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Bats C, Coombs ID, Farrant M, Cull-Candy SG. α-Bungarotoxin labelling of AMPA receptor-associated TARPs in living neurons. Neuroscience 2024:S0306-4522(24)00440-8. [PMID: 39209103 DOI: 10.1016/j.neuroscience.2024.08.036] [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: 05/21/2024] [Revised: 07/30/2024] [Accepted: 08/26/2024] [Indexed: 09/04/2024]
Abstract
In mammalian central neurons AMPARs are clustered at glutamatergic synapses where they mediate fast excitatory transmission. In addition to four pore-forming subunits (GluA1-4), AMPARs contain auxiliary transmembrane AMPAR regulatory proteins (γ2, γ3, γ4, γ5, γ7 or γ8) whose incorporation can vary between neuron types, brain regions, and stages of development. As well as modulating the functional properties of AMPARs, these auxiliary subunits play a central role in AMPAR trafficking. Directly visualizing TARPs could therefore provide a valuable insight into mechanisms underlying these processes. Although antibodies are routinely used for the detection of surface proteins, our experience suggests anti-TARP antibodies are too bulky to access their target, possibly due to close interactions between the extracellular domains of TARP and AMPAR subunits. We therefore assessed the utility of a small monovalent probe - fluorescent α-bungarotoxin (α-Btx) - for TARP labelling in living neurons. We inserted the bungarotoxin binding site (BBS) within the extracellular domain of TARPs to enable their detection in cells exposed to fluorescent α-Btx. Focusing on the prototypical TARP γ2, we demonstrate that the small size of fluorescent α-Btx allows it to bind to the BBS-tagged TARP when associated with AMPARs. Importantly, labelled γ2 enhances AMPAR function in the same way as unmodified γ2. In living neurons, fluorescent α-Btx-labelled γ2 associates with AMPAR clusters at synapses. As a proof-of-principle, we employed our method to compare the surface trafficking of γ2 and γ7 in cerebellar stellate neurons. Our approach provides a simple way to visualize TARPs within AMPARs in living cells.
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Affiliation(s)
- Cecile Bats
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - Ian D Coombs
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - Mark Farrant
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK.
| | - Stuart G Cull-Candy
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK.
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2
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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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3
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Certain N, Gan Q, Bennett J, Hsieh H, Wollmuth LP. Differential regulation of tetramerization of the AMPA receptor glutamate-gated ion channel by auxiliary subunits. J Biol Chem 2023; 299:105227. [PMID: 37673338 PMCID: PMC10558804 DOI: 10.1016/j.jbc.2023.105227] [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: 02/21/2023] [Revised: 08/21/2023] [Accepted: 08/24/2023] [Indexed: 09/08/2023] Open
Abstract
α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) auxiliary subunits are specialized, nontransient binding partners of AMPARs that modulate AMPAR channel gating properties and pharmacology, as well as their biogenesis and trafficking. The most well-characterized families of auxiliary subunits are transmembrane AMPAR regulatory proteins (TARPs), cornichon homologs (CNIHs), and the more recently discovered GSG1-L. These auxiliary subunits can promote or reduce surface expression of AMPARs (composed of GluA1-4 subunits) in neurons, thereby impacting their functional role in membrane signaling. Here, we show that CNIH-2 enhances the tetramerization of WT and mutant AMPARs, presumably by increasing the overall stability of the tetrameric complex, an effect that is mainly mediated by interactions with the transmembrane domain of the receptor. We also find CNIH-2 and CNIH-3 show receptor subunit-specific actions in this regard with CNIH-2 enhancing both GluA1 and GluA2 tetramerization, whereas CNIH-3 only weakly enhances GluA1 tetramerization. These results are consistent with the proposed role of CNIHs as endoplasmic reticulum cargo transporters for AMPARs. In contrast, TARP γ-2, TARP γ-8, and GSG1-L have no or negligible effect on AMPAR tetramerization. On the other hand, TARP γ-2 can enhance receptor tetramerization but only when directly fused with the receptor at a maximal stoichiometry. Notably, surface expression of functional AMPARs was enhanced by CNIH-2 to a greater extent than TARP γ-2, suggesting that this distinction aids in maturation and membrane expression. These experiments define a functional distinction between CNIHs and other auxiliary subunits in the regulation of AMPAR biogenesis.
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Affiliation(s)
- Noele Certain
- Graduate Program in Molecular and Cellular Pharmacology, Stony Brook University, Stony Brook, New York, USA
| | - Quan Gan
- Graduate Program in Neuroscience, Stony Brook University, Stony Brook, New York, USA
| | - Joseph Bennett
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, New York, USA
| | - Helen Hsieh
- Department of Surgery, Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, USA; Center for Nervous System Disorders, Stony Brook University, Stony Brook, New York, USA
| | - Lonnie P Wollmuth
- Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, New York, USA; Center for Nervous System Disorders, Stony Brook University, Stony Brook, New York, USA; Department of Biochemistry & Cell Biology, Stony Brook University, Stony Brook, New York, USA.
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4
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Zhan E, Jiang J, Wang Y, Zhang K, Tang T, Chen Y, Jia Z, Wang Q, Zhao C. Shisa reduces the sensitivity of homomeric RDL channel to GABA in the two-spotted spider mite, Tetranychus urticae Koch. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 192:105414. [PMID: 37105623 DOI: 10.1016/j.pestbp.2023.105414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 03/08/2023] [Accepted: 03/28/2023] [Indexed: 06/19/2023]
Abstract
The γ-aminobutyric acid receptors (GABARs) mediate fast inhibitory transmission in central nervous system of insects and are important targets of insecticides. An auxiliary subunit, Shisa7, was identified in mammals as a single-passing transmembrane protein. However, the homology gene(s) of Shisa in invertebrates has not been reported to date. In the present study, a homolog Shisa gene was identified from the two-spotted spider mite, Tetranychus urticae Koch. Its open reading frame had 927 base pairs and encoded 308 amino acid residues, which has a typical Shisa domain at 13th-181st amino acid residues. According to the phylogenetic tree, the invertebrate Shisa was categorized apart with those of vertebrate, and TuShisa showed closest relationship with the Shisa9 of velvet mite, Dinothrombium tinctorium (L.). In the electrophysiological assay with two-electrode voltage clamp, the GABA-activated TuRDL channel was functionally formed in the Africa clawed frog Xenopus laevis (Daudin) oocytes (EC50 = 53.34 μM). No GABA-activated current could be observed in TuShisa-expressed oocytes, whereas TuShisa could reduce the sensitivity of TuRDL/TuShisa (mass ratio of 1: 4) channel to GABA. The homology structural models of TuRDL and TuShisa were built by the SWISS-MODEL server, their interaction was predicted using Z-DOCK and three predicted hydrogen bonds and interface residues were analysed by PyMOL. Meanwhile, the key interface residues of TuShisa affected the stability of complex were calculated by Discovery Studio 2019. In conclusion, the TuShisa, as the first reported invertebrate Shisa, was explored and functionally examined as the GABARs auxiliary subunit. Our findings provide a basis for research of invertebrate Shisa.
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Affiliation(s)
- Enling Zhan
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Jie Jiang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Ying Wang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Kexin Zhang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Tao Tang
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, PR China.
| | - Yiqu Chen
- College of Plant Science, Tibet Agricultural and Animal Husbandry University, Nyingchi 860000, PR China.
| | - Zhongqiang Jia
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Qiuxia Wang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Chunqing Zhao
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
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5
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Perozzo AM, Brown PMGE, Bowie D. Alternative Splicing of the Flip/Flop Cassette and TARP Auxiliary Subunits Engage in a Privileged Relationship That Fine-Tunes AMPA Receptor Gating. J Neurosci 2023; 43:2837-2849. [PMID: 36931708 PMCID: PMC10124957 DOI: 10.1523/jneurosci.2293-22.2023] [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: 12/14/2022] [Revised: 02/10/2023] [Accepted: 03/13/2023] [Indexed: 03/19/2023] Open
Abstract
Alternative splicing of AMPA-type glutamate receptors (AMPARs) and allosteric modulation by auxiliary subunits, such as transmembrane AMPAR regulatory proteins (TARPs), are two important mechanisms that regulate the time course of glutamatergic neurotransmission. Prior work has shown that alternative splicing of the flip/flop cassette profoundly regulates TARP γ2 modulation, where flip receptor gating exhibits robust sensitivity to TARPs while flop isoforms are relatively insensitive to TARP modulation. Whether this splice variant-specific regulation extends to other auxiliary subunit families, such as cornichons (CNIHs), GSG1L, or CKAMPs, remains unknown. Here, we demonstrate that CNIH-3 modulation is unaffected by AMPAR alternative splicing due to inherent differences in how CNIH-3 and TARP γ2 modify channel gating. CNIH-3 slows receptor deactivation from the outset of current decay, consistent with structural evidence showing its point of contact at the level of the pore. In contrast, TARP γ2 acts via the KGK site of the ligand-binding domain (LBD) to slow the onset of desensitization. Although GSG1L and CKAMP44 primarily slow recovery from desensitization, their effects on channel gating are unaffected by alternative splicing, further underlining that structural events leading to the onset and recovery from desensitization are separable. Together, this work establishes that alternative splicing and TARP auxiliary subunits form a unique partnership that governs fast glutamatergic signaling at central synapses. Since proteomic studies suggest that all native AMPARs co-assemble with at least two TARPs, allosteric coupling between the flip/flop cassette and TARPs may represent a common design element in all AMPAR complexes of the mammalian brain.SIGNIFICANCE STATEMENT All fast excitatory neurotransmission in the mammalian brain is mediated by AMPA-type glutamate receptors (AMPARs). The time course of AMPAR gating can be regulated by two distinct mechanisms: alternative splicing of the flip/flop cassette and association with auxiliary subunits. Although these regulatory mechanisms have been well studied individually, it is not clear whether alternative splicing impacts auxiliary protein modulation of AMPARs. Here, we compare the four main families of AMPAR auxiliary subunits, transmembrane AMPAR regulatory proteins (TARPs; γ2), cornichons (CNIH-3), GSG1L and CKAMPs (CKAMP44), and find a privileged relationship between TARPs and the flip/flop cassette that is not shared by others. The flop cassette acts as a master switch to override TARP action, and this coupling represents a way to fine-tune AMPAR signaling.
