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Bergler F, Fuentes C, Kadir MF, Navarrete C, Supple J, Barrera NP, Edwardson JM. Activation of P2X4 receptors induces an increase in the area of the extracellular region and a decrease in receptor mobility. FEBS Lett 2020; 594:4381-4389. [PMID: 32979222 DOI: 10.1002/1873-3468.13942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 09/15/2020] [Indexed: 11/09/2022]
Abstract
The P2X4 receptor (P2X4R) is an ATP-gated cation channel. Here, we used fast-scan atomic force microscopy (AFM) to visualize changes in the structure and mobility of individual P2X4Rs in response to activation. P2X4Rs were purified from detergent extracts of transfected cells and integrated into lipid bilayers. Activation resulted in a rapid (2 s) and substantial (10-20 nm2 ) increase in the cross-sectional area of the extracellular region of the receptor and a corresponding decrease in receptor mobility. Both effects were blocked by the P2X4R antagonist 5-BDBD. Addition of cholesterol to the bilayer reduced receptor mobility, although the ATP-induced reduction in mobility was still observed. We suggest that the observed responses to activation may have functional consequences for purinergic signalling.
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Affiliation(s)
- Frederik Bergler
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Christian Fuentes
- Department of Pharmacology, University of Cambridge, Cambridge, UK.,Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Md Fahim Kadir
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Camilo Navarrete
- Department of Pharmacology, University of Cambridge, Cambridge, UK.,Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jack Supple
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Nelson P Barrera
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
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2
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Dawe GB, Kadir MF, Venskutonytė R, Perozzo AM, Yan Y, Alexander RP, Navarrete C, Santander EA, Arsenault M, Fuentes C, Aurousseau MR, Frydenvang K, Barrera NP, Kastrup JS, Edwardson JM, Bowie D. Nanoscale Mobility of the Apo State and TARP Stoichiometry Dictate the Gating Behavior of Alternatively Spliced AMPA Receptors. Neuron 2019; 102:976-992.e5. [DOI: 10.1016/j.neuron.2019.03.046] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 03/08/2019] [Accepted: 03/28/2019] [Indexed: 12/19/2022]
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3
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Batova AS, Bugay AN, Dushanov EB. Effect of mutant NMDA receptors on the oscillations in a model of hippocampus. J Bioinform Comput Biol 2019; 17:1940003. [PMID: 30866729 DOI: 10.1142/s0219720019400031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A computation approach to identify the effect of missense mutations on the protein function is proposed. Using molecular dynamics simulation we have analyzed the gating kinetics of mutant NMDA synaptic receptors carrying mutations in their NR2 subunits. Analysis of channel geometry and Mg ion binding allowed to estimate the receptor conductivity. As a result, it was possible to identify the effect of these mutations on the generation of theta and gamma rhythms by the hippocampal neural network. Obtained results can be adapted for the analysis and evaluation of possible cognitive impairments caused by neurological diseases or consequences of radiation and other negative factors.
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Affiliation(s)
- Anna Sergeevna Batova
- * Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna 141980, Moscow, Russia.,† Dubna State University, Universitetskaya St. 19, Dubna 141982, Moscow, Russia
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4
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Cui SJ, Fu Y, Liu Y, Kou XX, Zhang JN, Gan YH, Zhou YH, Wang XD. Chronic inflammation deteriorates structure and function of collagen fibril in rat temporomandibular joint disc. Int J Oral Sci 2019; 11:2. [PMID: 30783108 PMCID: PMC6381164 DOI: 10.1038/s41368-018-0036-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 08/23/2018] [Accepted: 08/28/2018] [Indexed: 11/09/2022] Open
Abstract
Collagen is the building component of temporomandibular joint (TMJ) discs and is often affected by inflammation in temporomandibular disorders. The macromechanical properties of collagen are deteriorated by chronic inflammation. However, the mechanism by which inflammation influences disc function remains unknown. The relationship between the ultrastructure and nanomechanical properties of collagen in inflamed discs should be clarified. Seven-week-old female Sprague-Dawley rats were randomly divided into two groups. Chronic TMJ inflammation was induced by intra-articular injection of complete Freund's adjuvant, and samples were harvested after 5 weeks. Picrosirius staining revealed multiple colours under polarized light, which represented alternative collagen bundles in inflamed discs. Using atomic force microscopy scanning, the magnitude of Young's modulus was reduced significantly accompanied with disordered collagen fibril arrangement with porous architecture of inflamed discs. Transmission electron microscopy scanning revealed a non-uniform distribution of collagen fibres, and oversized collagen fibrils were observed in inflamed discs. Fourier transform infrared microspectroscopy revealed a decrease in 1 338 cm-1/amide II area ratio of collagen in different regions. The peak positions of amide I and amide II bands were altered in inflamed discs, indicating collagen unfolding. Our results suggest that sustained inflammation deteriorates collagen structures, resulting in the deterioration of the ultrastructure and nanomechanical properties of rat TMJ discs.
