1
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Kelly-Castro EC, Shear R, Dindigal AH, Bhagwat M, Zhang H. MARK1 regulates dendritic spine morphogenesis and cognitive functions in vivo. Exp Neurol 2024; 376:114752. [PMID: 38484863 DOI: 10.1016/j.expneurol.2024.114752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/14/2024] [Accepted: 03/10/2024] [Indexed: 03/23/2024]
Abstract
Dendritic spines play a pivotal role in synaptic communication and are crucial for learning and memory processes. Abnormalities in spine morphology and plasticity are observed in neurodevelopmental and neuropsychiatric disorders, yet the underlying signaling mechanisms remain poorly understood. The microtubule affinity regulating kinase 1 (MARK1) has been implicated in neurodevelopmental disorders, and the MARK1 gene shows accelerated evolution in the human lineage suggesting a role in cognition. However, the in vivo role of MARK1 in synaptogenesis and cognitive functions remains unknown. Here we show that forebrain-specific conditional knockout (cKO) of Mark1 in mice causes defects in dendritic spine morphogenesis in hippocampal CA1 pyramidal neurons with a significant reduction in spine density. In addition, we found loss of MARK1 causes synaptic accumulation of GKAP and GluA2. Furthermore, we found that MARK1 cKO mice show defects in spatial learning in the Morris water maze and reduced anxiety-like behaviors in the elevated plus maze. Taken together, our data show a novel role for MARK1 in regulating dendritic spine morphogenesis and cognitive functions in vivo.
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Affiliation(s)
- Emily C Kelly-Castro
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, USA
| | - Rebecca Shear
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, USA
| | - Ankitha H Dindigal
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, USA
| | - Maitreyee Bhagwat
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, USA
| | - Huaye Zhang
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, USA.
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2
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Chen Y, Liu S, Jacobi AA, Jeng G, Ulrich JD, Stein IS, Patriarchi T, Hell JW. Rapid sequential clustering of NMDARs, CaMKII, and AMPARs upon activation of NMDARs at developing synapses. Front Synaptic Neurosci 2024; 16:1291262. [PMID: 38660466 PMCID: PMC11039796 DOI: 10.3389/fnsyn.2024.1291262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 03/22/2024] [Indexed: 04/26/2024] Open
Abstract
Rapid, synapse-specific neurotransmission requires the precise alignment of presynaptic neurotransmitter release and postsynaptic receptors. How postsynaptic glutamate receptor accumulation is induced during maturation is not well understood. We find that in cultures of dissociated hippocampal neurons at 11 days in vitro (DIV) numerous synaptic contacts already exhibit pronounced accumulations of the pre- and postsynaptic markers synaptotagmin, synaptophysin, synapsin, bassoon, VGluT1, PSD-95, and Shank. The presence of an initial set of AMPARs and NMDARs is indicated by miniature excitatory postsynaptic currents (mEPSCs). However, AMPAR and NMDAR immunostainings reveal rather smooth distributions throughout dendrites and synaptic enrichment is not obvious. We found that brief periods of Ca2+ influx through NMDARs induced a surprisingly rapid accumulation of NMDARs within 1 min, followed by accumulation of CaMKII and then AMPARs within 2-5 min. Postsynaptic clustering of NMDARs and AMPARs was paralleled by an increase in their mEPSC amplitudes. A peptide that blocked the interaction of NMDAR subunits with PSD-95 prevented the NMDAR clustering. NMDAR clustering persisted for 3 days indicating that brief periods of elevated glutamate fosters permanent accumulation of NMDARs at postsynaptic sites in maturing synapses. These data support the model that strong glutamatergic stimulation of immature glutamatergic synapses results in a fast and substantial increase in postsynaptic NMDAR content that required NMDAR binding to PSD-95 or its homologues and is followed by recruitment of CaMKII and subsequently AMPARs.
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Affiliation(s)
- Yucui Chen
- Department of Pharmacology, University of Iowa, Iowa City, IA, United States
| | - Shangming Liu
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Ariel A. Jacobi
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Grace Jeng
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Jason D. Ulrich
- Department of Pharmacology, University of Iowa, Iowa City, IA, United States
| | - Ivar S. Stein
- Department of Pharmacology, University of Iowa, Iowa City, IA, United States
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Tommaso Patriarchi
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Johannes W. Hell
- Department of Pharmacology, University of Iowa, Iowa City, IA, United States
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
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3
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Golan N, Ehrlich D, Bonanno J, O'Brien RF, Murillo M, Kauer SD, Ravindra N, Van Dijk D, Cafferty WB. Anatomical Diversity of the Adult Corticospinal Tract Revealed by Single-Cell Transcriptional Profiling. J Neurosci 2023; 43:7929-7945. [PMID: 37748862 PMCID: PMC10669816 DOI: 10.1523/jneurosci.0811-22.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/28/2023] [Accepted: 08/01/2023] [Indexed: 09/27/2023] Open
Abstract
The corticospinal tract (CST) forms a central part of the voluntary motor apparatus in all mammals. Thus, injury, disease, and subsequent degeneration within this pathway result in chronic irreversible functional deficits. Current strategies to repair the damaged CST are suboptimal in part because of underexplored molecular heterogeneity within the adult tract. Here, we combine spinal retrograde CST tracing with single-cell RNA sequencing (scRNAseq) in adult male and female mice to index corticospinal neuron (CSN) subtypes that differentially innervate the forelimb and hindlimb. We exploit publicly available datasets to confer anatomic specialization among CSNs and show that CSNs segregate not only along the forelimb and hindlimb axis but also by supraspinal axon collateralization. These anatomically defined transcriptional data allow us to use machine learning tools to build classifiers that discriminate between CSNs and cortical layer 2/3 and nonspinally terminating layer 5 neurons in M1 and separately identify limb-specific CSNs. Using these tools, CSN subtypes can be differentially identified to study postnatal patterning of the CST in vivo, leveraged to screen for novel limb-specific axon growth survival and growth activators in vitro, and ultimately exploited to repair the damaged CST after injury and disease.SIGNIFICANCE STATEMENT Therapeutic interventions designed to repair the damaged CST after spinal cord injury have remained functionally suboptimal in part because of an incomplete understanding of the molecular heterogeneity among subclasses of CSNs. Here, we combine spinal retrograde labeling with scRNAseq and annotate a CSN index by the termination pattern of their primary axon in the cervical or lumbar spinal cord and supraspinal collateral terminal fields. Using machine learning we have confirmed the veracity of our CSN gene lists to train classifiers to identify CSNs among all classes of neurons in primary motor cortex to study the development, patterning, homeostasis, and response to injury and disease, and ultimately target streamlined repair strategies to this critical motor pathway.
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Affiliation(s)
- Noa Golan
- Interdepartmental Neuroscience Program, Yale University School, New Haven, Connecticut 06511
- Department of Neurology, Yale University School, New Haven, Connecticut 06511
| | - Daniel Ehrlich
- Interdepartmental Neuroscience Program, Yale University School, New Haven, Connecticut 06511
- Department of Psychiatry, Yale University School, New Haven, Connecticut 06511
| | - James Bonanno
- Interdepartmental Neuroscience Program, Yale University School, New Haven, Connecticut 06511
- Department of Neurology, Yale University School, New Haven, Connecticut 06511
| | - Rory F O'Brien
- Department of Neurology, Yale University School, New Haven, Connecticut 06511
| | - Matias Murillo
- Interdepartmental Neuroscience Program, Yale University School, New Haven, Connecticut 06511
- Department of Neurology, Yale University School, New Haven, Connecticut 06511
| | - Sierra D Kauer
- Department of Neurology, Yale University School, New Haven, Connecticut 06511
| | - Neal Ravindra
- Department of Internal Medicine, Yale University School, New Haven, Connecticut 06511
- Department of Computer Science, Yale University School, New Haven, Connecticut 06511
| | - David Van Dijk
- Department of Internal Medicine, Yale University School, New Haven, Connecticut 06511
- Department of Computer Science, Yale University School, New Haven, Connecticut 06511
| | - William B Cafferty
- Department of Neurology, Yale University School, New Haven, Connecticut 06511
- Department of Neuroscience, Yale University School, New Haven, Connecticut 06511
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4
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Perozzo AM, Schwenk J, Kamalova A, Nakagawa T, Fakler B, Bowie D. GSG1L-containing AMPA receptor complexes are defined by their spatiotemporal expression, native interactome and allosteric sites. Nat Commun 2023; 14:6799. [PMID: 37884493 PMCID: PMC10603098 DOI: 10.1038/s41467-023-42517-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023] Open
Abstract
Transmembrane AMPA receptor regulatory proteins (TARPs) and germ cell-specific gene 1-like protein (GSG1L) are claudin-type AMPA receptor (AMPAR) auxiliary subunits that profoundly regulate glutamatergic synapse strength and plasticity. While AMPAR-TARP complexes have been extensively studied, less is known about GSG1L-containing AMPARs. Here, we show that GSG1L's spatiotemporal expression, native interactome and allosteric sites are distinct. GSG1L generally expresses late during brain development in a region-specific manner, constituting about 5% of all AMPAR complexes in adulthood. While GSG1L can co-assemble with TARPs or cornichons (CNIHs), it also assembles as the sole auxiliary subunit. Unexpectedly, GSG1L acts through two discrete evolutionarily-conserved sites on the agonist-binding domain with a weak allosteric interaction at the TARP/KGK site to slow desensitization, and a stronger interaction at a different site that slows recovery from desensitization. Together, these distinctions help explain GSG1L's evolutionary past and how it fulfills a unique signaling role within glutamatergic synapses.
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Affiliation(s)
- Amanda M Perozzo
- Integrated Program in Neuroscience, McGill University, Montreal, QC, H3A 1A1, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Jochen Schwenk
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Hermann-Herder-Str. 7, 79104, Freiburg, Germany
| | - Aichurok Kamalova
- Department of Molecular Physiology and Biophysics, Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Terunaga Nakagawa
- Department of Molecular Physiology and Biophysics, Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
- Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Bernd Fakler
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Hermann-Herder-Str. 7, 79104, Freiburg, Germany
- Signaling Research Centers BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Derek Bowie
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, H3G 1Y6, Canada.
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5
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Gangwar SP, Yen LY, Yelshanskaya MV, Korman A, Jones DR, Sobolevsky AI. Modulation of GluA2-γ5 synaptic complex desensitization, polyamine block and antiepileptic perampanel inhibition by auxiliary subunit cornichon-2. Nat Struct Mol Biol 2023; 30:1481-1494. [PMID: 37653241 PMCID: PMC10584687 DOI: 10.1038/s41594-023-01080-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 07/26/2023] [Indexed: 09/02/2023]
Abstract
Synaptic complexes of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors (AMPARs) with auxiliary subunits mediate most excitatory neurotransmission and can be targeted to treat neuropsychiatric and neurological disorders, including epilepsy. Here we present cryogenic-electron microscopy structures of rat GluA2 AMPAR complexes with inhibitory mouse γ5 and potentiating human cornichon-2 (CNIH2) auxiliary subunits. CNIH2 appears to destabilize the desensitized state of the complex by reducing the separation of the upper lobes in ligand-binding domain dimers. At the same time, CNIH2 stabilizes binding of polyamine spermidine to the selectivity filter of the closed ion channel. Nevertheless, CNIH2, and to a lesser extent γ5, attenuate polyamine block of the open channel and reduce the potency of the antiepileptic drug perampanel that inhibits the synaptic complex allosterically by binding to sites in the ion channel extracellular collar. These findings illustrate the fine-tuning of synaptic complex structure and function in an auxiliary subunit-dependent manner, which is critical for the study of brain region-specific neurotransmission and design of therapeutics for disease treatment.