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Affiliation(s)
- Amanda M Perozzo
- Integrated Program in Neuroscience, McGill University, Montréal, Quebec H3A 2B4, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec H3G 1Y6, Canada
| | - Patricia M G E Brown
- Integrated Program in Neuroscience, McGill University, Montréal, Quebec H3A 2B4, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec H3G 1Y6, Canada
| | - Derek Bowie
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec H3G 1Y6, Canada
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6
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Coombs I, Bats C, Sexton CA, Studniarczyk D, Cull-Candy SG, Farrant M. Enhanced functional detection of synaptic calcium-permeable AMPA receptors using intracellular NASPM. eLife 2023; 12:e66765. [PMID: 37042655 PMCID: PMC10168695 DOI: 10.7554/elife.66765] [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: 01/22/2021] [Accepted: 04/11/2023] [Indexed: 04/13/2023] Open
Abstract
Calcium-permeable AMPA-type glutamate receptors (CP-AMPARs) contribute to many forms of synaptic plasticity and pathology. They can be distinguished from GluA2-containing calcium-impermeable AMPARs by the inward rectification of their currents, which reflects voltage-dependent channel block by intracellular spermine. However, the efficacy of this weakly permeant blocker is differentially altered by the presence of AMPAR auxiliary subunits - including transmembrane AMPAR regulatory proteins, cornichons, and GSG1L - which are widely expressed in neurons and glia. This complicates the interpretation of rectification as a measure of CP-AMPAR expression. Here, we show that the inclusion of the spider toxin analog 1-naphthylacetyl spermine (NASPM) in the intracellular solution results in a complete block of GluA1-mediated outward currents irrespective of the type of associated auxiliary subunit. In neurons from GluA2-knockout mice expressing only CP-AMPARs, intracellular NASPM, unlike spermine, completely blocks outward synaptic currents. Thus, our results identify a functional measure of CP-AMPARs, that is unaffected by their auxiliary subunit content.
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Affiliation(s)
- Ian Coombs
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
| | - Cécile Bats
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
| | - Craig A Sexton
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
| | - Dorota Studniarczyk
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
| | - Stuart G Cull-Candy
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
| | - Mark Farrant
- Department of Neuroscience, Physiology and Pharmacology, University College LondonLondonUnited Kingdom
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7
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Zhang D, Lape R, Shaikh SA, Kohegyi BK, Watson JF, Cais O, Nakagawa T, Greger IH. Modulatory mechanisms of TARP γ8-selective AMPA receptor therapeutics. Nat Commun 2023; 14:1659. [PMID: 36966141 PMCID: PMC10039940 DOI: 10.1038/s41467-023-37259-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 03/09/2023] [Indexed: 03/27/2023] Open
Abstract
AMPA glutamate receptors (AMPARs) mediate excitatory neurotransmission throughout the brain. Their signalling is uniquely diversified by brain region-specific auxiliary subunits, providing an opportunity for the development of selective therapeutics. AMPARs associated with TARP γ8 are enriched in the hippocampus, and are targets of emerging anti-epileptic drugs. To understand their therapeutic activity, we determined cryo-EM structures of the GluA1/2-γ8 receptor associated with three potent, chemically diverse ligands. We find that despite sharing a lipid-exposed and water-accessible binding pocket, drug action is differentially affected by binding-site mutants. Together with patch-clamp recordings and MD simulations we also demonstrate that ligand-triggered reorganisation of the AMPAR-TARP interface contributes to modulation. Unexpectedly, one ligand (JNJ-61432059) acts bifunctionally, negatively affecting GluA1 but exerting positive modulatory action on GluA2-containing AMPARs, in a TARP stoichiometry-dependent manner. These results further illuminate the action of TARPs, demonstrate the sensitive balance between positive and negative modulatory action, and provide a mechanistic platform for development of both positive and negative selective AMPAR modulators.
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Affiliation(s)
- Danyang Zhang
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Remigijus Lape
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Saher A Shaikh
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Bianka K Kohegyi
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Jake F Watson
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
- IST Austria, Klosterneuburg, Austria
| | - Ondrej Cais
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Terunaga Nakagawa
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, Nashville, USA
| | - Ingo H Greger
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK.
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8
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Certain N, Gan Q, Bennett J, Hsieh H, Wollmuth LP. Differential regulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (AMPA) receptor tetramerization by auxiliary subunits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.07.527516. [PMID: 36798164 PMCID: PMC9934675 DOI: 10.1101/2023.02.07.527516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
AMPA receptor (AMPAR) auxiliary subunits are specialized, non-transient binding partners of AMPARs that modulate their ion channel gating properties and pharmacology, as well as their biogenesis and trafficking. The most well characterized families of auxiliary subunits are transmembrane AMPAR regulatory proteins (TARPs) and cornichon homologs (CNIHs) and the more recently discovered GSG1-L. These auxiliary subunits can promote or reduce surface expression of AMPARs in neurons, thereby impacting their functional role in membrane signaling. Here, we show that CNIH-2 enhances the tetramerization of wild type and mutant AMPARs, possibly by increasing the overall stability of the tetrameric complex, an effect that is mainly mediated by interactions with the transmembrane domain of the receptor. We also find CNIH-2 and CNIH-3 show receptor subunit-specific actions in this regard with CNIH-2 enhancing both GluA1 and GluA2 tetramerization whereas CNIH-3 only weakly enhances GluA1 tetramerization. These results are consistent with the proposed role of CNIHs as endoplasmic reticulum cargo transporters for AMPARs. In contrast, TARP γ-2, TARP γ-8, and GSG1-L have no or negligible effect on AMPAR tetramerization. On the other hand, TARP γ-2 can enhance receptor tetramerization but only when directly fused with the receptor at a maximal stoichiometry. Notably, surface expression of functional AMPARs was enhanced by CNIH-2 to a greater extent than TARP γ-2 suggesting that this distinction aids in maturation and membrane expression. These experiments define a functional distinction between CNIHs and other auxiliary subunits in the regulation of AMPAR biogenesis.
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9
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Abstract
Knowledge of the biology of ionotropic glutamate receptors (iGluRs) is a prerequisite for any student of the neurosciences. But yet, half a century ago, the situation was quite different. There was fierce debate on whether simple amino acids, such as l-glutamic acid (L-Glu), should even be considered as putative neurotransmitter candidates that drive excitatory synaptic signaling in the vertebrate brain. Organic chemist, Jeff Watkins, and physiologist, Dick Evans, were amongst the pioneering scientists who shed light on these tribulations. By combining their technical expertise, they performed foundational work that explained that the actions of L-Glu were, in fact, mediated by a family of ion-channels that they named NMDA-, AMPA- and kainate-selective iGluRs. To celebrate and reflect upon their seminal work, Neuropharmacology has commissioned a series of issues that are dedicated to each member of the Glutamate receptor superfamily that includes both ionotropic and metabotropic classes. This issue brings together nine timely reviews from researchers whose work has brought renewed focus on AMPA receptors (AMPARs), the predominant neurotransmitter receptor at central synapses. Together with the larger collection of papers on other GluR family members, these issues highlight that the excitement, passion, and clarity that Watkins and Evans brought to the study of iGluRs is unlikely to fade as we move into a new era on this most interesting of ion-channel families.
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10
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Coombs ID, Cull-Candy SG. Single-channel mechanisms underlying the function, diversity and plasticity of AMPA receptors. Neuropharmacology 2021; 198:108781. [PMID: 34480912 DOI: 10.1016/j.neuropharm.2021.108781] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 08/18/2021] [Accepted: 08/31/2021] [Indexed: 12/29/2022]
Abstract
The functional properties of AMPA receptors shape many of the essential features of excitatory synaptic signalling in the brain, including high-fidelity point-to-point transmission and long-term plasticity. Understanding the behaviour and regulation of single AMPAR channels is fundamental in unravelling how central synapses carry, process and store information. There is now an abundance of data on the importance of alternative splicing, RNA editing, and phosphorylation of AMPAR subunits in determining central synaptic diversity. Furthermore, auxiliary subunits have emerged as pivotal players that regulate AMPAR channel properties and add further diversity. Single-channel studies have helped reveal a fascinating picture of the unique behaviour of AMPAR channels - their concentration-dependent single-channel conductance, the basis of their multiple-conductance states, and the influence of auxiliary proteins in controlling many of their gating and conductance properties. Here we summarize basic hallmarks of AMPAR single-channels, in relation to function, diversity and plasticity. We also present data that reveal an unexpected feature of AMPAR sublevel behaviour. This article is part of the special Issue on 'Glutamate Receptors - AMPA receptors'.