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Affiliation(s)
- Sheng-Jie Cui
- Department of Orthodontics, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China.,Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China
| | - Yu Fu
- Department of Orthodontics, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China.,Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China
| | - Yan Liu
- Department of Orthodontics, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China.,Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China
| | - Xiao-Xing Kou
- Department of Orthodontics, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China.,Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China
| | - Jie-Ni Zhang
- Department of Orthodontics, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China.,Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China
| | - Ye-Hua Gan
- Center for Temporomandibular Disorders and Orofacial Pain, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China
| | - Yan-Heng Zhou
- Department of Orthodontics, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China. .,Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China.
| | - Xue-Dong Wang
- Department of Orthodontics, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China. .,Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, 22# Zhongguancun South Avenue, Haidian District, Beijing, China.
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5
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Montenegro FA, Cantero JR, Barrera NP. Combining Mass Spectrometry and X-Ray Crystallography for Analyzing Native-Like Membrane Protein Lipid Complexes. Front Physiol 2017; 8:892. [PMID: 29170643 PMCID: PMC5684187 DOI: 10.3389/fphys.2017.00892] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/24/2017] [Indexed: 01/22/2023] Open
Abstract
Membrane proteins represent a challenging family of macromolecules, particularly related to the methodology aimed at characterizing their three-dimensional structure. This is mostly due to their amphipathic nature as well as requirements of ligand bindings to stabilize or control their function. Recently, Mass Spectrometry (MS) has become an important tool to identify the overall stoichiometry of native-like membrane proteins complexed to ligand bindings as well as to provide insights into the transport mechanism across the membrane, with complementary information coming from X-ray crystallography. This perspective article emphasizes MS findings coupled with X-ray crystallography in several membrane protein lipid complexes, in particular transporters, ion channels and molecular machines, with an overview of techniques that allows a more thorough structural interpretation of the results, which can help us to unravel hidden mysteries on the membrane protein function.
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Affiliation(s)
- Felipe A Montenegro
- Laboratory of Nanophysiology and Structural Biology, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jorge R Cantero
- Laboratory of Nanophysiology and Structural Biology, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nelson P Barrera
- Laboratory of Nanophysiology and Structural Biology, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
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6
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Xu M, Fan Q, Zhang J, Chen Y, Xu R, Chen L, Zhao P, Tian Y. NFAT3/c4-mediated excitotoxicity in hippocampal apoptosis during radiation-induced brain injury. JOURNAL OF RADIATION RESEARCH 2017; 58:827-833. [PMID: 28992110 PMCID: PMC5710526 DOI: 10.1093/jrr/rrx041] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Indexed: 05/09/2023]
Abstract
Whole brain irradiation (WBI) has become an indispensible tool in the treatment of head and neck cancer, and it has greatly improved patient survival rate and total survival time. In addition, prophylactic cranial irradiation (PCI) has dramatically decreased the incidence of brain metastatic carcinoma. However, WBI may induce temporary functional deficits or even progressive, irreversible cognitive dysfunction that compromises the quality of life for survivors. Unfortunately, the exact molecular mechanisms for cognitive damage remain elusive, and no treatment or preventative measures are available for use in the clinic. In the present study, the nuclear factor of activated T cells isoform 4 (NFAT3/c4) was found to play a vital role in excitotoxic hippocampus cell apoptosis induced by radiation. Sprague-Dawley (SD) rats received 20 Gy WBI, after which we detected NFAT3/c4-mediated excitotoxicity. We found that radiation caused hippocampus excitotoxicity, resulting from overactivation of the N-methyl-D-aspartate receptor (NMDAR) and always accompanied by subsequent elevation of the intracellular calcium level and activation of calcineurin (CaN). P-NFAT3/c4 was the principal downstream target of CaN, including regulation of its nuclear translocation as well as transcriptional activities. Radiation recruited NMDAR/NFAT3/c4 activation and subsequent Bax induction in hippocampus cells. Once treated with the NFAT3/c4 inhibitor 11R-VIVIT peptide pre-irradiation, hippocampal proliferation and neuron survival (dentate gyrus cells in particular) were protected from radiation-induced injury, resulting in inhibition of the apoptosis marker Bax. Our principal aim was to illuminate the role of NFAT3/c4-mediated excitotoxicity in hippocampal apoptosis during radiation-induced brain injury. This study is the first time that radiation-induced activation of NFAT3/c4 has been recorded, and our results suggest that NFAT3/c4 may be a novel target for prevention and treatment of radiation-induced brain injury.
