partially crosses the membrane, and against which alpha-helices from each subunit are packed; a third alpha-helix packs against these two helices in each subunit. Much, but not all, of the available data were consistent with this structure. Modifying the beta-barrel to a loop-like topology produced a model consistent with available data.
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MESH Headings
- Amino Acid Sequence
- Animals
- Binding Sites
- Biophysical Phenomena
- Biophysics
- Disulfides/chemistry
- Excitatory Amino Acid Agonists/metabolism
- Goldfish
- Models, Molecular
- Molecular Sequence Data
- Molecular Weight
- Protein Conformation
- Protein Structure, Secondary
- Receptors, AMPA/chemistry
- Receptors, AMPA/genetics
- Receptors, Glutamate/chemistry
- Receptors, Glutamate/genetics
- Receptors, Glutamate/metabolism
- Receptors, Kainic Acid/chemistry
- Receptors, Kainic Acid/genetics
- Sequence Homology, Amino Acid
- Signal Transduction
- GluK2 Kainate Receptor
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Affiliation(s)
- M J Sutcliffe
- Department of chemistry, University of Leicester, England
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