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Affiliation(s)
- Ian D Coombs
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
| | - Stuart G Cull-Candy
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
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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: 18] [Impact Index Per Article: 6.0] [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: 256] [Impact Index Per Article: 85.3] [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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Matthews PM, Pinggera A, Kampjut D, Greger IH. Biology of AMPA receptor interacting proteins - From biogenesis to synaptic plasticity. Neuropharmacology 2021; 197:108709. [PMID: 34271020 DOI: 10.1016/j.neuropharm.2021.108709] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/19/2021] [Accepted: 07/08/2021] [Indexed: 12/19/2022]
Abstract
AMPA-type glutamate receptors mediate the majority of excitatory synaptic transmission in the central nervous system. Their signaling properties and abundance at synapses are both crucial determinants of synapse efficacy and plasticity, and are therefore under sophisticated control. Unique to this ionotropic glutamate receptor (iGluR) is the abundance of interacting proteins that contribute to its complex regulation. These include transient interactions with the receptor cytoplasmic tail as well as the N-terminal domain locating to the synaptic cleft, both of which are involved in AMPAR trafficking and receptor stabilization at the synapse. Moreover, an array of transmembrane proteins operate as auxiliary subunits that in addition to receptor trafficking and stabilization also substantially impact AMPAR gating and pharmacology. Here, we provide an overview of the catalogue of AMPAR interacting proteins, and how they contribute to the complex biology of this central glutamate receptor.
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Affiliation(s)
- Peter M Matthews
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Alexandra Pinggera
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Domen Kampjut
- 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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14
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Cull‐Candy SG, Farrant M. Ca 2+ -permeable AMPA receptors and their auxiliary subunits in synaptic plasticity and disease. J Physiol 2021; 599:2655-2671. [PMID: 33533533 PMCID: PMC8436767 DOI: 10.1113/jp279029] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 01/28/2021] [Indexed: 12/14/2022] Open
Abstract
AMPA receptors are tetrameric glutamate-gated ion channels that mediate a majority of fast excitatory neurotransmission in the brain. They exist as calcium-impermeable (CI-) and calcium-permeable (CP-) subtypes, the latter of which lacks the GluA2 subunit. CP-AMPARs display an array of distinctive biophysical and pharmacological properties that allow them to be functionally identified. This has revealed that they play crucial roles in diverse forms of central synaptic plasticity. Here we summarise the functional hallmarks of CP-AMPARs and describe how these are modified by the presence of auxiliary subunits that have emerged as pivotal regulators of AMPARs. A lasting change in the prevalence of GluA2-containing AMPARs, and hence in the fraction of CP-AMPARs, is a feature in many maladaptive forms of synaptic plasticity and neurological disorders. These include modifications of glutamatergic transmission induced by inflammatory pain, fear conditioning, cocaine exposure, and anoxia-induced damage in neurons and glia. Furthermore, defective RNA editing of GluA2 can cause altered expression of CP-AMPARs and is implicated in motor neuron damage (amyotrophic lateral sclerosis) and the proliferation of cells in malignant gliomas. A number of the players involved in CP-AMPAR regulation have been identified, providing useful insight into interventions that may prevent the aberrant CP-AMPAR expression. Furthermore, recent molecular and pharmacological developments, particularly the discovery of TARP subtype-selective drugs, offer the exciting potential to modify some of the harmful effects of increased CP-AMPAR prevalence in a brain region-specific manner.
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Affiliation(s)
- Stuart G. Cull‐Candy
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonGower StreetLondonWC1E 6BTUK
| | - Mark Farrant
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonGower StreetLondonWC1E 6BTUK
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15
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Kamalova A, Futai K, Delpire E, Nakagawa T. AMPA Receptor Auxiliary Subunit GSG1L Suppresses Short-Term Facilitation in Corticothalamic Synapses and Determines Seizure Susceptibility. Cell Rep 2021; 32:107921. [PMID: 32697982 PMCID: PMC7425083 DOI: 10.1016/j.celrep.2020.107921] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 05/06/2020] [Accepted: 06/26/2020] [Indexed: 01/29/2023] Open
Abstract
The anterior thalamus (AT) is critical for memory formation, processing navigational information, and seizure initiation. However, the molecular mechanisms that regulate synaptic function of AT neurons remain largely unexplored. We report that AMPA receptor auxiliary subunit GSG1L controls short-term plasticity in AT synapses that receive inputs from the cortex, but not in those receiving inputs from other pathways. A canonical auxiliary subunit stargazin co-exists in these neurons but is functionally absent from corticothalamic synapses. In GSG1L knockout mice, AT neurons exhibit hyperexcitability and the animals have increased susceptibility to seizures, consistent with a negative regulatory role of GSG1L. We hypothesize that negative regulation of synaptic function by GSG1L plays a critical role in maintaining optimal excitation in the AT. Kamalova et al. report the phenotypes of GSG1L KO mice. The synaptic function of AMPAR auxiliary subunit GSG1L in the anterior thalamus is input specific. GSG1L suppresses short-term facilitation and decreases AMPAR activity specifically in corticothalamic synapses, where stargazin is functionally absent. GSG1L KO mice exhibit hyperexcitability and seizure susceptibility.
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Affiliation(s)
- Aichurok Kamalova
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, Nashville, TN 37232, USA; Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN 37232, USA
| | - Kensuke Futai
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Eric Delpire
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, Nashville, TN 37232, USA; Vanderbilt Brain Institute, Vanderbilt University, School of Medicine, Nashville, TN 37232, USA; Department of Anesthesiology, 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; 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.
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16
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Bowie D. Neurotransmitter-gated ion channels, still front and centre stage. J Physiol 2021; 599:389-395. [PMID: 33448020 DOI: 10.1113/jp280800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Derek Bowie
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, H3G 1Y6, Canada
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17
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Han W, Shepard RD, Lu W. Regulation of GABA ARs by Transmembrane Accessory Proteins. Trends Neurosci 2021; 44:152-165. [PMID: 33234346 PMCID: PMC7855156 DOI: 10.1016/j.tins.2020.10.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/08/2020] [Accepted: 10/20/2020] [Indexed: 12/13/2022]
Abstract
The vast majority of fast inhibitory transmission in the brain is mediated by GABA acting on GABAA receptors (GABAARs), which provides inhibitory balance to excitatory drive and controls neuronal output. GABAARs are also effectively targeted by clinically important drugs for treatment in a number of neurological disorders. It has long been hypothesized that function and pharmacology of GABAARs are determined by the channel pore-forming subunits. However, recent studies have provided new dimensions in studying GABAARs due to several transmembrane proteins that interact with GABAARs and modulate their trafficking and function. In this review, we summarize recent findings on these novel GABAAR transmembrane regulators and highlight a potential avenue to develop new GABAAR psychopharmacology by targeting these receptor-associated membrane proteins.
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Affiliation(s)
- Wenyan Han
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ryan D Shepard
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wei Lu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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18
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Phillips MB, Nigam A, Johnson JW. Interplay between Gating and Block of Ligand-Gated Ion Channels. Brain Sci 2020; 10:brainsci10120928. [PMID: 33271923 PMCID: PMC7760600 DOI: 10.3390/brainsci10120928] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/21/2020] [Accepted: 11/26/2020] [Indexed: 02/03/2023] Open
Abstract
Drugs that inhibit ion channel function by binding in the channel and preventing current flow, known as channel blockers, can be used as powerful tools for analysis of channel properties. Channel blockers are used to probe both the sophisticated structure and basic biophysical properties of ion channels. Gating, the mechanism that controls the opening and closing of ion channels, can be profoundly influenced by channel blocking drugs. Channel block and gating are reciprocally connected; gating controls access of channel blockers to their binding sites, and channel-blocking drugs can have profound and diverse effects on the rates of gating transitions and on the stability of channel open and closed states. This review synthesizes knowledge of the inherent intertwining of block and gating of excitatory ligand-gated ion channels, with a focus on the utility of channel blockers as analytic probes of ionotropic glutamate receptor channel function.
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Affiliation(s)
- Matthew B. Phillips
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; (M.B.P.); (A.N.)
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Aparna Nigam
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; (M.B.P.); (A.N.)
| | - Jon W. Johnson
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; (M.B.P.); (A.N.)