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Affiliation(s)
- Meiling Xu
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, San Xiang Road No. 1055, Suzhou, Jiangsu 215004, China
| | - Qiuhong Fan
- Institute of Radiotherapy & Oncology, Soochow University
| | - Junjun Zhang
- Suzhou Key Laboratory for Radiation Oncology, San Xiang Road No. 1055, Suzhou 215004, China
| | - Yanfang Chen
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, San Xiang Road No. 1055, Suzhou, Jiangsu 215004, China
| | - Ruizhe Xu
- Institute of Radiotherapy & Oncology, Soochow University
| | - Liesong Chen
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, San Xiang Road No. 1055, Suzhou, Jiangsu 215004, China
| | - Peifeng Zhao
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, San Xiang Road No. 1055, Suzhou, Jiangsu 215004, China
| | - Ye Tian
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, San Xiang Road No. 1055, Suzhou, Jiangsu 215004, China
- Corresponding author. Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, San Xiang Road No. 1055, Suzhou, Jiangsu 215004, China. Tel.: +86-512-6778-3430; Fax: +86-512-6828-4303; E-mail:
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7
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SUMINO A, YAMAMOTO D, SUMIKAMA T, IWAMOTO M, DEWA T, OIKI S. Structure and Dynamics of Membrane-embedded KcsA Potassium Channel Revealed by Atomic Force Microscopy. ACTA ACUST UNITED AC 2015. [DOI: 10.2142/biophys.55.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Ayumi SUMINO
- PRESTO, Japan Science and Technology Agency (JST)
- Department of Molecular Physiology and Biophysics, Faculty of Medical Sciences, University of Fukui
| | | | - Takashi SUMIKAMA
- Department of Molecular Physiology and Biophysics, Faculty of Medical Sciences, University of Fukui
| | - Masayuki IWAMOTO
- Department of Molecular Physiology and Biophysics, Faculty of Medical Sciences, University of Fukui
| | - Takehisa DEWA
- Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology
| | - Shigetoshi OIKI
- Department of Molecular Physiology and Biophysics, Faculty of Medical Sciences, University of Fukui
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8
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Henderson RM. Structural dynamics of single molecules studied with high-speed atomic force microscopy. Expert Opin Drug Discov 2014; 10:221-9. [DOI: 10.1517/17460441.2015.998195] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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9
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Yoshida A, Sakai N, Uekusa Y, Deguchi K, Gilmore JL, Kumeta M, Ito S, Takeyasu K. Probing in vivo dynamics of mitochondria and cortical actin networks using high-speed atomic force/fluorescence microscopy. Genes Cells 2014; 20:85-94. [PMID: 25440894 DOI: 10.1111/gtc.12204] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 10/06/2014] [Indexed: 12/12/2022]
Abstract
The dynamics of the cell membrane and submembrane structures are closely linked, facilitating various cellular activities. Although cell surface research and cortical actin studies have shown independent mechanisms for the cell membrane and the actin network, it has been difficult to obtain a comprehensive understanding of the dynamics of these structures in live cells. Here, we used a combined atomic force/optical microscope system to analyze membrane-based cellular events at nanometer-scale resolution in live cells. Imaging the COS-7 cell surface showed detailed structural properties of membrane invagination events corresponding to endocytosis and exocytosis. In addition, the movement of mitochondria and the spatiotemporal dynamics of the cortical F-actin network were directly visualized in vivo. Cortical actin microdomains with sizes ranging from 1.7×10(4) to 1.4×10(5) nm2 were dynamically rearranged by newly appearing actin filaments, which sometimes accompanied membrane invaginations, suggesting that these events are integrated with the dynamic regulation of submembrane organizations maintained by actin turnovers. These results provide novel insights into the structural aspects of the entire cell membrane machinery which can be visualized with high temporal and spatial resolution.