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Affiliation(s)
- Shanti Pal Gangwar
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Laura Y Yen
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Cellular and Molecular Physiology and Biophysics Graduate Program, Columbia University Irving Medical Center, New York, NY, USA
| | - Maria V Yelshanskaya
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Aryeh Korman
- Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA
| | - Drew R Jones
- Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
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6
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Pilch KS, Ramgoolam KH, Dolphin AC. Involvement of Ca V 2.2 channels and α 2 δ-1 in homeostatic synaptic plasticity in cultured hippocampal neurons. J Physiol 2022; 600:5333-5351. [PMID: 36377048 PMCID: PMC10107484 DOI: 10.1113/jp283600] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 11/08/2022] [Indexed: 11/16/2022] Open
Abstract
In the mammalian brain, presynaptic CaV 2 channels play a pivotal role in synaptic transmission by mediating fast neurotransmitter exocytosis via influx of Ca2+ into the active zone of presynaptic terminals. However, the distribution and modulation of CaV 2.2 channels at plastic hippocampal synapses remains to be elucidated. Here, we assess CaV 2.2 channels during homeostatic synaptic plasticity, a compensatory form of homeostatic control preventing excessive or insufficient neuronal activity during which extensive active zone remodelling has been described. We show that chronic silencing of neuronal activity in mature hippocampal cultures resulted in elevated presynaptic Ca2+ transients, mediated by increased levels of CaV 2.2 channels at the presynaptic site. This work focused further on the role of α2 δ-1 subunits, important regulators of synaptic transmission and CaV 2.2 channel abundance at the presynaptic membrane. We found that α2 δ-1 overexpression reduces the contribution of CaV 2.2 channels to total Ca2+ flux without altering the amplitude of the Ca2+ transients. Levels of endogenous α2 δ-1 decreased during homeostatic synaptic plasticity, whereas the overexpression of α2 δ-1 prevented homeostatic synaptic plasticity in hippocampal neurons. Together, this study reveals a key role for CaV 2.2 channels and novel roles for α2 δ-1 during synaptic plastic adaptation. KEY POINTS: The roles of CaV 2.2 channels and α2 δ-1 in homeostatic synaptic plasticity in hippocampal neurons in culture were examined. Chronic silencing of neuronal activity resulted in elevated presynaptic Ca2+ transients, mediated by increased levels of CaV 2.2 channels at presynaptic sites. The level of endogenous α2 δ-1 decreased during homeostatic synaptic plasticity, whereas overexpression of α2 δ-1 prevented homeostatic synaptic plasticity in hippocampal neurons. Together, this study reveals a key role for CaV 2.2 channels and novel roles for α2 δ-1 during synaptic plastic adaptation.
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Affiliation(s)
- Kjara S. Pilch
- Department of NeurosciencePhysiology and PharmacologyUniversity College LondonLondonUK
| | - Krishma H. Ramgoolam
- Department of NeurosciencePhysiology and PharmacologyUniversity College LondonLondonUK
| | - Annette C. Dolphin
- Department of NeurosciencePhysiology and PharmacologyUniversity College LondonLondonUK
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7
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Bauer CS, Cohen RN, Sironi F, Livesey MR, Gillingwater TH, Highley JR, Fillingham DJ, Coldicott I, Smith EF, Gibson YB, Webster CP, Grierson AJ, Bendotti C, De Vos KJ. An interaction between synapsin and C9orf72 regulates excitatory synapses and is impaired in ALS/FTD. Acta Neuropathol 2022; 144:437-464. [PMID: 35876881 PMCID: PMC9381633 DOI: 10.1007/s00401-022-02470-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 06/17/2022] [Accepted: 07/08/2022] [Indexed: 12/16/2022]
Abstract
Dysfunction and degeneration of synapses is a common feature of amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD). A GGGGCC hexanucleotide repeat expansion in the C9ORF72 gene is the main genetic cause of ALS/FTD (C9ALS/FTD). The repeat expansion leads to reduced expression of the C9orf72 protein. How C9orf72 haploinsufficiency contributes to disease has not been resolved. Here we identify the synapsin family of synaptic vesicle proteins, the most abundant group of synaptic phosphoproteins, as novel interactors of C9orf72 at synapses and show that C9orf72 plays a cell-autonomous role in the regulation of excitatory synapses. We mapped the interaction of C9orf72 and synapsin to the N-terminal longin domain of C9orf72 and the conserved C domain of synapsin, and show interaction of the endogenous proteins in synapses. Functionally, C9orf72 deficiency reduced the number of excitatory synapses and decreased synapsin levels at remaining synapses in vitro in hippocampal neuron cultures and in vivo in the hippocampal mossy fibre system of C9orf72 knockout mice. Consistent with synaptic dysfunction, electrophysiological recordings identified impaired excitatory neurotransmission and network function in hippocampal neuron cultures with reduced C9orf72 expression, which correlated with a severe depletion of synaptic vesicles from excitatory synapses in the hippocampus of C9orf72 knockout mice. Finally, neuropathological analysis of post-mortem sections of C9ALS/FTD patient hippocampus with C9orf72 haploinsufficiency revealed a marked reduction in synapsin, indicating that disruption of the interaction between C9orf72 and synapsin may contribute to ALS/FTD pathobiology. Thus, our data show that C9orf72 plays a cell-autonomous role in the regulation of neurotransmission at excitatory synapses by interaction with synapsin and modulation of synaptic vesicle pools, and identify a novel role for C9orf72 haploinsufficiency in synaptic dysfunction in C9ALS/FTD.
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Affiliation(s)
- Claudia S Bauer
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Rebecca N Cohen
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Francesca Sironi
- Laboratory of Molecular Neurobiology, Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milan, Italy
| | - Matthew R Livesey
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Thomas H Gillingwater
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK
- Euan MacDonald Centre for Motor Neuron Disease Research, Chancellor's Building, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - J Robin Highley
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Daniel J Fillingham
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Ian Coldicott
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Emma F Smith
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Yolanda B Gibson
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Christopher P Webster
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Andrew J Grierson
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Caterina Bendotti
- Laboratory of Molecular Neurobiology, Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156, Milan, Italy
| | - Kurt J De Vos
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK.
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
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8
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Kumari A, Rahaman A, Zeng XA, Farooq MA, Huang Y, Yao R, Ali M, Ishrat R, Ali R. Temporal Cortex Microarray Analysis Revealed Impaired Ribosomal Biogenesis and Hyperactivity of the Glutamatergic System: An Early Signature of Asymptomatic Alzheimer's Disease. Front Neurosci 2022; 16:966877. [PMID: 35958988 PMCID: PMC9359077 DOI: 10.3389/fnins.2022.966877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 06/23/2022] [Indexed: 11/21/2022] Open
Abstract
Pathogenic aging is regarded as asymptomatic AD when there is no cognitive deficit except for neuropathology consistent with Alzheimer's disease. These individuals are highly susceptible to developing AD. Braak and Braak's theory specific to tau pathology illustrates that the brain's temporal cortex region is an initiation site for early AD progression. So, the hub gene analysis of this region may reveal early altered biological cascades that may be helpful to alleviate AD in an early stage. Meanwhile, cognitive processing also drags its attention because cognitive impairment is the ultimate result of AD. Therefore, this study aimed to explore changes in gene expression of aged control, asymptomatic AD (AsymAD), and symptomatic AD (symAD) in the temporal cortex region. We used microarray data sets to identify differentially expressed genes (DEGs) with the help of the R programming interface. Further, we constructed the protein-protein interaction (PPI) network by performing the STRING plugin in Cytoscape and determined the hub genes via the CytoHubba plugin. Furthermore, we conducted Gene Ontology (GO) enrichment analysis via Bioconductor's cluster profile package. Resultant, the AsymAD transcriptome revealed the early-stage changes of glutamatergic hyperexcitability. Whereas the connectivity of major hub genes in this network indicates a shift from initially reduced rRNA biosynthesis in the AsymAD group to impaired protein synthesis in the symAD group. Both share the phenomenon of breaking tight junctions and others. In conclusion, this study offers new understandings of the early biological vicissitudes that occur in the brain before the manifestation of symAD and gives new promising therapeutic targets for early AD intervention.
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Affiliation(s)
- Ankita Kumari
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Guangdong Key Laboratory of Food Intelligent Manufacturing, Foshan University, Foshan, China
- Overseas Expertise Introduction Centre for Discipline Innovation of Food Nutrition and Human Health (111 Centre), Guangzhou, China
| | - Abdul Rahaman
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Guangdong Key Laboratory of Food Intelligent Manufacturing, Foshan University, Foshan, China
- Overseas Expertise Introduction Centre for Discipline Innovation of Food Nutrition and Human Health (111 Centre), Guangzhou, China
- Abdul Rahaman
| | - Xin-An Zeng
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Guangdong Key Laboratory of Food Intelligent Manufacturing, Foshan University, Foshan, China
- Overseas Expertise Introduction Centre for Discipline Innovation of Food Nutrition and Human Health (111 Centre), Guangzhou, China
- *Correspondence: Xin-An Zeng
| | - Muhammad Adil Farooq
- Institute of Food Science and Technology, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, Pakistan
| | - Yanyan Huang
- Guangdong Key Laboratory of Food Intelligent Manufacturing, Foshan University, Foshan, China
| | - Runyu Yao
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Overseas Expertise Introduction Centre for Discipline Innovation of Food Nutrition and Human Health (111 Centre), Guangzhou, China
| | - Murtaza Ali
- School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Guangdong Key Laboratory of Food Intelligent Manufacturing, Foshan University, Foshan, China
- Overseas Expertise Introduction Centre for Discipline Innovation of Food Nutrition and Human Health (111 Centre), Guangzhou, China
| | - Romana Ishrat
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
- Romana Ishrat
| | - Rafat Ali
- Center for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
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9
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Herguedas B, Kohegyi BK, Dohrke JN, Watson JF, Zhang D, Ho H, Shaikh SA, Lape R, Krieger JM, Greger IH. Mechanisms underlying TARP modulation of the GluA1/2-γ8 AMPA receptor. Nat Commun 2022; 13:734. [PMID: 35136046 PMCID: PMC8826358 DOI: 10.1038/s41467-022-28404-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 01/13/2022] [Indexed: 01/01/2023] Open
Abstract
AMPA-type glutamate receptors (AMPARs) mediate rapid signal transmission at excitatory synapses in the brain. Glutamate binding to the receptor’s ligand-binding domains (LBDs) leads to ion channel activation and desensitization. Gating kinetics shape synaptic transmission and are strongly modulated by transmembrane AMPAR regulatory proteins (TARPs) through currently incompletely resolved mechanisms. Here, electron cryo-microscopy structures of the GluA1/2 TARP-γ8 complex, in both open and desensitized states (at 3.5 Å), reveal state-selective engagement of the LBDs by the large TARP-γ8 loop (‘β1’), elucidating how this TARP stabilizes specific gating states. We further show how TARPs alter channel rectification, by interacting with the pore helix of the selectivity filter. Lastly, we reveal that the Q/R-editing site couples the channel constriction at the filter entrance to the gate, and forms the major cation binding site in the conduction path. Our results provide a mechanistic framework of how TARPs modulate AMPAR gating and conductance. AMPA glutamate receptors, mediate the majority of excitatory signaling in the brain. Here the authors show how the auxiliary subunit TARP-γ8 shapes gating kinetics, ion conductance and rectification properties of the heteromeric GluA1/2 AMPA receptor.