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Correspondence: ; Tel.: +1-(412)-624-4295
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19
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Devi SPS, Cheng Y, Tomita S, Howe JR, Zhang W. TARPs Modulate Receptor-Mediated Paired-Pulse Depression and Recovery from Desensitization. J Neurosci 2020; 40:8233-8247. [PMID: 32994336 PMCID: PMC7577600 DOI: 10.1523/jneurosci.3026-19.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 08/07/2020] [Accepted: 09/14/2020] [Indexed: 11/21/2022] Open
Abstract
Transmembrane AMPA receptor regulatory proteins (TARPs) are auxiliary AMPA receptor subunits that play a key role in receptor trafficking and in modulating receptor gating. The ability of TARPs to slow both deactivation and desensitization is isoform specific. However, TARP isoform-specific modulation of receptor properties remains uncharacterized. Here, we compare the isoform-specific effects of γ-2, γ-3, γ-4, and γ-8 TARPs on recovery from desensitization and responses to pairs of brief applications of glutamate. All four isoforms were able to reduce receptor-mediated paired-pulse depression and significantly speed recovery from desensitization in an isoform-specific manner. In the presence of TARPs, recovery time courses were observed to contain two components, fast and slow. The proportion of fast and slow components was determined by the TARP isoform. The time constant of recovery was also altered by the duration of glutamate application. When studies with TARP chimeras were performed, TARP extracellular loops were found to play a vital role in TARP modulation of recovery. Thus, isoform-specific differences in TARP modulation of recovery from desensitization influence receptor responses to repeated brief applications of glutamate, and these differences may impact frequency-dependent synaptic signaling in the mammalian central nervous system.SIGNIFICANCE STATEMENT AMPA receptors are major determinants of excitatory synaptic strength. The channel kinetics of AMPA receptors contribute to the kinetics of synaptic transmission. Transmembrane AMPA receptor regulatory proteins (TARPs) auxiliary subunits can modulate the decay kinetics of AMPA receptors. However, whether TARP isoforms specifically modulate receptor recovery is unclear. Here, we investigated the recovery kinetics of AMPA receptors by expressing various TARP isoforms and chimeras. We observed that the TARP isoforms and duration of glutamate application uniquely modulate time constants and the proportion of fast and slow components through a previously unidentified TARP domain. Given the impact of recovery kinetics on receptor responses to repetitive stimulation such as synaptic transmission, this work will be of great interest in the field of excitatory synaptic transmission research.
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Affiliation(s)
- Suma Priya Sudarsana Devi
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
- Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama 35233
| | - Yiru Cheng
- Department of Pharmacology of Chinese Materia Medica, Institution of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, Hebei Province 050017, China
| | - Susumu Tomita
- Department of Cellular and Molecular Physiology, Department of Neuroscience, and Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06520
| | - James R Howe
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Wei Zhang
- Department of Pharmacology of Chinese Materia Medica, Institution of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, Hebei Province 050017, China
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20
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Dolgacheva LP, Tuleukhanov ST, Zinchenko VP. Participation of Ca2+-Permeable AMPA Receptors in Synaptic Plasticity. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2020. [DOI: 10.1134/s1990747820030046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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Pfisterer U, Petukhov V, Demharter S, Meichsner J, Thompson JJ, Batiuk MY, Asenjo-Martinez A, Vasistha NA, Thakur A, Mikkelsen J, Adorjan I, Pinborg LH, Pers TH, von Engelhardt J, Kharchenko PV, Khodosevich K. Identification of epilepsy-associated neuronal subtypes and gene expression underlying epileptogenesis. Nat Commun 2020; 11:5038. [PMID: 33028830 PMCID: PMC7541486 DOI: 10.1038/s41467-020-18752-7] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 09/08/2020] [Indexed: 11/20/2022] Open
Abstract
Epilepsy is one of the most common neurological disorders, yet its pathophysiology is poorly understood due to the high complexity of affected neuronal circuits. To identify dysfunctional neuronal subtypes underlying seizure activity in the human brain, we have performed single-nucleus transcriptomics analysis of >110,000 neuronal transcriptomes derived from temporal cortex samples of multiple temporal lobe epilepsy and non-epileptic subjects. We found that the largest transcriptomic changes occur in distinct neuronal subtypes from several families of principal neurons (L5-6_Fezf2 and L2-3_Cux2) and GABAergic interneurons (Sst and Pvalb), whereas other subtypes in the same families were less affected. Furthermore, the subtypes with the largest epilepsy-related transcriptomic changes may belong to the same circuit, since we observed coordinated transcriptomic shifts across these subtypes. Glutamate signaling exhibited one of the strongest dysregulations in epilepsy, highlighted by layer-wise transcriptional changes in multiple glutamate receptor genes and strong upregulation of genes coding for AMPA receptor auxiliary subunits. Overall, our data reveal a neuronal subtype-specific molecular phenotype of epilepsy. The pathophysiology of epilepsy is unclear. Here, the authors present single-nuclei transcriptomic profiling of human temporal lobe epilepsy from patients. They identified epilepsy-associated neuronal subtypes, and a panel of dysregulated genes, predicting neuronal circuits contributing to epilepsy.
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Affiliation(s)
- Ulrich Pfisterer
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Viktor Petukhov
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.,Department of Biomedical Informatics, Harvard Medical School, Boston, MA, 02115, USA
| | - Samuel Demharter
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Johanna Meichsner
- Institute of Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Jonatan J Thompson
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Mykhailo Y Batiuk
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Andrea Asenjo-Martinez
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Navneet A Vasistha
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Ashish Thakur
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Jens Mikkelsen
- Department of Neurology and Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Istvan Adorjan
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Lars H Pinborg
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, 2200, Copenhagen, Denmark.,Epilepsy Clinic, Department of Neurology, Copenhagen University Hospital, Rigshospitalet, 2200, Copenhagen, Denmark
| | - Tune H Pers
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Jakob von Engelhardt
- Institute of Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Peter V Kharchenko
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, 02115, USA
| | - Konstantin Khodosevich
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.
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22
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Wei M, Wang M, Wang J, Su F, Wang Y, Sun M, Wang S, Liu M, Wang H, Lu M, Li W, Gong Y, Yang L, Zhang C. PORCN Negatively Regulates AMPAR Function Independently of Subunit Composition and the Amino-Terminal and Carboxy-Terminal Domains of AMPARs. Front Cell Dev Biol 2020; 8:829. [PMID: 32984326 PMCID: PMC7477090 DOI: 10.3389/fcell.2020.00829] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/04/2020] [Indexed: 11/13/2022] Open
Abstract
Most fast excitatory synaptic transmissions in the mammalian brain are mediated by α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors (AMPARs), which are ligand-gated cation channels. The membrane expression level of AMPARs is largely determined by auxiliary subunits in AMPAR macromolecules, including porcupine O-acyltransferase (PORCN), which negatively regulates AMPAR trafficking to the plasma membrane. However, whether PORCN-mediated regulation depends on AMPAR subunit composition or particular regions of a subunit has not been determined. We systematically examined the effects of PORCN on the ligand-gated current and surface expression level of GluA1, GluA2, and GluA3 AMPAR subunits, alone and in combination, as well as the PORCN-GluA interaction in heterologous HEK293T cells. PORCN inhibited glutamate-induced currents and the surface expression of investigated GluA AMPAR subunits in a subunit-independent manner. These inhibitory effects required neither the amino-terminal domain (ATD) nor the carboxy-terminal domain (CTD) of GluA subunits. In addition, PORCN interacted with AMPARs independently of their ATD or CTD. Thus, the functional inhibition of AMPARs by PORCN in transfected heterologous cells was independent of the ATD, CTD, and subunit composition of AMPARs.
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Affiliation(s)
- Mengping Wei
- PKU-IDG/McGovern Institute for Brain Research, School of Life Sciences, Peking University, Beijing, China.,Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Meng Wang
- Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Jue Wang
- Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Feng Su
- Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Yangzhen Wang
- Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China.,School of Life Sciences, Tsinghua University, Beijing, China
| | - Meng Sun
- Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Shanshan Wang
- PKU-IDG/McGovern Institute for Brain Research, School of Life Sciences, Peking University, Beijing, China.,Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Mengna Liu
- PKU-IDG/McGovern Institute for Brain Research, School of Life Sciences, Peking University, Beijing, China.,Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Hongyi Wang
- Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Mingyang Lu
- Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Wei Li
- Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Yutian Gong
- Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Lei Yang
- Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Chen Zhang
- PKU-IDG/McGovern Institute for Brain Research, School of Life Sciences, Peking University, Beijing, China.,Beijing Key Laboratory of Neural Regeneration and Repair, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
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23
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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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24
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Coombs ID, Soto D, McGee TP, Gold MG, Farrant M, Cull-Candy SG. Homomeric GluA2(R) AMPA receptors can conduct when desensitized. Nat Commun 2019; 10:4312. [PMID: 31541113 PMCID: PMC6754398 DOI: 10.1038/s41467-019-12280-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 08/28/2019] [Indexed: 11/21/2022] Open
Abstract
Desensitization is a canonical property of ligand-gated ion channels, causing progressive current decline in the continued presence of agonist. AMPA-type glutamate receptors (AMPARs), which mediate fast excitatory signaling throughout the brain, exhibit profound desensitization. Recent cryo-EM studies of AMPAR assemblies show their ion channels to be closed in the desensitized state. Here we present evidence that homomeric Q/R-edited AMPARs still allow ions to flow when the receptors are desensitized. GluA2(R) expressed alone, or with auxiliary subunits (γ-2, γ-8 or GSG1L), generates large fractional steady-state currents and anomalous current-variance relationships. Our results from fluctuation analysis, single-channel recording, and kinetic modeling, suggest that the steady-state current is mediated predominantly by conducting desensitized receptors. When combined with crystallography this unique functional readout of a hitherto silent state enabled us to examine cross-linked cysteine mutants to probe the conformation of the desensitized ligand binding domain of functioning AMPAR complexes. AMPA-type glutamate receptors, which mediate fast excitatory signaling throughout the brain, exhibit profound desensitization, causing a progressive current decline in the continued presence of agonist. Here authors show that homomeric Q/R edited AMPARs still allow ions to flow when the receptors are desensitized.