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Affiliation(s)
- Aiko Yoshida
- Graduate School of Biostudies, Kyoto University, Yoshida-konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
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10
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Ando T. High-speed AFM imaging. Curr Opin Struct Biol 2014; 28:63-8. [DOI: 10.1016/j.sbi.2014.07.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 07/22/2014] [Accepted: 07/22/2014] [Indexed: 11/26/2022]
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11
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Balasuriya D, Takahashi H, Srivats S, Edwardson JM. Activation-induced structural change in the GluN1/GluN3A excitatory glycine receptor. Biochem Biophys Res Commun 2014; 450:1452-7. [PMID: 25017909 DOI: 10.1016/j.bbrc.2014.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 07/02/2014] [Indexed: 11/26/2022]
Abstract
Unlike GluN2-containing N-methyl-d-aspartate (NMDA) receptors, which require both glycine and glutamate for activation, receptors composed of GluN1 and GluN3 subunits are activated by glycine alone. Here, we used atomic force microscopy (AFM) imaging to examine the response to activation of the GluN1/GluN3A excitatory glycine receptor. GluN1 and GluN3A subunits were shown to interact intimately within transfected tsA 201 cells. Isolated GluN1/GluN3A receptors integrated into lipid bilayers responded to addition of either glycine or d-serine, but not glutamate, with a ∼1 nm reduction in height of the extracellular domain. The height reduction in response to glycine was abolished by the glycine antagonist 5,7-dichlorokynurenic acid. Our results represent the first demonstration of the effect of activation on the conformation of this receptor.
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Affiliation(s)
- Dilshan Balasuriya
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Hirohide Takahashi
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Shyam Srivats
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - J Michael Edwardson
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom.
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12
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Ando T, Uchihashi T, Scheuring S. Filming biomolecular processes by high-speed atomic force microscopy. Chem Rev 2014; 114:3120-88. [PMID: 24476364 PMCID: PMC4076042 DOI: 10.1021/cr4003837] [Citation(s) in RCA: 239] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Indexed: 12/21/2022]
Affiliation(s)
- Toshio Ando
- Department of Physics, and Bio-AFM Frontier
Research Center, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
- CREST,
Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi 332-0012, Japan
| | - Takayuki Uchihashi
- Department of Physics, and Bio-AFM Frontier
Research Center, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
- CREST,
Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi 332-0012, Japan
| | - Simon Scheuring
- U1006
INSERM/Aix-Marseille Université, Parc Scientifique et Technologique
de Luminy Bâtiment Inserm TPR2 bloc 5, 163 avenue de Luminy, 13288 Marseille Cedex 9, France
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13
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Dai J, Zhou HX. An NMDA receptor gating mechanism developed from MD simulations reveals molecular details underlying subunit-specific contributions. Biophys J 2013; 104:2170-81. [PMID: 23708357 DOI: 10.1016/j.bpj.2013.04.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/09/2013] [Accepted: 04/10/2013] [Indexed: 12/22/2022] Open
Abstract
N-methyl-D-aspartate (NMDA) receptors are obligate heterotetrameric ligand-gated ion channels that play critical roles in learning and memory. Here, using targeted molecular dynamics simulations, we developed an atomistic model for the gating of the GluN1/GluN2A NMDA receptor. Upon agonist binding, lobe closure of the ligand-binding domain produced outward pulling of the M3-D2 linkers, leading to outward movements of the C-termini of the pore-lining M3 helices and opening of the channel. The GluN2A subunits, similar to the distal (B/D) subunits in the homotetrameric GluA2 α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionate receptor, had greater M3 outward movements and thus contributed more to channel gating than the GluN1 subunits. Our gating model is validated by functional studies, including cysteine modification data indicating wider accessibility to the GluN1 M3 helices than to the GluN2A M3 helices from the lumen of the open channel, and reveals why the Lurcher mutation in GluN1 has a stronger ability in maintaining channel opening than the counterpart in GluN2A. The resulting structural model for the open state provides an explanation for the Ca(2+) permeability of NMDA receptors, and the structural differences between the closed and open states form the basis for drug design.