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Affiliation(s)
- Beatriz Herguedas
- Neurobiology Division MRC Laboratory of Molecular Biology, Cambridge, UK.,Institute for Biocomputation and Physics of Complex Systems (BIFI) and Laboratorio de Microscopías Avanzadas (LMA), University of Zaragoza, 50018, Zaragoza, Spain
| | - Bianka K Kohegyi
- Neurobiology Division MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Jan-Niklas Dohrke
- Neurobiology Division MRC Laboratory of Molecular Biology, Cambridge, UK.,Universitätsmedizin Göttingen, Georg-August-Universität, 37075, Göttingen, Germany
| | - Jake F Watson
- Neurobiology Division MRC Laboratory of Molecular Biology, Cambridge, UK.,Institute of Science and Technology (IST) Austria, Am Campus 1, 3400, Klosterneuburg, Austria
| | - Danyang Zhang
- Neurobiology Division MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Hinze Ho
- Neurobiology Division MRC Laboratory of Molecular Biology, Cambridge, UK.,Department of Physiology, Development and Neuroscience, University of Cambridge, Physiological Laboratory, Cambridge, UK
| | - Saher A Shaikh
- Neurobiology Division MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Remigijus Lape
- Neurobiology Division MRC Laboratory of Molecular Biology, Cambridge, UK
| | - James M Krieger
- Neurobiology Division MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Ingo H Greger
- Neurobiology Division MRC Laboratory of Molecular Biology, Cambridge, UK.
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10
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Ahmed KT, Amin MR, Razmara P, Roy B, Cai R, Tang J, Chen XZ, Ali DW. Expression and Development of TARP γ-4 in Embryonic Zebrafish. Dev Neurosci 2022; 44:518-531. [PMID: 35728564 DOI: 10.1159/000525578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 05/19/2022] [Indexed: 11/19/2022] Open
Abstract
Fast excitatory synaptic transmission in the CNS is mediated by the neurotransmitter glutamate, binding to and activating AMPA receptors (AMPARs). AMPARs are known to interact with auxiliary proteins that modulate their behavior. One such family of proteins is the transmembrane AMPAR-related proteins, known as TARPs. Little is known about the role of TARPs during development or about their function in nonmammalian organisms. Here, we report on the presence of TARP γ-4 in developing zebrafish. We find that zebrafish express 2 forms of TARP γ-4: γ-4a and γ-4b as early as 12 h post-fertilization. Sequence analysis shows that both γ-4a and γ-4b shows great level of variation particularly in the intracellular C-terminal domain compared to rat, mouse, and human γ-4. RT-qPCR showed a gradual increase in the expression of γ-4a throughout the first 5 days of development, whereas γ-4b levels were constant until day 5 when levels increased significantly. Knockdown of TARP γ-4a and γ-4b via either splice-blocking morpholinos or translation-blocking morpholinos resulted in embryos that exhibited deficits in C-start escape responses, showing reduced C-bend angles. Morphant larvae displayed reduced bouts of swimming. Whole-cell patch-clamp recordings of AMPAR-mediated currents from Mauthner cells showed a reduction in the frequency of mEPCs but no change in amplitude or kinetics. Together, these results suggest that γ-4a and γ-4b are required for proper neuronal development.
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Affiliation(s)
- Kazi Tanveer Ahmed
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Md Ruhul Amin
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Parastoo Razmara
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Birbickram Roy
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Ruiqi Cai
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
| | - Jingfeng Tang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
| | - Xing-Zhen Chen
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
| | - Declan William Ali
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
- Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada
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11
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Structure and desensitization of AMPA receptor complexes with type II TARP γ5 and GSG1L. Mol Cell 2021; 81:4771-4783.e7. [PMID: 34678168 DOI: 10.1016/j.molcel.2021.09.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 08/27/2021] [Accepted: 09/28/2021] [Indexed: 12/29/2022]
Abstract
AMPA receptors (AMPARs) mediate the majority of excitatory neurotransmission. Their surface expression, trafficking, gating, and pharmacology are regulated by auxiliary subunits. Of the two types of TARP auxiliary subunits, type I TARPs assume activating roles, while type II TARPs serve suppressive functions. We present cryo-EM structures of GluA2 AMPAR in complex with type II TARP γ5, which reduces steady-state currents, increases single-channel conductance, and slows recovery from desensitization. Regulation of AMPAR function depends on its ligand-binding domain (LBD) interaction with the γ5 head domain. GluA2-γ5 complex shows maximum stoichiometry of two TARPs per AMPAR tetramer, being different from type I TARPs but reminiscent of the auxiliary subunit GSG1L. Desensitization of both GluA2-GSG1L and GluA2-γ5 complexes is accompanied by rupture of LBD dimer interface, while GluA2-γ5 but not GluA2-GSG1L LBD dimers remain two-fold symmetric. Different structural architectures and desensitization mechanisms of complexes with auxiliary subunits endow AMPARs with broad functional capabilities.
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12
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Hansen KB, Wollmuth LP, Bowie D, Furukawa H, Menniti FS, Sobolevsky AI, Swanson GT, Swanger SA, Greger IH, Nakagawa T, McBain CJ, Jayaraman V, Low CM, Dell'Acqua ML, Diamond JS, Camp CR, Perszyk RE, Yuan H, Traynelis SF. Structure, Function, and Pharmacology of Glutamate Receptor Ion Channels. Pharmacol Rev 2021; 73:298-487. [PMID: 34753794 PMCID: PMC8626789 DOI: 10.1124/pharmrev.120.000131] [Citation(s) in RCA: 216] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Many physiologic effects of l-glutamate, the major excitatory neurotransmitter in the mammalian central nervous system, are mediated via signaling by ionotropic glutamate receptors (iGluRs). These ligand-gated ion channels are critical to brain function and are centrally implicated in numerous psychiatric and neurologic disorders. There are different classes of iGluRs with a variety of receptor subtypes in each class that play distinct roles in neuronal functions. The diversity in iGluR subtypes, with their unique functional properties and physiologic roles, has motivated a large number of studies. Our understanding of receptor subtypes has advanced considerably since the first iGluR subunit gene was cloned in 1989, and the research focus has expanded to encompass facets of biology that have been recently discovered and to exploit experimental paradigms made possible by technological advances. Here, we review insights from more than 3 decades of iGluR studies with an emphasis on the progress that has occurred in the past decade. We cover structure, function, pharmacology, roles in neurophysiology, and therapeutic implications for all classes of receptors assembled from the subunits encoded by the 18 ionotropic glutamate receptor genes. SIGNIFICANCE STATEMENT: Glutamate receptors play important roles in virtually all aspects of brain function and are either involved in mediating some clinical features of neurological disease or represent a therapeutic target for treatment. Therefore, understanding the structure, function, and pharmacology of this class of receptors will advance our understanding of many aspects of brain function at molecular, cellular, and system levels and provide new opportunities to treat patients.
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Affiliation(s)
- Kasper B Hansen
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Lonnie P Wollmuth
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Derek Bowie
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Hiro Furukawa
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Frank S Menniti
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Alexander I Sobolevsky
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Geoffrey T Swanson
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Sharon A Swanger
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Ingo H Greger
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Terunaga Nakagawa
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Chris J McBain
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Vasanthi Jayaraman
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Chian-Ming Low
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Mark L Dell'Acqua
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Jeffrey S Diamond
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Chad R Camp
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Riley E Perszyk
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Hongjie Yuan
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
| | - Stephen F Traynelis
- Center for Structural and Functional Neuroscience, Center for Biomolecular Structure and Dynamics, Division of Biological Sciences, University of Montana, Missoula, MT (K.B.H.); Department of Neurobiology and Behavior, Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY (L.P.W.); Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada (D.B.); WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY (H.F.); MindImmune Therapeutics, Inc., The George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI (F.S.M.); Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY (A.I.S.); Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (G.T.S.); Fralin Biomedical Research Institute at Virginia Tech Carilion, Virginia Tech, Roanoke, VA and Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA (S.A.S.); Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom (I.H.G.); Department of Molecular Physiology and Biophysics, Center for Structural Biology, Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN (T.N.); Eunice Kennedy Shriver National Institute of Child Health and Human Development (C.J.M.), and Synaptic Physiology Section, NINDS Intramural Research Program, National Institutes of Health, Bethesda, MD (J.S.D.); Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, TX (V.J.); Department of Pharmacology, Department of Anaesthesia, Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (C.-M.L.); Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO (M.L.D.); and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA (C.R.C., R.E.P., H.Y., S.F.T.)
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13
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Hardt S, Tascio D, Passlick S, Timmermann A, Jabs R, Steinhäuser C, Seifert G. Auxiliary Subunits Control Function and Subcellular Distribution of AMPA Receptor Complexes in NG2 Glia of the Developing Hippocampus. Front Cell Neurosci 2021; 15:669717. [PMID: 34177466 PMCID: PMC8222826 DOI: 10.3389/fncel.2021.669717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/18/2021] [Indexed: 11/13/2022] Open
Abstract
Synaptic and axonal glutamatergic signaling to NG2 glia in white matter is critical for the cells' differentiation and activity dependent myelination. However, in gray matter the impact of neuron-to-NG2 glia signaling is still elusive, because most of these cells keep their non-myelinating phenotype throughout live. Early in postnatal development, hippocampal NG2 glia express AMPA receptors with a significant Ca2+ permeability allowing for plasticity of the neuron-glia synapses, but whether this property changes by adulthood is not known. Moreover, it is unclear whether NG2 glia express auxiliary transmembrane AMPA receptor related proteins (TARPs), which modify AMPA receptor properties, including their Ca2+ permeability. Through combined molecular and functional analyses, here we show that hippocampal NG2 glia abundantly express TARPs γ4, γ7, and γ8 as well as cornichon (CNIH)-2. TARP γ8 undergoes profound downregulation during development. Receptors of adult NG2 glia showed an increased sensitivity to blockers of Ca2+ permeable AMPA receptors, but this increase mainly concerned receptors located close to the soma. Evoked synaptic currents of NG2 glia were also sensitive to blockers of Ca2+ permeable AMPA receptors. The presence of AMPA receptors with varying Ca2+ permeability during postnatal maturation may be important for the cells' ability to sense and respond to local glutamatergic activity and for regulating process motility, differentiation, and proliferation.