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Affiliation(s)
- Ian D Coombs
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - David Soto
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.,Department of Biomedicine, Neurophysiology Laboratory, Medical School, Institute of Neurosciences, University of Barcelona, Casanova 143, 08036, Barcelona, Spain
| | - Thomas P McGee
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Matthew G Gold
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Mark Farrant
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
| | - Stuart G Cull-Candy
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
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25
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Structural biology of glutamate receptor ion channels: towards an understanding of mechanism. Curr Opin Struct Biol 2019; 57:185-195. [PMID: 31185364 DOI: 10.1016/j.sbi.2019.05.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/03/2019] [Accepted: 05/06/2019] [Indexed: 12/21/2022]
Abstract
Ionotropic glutamate receptors (iGluRs) are tetrameric ion channels that mediate signal transmission at neuronal synapses, where they contribute centrally to the postsynaptic plasticity that underlies learning and memory. Receptor activation by l-glutamate triggers complex allosteric cascades that are transmitted through the layered and highly flexible receptor assembly culminating in opening a cation-selective pore. This process is shaped by the arrangement of the four core subunits as well as the presence of various auxiliary subunits, and is subject to regulation by an array of small molecule modulators targeting a number of sites throughout the complex. Here, we discuss recent structures of iGluR homomers and heteromers illuminating the organization and subunit arrangement of the core tetramer, co-assembled with auxiliary subunits and in complex with allosteric modulators.
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26
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Lujan B, Dagostin A, von Gersdorff H. Presynaptic Diversity Revealed by Ca 2+-Permeable AMPA Receptors at the Calyx of Held Synapse. J Neurosci 2019; 39:2981-2994. [PMID: 30679394 PMCID: PMC6468103 DOI: 10.1523/jneurosci.2565-18.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/14/2018] [Accepted: 01/03/2019] [Indexed: 02/06/2023] Open
Abstract
GluA2-lacking Ca2+-permeable AMPARs (CP-AMPARs) play integral roles in synaptic plasticity and can mediate excitotoxic cellular signaling at glutamatergic synapses. However, the developmental profile of functional CP-AMPARs at the auditory brainstem remains poorly understood. Through a combination of electrophysiological and live-cell Ca2+ imaging from mice of either sex, we show that the synaptic release of glutamate from the calyx of Held nerve terminal activates CP-AMPARs in the principal cells of the medial nucleus of the trapezoid body in the brainstem. This leads to significant Ca2+ influx through these receptors before the onset of hearing at postnatal day 12 (P12). Using a selective open channel blocker of CP-AMPARs, IEM-1460, we estimate that ∼80% of the AMPAR population are permeable to Ca2+ at immature P4-P5 synapses. However, after the onset of hearing, Ca2+ influx through these receptors was greatly reduced. We estimate that CP-AMPARs comprise approximately 40% and 33% of the AMPAR population at P18-P22 and P30-P34, respectively. By quantifying the rate of EPSC block by IEM-1460, we found an increased heterogeneity in glutamate release probability for adult-like calyces (P30-P34). Using tetraethylammonium (TEA), a presynaptic potassium channel blocker, we show that the apparent reduction of CP-AMPARs in more mature synapses is not a consequence of presynaptic action potential (AP) speeding. Finally, through postsynaptic AP recordings, we show that inhibition of CP-AMPARs reduces spike fidelity in juvenile synapses, but not in more mature synapses. We conclude that the expression of functional CP-AMPARs declines over early postnatal development in the calyx of Held synapse.SIGNIFICANCE STATEMENT The calyx of Held synapse is pivotal to the circuitry that computes sound localization. Postsynaptic Ca2+ influx via AMPARs may be critical for signaling the maturation of this brainstem synapse. The GluA4 subunit may dominate the AMPAR complex at mature synapses because of its fast gating kinetics and large unitary conductance. The expectation is that AMPARs dominated by GluA4 subunits should be highly Ca2+ permeable. However, we find that Ca2+-permeable AMPAR expression declines during postnatal development. Using the rate of EPSC block by IEM-1460, an open channel blocker of Ca2+-permeable AMPARs, we propose a novel method to determine glutamate release probability and uncover an increased heterogeneity in release probability for more mature calyces of Held nerve terminals.
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Affiliation(s)
- Brendan Lujan
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
| | - Andre Dagostin
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
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27
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Ethanol Experience Enhances Glutamatergic Ventral Hippocampal Inputs to D1 Receptor-Expressing Medium Spiny Neurons in the Nucleus Accumbens Shell. J Neurosci 2019; 39:2459-2469. [PMID: 30692226 DOI: 10.1523/jneurosci.3051-18.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/11/2019] [Accepted: 01/15/2019] [Indexed: 02/05/2023] Open
Abstract
A growing number of studies implicate alterations in glutamatergic signaling within the reward circuitry of the brain during alcohol abuse and dependence. A key integrator of glutamatergic signaling in the reward circuit is the nucleus accumbens, more specifically, the dopamine D1 receptor-expressing medium spiny neurons (D1-MSNs) within this region, which have been implicated in the formation of dependence to many drugs of abuse including alcohol. D1-MSNs receive glutamatergic input from several brain regions; however, it is not currently known how individual inputs onto D1-MSNs are altered by alcohol experience. Here, we investigate input-specific adaptations in glutamatergic transmission in response to varying levels of alcohol experience. Virally mediated expression of Channelrhodopsin in ventral hippocampal (vHipp) glutamate neurons of male mice allowed for selective activation of vHipp to D1-MSN synapses. Therefore, we were able to compare synaptic adaptations in response to low and high alcohol experience in vitro and in vivo Alcohol experience enhanced glutamatergic activity and abolished LTD at vHipp to D1-MSN synapses. Following chronic alcohol experience, GluA2-lacking AMPARs, which are Ca permeable, were inserted into vHipp to D1-MSN synapses. These findings support the reversal of alcohol-induced insertion of Ca-permeable AMPARs and the enhancement of glutamatergic activity at vHipp to D1-MSNs as potential targets for intervention during early exposure to alcohol.SIGNIFICANCE STATEMENT Given the roles of the nucleus accumbens (NAc) in integrating cortical and allocortical information and in reward learning, it is vital to understand how inputs to this region are altered by drugs of abuse such as alcohol. The strength of excitatory inputs from the ventral hippocampus (vHipp) to the NAc has been positively associated with reward-related behaviors, but it is unclear whether or how ethanol affects these inputs. Here we show that vHipp-NAc synapses indeed are altered by ethanol exposure, with vHipp glutamatergic input to the NAc being enhanced following chronic ethanol experience. This work provides insight into ethanol-induced alterations of vHipp-NAc synapses and suggests that, similarly to drugs such as cocaine, the strengthening of these synapses promotes reward behavior.
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28
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Bowie D. Polyamine-mediated channel block of ionotropic glutamate receptors and its regulation by auxiliary proteins. J Biol Chem 2018; 293:18789-18802. [PMID: 30333231 DOI: 10.1074/jbc.tm118.003794] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Most excitatory neurotransmission in the mammalian brain is mediated by a family of plasma membrane-bound signaling proteins called ionotropic glutamate receptors (iGluRs). iGluRs assemble at central synapses as tetramers, forming a central ion-channel pore whose primary function is to rapidly transport Na+ and Ca2+ in response to binding the neurotransmitter l-glutamic acid. The pore of iGluRs is also accessible to bulkier cytoplasmic cations, such as the polyamines spermine, spermidine, and putrescine, which are drawn into the permeation pathway, but get stuck and block the movement of other ions. The degree of this polyamine-mediated channel block is highly regulated by processes that control the free cytoplasmic polyamine concentration, the membrane potential, or the iGluR subunit composition. Recently, an additional regulation by auxiliary proteins, most notably transmembrane AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptor regulatory proteins (TARPs), cornichons, and neuropilin and tolloid-like proteins (NETOs), has been identified. Here, I review what we have learned of polyamine block of iGluRs and its regulation by auxiliary subunits. TARPs, cornichons, and NETOs attenuate the channel block by enabling polyamines to exit the pore. As a result, polyamine permeation occurs at more negative and physiologically relevant membrane potentials. The structural basis for enhanced polyamine transport remains unresolved, although alterations in both channel architecture and charge-screening mechanisms have been proposed. That auxiliary subunits can attenuate the polyamine block reveals an unappreciated impact of polyamine permeation in shaping the signaling properties of neuronal AMPA- and kainate-type iGluRs. Moreover, enhanced polyamine transport through iGluRs may have a role in regulating cellular polyamine levels.