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Affiliation(s)
- Jian Dai
- Department of Physics and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA
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14
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Sirrieh RE, MacLean DM, Jayaraman V. Amino-terminal domain tetramer organization and structural effects of zinc binding in the N-methyl-D-aspartate (NMDA) receptor. J Biol Chem 2013; 288:22555-64. [PMID: 23792960 PMCID: PMC3829342 DOI: 10.1074/jbc.m113.482356] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/19/2013] [Indexed: 12/31/2022] Open
Abstract
N-Methyl-D-aspartate (NMDA) receptors mediate excitatory neurotransmission in the mammalian central nervous system. An important feature of these receptors is their capacity for allosteric regulation by small molecules, such as zinc, which bind to their amino-terminal domain (ATD). Zinc inhibition through high affinity binding to the ATD has been examined through functional studies; however, there is no direct measurement of associated conformational changes. We used luminescence resonance energy transfer to show that the ATDs undergo a cleft closure-like conformational change upon binding zinc, but no changes are observed in intersubunit distances. Furthermore, we find that the ATDs are more closely packed than the related AMPA receptors. These results suggest that the stability of the upper lobe contacts between ATDs allow for the efficient propagation of the cleft closure conformational change toward the ligand-binding domain and transmembrane segments, ultimately inhibiting the channel.
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Affiliation(s)
- Rita E. Sirrieh
- From the Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, Texas 77030
| | - David M. MacLean
- From the Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, Texas 77030
| | - Vasanthi Jayaraman
- From the Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center, Houston, Texas 77030
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15
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Balasuriya D, Goetze TA, Barrera NP, Stewart AP, Suzuki Y, Edwardson JM. α-Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors adopt different subunit arrangements. J Biol Chem 2013; 288:21987-98. [PMID: 23760273 PMCID: PMC3724652 DOI: 10.1074/jbc.m113.469205] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Ionotropic glutamate receptors are widely distributed in the central nervous system and play a major role in excitatory synaptic transmission. All three ionotropic glutamate subfamilies (i.e. AMPA-type, kainate-type, and NMDA-type) assemble as tetramers of four homologous subunits. There is good evidence that both heteromeric AMPA and kainate receptors have a 2:2 subunit stoichiometry and an alternating subunit arrangement. Recent studies based on presumed structural homology have indicated that NMDA receptors adopt the same arrangement. Here, we use atomic force microscopy imaging of receptor-antibody complexes to show that whereas the GluA1/GluA2 AMPA receptor assembles with an alternating (i.e. 1/2/1/2) subunit arrangement, the GluN1/GluN2A NMDA receptor adopts an adjacent (i.e. 1/1/2/2) arrangement. We conclude that the two types of ionotropic glutamate receptor are built in different ways from their constituent subunits. This surprising finding necessitates a reassessment of the assembly of these important receptors.
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Affiliation(s)
- Dilshan Balasuriya
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
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