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Affiliation(s)
- Stefan Hardt
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Dario Tascio
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Stefan Passlick
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Aline Timmermann
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Ronald Jabs
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Gerald Seifert
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
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14
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Ramos-Vicente D, Grant SG, Bayés À. Metazoan evolution and diversity of glutamate receptors and their auxiliary subunits. Neuropharmacology 2021; 195:108640. [PMID: 34116111 DOI: 10.1016/j.neuropharm.2021.108640] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/27/2021] [Accepted: 06/01/2021] [Indexed: 01/18/2023]
Abstract
Glutamate is the major excitatory neurotransmitter in vertebrate and invertebrate nervous systems. Proteins involved in glutamatergic neurotransmission, and chiefly glutamate receptors and their auxiliary subunits, play key roles in nervous system function. Thus, understanding their evolution and uncovering their diversity is essential to comprehend how nervous systems evolved, shaping cognitive function. Comprehensive phylogenetic analysis of these proteins across metazoans have revealed that their evolution is much more complex than what can be anticipated from vertebrate genomes. This is particularly true for ionotropic glutamate receptors (iGluRs), as their current classification into 6 classes (AMPA, Kainate, Delta, NMDA1, NMDA2 and NMDA3) would be largely incomplete. New work proposes a classification of iGluRs into 4 subfamilies that encompass 10 classes. Vertebrate AMPA, Kainate and Delta receptors would belong to one of these subfamilies, named AKDF, the NMDA subunits would constitute another subfamily and non-vertebrate iGluRs would be organised into the previously unreported Epsilon and Lambda subfamilies. Similarly, the animal evolution of metabotropic glutamate receptors has resulted in the formation of four classes of these receptors, instead of the three currently recognised. Here we review our current knowledge on the animal evolution of glutamate receptors and their auxiliary subunits. This article is part of the special issue on 'Glutamate Receptors - Orphan iGluRs'.
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Affiliation(s)
- David Ramos-Vicente
- Molecular Physiology of the Synapse Laboratory, Biomedical Research Institute Sant Pau, Barcelona, Spain; Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Seth Gn Grant
- Centre for Clinical Brain Sciences, Chancellor's Building, Edinburgh BioQuarter, University of Edinburgh, Edinburgh, EH16 4SB, UK; Simons Initiative for the Developing Brain (SIDB), Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Àlex Bayés
- Molecular Physiology of the Synapse Laboratory, Biomedical Research Institute Sant Pau, Barcelona, Spain; Universitat Autònoma de Barcelona, Barcelona, Spain.
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15
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Transcriptomic expression of AMPA receptor subunits and their auxiliary proteins in the human brain. Neurosci Lett 2021; 755:135938. [PMID: 33915226 DOI: 10.1016/j.neulet.2021.135938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 11/21/2022]
Abstract
Receptors to glutamate of the AMPA type (AMPARs) serve as the major gates of excitation in the human brain, where they participate in fundamental processes underlying perception, cognition and movement. Due to their central role in brain function, dysregulation of these receptors has been implicated in neuropathological states associated with a large variety of diseases that manifest with abnormal behaviors. The participation of functional abnormalities of AMPARs in brain disorders is strongly supported by genomic, transcriptomic and proteomic studies. Most of these studies have focused on the expression and function of the subunits that make up the channel and define AMPARs (GRIA1-GRIA4), as well of some accessory proteins. However, it is increasingly evident that native AMPARs are composed of a complex array of accessory proteins that regulate their trafficking, localization, kinetics and pharmacology, and a better understanding of the diversity and regional expression of these accessory proteins is largely needed. In this review we will provide an update on the state of current knowledge of AMPA receptors subunits in the context of their accessory proteins at the transcriptome level. We also summarize the regional expression in the human brain and its correlation with the channel forming subunits. Finally, we discuss some of the current limitations of transcriptomic analysis and propose potential ways to overcome them.
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16
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Auxiliary subunits of the AMPA receptor: The Shisa family of proteins. Curr Opin Pharmacol 2021; 58:52-61. [PMID: 33892364 DOI: 10.1016/j.coph.2021.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 03/01/2021] [Accepted: 03/01/2021] [Indexed: 11/15/2022]
Abstract
AMPA receptors mediate fast synaptic transmission in the CNS and can assemble with several types of auxiliary proteins in a spatio-temporal manner, from newly synthesized AMPA receptor tetramers to mature AMPA receptors in the cell membrane. As such, the interaction of auxiliary subunits with the AMPA receptor plays a major role in the regulation of AMPA receptor biogenesis, trafficking, and biophysical properties. Throughout the years, various 'families' of proteins have been identified and today the approximate full complement of AMPAR auxiliary proteins is known. This review presents the current knowledge on the most prominent AMPA-receptor-interacting auxiliary proteins, highlights recent results regarding the Shisa protein family, and provides a discussion on future research that might contribute to the discovery of novel pharmacological targets of auxiliary subunits.
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17
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Rosenbaum MI, Clemmensen LS, Bredt DS, Bettler B, Strømgaard K. Targeting receptor complexes: a new dimension in drug discovery. Nat Rev Drug Discov 2020; 19:884-901. [PMID: 33177699 DOI: 10.1038/s41573-020-0086-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2020] [Indexed: 12/11/2022]
Abstract
Targeting receptor proteins, such as ligand-gated ion channels and G protein-coupled receptors, has directly enabled the discovery of most drugs developed to modulate receptor signalling. However, as the search for novel and improved drugs continues, an innovative approach - targeting receptor complexes - is emerging. Receptor complexes are composed of core receptor proteins and receptor-associated proteins, which have profound effects on the overall receptor structure, function and localization. Hence, targeting key protein-protein interactions within receptor complexes provides an opportunity to develop more selective drugs with fewer side effects. In this Review, we discuss our current understanding of ligand-gated ion channel and G protein-coupled receptor complexes and discuss strategies for their pharmacological modulation. Although such strategies are still in preclinical development for most receptor complexes, they exemplify how receptor complexes can be drugged, and lay the groundwork for this nascent area of research.
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Affiliation(s)
- Mette Ishøy Rosenbaum
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Louise S Clemmensen
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - David S Bredt
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, San Diego, CA, USA
| | - Bernhard Bettler
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Kristian Strømgaard
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
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18
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Ramos-Vicente D, Bayés À. AMPA receptor auxiliary subunits emerged during early vertebrate evolution by neo/subfunctionalization of unrelated proteins. Open Biol 2020; 10:200234. [PMID: 33108974 PMCID: PMC7653359 DOI: 10.1098/rsob.200234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In mammalian synapses, the function of ionotropic glutamate receptors is critically modulated by auxiliary subunits. Most of these specifically regulate the synaptic localization and electrophysiological properties of AMPA-type glutamate receptors (AMPARs). Here, we comprehensively investigated the animal evolution of the protein families that contain AMPAR auxiliary subunits (ARASs). We observed that, on average, vertebrates have four times more ARASs than other animal species. We also demonstrated that ARASs belong to four unrelated protein families: CACNG-GSG1, cornichon, shisa and Dispanin C. Our study demonstrates that, despite the ancient origin of these four protein families, the majority of ARASs emerged during vertebrate evolution by independent but convergent processes of neo/subfunctionalization that resulted in the multiple ARASs found in present vertebrate genomes. Importantly, although AMPARs appeared and diversified in the ancestor of bilateral animals, the ARAS expansion did not occur until much later, in early vertebrate evolution. We propose that the surge in ARASs and consequent increase in AMPAR functionalities, contributed to the increased complexity of vertebrate brains and cognitive functions.
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Affiliation(s)
- David Ramos-Vicente
- Molecular Physiology of the Synapse Laboratory, Biomedical Research Institute Sant Pau, Barcelona, Spain.,Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Àlex Bayés
- Molecular Physiology of the Synapse Laboratory, Biomedical Research Institute Sant Pau, Barcelona, Spain.,Universitat Autònoma de Barcelona, Barcelona, Spain
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19
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Schwenk J, Fakler B. Building of AMPA‐type glutamate receptors in the endoplasmic reticulum and its implication for excitatory neurotransmission. J Physiol 2020; 599:2639-2653. [DOI: 10.1113/jp279025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 07/21/2020] [Indexed: 11/08/2022] Open
Affiliation(s)
- Jochen Schwenk
- Institute of Physiology, Faculty of Medicine University of Freiburg Hermann‐Herder‐Str. 7 Freiburg 79104 Germany
| | - Bernd Fakler
- Institute of Physiology, Faculty of Medicine University of Freiburg Hermann‐Herder‐Str. 7 Freiburg 79104 Germany
- Signalling Research Centres BIOSS and CIBSS Schänzlestr. 18 Freiburg 79104 Germany
- Center for Basics in NeuroModulation Breisacherstr. 4 Freiburg 79106 Germany
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20
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Tian J, Guo L, Sui S, Driskill C, Phensy A, Wang Q, Gauba E, Zigman JM, Swerdlow RH, Kroener S, Du H. Disrupted hippocampal growth hormone secretagogue receptor 1α interaction with dopamine receptor D1 plays a role in Alzheimer's disease. Sci Transl Med 2020; 11:11/505/eaav6278. [PMID: 31413143 PMCID: PMC6776822 DOI: 10.1126/scitranslmed.aav6278] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 06/24/2019] [Indexed: 12/12/2022]
Abstract
Hippocampal lesions are a defining pathology of Alzheimer's disease (AD). However, the molecular mechanisms that underlie hippocampal synaptic injury in AD have not been fully elucidated. Current therapeutic efforts for AD treatment are not effective in correcting hippocampal synaptic deficits. Growth hormone secretagogue receptor 1α (GHSR1α) is critical for hippocampal synaptic physiology. Here, we report that GHSR1α interaction with β-amyloid (Aβ) suppresses GHSR1α activation, leading to compromised GHSR1α regulation of dopamine receptor D1 (DRD1) in the hippocampus from patients with AD. The simultaneous application of the selective GHSR1α agonist MK0677 with the selective DRD1 agonist SKF81297 rescued Ghsr1α function from Aβ inhibition, mitigating hippocampal synaptic injury and improving spatial memory in an AD mouse model. Our data reveal a mechanism of hippocampal vulnerability in AD and suggest that a combined activation of GHSR1α and DRD1 may be a promising approach for treating AD.
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Affiliation(s)
- Jing Tian
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Lan Guo
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Shaomei Sui
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA.,Department of Neurology, Qianfoshan Hospital, Shandong First Medical University, Jinan, Shandong 250014, China
| | - Christopher Driskill
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Aarron Phensy
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Qi Wang
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA.,Department of Neurology, Qianfoshan Hospital, Shandong First Medical University, Jinan, Shandong 250014, China
| | - Esha Gauba
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Jeffrey M Zigman
- Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Russell H Swerdlow
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Sven Kroener
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Heng Du
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX 75080, USA.