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Affiliation(s)
- Derek Bowie
- From the Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 0B1, Canada
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29
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Rozov A, Zakharova Y, Vazetdinova A, Valiullina-Rakhmatullina F. The Role of Polyamine-Dependent Facilitation of Calcium Permeable AMPARs in Short-Term Synaptic Enhancement. Front Cell Neurosci 2018; 12:345. [PMID: 30364146 PMCID: PMC6191566 DOI: 10.3389/fncel.2018.00345] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 09/18/2018] [Indexed: 11/13/2022] Open
Abstract
Depending on subunit composition AMPA receptor channels can be subdivided into two groups: GluA2-containing calcium impermeable AMPARs, and GluA2-lacking calcium permeable, AMPARs. These two groups differ in a number of biophysical properties and, most likely, in their functional role at glutamatergic synapses. GluA2-lacking channels have received a lot of attention over the last two decades mainly due to high calcium permeability, which was suggested to play a significant role in the induction of long-term synaptic plasticity in healthy tissue and neuronal death under neuropathological conditions. However, calcium permeable AMPARs possess another property that can contribute substantially to frequency dependent dynamics of synaptic efficacy. In the closed state calcium permeable AMPARs are blocked by endogenous polyamines, however, repetitive activation leads to progressive relief from the block and to the facilitation of ion flux through these channels. Polyamine-dependent facilitation of AMPARs can contribute to short-term plasticity at synapses that have high initial release probability and express calcium permeable AMPARs. During synaptic transmission activity-dependent relief from polyamine block of postsynaptic calcium-permeable AMPARs either counteracts presynaptic short-term depression in a frequency-dependent manner or, under specific stimulation conditions, induces facilitation of a synaptic response. Taking into account the fact that expression of calcium permeable AMPARs is developmentally regulated, depends on network activity and increases in diseased brain states, polyamine-dependent facilitation of calcium permeable AMPARs is an important, entirely postsynaptic mechanism of synaptic gain regulation.
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Affiliation(s)
- Andrei Rozov
- Laboratory of Neurobiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia.,Department of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Yulia Zakharova
- Laboratory of Neurobiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Alina Vazetdinova
- Laboratory of Neurobiology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
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30
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Jacobi E, von Engelhardt J. AMPA receptor complex constituents: Control of receptor assembly, membrane trafficking and subcellular localization. Mol Cell Neurosci 2018; 91:67-75. [DOI: 10.1016/j.mcn.2018.05.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 05/15/2018] [Accepted: 05/24/2018] [Indexed: 11/29/2022] Open
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31
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Gratacòs-Batlle E, Olivella M, Sánchez-Fernández N, Yefimenko N, Miguez-Cabello F, Fadó R, Casals N, Gasull X, Ambrosio S, Soto D. Mechanisms of CPT1C-Dependent AMPAR Trafficking Enhancement. Front Mol Neurosci 2018; 11:275. [PMID: 30135643 PMCID: PMC6092487 DOI: 10.3389/fnmol.2018.00275] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 07/20/2018] [Indexed: 12/19/2022] Open
Abstract
In neurons, AMPA receptor (AMPAR) function depends essentially on their constituent components:the ion channel forming subunits and ion channel associated proteins. On the other hand, AMPAR trafficking is tightly regulated by a vast number of intracellular neuronal proteins that bind to AMPAR subunits. It has been recently shown that the interaction between the GluA1 subunit of AMPARs and carnitine palmitoyltransferase 1C (CPT1C), a novel protein partner of AMPARs, is important in modulating surface expression of these ionotropic glutamate receptors. Indeed, synaptic transmission in CPT1C knockout (KO) mice is diminished supporting a positive trafficking role for that protein. However, the molecular mechanisms of such modulation remain unknown although a putative role of CPT1C in depalmitoylating GluA1 has been hypothesized. Here, we explore that possibility and show that CPT1C effect on AMPARs is likely due to changes in the palmitoylation state of GluA1. Based on in silico analysis, Ser 252, His 470 and Asp 474 are predicted to be the catalytic triad responsible for CPT1C palmitoyl thioesterase (PTE) activity. When these residues are mutated or when PTE activity is inhibited, the CPT1C effect on AMPAR trafficking is abolished, validating the CPT1C catalytic triad as being responsible for PTE activity on AMPAR. Moreover, the histidine residue (His 470) of CPT1C is crucial for the increase in GluA1 surface expression in neurons and the H470A mutation impairs the depalmitoylating catalytic activity of CPT1C. Finally, we show that CPT1C effect seems to be specific for this CPT1 isoform and it takes place solely at endoplasmic reticulum (ER). This work adds another facet to the impressive degree of molecular mechanisms regulating AMPAR physiology.
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Affiliation(s)
- 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.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Mireia Olivella
- Grup de Recerca en Bioinformàtica i Estadística Mèdica, Universitat de Vic, 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 Neurobiologia, Department de Patologia i Terapèutica Experimental, Facultat de Medicina i Ciències de la Salut, Campus Universitari de Bellvitge, Universitat de Barcelona, Barcelona, Spain
| | - 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
| | - Rut Fadó
- Department de Ciències Bàsiques, Facultat de Medicina i Ciències de la Salut, Universitat Internacional de Catalunya, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, Barcelona, Spain
| | - Núria Casals
- Department de Ciències Bàsiques, Facultat de Medicina i Ciències de la Salut, Universitat Internacional de Catalunya, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, 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
| | - Santiago Ambrosio
- Unitat de Bioquímica, Departament de Ciències Fisiològiques, Facultat de Medicina i Ciències de la Salut, Campus Universitari de Bellvitge, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques de Bellvitge (IDIBELL), 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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32
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An Essential Role for the Tetraspanin LHFPL4 in the Cell-Type-Specific Targeting and Clustering of Synaptic GABA A Receptors. Cell Rep 2018; 21:70-83. [PMID: 28978485 PMCID: PMC5640807 DOI: 10.1016/j.celrep.2017.09.025] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 07/17/2017] [Accepted: 09/06/2017] [Indexed: 02/04/2023] Open
Abstract
Inhibitory synaptic transmission requires the targeting and stabilization of GABAA receptors (GABAARs) at synapses. The mechanisms responsible remain poorly understood, and roles for transmembrane accessory proteins have not been established. Using molecular, imaging, and electrophysiological approaches, we identify the tetraspanin LHFPL4 as a critical regulator of postsynaptic GABAAR clustering in hippocampal pyramidal neurons. LHFPL4 interacts tightly with GABAAR subunits and is selectively enriched at inhibitory synapses. In LHFPL4 knockout mice, there is a dramatic cell-type-specific reduction in GABAAR and gephyrin clusters and an accumulation of large intracellular gephyrin aggregates in vivo. While GABAARs are still trafficked to the neuronal surface in pyramidal neurons, they are no longer localized at synapses, resulting in a profound loss of fast inhibitory postsynaptic currents. Hippocampal interneuron currents remain unaffected. Our results establish LHFPL4 as a synapse-specific tetraspanin essential for inhibitory synapse function and provide fresh insights into the molecular make-up of inhibitory synapses. LHFPL4 is a tetraspanin enriched at inhibitory synapses that complexes with GABAARs LHFPL4 is important for GABAAR clustering both in vitro and in vivo LHFPL4 is required for the surface clustering but not the trafficking of GABAARs GABAergic synaptic inputs on CA1 pyramidal neurons, but not interneurons, require LHFPL4
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33
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Abstract
Ionotropic glutamate receptors (AMPA, NMDA, and kainate receptors) play a central role in excitatory glutamatergic signaling throughout the brain. As a result, functional changes, especially long-lasting forms of plasticity, have the potential to profoundly alter neuronal function and the expression of adaptive and pathological behaviors. Thus, alcohol-related adaptations in ionotropic glutamate receptors are of great interest, since they could promote excessive alcohol consumption, even after long-term abstinence. Alcohol- and drug-related adaptations in NMDARs have been recently reviewed, while less is known about kainate receptor adaptations. Thus, we focus here on functional changes in AMPARs, tetramers composed of GluA1-4 subunits. Long-lasting increases or decreases in AMPAR function, the so-called long-term potentiation or depression, have widely been considered to contribute to normal and pathological memory states. In addition, a great deal has been learned about the acute regulation of AMPARs by signaling pathways, scaffolding and auxiliary proteins, intracellular trafficking, and other mechanisms. One important common adaptation is a shift in AMPAR subunit composition from GluA2-containing, calcium-impermeable AMPARs (CIARs) to GluA2-lacking, calcium-permeable AMPARs (CPARs), which is observed under a broad range of conditions including intoxicant exposure or intake, stress, novelty, food deprivation, and ischemia. This shift has the potential to facilitate AMPAR currents, since CPARs have much greater single-channel currents than CIARs, as well as faster AMPAR activation kinetics (although with faster inactivation) and calcium-related activity. Many tools have been developed to interrogate particular aspects of AMPAR signaling, including compounds that selectively inhibit CPARs, raising exciting translational possibilities. In addition, recent studies have used transgenic animals and/or optogenetics to identify AMPAR adaptations in particular cell types and glutamatergic projections, which will provide critical information about the specific circuits that CPARs act within. Also, less is known about the specific nature of alcohol-related AMPAR adaptations, and thus we use other examples that illustrate more fully how particular AMPAR changes might influence intoxicant-related behavior. Thus, by identifying alcohol-related AMPAR adaptations, the specific molecular events that underlie them, and the cells and projections in which they occur, we hope to better inform the development of new therapeutic interventions for addiction.