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21
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Jacobi E, Engelhardt J. Modulation of information processing by AMPA receptor auxiliary subunits. J Physiol 2020; 599:471-483. [DOI: 10.1113/jp276698] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/25/2020] [Indexed: 12/13/2022] Open
Affiliation(s)
- Eric Jacobi
- Institute of Pathophysiology University Medical Center of the Johannes Gutenberg University Mainz Mainz Germany
- Focus Program Translational Neurosciences (FTN) University Medical Center of the Johannes Gutenberg‐University Mainz Mainz Germany
| | - Jakob Engelhardt
- Institute of Pathophysiology University Medical Center of the Johannes Gutenberg University Mainz Mainz Germany
- Focus Program Translational Neurosciences (FTN) University Medical Center of the Johannes Gutenberg‐University Mainz Mainz Germany
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22
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Miguez-Cabello F, Sánchez-Fernández N, Yefimenko N, Gasull X, Gratacòs-Batlle E, Soto D. AMPAR/TARP stoichiometry differentially modulates channel properties. eLife 2020; 9:53946. [PMID: 32452760 PMCID: PMC7299370 DOI: 10.7554/elife.53946] [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: 11/25/2019] [Accepted: 05/24/2020] [Indexed: 11/15/2022] Open
Abstract
AMPARs control fast synaptic communication between neurons and their function relies on auxiliary subunits, which importantly modulate channel properties. Although it has been suggested that AMPARs can bind to TARPs with variable stoichiometry, little is known about the effect that this stoichiometry exerts on certain AMPAR properties. Here we have found that AMPARs show a clear stoichiometry-dependent modulation by the prototypical TARP γ2 although the receptor still needs to be fully saturated with γ2 to show some typical TARP-induced characteristics (i.e. an increase in channel conductance). We also uncovered important differences in the stoichiometric modulation between calcium-permeable and calcium-impermeable AMPARs. Moreover, in heteromeric AMPARs, γ2 positioning in the complex is important to exert certain TARP-dependent features. Finally, by comparing data from recombinant receptors with endogenous AMPAR currents from mouse cerebellar granule cells, we have determined a likely presence of two γ2 molecules at somatic receptors in this cell type.
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Affiliation(s)
- Federico Miguez-Cabello
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Nuria Sánchez-Fernández
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Natalia Yefimenko
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Xavier Gasull
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Esther Gratacòs-Batlle
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - David Soto
- Laboratori de Neurofisiologia, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
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23
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Bissen D, Foss F, Acker-Palmer A. AMPA receptors and their minions: auxiliary proteins in AMPA receptor trafficking. Cell Mol Life Sci 2019; 76:2133-2169. [PMID: 30937469 PMCID: PMC6502786 DOI: 10.1007/s00018-019-03068-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/12/2019] [Accepted: 03/07/2019] [Indexed: 12/12/2022]
Abstract
To correctly transfer information, neuronal networks need to continuously adjust their synaptic strength to extrinsic stimuli. This ability, termed synaptic plasticity, is at the heart of their function and is, thus, tightly regulated. In glutamatergic neurons, synaptic strength is controlled by the number and function of AMPA receptors at the postsynapse, which mediate most of the fast excitatory transmission in the central nervous system. Their trafficking to, at, and from the synapse, is, therefore, a key mechanism underlying synaptic plasticity. Intensive research over the last 20 years has revealed the increasing importance of interacting proteins, which accompany AMPA receptors throughout their lifetime and help to refine the temporal and spatial modulation of their trafficking and function. In this review, we discuss the current knowledge about the roles of key partners in regulating AMPA receptor trafficking and focus especially on the movement between the intracellular, extrasynaptic, and synaptic pools. We examine their involvement not only in basal synaptic function, but also in Hebbian and homeostatic plasticity. Included in our review are well-established AMPA receptor interactants such as GRIP1 and PICK1, the classical auxiliary subunits TARP and CNIH, and the newest additions to AMPA receptor native complexes.
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Affiliation(s)
- Diane Bissen
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
- Max Planck Institute for Brain Research, Max von Laue Str. 4, 60438, Frankfurt am Main, Germany
| | - Franziska Foss
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
| | - Amparo Acker-Palmer
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany.
- Max Planck Institute for Brain Research, Max von Laue Str. 4, 60438, Frankfurt am Main, Germany.
- Cardio-Pulmonary Institute (CPI), Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany.
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24
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Phosphorylation of the AMPAR-TARP Complex in Synaptic Plasticity. Proteomes 2018; 6:proteomes6040040. [PMID: 30297624 PMCID: PMC6313930 DOI: 10.3390/proteomes6040040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/04/2018] [Accepted: 10/06/2018] [Indexed: 11/17/2022] Open
Abstract
Synaptic plasticity has been considered a key mechanism underlying many brain functions including learning, memory, and drug addiction. An increase or decrease in synaptic activity of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) complex mediates the phenomena as shown in the cellular models of synaptic plasticity, long-term potentiation (LTP), and depression (LTD). In particular, protein phosphorylation shares the spotlight in expressing the synaptic plasticity. This review summarizes the studies on phosphorylation of the AMPAR pore-forming subunits and auxiliary proteins including transmembrane AMPA receptor regulatory proteins (TARPs) and discusses its role in synaptic plasticity.
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25
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Lee MR, Gardinier KM, Gernert DL, Schober DA, Wright RA, Wang H, Qian Y, Witkin JM, Nisenbaum ES, Kato AS. Structural Determinants of the γ-8 TARP Dependent AMPA Receptor Antagonist. ACS Chem Neurosci 2017; 8:2631-2647. [PMID: 28825787 DOI: 10.1021/acschemneuro.7b00186] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The forebrain specific AMPA receptor antagonist, LY3130481/CERC-611, which selectively antagonizes the AMPA receptors associated with TARP γ-8, an auxiliary subunit enriched in the forebrain, has potent antiepileptic activities without motor side effects. We designated the compounds with such activities as γ-8 TARP dependent AMPA receptor antagonists (γ-8 TDAAs). In this work, we further investigated the mechanisms of action using a radiolabeled γ-8 TDAA and ternary structural modeling with mutational validations to characterize the LY3130481 binding to γ-8. The radioligand binding to the cells heterologously expressing GluA1 and/or γ-8 revealed that γ-8 TDAAs binds to γ-8 alone without AMPA receptors. Homology modeling of γ-8, based on the crystal structures of a distant TARP homologue, murine claudin 19, in conjunction with knowledge of two γ-8 residues previously identified as critical for the LY3130481 TARP-dependent selectivity provided the basis for a binding mode prediction. This allowed further rational mutational studies for characterization of the structural determinants in TARP γ-8 for LY3130481 activities, both thermodynamically as well as kinetically.
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Affiliation(s)
- Matthew R. Lee
- Lilly
Biotechnology Center, Eli Lilly and Company, 10300 Campus Point Dr. #200, San Diego, California 92121, United States
| | - Kevin M. Gardinier
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Douglas L. Gernert
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Douglas A. Schober
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Rebecca A. Wright
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - He Wang
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Yuewei Qian
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Jeffrey M. Witkin
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Eric S. Nisenbaum
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
| | - Akihiko S. Kato
- Neuroscience
Discovery, Lilly Research Laboratory, 355 E Merril St., Indianapolis, Indiana 46285, United States
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26
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Kato AS, Witkin JM. Auxiliary subunits of AMPA receptors: The discovery of a forebrain-selective antagonist, LY3130481/CERC-611. Biochem Pharmacol 2017; 147:191-200. [PMID: 28987594 DOI: 10.1016/j.bcp.2017.09.015] [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: 06/23/2017] [Accepted: 09/27/2017] [Indexed: 12/11/2022]
Abstract
Drugs originate from the discovery of compounds, natural or synthetic, that bind to proteins (receptors, enzymes, transporters, etc.), the interaction of which modulates biological cascades that have potential therapeutic benefit. Rational strategies for identifying novel drug therapies are typically based on knowledge of the structure of the target proteins and the design of new chemical entities that modulate these proteins in a beneficial manner. The present review discusses a novel approach to drug discovery based on the identification and characterization of auxiliary proteins, the transmembrane AMPA receptor regulatory proteins (TARPs) that are associated with AMPA receptors. Utilizing these auxiliary proteins in compound screening led to the discovery of the TARP-dependent-AMPA forebrain selective receptor antagonist (TDAA), LY3130481/CERC-611 that is currently in clinical development for epilepsy.
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Affiliation(s)
- Akihiko S Kato
- Neuroscience Discovery Research, Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN 46285-0510, United States.
| | - Jeffrey M Witkin
- Neuroscience Discovery Research, Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN 46285-0510, United States.
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27
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Hawken NM, Zaika EI, Nakagawa T. Engineering defined membrane-embedded elements of AMPA receptor induces opposing gating modulation by cornichon 3 and stargazin. J Physiol 2017; 595:6517-6539. [PMID: 28815591 DOI: 10.1113/jp274897] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 08/04/2017] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The AMPA-type ionotropic glutamate receptors (AMPARs) mediate the majority of excitatory synaptic transmission and their function impacts learning, cognition and behaviour. The gating of AMPARs occurs in milliseconds, precisely controlled by a variety of auxiliary subunits that are expressed differentially in the brain, but the difference in mechanisms underlying AMPAR gating modulation by auxiliary subunits remains elusive and is investigated. The elements of the AMPAR that are functionally recruited by auxiliary subunits, stargazin and cornichon 3, are located not only in the extracellular domains but also in the lipid-accessible surface of the AMPAR. We reveal that the two auxiliary subunits require a shared surface on the transmembrane domain of the AMPAR for their function, but the gating is influenced by this surface in opposing directions for each auxiliary subunit. Our results provide new insights into the mechanistic difference of AMPAR modulation by auxiliary subunits and a conceptual framework for functional engineering of the complex. ABSTRACT During excitatory synaptic transmission, various structurally unrelated transmembrane auxiliary subunits control the function of AMPA receptors (AMPARs), but the underlying mechanisms remain unclear. We identified lipid-exposed residues in the transmembrane domain (TMD) of the GluA2 subunit of AMPARs that are critical for the function of AMPAR auxiliary subunits, stargazin (Stg) and cornichon 3 (CNIH3). These residues are essential for stabilizing the AMPAR-CNIH3 complex in detergents and overlap with the contacts made between GluA2 TMD and Stg in the cryoEM structures. Mutating these residues had opposite effects on gating modulation and complex stability when Stg- and CNIH3-bound AMPARs were compared. Specifically, in detergent the GluA2-A793F formed an unstable complex with CNIIH3 but in the membrane the GluA2-A793F-CNIH3 complex expressed a gain of function. In contrast, the GluA2-A793F-Stg complex was stable, but had diminished gating modulation. GluA2-C528L destabilized the AMPAR-CNIH3 complex but stabilized the AMPAR-Stg complex, with overall loss of function in gating modulation. Furthermore, loss-of-function mutations in this TMD region cancelled the effects of a gain-of-function Stg carrying mutation in its extracellular loop, demonstrating that both the extracellular and the TMD elements contribute independently to gating modulation. The elements of AMPAR functionally recruited by auxiliary subunits are, therefore, located not only in the extracellular domains but also in the lipid accessible surface of the AMPAR. The TMD surface we defined is a potential target for auxiliary subunit-specific compounds, because engineering of this hotspot induces opposing functional outcomes by Stg and CNIH3. The collection of mutant-phenotype mapping provides a framework for engineering AMPAR gating using auxiliary subunits.