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34
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Ion permeation in ionotropic glutamate receptors: Still dynamic after all these years. CURRENT OPINION IN PHYSIOLOGY 2017; 2:36-41. [PMID: 29607422 DOI: 10.1016/j.cophys.2017.12.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that mediate the vast majority of fast synaptic transmission in the nervous system. When the iGluR ion channel is in the open or conducting conformation, it is non-selective for monovalent cations, driving membrane excitation. Often the channel is also permeable to Ca2+. This process of Ca2+ permeation and its physiological and pathological consequences depend strongly on the specific iGluR subtype as well as the specific subunits in the oligomeric complex. Recent evidence has highlighted additional levels of diversity to this process including a dependence on specific auxiliary subunits in non-NMDARs and post-translational modifications in NMDARs. Various de novo missense mutations associated with neurological disease in NMDAR subunits have been identified in regions critical to Ca2+ influx. These features highlight the dynamics of Ca2+ influx mediated by iGluRs and its critical role in synaptic physiology and pathology.
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35
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Han W, Wang H, Li J, Zhang S, Lu W. Ferric Chelate Reductase 1 Like Protein (FRRS1L) Associates with Dynein Vesicles and Regulates Glutamatergic Synaptic Transmission. Front Mol Neurosci 2017; 10:402. [PMID: 29276473 PMCID: PMC5727121 DOI: 10.3389/fnmol.2017.00402] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 11/20/2017] [Indexed: 12/23/2022] Open
Abstract
In the brain, AMPA receptors (AMPARs)-mediated excitatory synaptic transmission is critically regulated by the receptor auxiliary subunits. Recent proteomic studies have identified that Ferric Chelate Reductase 1 Like protein (FRRS1L), whose mutations in human lead to epilepsy, choreoathetosis, and cognitive deficits, is present in native AMPAR complexes in the brain. Here we have characterized FRRS1L in both heterologous cells and in mouse neurons. We found that FRRS1L interacts with both GluA1 and GluA2 subunits of AMPARs, but does not form dimers/oligomers, in HEK cells. In mouse hippocampal neurons, recombinant FRRS1L at the neuronal surface partially co-localizes with GluA1 and primarily localizes at non-synaptic membranes. In addition, native FRRS1L in hippocampus is localized at dynein, but not kinesin5B, vesicles. Functionally, over-expression of FRRS1L in hippocampal neurons does not change glutamatergic synaptic transmission. In contrast, single-cell knockout (KO) of FRRS1L strongly reduces the expression levels of the GluA1 subunit at the neuronal surface, and significantly decreases AMPAR-mediated synaptic transmission in mouse hippocampal pyramidal neurons. Taken together, these data characterize FRRS1L in heterologous cells and neurons, and reveal an important role of FRRS1L in the regulation of excitatory synaptic strength.
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Affiliation(s)
- Wenyan Han
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Huiqing Wang
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States.,Department of Neurosurgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China.,Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jun Li
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Shizhong Zhang
- Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Wei Lu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
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36
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Abstract
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Ionotropic
glutamate receptors (iGluRs) are ligand-gated ion channels
that mediate the majority of excitatory neurotransmission in the central
nervous system. iGluRs open their ion channels in response to binding
of the neurotransmitter glutamate, rapidly depolarize the postsynaptic
neuronal membrane, and initiate signal transduction. Recent studies
using X-ray crystallography and cryo-electron microscopy have determined
full-length iGluR structures that (1) uncover the receptor architecture
in an unliganded, resting state, (2) reveal conformational changes
produced by ligands in order to activate iGluRs, open their ion channels,
and conduct ions, and (3) show how activated, glutamate-bound iGluRs
can adopt a nonconducting desensitized state. These new findings,
combined with the results of previous structural and functional experiments,
kinetic and molecular modeling, mutagenesis, and biochemical analyses,
provide new views on the structural mechanisms of iGluR gating.
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Affiliation(s)
- Edward C Twomey
- Department of Biochemistry and Molecular Biophysics and ‡Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University , 650 West 168th Street, New York, New York 10032, United States
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics and ‡Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University , 650 West 168th Street, New York, New York 10032, United States
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37
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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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38
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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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39
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The Challenge of Interpreting Glutamate-Receptor Ion-Channel Structures. Biophys J 2017; 113:2143-2151. [PMID: 28844473 DOI: 10.1016/j.bpj.2017.07.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/12/2017] [Accepted: 07/25/2017] [Indexed: 11/24/2022] Open
Abstract
Ion channels activated by glutamate mediate excitatory synaptic transmission in the central nervous system. Similar to other ligand-gated ion channels, their gating cycle begins with transitions from a ligand-free closed state to glutamate-bound active and desensitized states. In an attempt to reveal the molecular mechanisms underlying gating, numerous structures for glutamate receptors have been solved in complexes with agonists, antagonists, allosteric modulators, and auxiliary proteins. The embarrassingly rich library of structures emerging from this work reveals very dynamic molecules with a more complex conformational spectrum than anticipated from functional studies. Unanticipated conformations solved for complexes with competitive antagonists and a lack of understanding of the structural basis for ion channel subconductance states further highlight challenges that have yet to be addressed.
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40
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Neuroligins Are Selectively Essential for NMDAR Signaling in Cerebellar Stellate Interneurons. J Neurosci 2017; 36:9070-83. [PMID: 27581450 DOI: 10.1523/jneurosci.1356-16.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 07/16/2016] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED Neuroligins are postsynaptic cell-adhesion molecules that contribute to synapse specification. However, many other postsynaptic cell-adhesion molecules are known and the relative contributions of neuroligins versus other such molecules in different types of synapses and neurons remains largely unknown. Here, we have studied the role of neuroligins in cerebellar stellate interneurons that participate in a well defined circuit that converges on Purkinje cells as the major output neurons of cerebellar cortex. By crossing triple conditional knock-out (cKO) mice targeting all three major neuroligins [neuroligin-1 to neuroligin-3 (NL123)] with parvalbumin-Cre (PV-Cre) transgenic mice, we deleted neuroligins from inhibitory cerebellar interneurons and Purkinje cells, allowing us to study the effects of neuroligin deletions on cerebellar stellate cell synapses by electrophysiology in acute slices. PV-Cre/NL123 cKO mice did not exhibit gross alterations of cerebellar structure or cerebellar interneuron morphology. Strikingly, electrophysiological recordings in stellate cells from these PV-Cre/NL123 cKO mice revealed a large decrease in NMDAR-mediated excitatory synaptic responses, which, in stellate cells, are largely extrasynaptic, without a change in AMPA-receptor-mediated responses. Parallel analyses in PV-Cre/NL1 mice that are single NL1 cKO mice uncovered the same phenotype, demonstrating that NL1 is responsible for recruiting extrasynaptic NMDARs. Moreover, we observed only a modest impairment in inhibitory synaptic responses in stellate cells lacking NL123 despite a nearly complete suppression of inhibitory synaptic transmission in Purkinje cells by the same genetic manipulation. Our results suggest that, unlike other types of neurons investigated, neuroligins are selectively essential in cerebellar stellate interneurons for enabling the function of extrasynaptic NMDARs. SIGNIFICANCE STATEMENT Neuroligins are postsynaptic cell-adhesion molecules genetically linked to autism. However, the contributions of neuroligins to interneuron functions remain largely unknown. Here, we analyzed the role of neuroligins in cerebellar stellate interneurons. We deleted neuroligin-1, neuroligin-2, and neuroligin-3, the major cerebellar neuroligin isoforms, from stellate cells in triple NL123 conditional knock-out mice and analyzed synaptic responses by acute slice electrophysiology. We find that neuroligins are selectively essential for extrasynaptic NMDAR-mediated signaling, but dispensable for both AMPAR-mediated and inhibitory synaptic transmission. Our results reveal a critical and selective role for neuroligins in the regulation of NMDAR responses in cerebellar stellate interneurons.