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Affiliation(s)
- Natalie M Hawken
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, Nashville, TN, 37232, USA
| | - Elena I Zaika
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, Nashville, TN, 37232, USA
| | - Terunaga Nakagawa
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, Nashville, TN, 37232, USA.,Center for Structural Biology, Vanderbilt University, School of Medicine, Nashville, TN, 37232, USA.,Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN, 37232, USA
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28
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Riva I, Eibl C, Volkmer R, Carbone AL, Plested AJ. Control of AMPA receptor activity by the extracellular loops of auxiliary proteins. eLife 2017; 6:28680. [PMID: 28871958 PMCID: PMC5599240 DOI: 10.7554/elife.28680] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/28/2017] [Indexed: 11/13/2022] Open
Abstract
At synapses throughout the mammalian brain, AMPA receptors form complexes with auxiliary proteins, including TARPs. However, how TARPs modulate AMPA receptor gating remains poorly understood. We built structural models of TARP-AMPA receptor complexes for TARPs γ2 and γ8, combining recent structural studies and de novo structure predictions. These models, combined with peptide binding assays, provide evidence for multiple interactions between GluA2 and variable extracellular loops of TARPs. Substitutions and deletions of these loops had surprisingly rich effects on the kinetics of glutamate-activated currents, without any effect on assembly. Critically, by altering the two interacting loops of γ2 and γ8, we could entirely remove all allosteric modulation of GluA2, without affecting formation of AMPA receptor-TARP complexes. Likewise, substitutions in the linker domains of GluA2 completely removed any effect of γ2 on receptor kinetics, indicating a dominant role for this previously overlooked site proximal to the AMPA receptor channel gate.
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Affiliation(s)
- Irene Riva
- Institute of Biology, Cellular Biophysics, Humboldt Universität zu Berlin, Berlin, Germany.,Molecular Physiology and Cell Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Clarissa Eibl
- Institute of Biology, Cellular Biophysics, Humboldt Universität zu Berlin, Berlin, Germany.,Molecular Physiology and Cell Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Rudolf Volkmer
- Chemical Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Anna L Carbone
- Institute of Biology, Cellular Biophysics, Humboldt Universität zu Berlin, Berlin, Germany.,Molecular Physiology and Cell Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Andrew Jr Plested
- Institute of Biology, Cellular Biophysics, Humboldt Universität zu Berlin, Berlin, Germany.,Molecular Physiology and Cell Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
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29
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Forebrain-selective AMPA-receptor antagonism guided by TARP γ-8 as an antiepileptic mechanism. Nat Med 2016; 22:1496-1501. [DOI: 10.1038/nm.4221] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 09/30/2016] [Indexed: 12/12/2022]
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30
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Compans B, Choquet D, Hosy E. Review on the role of AMPA receptor nano-organization and dynamic in the properties of synaptic transmission. NEUROPHOTONICS 2016; 3:041811. [PMID: 27981061 PMCID: PMC5109202 DOI: 10.1117/1.nph.3.4.041811] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 10/19/2016] [Indexed: 06/06/2023]
Abstract
Receptor trafficking and its regulation have appeared in the last two decades to be a major controller of basal synaptic transmission and its activity-dependent plasticity. More recently, considerable advances in super-resolution microscopy have begun deciphering the subdiffraction organization of synaptic elements and their functional roles. In particular, the dynamic nanoscale organization of neurotransmitter receptors in the postsynaptic membrane has recently been suggested to play a major role in various aspects of synapstic function. We here review the recent advances in our understanding of alpha-amino-3-hydroxy-5-méthyl-4-isoxazolepropionic acid subtype glutamate receptors subsynaptic organization and their role in short- and long-term synaptic plasticity.
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Affiliation(s)
- Benjamin Compans
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux F-33000, France
- Interdisciplinary Institute for Neuroscience, CNRS, UMR 5297, Bordeaux F-33000, France
| | - Daniel Choquet
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux F-33000, France
- Interdisciplinary Institute for Neuroscience, CNRS, UMR 5297, Bordeaux F-33000, France
- University of Bordeaux, Bordeaux Imaging Center, UMS 3420 CNRS, US4 INSERM, France
| | - Eric Hosy
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux F-33000, France
- Interdisciplinary Institute for Neuroscience, CNRS, UMR 5297, Bordeaux F-33000, France
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31
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CNQX facilitates inhibitory synaptic transmission in rat hypoglossal nucleus. Brain Res 2016; 1637:71-80. [DOI: 10.1016/j.brainres.2016.02.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 01/26/2016] [Accepted: 02/11/2016] [Indexed: 11/21/2022]
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32
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Superactivation of AMPA receptors by auxiliary proteins. Nat Commun 2016; 7:10178. [PMID: 26744192 PMCID: PMC4729862 DOI: 10.1038/ncomms10178] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/11/2015] [Indexed: 12/15/2022] Open
Abstract
Glutamate receptors form complexes in the brain with auxiliary proteins, which control their activity during fast synaptic transmission through a seemingly bewildering array of effects. Here we devise a way to isolate the activation of complexes using polyamines, which enables us to show that transmembrane AMPA receptor regulatory proteins (TARPs) exert their effects principally on the channel opening reaction. A thermodynamic argument suggests that because TARPs promote channel opening, receptor activation promotes AMPAR-TARP complexes into a superactive state with high open probability. A simple model based on this idea predicts all known effects of TARPs on AMPA receptor function. This model also predicts unexpected phenomena including massive potentiation in the absence of desensitization and supramaximal recovery that we subsequently detected in electrophysiological recordings. This transient positive feedback mechanism has implications for information processing in the brain, because it should allow activity-dependent facilitation of excitatory synaptic transmission through a postsynaptic mechanism. Transmembrane AMPA receptor regulatory proteins (TARPs) exert a number of effects on fast glutamatergic synaptic transmission. Here, the authors model the interactions of two such proteins, Stargazin and γ-8, and propose a simple kinetic mechanism by which TARPs modulate channel opening reaction.
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33
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Roy B, Ahmed KT, Cunningham ME, Ferdous J, Mukherjee R, Zheng W, Chen XZ, Ali DW. Zebrafish TARP Cacng2 is required for the expression and normal development of AMPA receptors at excitatory synapses. Dev Neurobiol 2015; 76:487-506. [PMID: 26178704 DOI: 10.1002/dneu.22327] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 07/01/2015] [Accepted: 07/14/2015] [Indexed: 01/03/2023]
Abstract
Fast excitatory synaptic transmission in the CNS is mediated by the neurotransmitter glutamate, binding to and activating AMPA receptors (AMPARs). AMPARs are known to interact with auxiliary proteins that modulate their behavior. One such family of proteins is the transmembrane AMPA receptor-related proteins, known as TARPs. Little is known about the role of TARPs during development, or about their function in non-mammalian organisms. Here we report the presence of TARPs, specifically the prototypical TARP, stargazin, in developing zebrafish. We find that zebrafish express two forms of stargazin, Cacng2a and Cacng2b from as early as 12-h post fertilization (hpf). Knockdown of Cacng2a and Cacng2b via splice-blocking morpholinos resulted in embryos that exhibited deficits in C-start escape responses, showing reduced C-bend angles, smaller tail velocities and aberrant C-bend turning directions. Injection of the morphants with Cacng2a or 2b mRNA rescued the morphological phenotype and the synaptic deficits. To investigate the effect of reduced Cacng2a and 2b levels on synaptic physiology, we performed whole cell patch clamp recordings of AMPA mEPSCs from zebrafish Mauthner cells. Knockdown of Cacng2a results in reduced AMPA currents and lower mEPSC frequencies, whereas knockdown of Cacng2b displayed no significant change in mEPSC amplitude or frequency. Non-stationary fluctuation analysis confirmed a reduction in the number of active synaptic receptors in the Cacng2a but not in the Cacng2b morphants. Together, these results suggest that Cacng2a is required for normal trafficking and function of synaptic AMPARs, while Cacng2b is largely non-functional with respect to the development of AMPA synaptic transmission.
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Affiliation(s)
- Birbickram Roy
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
| | - Kazi T Ahmed
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
| | - Marcus E Cunningham
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
| | - Jannatul Ferdous
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
| | - Rajarshi Mukherjee
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9
| | - Wang Zheng
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada, T6G 2H7
| | - Xing-Zhen Chen
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada, T6G 2H7
| | - Declan W Ali
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9.,Department of Physiology, University of Alberta, Edmonton, Alberta, Canada, T6G 2H7.,Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada, T6G 2E1
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34
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35
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Relative contribution of TARPs γ-2 and γ-7 to cerebellar excitatory synaptic transmission and motor behavior. Proc Natl Acad Sci U S A 2015; 112:E371-9. [PMID: 25583485 DOI: 10.1073/pnas.1423670112] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Transmembrane AMPA receptor regulatory proteins (TARPs) play an essential role in excitatory synaptic transmission throughout the central nervous system (CNS) and exhibit subtype-specific effects on AMPA receptor (AMPAR) trafficking, gating, and pharmacology. The function of TARPs has largely been determined through work on canonical type I TARPs such as stargazin (TARP γ-2), absent in the ataxic stargazer mouse. Little is known about the function of atypical type II TARPs, such as TARP γ-7, which exhibits variable effects on AMPAR function. Because γ-2 and γ-7 are both strongly expressed in multiple cell types in the cerebellum, we examined the relative contribution of γ-2 and γ-7 to both synaptic transmission in the cerebellum and motor behavior by using both the stargazer mouse and a γ-7 knockout (KO) mouse. We found that the loss of γ-7 alone had little effect on climbing fiber (cf) responses in Purkinje neurons (PCs), yet the additional loss of γ-2 all but abolished cf responses. In contrast, γ-7 failed to make a significant contribution to excitatory transmission in stellate cells and granule cells. In addition, we generated a PC-specific deletion of γ-2, with and without γ-7 KO background, to examine the relative contribution of γ-2 and γ-7 to PC-dependent motor behavior. Selective deletion of γ-2 in PCs had little effect on motor behavior, yet the additional loss of γ-7 resulted in a severe disruption in motor behavior. Thus, γ-7 is capable of supporting a component of excitatory transmission in PCs, sufficient to maintain essentially normal motor behavior, in the absence of γ-2.