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41
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Diversity in AMPA receptor complexes in the brain. Curr Opin Neurobiol 2017; 45:32-38. [DOI: 10.1016/j.conb.2017.03.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/28/2017] [Accepted: 03/03/2017] [Indexed: 11/23/2022]
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42
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Bettler B, Fakler B. Ionotropic AMPA-type glutamate and metabotropic GABAB receptors: determining cellular physiology by proteomes. Curr Opin Neurobiol 2017; 45:16-23. [DOI: 10.1016/j.conb.2017.02.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 02/15/2017] [Indexed: 02/07/2023]
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43
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Twomey EC, Yelshanskaya MV, Grassucci RA, Frank J, Sobolevsky AI. Structural Bases of Desensitization in AMPA Receptor-Auxiliary Subunit Complexes. Neuron 2017; 94:569-580.e5. [PMID: 28472657 PMCID: PMC5492975 DOI: 10.1016/j.neuron.2017.04.025] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 04/10/2017] [Accepted: 04/17/2017] [Indexed: 02/09/2023]
Abstract
Fast excitatory neurotransmission is mediated by AMPA-subtype ionotropic glutamate receptors (AMPARs). AMPARs, localized at post-synaptic densities, are regulated by transmembrane auxiliary subunits that modulate AMPAR assembly, trafficking, gating, and pharmacology. Aberrancies in AMPAR-mediated signaling are associated with numerous neurological disorders. Here, we report cryo-EM structures of an AMPAR in complex with the auxiliary subunit GSG1L in the closed and desensitized states. GSG1L favors the AMPAR desensitized state, where channel closure is facilitated by profound structural rearrangements in the AMPAR extracellular domain, with ligand-binding domain dimers losing their local 2-fold rotational symmetry. Our structural and functional experiments suggest that AMPAR auxiliary subunits share a modular architecture and use a common transmembrane scaffold for distinct extracellular modules to differentially regulate AMPAR gating. By comparing the AMPAR-GSG1L complex structures, we map conformational changes accompanying AMPAR recovery from desensitization and reveal structural bases for regulation of synaptic transmission by auxiliary subunits.
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Affiliation(s)
- Edward C Twomey
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168(th) Street, New York, NY 10032, USA; Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University, 650 West 168(th) Street, New York, NY 10032, USA
| | - Maria V Yelshanskaya
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168(th) Street, New York, NY 10032, USA
| | - Robert A Grassucci
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168(th) Street, New York, NY 10032, USA; Howard Hughes Medical Institute, 650 West 168(th) Street, New York, NY 10032, USA
| | - Joachim Frank
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168(th) Street, New York, NY 10032, USA; Department of Biological Sciences, Columbia University, 650 West 168(th) Street, New York, NY 10032, USA; Howard Hughes Medical Institute, 650 West 168(th) Street, New York, NY 10032, USA.
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168(th) Street, New York, NY 10032, USA.
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44
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Greger IH, Watson JF, Cull-Candy SG. Structural and Functional Architecture of AMPA-Type Glutamate Receptors and Their Auxiliary Proteins. Neuron 2017; 94:713-730. [DOI: 10.1016/j.neuron.2017.04.009] [Citation(s) in RCA: 169] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/04/2017] [Accepted: 04/05/2017] [Indexed: 12/20/2022]
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45
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Baucum AJ. Proteomic Analysis of Postsynaptic Protein Complexes Underlying Neuronal Plasticity. ACS Chem Neurosci 2017; 8:689-701. [PMID: 28211672 DOI: 10.1021/acschemneuro.7b00008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Normal neuronal communication and synaptic plasticity at glutamatergic synapses requires dynamic regulation of postsynaptic molecules. Protein expression and protein post-translational modifications regulate protein interactions that underlie this organization. In this Review, we highlight data obtained over the last 20 years that have used qualitative and quantitative proteomics-based approaches to identify postsynaptic protein complexes. Herein, we describe how these proteomics studies have helped lay the foundation for understanding synaptic physiology and perturbations in synaptic signaling observed in different pathologies. We also describe emerging technologies that can be useful in these analyses. We focus on protein complexes associated with the highly abundant and functionally critical proteins: calcium/calmodulin-dependent protein kinase II, the N-methyl-d-aspartate, and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid glutamate receptors, and postsynaptic density protein of 95 kDa.
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Affiliation(s)
- Anthony J. Baucum
- Department of Biology, Stark Neurosciences
Research Institute, Indiana University-Purdue University Indianapolis, 723 W. Michigan St., Indianapolis, Indiana 46202, United States
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46
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Genetic architecture of bone quality variation in layer chickens revealed by a genome-wide association study. Sci Rep 2017; 7:45317. [PMID: 28383518 PMCID: PMC5382839 DOI: 10.1038/srep45317] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 02/23/2017] [Indexed: 11/15/2022] Open
Abstract
Skeletal problems in layer chickens are gaining attention due to animal welfare and economic losses in the egg industry. The genetic improvement of bone traits has been proposed as a potential solution to these issues; however, genetic architecture is not well understood. We conducted a genome-wide association study (GWAS) on bone quality using a sample of 1534 hens genotyped with a 600 K Chicken Genotyping Array. Using a linear mixed model approach, a novel locus close to GSG1L, associated with femur bone mineral density (BMD), was uncovered in this study. In addition, nine SNPs in genes were associated with bone quality. Three of these genes, RANKL, ADAMTS and SOST, were known to be associated with osteoporosis in humans, which makes them good candidate genes for osteoporosis in chickens. Genomic partitioning analysis supports the fact that common variants contribute to the variations of bone quality. We have identified several strong candidate genes and genomic regions associated with bone traits measured in end-of-lay cage layers, which accounted for 1.3–7.7% of the phenotypic variance. These SNPs could provide the relevant information to help elucidate which genes affect bone quality in chicken.
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47
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Azumaya CM, Days EL, Vinson PN, Stauffer S, Sulikowski G, Weaver CD, Nakagawa T. Screening for AMPA receptor auxiliary subunit specific modulators. PLoS One 2017; 12:e0174742. [PMID: 28358902 PMCID: PMC5373622 DOI: 10.1371/journal.pone.0174742] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 03/14/2017] [Indexed: 12/18/2022] Open
Abstract
AMPA receptors (AMPAR) are ligand gated ion channels critical for synaptic transmission and plasticity. Their dysfunction is implicated in a variety of psychiatric and neurological diseases ranging from major depressive disorder to amyotrophic lateral sclerosis. Attempting to potentiate or depress AMPAR activity is an inherently difficult balancing act between effective treatments and debilitating side effects. A newly explored strategy to target subsets of AMPARs in the central nervous system is to identify compounds that affect specific AMPAR-auxiliary subunit complexes. This exploits diverse spatio-temporal expression patterns of known AMPAR auxiliary subunits, providing means for designing brain region-selective compounds. Here we report a high-throughput screening-based pipeline that can identify compounds that are selective for GluA2-CNIH3 and GluA2-stargazin complexes. These compounds will help us build upon the growing library of AMPAR-auxiliary subunit specific inhibitors, which have thus far all been targeted to TARP γ-8. We used a cell-based assay combined with a voltage-sensitive dye (VSD) to identify changes in glutamate-gated cation flow across the membranes of HEK cells co-expressing GluA2 and an auxiliary subunit. We then used a calcium flux assay to further validate hits picked from the VSD assay. VU0612951 and VU0627849 are candidate compounds from the initial screen that were identified as negative and positive allosteric modulators (NAM and PAM), respectively. They both have lower IC50/EC50s on complexes containing stargazin and CNIH3 than GSG1L or the AMPAR alone. We have also identified a candidate compound, VU0539491, that has NAM activity in GluA2(R)-CNIH3 and GluA2(Q) complexes and PAM activity in GluA2(Q)-GSG1L complexes.
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Affiliation(s)
- Caleigh M Azumaya
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Emily L Days
- Vanderbilt Institute of Chemical Biology High Throughput Screening Core, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Paige N Vinson
- Vanderbilt Institute of Chemical Biology High Throughput Screening Core, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Shaun Stauffer
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States of America.,Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Gary Sulikowski
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, United States of America
| | - C David Weaver
- Vanderbilt Institute of Chemical Biology High Throughput Screening Core, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America.,Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Terunaga Nakagawa
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America.,Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America.,Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
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48
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Mao X, Gu X, Lu W. GSG1L regulates the strength of AMPA receptor-mediated synaptic transmission but not AMPA receptor kinetics in hippocampal dentate granule neurons. J Neurophysiol 2016; 117:28-35. [PMID: 27707810 DOI: 10.1152/jn.00307.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 10/03/2016] [Indexed: 11/22/2022] Open
Abstract
GSG1L is an AMPA receptor (AMPAR) auxiliary subunit that regulates AMPAR trafficking and function in hippocampal CA1 pyramidal neurons. However, its physiological roles in other types of neurons remain to be characterized. Here, we investigated the role of GSG1L in hippocampal dentate granule cells and found that GSG1L is important for the regulation of synaptic strength but is not critical for the modulation of AMPAR deactivation and desensitization kinetics. These data demonstrate a neuronal type-specific role of GSG1L and suggest that physiological function of AMPAR auxiliary subunits may vary in different types of neurons. NEW & NOTEWORTHY GSG1L is a newly identified AMPA receptor (AMPAR) auxiliary subunit and plays a unique role in the regulation of AMPAR trafficking and function in hippocampal CA1 pyramidal neurons. However, its role in the regulation of AMPARs in hippocampal dentate granule cells remains to be characterized. The current work reveals that GSG1L regulates strength of AMPAR-mediated synaptic transmission but not the receptor kinetic properties in hippocampal dentate granule neurons.
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Affiliation(s)
- Xia Mao
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Xinglong Gu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Wei Lu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
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