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36
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Howe JR. Modulation of non-NMDA receptor gating by auxiliary subunits. J Physiol 2014; 593:61-72. [PMID: 25556788 DOI: 10.1113/jphysiol.2014.273904] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 08/18/2014] [Indexed: 01/15/2023] Open
Abstract
During the past decade, considerable evidence has accumulated that non-NMDA glutamate receptors (both AMPA and kainate subtypes) are modulated by the association of the core tetrameric receptor with auxiliary proteins that are integral components of native receptor assemblies. This short review focuses on the effect of two types of auxiliary subunits on the biophysical properties and kinetic behaviour of AMPA and kainate receptors at the level of single receptor molecules. Type I transmembrane AMPA receptor proteins increase the number of AMPA receptor openings that result from a single receptor activation as well as the proportion of openings to conductance levels above 30 pS, resulting in larger peak ensemble currents that decay more slowly and bi-exponentially. Co-expression of Neto1 and 2 with pore-forming kainate receptor subunits also increases the duration of bursts and destabilizes desensitized states, resulting in a rapid component of recovery and clusters of bursts that produce a slow component in desensitization decays. The distinct gating seen in the presence of auxiliary subunits reflects slow switching between gating modes with different single-channel kinetics and open probability. At any given time, the relative proportions of receptors in each gating mode determine both the shape and the amplitude of synaptic currents.
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Affiliation(s)
- James R Howe
- Department of Pharmacology, Yale University School of Medicine, SHM B-251, 333 Cedar Street, New Haven, CT, 06520-8066, USA
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37
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Haering SC, Tapken D, Pahl S, Hollmann M. Auxiliary subunits: shepherding AMPA receptors to the plasma membrane. MEMBRANES 2014; 4:469-90. [PMID: 25110960 PMCID: PMC4194045 DOI: 10.3390/membranes4030469] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 07/17/2014] [Accepted: 07/25/2014] [Indexed: 11/24/2022]
Abstract
Ionotropic glutamate receptors (iGluRs) are tetrameric ligand-gated cation channels that mediate excitatory signal transmission in the central nervous system (CNS) of vertebrates. The members of the iGluR subfamily of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPARs) mediate most of the fast excitatory signal transmission, and their abundance in the postsynaptic membrane is a major determinant of the strength of excitatory synapses. Therefore, regulation of AMPAR trafficking to the postsynaptic membrane is an important constituent of mechanisms involved in learning and memory formation, such as long-term potentiation (LTP) and long-term depression (LTD). Auxiliary subunits play a critical role in the facilitation and regulation of AMPAR trafficking and function. The currently identified auxiliary subunits of AMPARs are transmembrane AMPA receptor regulatory proteins (TARPs), suppressor of lurcher (SOL), cornichon homologues (CNIHs), synapse differentiation-induced gene I (SynDIG I), cysteine-knot AMPAR modulating proteins 44 (CKAMP44), and germ cell-specific gene 1-like (GSG1L) protein. In this review we summarize our current knowledge of the modulatory influence exerted by these important but still underappreciated proteins.
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Affiliation(s)
- Simon C Haering
- Department of Biochemistry I-Receptor Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44780 Bochum, Germany.
| | - Daniel Tapken
- Department of Biochemistry I-Receptor Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44780 Bochum, Germany.
| | - Steffen Pahl
- Department of Biochemistry I-Receptor Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44780 Bochum, Germany.
| | - Michael Hollmann
- Department of Biochemistry I-Receptor Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44780 Bochum, Germany.
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Fragile X mental retardation protein controls synaptic vesicle exocytosis by modulating N-type calcium channel density. Nat Commun 2014; 5:3628. [PMID: 24709664 PMCID: PMC3982139 DOI: 10.1038/ncomms4628] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 03/12/2014] [Indexed: 12/25/2022] Open
Abstract
Fragile X syndrome (FXS), the most common heritable form of mental retardation, is
characterized by synaptic dysfunction. Synaptic transmission depends critically on
presynaptic calcium entry via voltage-gated calcium (CaV) channels. Here
we show that the functional expression of neuronal N-type CaV channels
(CaV2.2) is
regulated by fragile X mental retardation
protein (FMRP).
We find that FMRP knockdown in
dorsal root ganglion neurons increases CaV channel density in somata and
in presynaptic terminals. We then show that FMRP controls CaV2.2 surface expression by targeting the channels
to the proteasome for degradation. The interaction between FMRP and CaV2.2 occurs between the carboxy-terminal domain
of FMRP and domains of
CaV2.2 known to
interact with the neurotransmitter release machinery. Finally, we show that
FMRP controls synaptic
exocytosis via CaV2.2
channels. Our data indicate that FMRP is a potent regulator of presynaptic activity, and its loss
is likely to contribute to synaptic dysfunction in FXS. Mutations in the fragile X mental retardation protein are
implicated in synaptic dysfunction in fragile X syndrome. Here, Ferron et al.
show that fragile X mental retardation protein maintains proper neurotransmission by
regulating the density of N-type calcium channels in the presynaptic terminal.
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Hamad MIK, Jack A, Klatt O, Lorkowski M, Strasdeit T, Kott S, Sager C, Hollmann M, Wahle P. Type I TARPs promote dendritic growth of early postnatal neocortical pyramidal cells in organotypic cultures. Development 2014; 141:1737-48. [PMID: 24667327 DOI: 10.1242/dev.099697] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazole propionate glutamate receptors (AMPARs) have been implicated in the establishment of dendritic architecture. The transmembrane AMPA receptor regulatory proteins (TARPs) regulate AMPAR function and trafficking into synaptic membranes. In the current study, we employ type I and type II TARPs to modulate expression levels and function of endogenous AMPARs and investigate in organotypic cultures (OTCs) of rat occipital cortex whether this influences neuronal differentiation. Our results show that in early development [5-10 days in vitro (DIV)] only the type I TARP γ-8 promotes pyramidal cell dendritic growth by increasing spontaneous calcium amplitude and GluA2/3 expression in soma and dendrites. Later in development (10-15 DIV), the type I TARPs γ-2, γ-3 and γ-8 promote dendritic growth, whereas γ-4 reduced dendritic growth. The type II TARPs failed to alter dendritic morphology. The TARP-induced dendritic growth was restricted to the apical dendrites of pyramidal cells and it did not affect interneurons. Moreover, we studied the effects of short hairpin RNA-induced knockdown of endogenous γ-8 and showed a reduction of dendritic complexity and amplitudes of spontaneous calcium transients. In addition, the cytoplasmic tail (CT) of γ-8 was required for dendritic growth. Single-cell calcium imaging showed that the γ-8 CT domain increases amplitude but not frequency of calcium transients, suggesting a regulatory mechanism involving the γ-8 CT domain in the postsynaptic compartment. Indeed, the effect of γ-8 overexpression was reversed by APV, indicating a contribution of NMDA receptors. Our results suggest that selected type I TARPs influence activity-dependent dendritogenesis of immature pyramidal neurons.
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Affiliation(s)
- Mohammad I K Hamad
- Developmental Neurobiology Group, Faculty for Biology and Biotechnology, Ruhr University Bochum, Bochum 44780, Germany
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40
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Hofmann F, Flockerzi V, Kahl S, Wegener JW. L-type CaV1.2 calcium channels: from in vitro findings to in vivo function. Physiol Rev 2014; 94:303-26. [PMID: 24382889 DOI: 10.1152/physrev.00016.2013] [Citation(s) in RCA: 233] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The L-type Cav1.2 calcium channel is present throughout the animal kingdom and is essential for some aspects of CNS function, cardiac and smooth muscle contractility, neuroendocrine regulation, and multiple other processes. The L-type CaV1.2 channel is built by up to four subunits; all subunits exist in various splice variants that potentially affect the biophysical and biological functions of the channel. Many of the CaV1.2 channel properties have been analyzed in heterologous expression systems including regulation of the L-type CaV1.2 channel by Ca(2+) itself and protein kinases. However, targeted mutations of the calcium channel genes confirmed only some of these in vitro findings. Substitution of the respective serines by alanine showed that β-adrenergic upregulation of the cardiac CaV1.2 channel did not depend on the phosphorylation of the in vitro specified amino acids. Moreover, well-established in vitro phosphorylation sites of the CaVβ2 subunit of the cardiac L-type CaV1.2 channel were found to be irrelevant for the in vivo regulation of the channel. However, the molecular basis of some kinetic properties, such as Ca(2+)-dependent inactivation and facilitation, has been approved by in vivo mutagenesis of the CaV1.2α1 gene. This article summarizes recent findings on the in vivo relevance of well-established in vitro results.
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α2δ-1 gene deletion affects somatosensory neuron function and delays mechanical hypersensitivity in response to peripheral nerve damage. J Neurosci 2013; 33:16412-26. [PMID: 24133248 DOI: 10.1523/jneurosci.1026-13.2013] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The α2δ-1 subunit of voltage-gated calcium channels is upregulated after sensory nerve injury and is also the therapeutic target of gabapentinoid drugs. It is therefore likely to play a key role in the development of neuropathic pain. In this study, we have examined mice in which α2δ-1 gene expression is disrupted, to determine whether α2δ-1 is involved in various modalities of nociception, and for the development of behavioral hypersensitivity after partial sciatic nerve ligation (PSNL). We find that naive α2δ-1(-/-) mice show a marked behavioral deficit in mechanical and cold sensitivity, but no change in thermal nociception threshold. The lower mechanical sensitivity is mirrored by a reduced in vivo electrophysiological response of dorsal horn wide dynamic range neurons. The CaV2.2 level is reduced in brain and spinal cord synaptosomes from α2δ-1(-/-) mice, and α2δ-1(-/-) DRG neurons exhibit lower calcium channel current density. Furthermore, a significantly smaller number of DRG neurons respond to the TRPM8 agonist menthol. After PSNL, α2δ-1(-/-) mice show delayed mechanical hypersensitivity, which only develops at 11 d after surgery, whereas in wild-type littermates it is maximal at the earliest time point measured (3 d). There is no compensatory upregulation of α2δ-2 or α2δ-3 after PSNL in α2δ-1(-/-) mice, and other transcripts, including neuropeptide Y and activating transcription factor-3, are upregulated normally. Furthermore, the ability of pregabalin to alleviate mechanical hypersensitivity is lost in PSNL α2δ-1(-/-) mice. Thus, α2δ-1 is essential for rapid development of mechanical hypersensitivity in a nerve injury model of neuropathic pain.
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Xiong L, Wen Y, Miao X, Yang Z. NT5E and FcGBP as key regulators of TGF-1-induced epithelial-mesenchymal transition (EMT) are associated with tumor progression and survival of patients with gallbladder cancer. Cell Tissue Res 2013; 355:365-74. [PMID: 24310606 PMCID: PMC3921456 DOI: 10.1007/s00441-013-1752-1] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Accepted: 10/31/2013] [Indexed: 11/28/2022]
Abstract
Epithelial–mesenchymal transitions (EMTs) are essential manifestations of epithelial cell plasticity during tumor progression. Transforming growth factor-β(TGF-β) modulates epithelial plasticity in tumor physiological contexts by inducing EMT, which is associated with the altered expression of genes. In the present study, we used DNA micro-array analysis to search for differentially expressed genes in the TGF-β1 induced gallbladder carcinoma cell line (GBC-SD cells), as compared with normal GBC-SD cells. We identified 225 differentially expressed genes, including 144 that were over-expressed and 81 that were under-expressed in the TGF-β1 induced GBC-SD cells. NT5E (CD73) is the most increased gene, while the Fc fragment of the IgG binding protein (FcGBP) is the most decreased gene. The expression patterns of these two genes in gallbladder adenocarcinoma and chronic cholecystitis tissue were consistent with the micro-array data. Immunochemistry and clinicopathological results showed that the expression of NT5E and FcGBP in gallbladder adenocarcinoma is an independent marker for evaluation of the disease progression, clinical biological behaviors and prognosis. The data from the current study indicate that differential NT5E and FcGBP expressions could be further evaluated as biomarkers for predicting survival of patients with gallbladder cancer and that NT5E and FcGBP could be promising targets in the control of gallbladder cancer progression.
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Affiliation(s)
- Li Xiong
- Research Laboratory of Hepatobiliary Diseases, Second Xiangya Hospital, Central South University, 139# Middle Renmin road, Changsha, Hunan, 410011, China
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43
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Larsson M, Agalave N, Watanabe M, Svensson C. Distribution of transmembrane AMPA receptor regulatory protein (TARP) isoforms in the rat spinal cord. Neuroscience 2013; 248:180-93. [DOI: 10.1016/j.neuroscience.2013.05.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 05/13/2013] [Accepted: 05/31/2013] [Indexed: 02/08/2023]
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44
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Studniarczyk D, Coombs I, Cull-Candy SG, Farrant M. TARP γ-7 selectively enhances synaptic expression of calcium-permeable AMPARs. Nat Neurosci 2013; 16:1266-74. [PMID: 23872597 PMCID: PMC3858651 DOI: 10.1038/nn.3473] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 06/13/2013] [Indexed: 12/14/2022]
Abstract
Regulation of calcium-permeable AMPA receptors (CP-AMPARs) is crucial in normal synaptic function and neurological disease states. Although transmembrane AMPAR regulatory proteins (TARPs) such as stargazin (γ-2) modulate the properties of calcium-impermeable AMPARs (CI-AMPARs) and promote their synaptic targeting, the TARP-specific rules governing CP-AMPAR synaptic trafficking remain unclear. We used RNA interference to manipulate AMPAR-subunit and TARP expression in γ-2-lacking stargazer cerebellar granule cells--the classic model of TARP deficiency. We found that TARP γ-7 selectively enhanced the synaptic expression of CP-AMPARs and suppressed CI-AMPARs, identifying a pivotal role of γ-7 in regulating the prevalence of CP-AMPARs. In the absence of associated TARPs, both CP-AMPARs and CI-AMPARs were able to localize to synapses and mediate transmission, although their properties were altered. Our results also establish that TARPed synaptic receptors in granule cells require both γ-2 and γ-7 and reveal an unexpected basis for the loss of AMPAR-mediated transmission in stargazer mice.
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Affiliation(s)
- Dorota Studniarczyk
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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45
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Drummond JB, Tucholski J, Haroutunian V, Meador-Woodruff JH. Transmembrane AMPA receptor regulatory protein (TARP) dysregulation in anterior cingulate cortex in schizophrenia. Schizophr Res 2013; 147:32-38. [PMID: 23566497 PMCID: PMC3650109 DOI: 10.1016/j.schres.2013.03.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 03/07/2013] [Accepted: 03/11/2013] [Indexed: 02/09/2023]
Abstract
The glutamate hypothesis of schizophrenia proposes that abnormal glutamatergic neurotransmission occurs in this illness, and a major contribution may involve dysregulation of the AMPA subtype of ionotropic glutamate receptor (AMPAR). Transmembrane AMPAR regulatory proteins (TARPs) form direct associations with AMPARs to modulate the trafficking and biophysical functions of these receptors, and their dysregulation may alter the localization and activity of AMPARs, thus having a potential role in the pathophysiology of schizophrenia. We performed comparative quantitative real-time PCR and Western blot analysis to measure transcript (schizophrenia, N=25; comparison subjects, N=25) and protein (schizophrenia, N=36; comparison subjects, N=33) expression of TARPs (γ subunits 1-8) in the anterior cingulate cortex (ACC) in schizophrenia and a comparison group. TARP expression was also measured in frontal cortex of rats chronically treated with haloperidol decanoate (28.5mg/kg every three weeks for nine months) to determine the effect of antipsychotic treatment on the expression of these molecules. We found decreased transcript expression of TARP γ-8 in schizophrenia. At the protein level, γ-3 and γ-5 were increased, while γ-4, γ-7 and γ-8 were decreased in schizophrenia. No changes in any of the molecules were noted in the frontal cortex of haloperidol-treated rats. TARPs are abnormally expressed at transcript and protein levels in ACC in schizophrenia, and these changes are likely due to the illness and not to the antipsychotic treatment. Alterations in the expression of TARPs may contribute to the pathophysiology of schizophrenia, and represent a potential mechanism of glutamatergic dysregulation in this illness.
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Affiliation(s)
- Jana B. Drummond
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, CIRC 589A, 1719 6th Ave South, Birmingham, AI 25294 USA
,Corresponding author. . Tel.: 205.996.6164; fax: 205.975.4879
| | - Janusz Tucholski
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, CIRC 589A, 1719 6th Ave South, Birmingham, AI 25294 USA
| | - Vahram Haroutunian
- Department of Psychiatry, Mount Sinai School of Medicine, James J Peters Veteran Adminis Room 4F-20 130 West Kingsbridge Road Bronx, NY 10468 USA
| | - James H. Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, CIRC 589A, 1719 6th Ave South, Birmingham, AI 25294 USA
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46
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Bats C, Farrant M, Cull-Candy SG. A role of TARPs in the expression and plasticity of calcium-permeable AMPARs: evidence from cerebellar neurons and glia. Neuropharmacology 2013; 74:76-85. [PMID: 23583927 PMCID: PMC3751754 DOI: 10.1016/j.neuropharm.2013.03.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 03/21/2013] [Accepted: 03/28/2013] [Indexed: 02/04/2023]
Abstract
The inclusion of GluA2 subunits has a profound impact on the channel properties of AMPA receptors (AMPARs), in particular rendering them impermeable to calcium. While GluA2-containing AMPARs are the most abundant in the central nervous system, GluA2-lacking calcium-permeable AMPARs are also expressed in wide variety of neurons and glia. Accumulating evidence suggests that the dynamic control of the GluA2 content of AMPARs plays a critical role in development, synaptic plasticity, and diverse neurological conditions ranging from ischemia-induced brain damage to drug addiction. It is thus important to understand the molecular mechanisms involved in regulating the balance of AMPAR subtypes, particularly the role of their co-assembled auxiliary subunits. The discovery of transmembrane AMPAR regulatory proteins (TARPs), initially within the cerebellum, has transformed the field of AMPAR research. It is now clear that these auxiliary subunits play a key role in multiple aspects of AMPAR trafficking and function in the brain. Yet, their precise role in AMPAR subtype-specific regulation has only recently received particular attention. Here we review recent findings on the differential regulation of calcium-permeable (CP-) and -impermeable (CI-) AMPARs in cerebellar neurons and glial cells, and discuss the critical involvement of TARPs in this process. This article is part of the Special Issue entitled ‘Glutamate Receptor-Dependent Synaptic Plasticity’. Calcium-permeable AMPARs are present in various cerebellar neurons and glial cells. The contribution of calcium-permeable AMPARs to transmission is dynamically regulated. TARPs influence the relative expression of AMPAR subtypes. Evidence suggests that TARPs play a role in calcium-permeable AMPAR plasticity.
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Affiliation(s)
- Cécile Bats
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
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47
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Kopach O, Voitenko N. Extrasynaptic AMPA receptors in the dorsal horn: Evidence and functional significance. Brain Res Bull 2013. [DOI: 10.1016/j.brainresbull.2012.11.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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48
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Sumioka A. Auxiliary subunits provide new insights into regulation of AMPA receptor trafficking. J Biochem 2013; 153:331-7. [PMID: 23426437 DOI: 10.1093/jb/mvt015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Glutamate is a major excitatory neurotransmitter in the vertebrate brain. Among the ionotropic glutamate receptors, α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) glutamate receptors are the major receptors mediating excitatory fast synaptic transmission. AMPA receptors are also responsible for modifying synaptic strength through the regulation of their numbers at synapses. Their high regulatability, therefore, could contribute to the mechanisms of synaptic plasticity. The mechanisms regulating AMPA receptor trafficking have evoked great interest through the decades. Recent studies show that in the brain, AMPA receptors make complexes with transmembrane AMPA regulatory proteins (TARPs), which serve as auxiliary subunits. TARPs are required for AMPA receptor function and trafficking. After the initial discovery of TARPs, several other AMPA receptor auxiliary subunits were identified: CNIH-2, CNIH-3, CKAMP44, SynDIG1, SOL-1, SOL-2 and GSG-1L. This review discusses progress in identifying the role of auxiliary subunits in AMPA receptor trafficking.
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Affiliation(s)
- Akio Sumioka
- Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Morioka-cho Gengo 35, Oobu city, Aichi 474-8511, Japan.
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49
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Erbin interacts with TARP γ-2 for surface expression of AMPA receptors in cortical interneurons. Nat Neurosci 2013; 16:290-9. [DOI: 10.1038/nn.3320] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 12/24/2012] [Indexed: 12/15/2022]
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50
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Glutamate receptor δ2 associates with metabotropic glutamate receptor 1 (mGluR1), protein kinase Cγ, and canonical transient receptor potential 3 and regulates mGluR1-mediated synaptic transmission in cerebellar Purkinje neurons. J Neurosci 2013; 32:15296-308. [PMID: 23115168 DOI: 10.1523/jneurosci.0705-12.2012] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cerebellar motor coordination and cerebellar Purkinje cell synaptic function require metabotropic glutamate receptor 1 (mGluR1, Grm1). We used an unbiased proteomic approach to identify protein partners for mGluR1 in cerebellum and discovered glutamate receptor δ2 (GluRδ2, Grid2, GluΔ2) and protein kinase Cγ (PKCγ) as major interactors. We also found canonical transient receptor potential 3 (TRPC3), which is also needed for mGluR1-dependent slow EPSCs and motor coordination and associates with mGluR1, GluRδ2, and PKCγ. Mutation of GluRδ2 changes subcellular fractionation of mGluR1 and TRPC3 to increase their surface expression. Fitting with this, mGluR1-evoked inward currents are increased in GluRδ2 mutant mice. Moreover, loss of GluRδ2 disrupts the time course of mGluR1-dependent synaptic transmission at parallel fiber-Purkinje cells synapses. Thus, GluRδ2 is part of the mGluR1 signaling complex needed for cerebellar synaptic function and motor coordination, explaining the shared cerebellar motor phenotype that manifests in mutants of the mGluR1 and GluRδ2 signaling pathways.
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