1
|
YE J, LI X, PAN Z, WU Z, ZHU Y, ZHANG W, LU J, XU S, QIN P, LIU Y, LI Y, LING Y, FANG F. Grid1 regulates the onset of puberty in female rats. J Vet Med Sci 2024; 86:497-506. [PMID: 38479882 PMCID: PMC11144544 DOI: 10.1292/jvms.23-0208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 02/26/2024] [Indexed: 05/08/2024] Open
Abstract
The study aimed to investigate the effect of Grid1, encoding the glutamate ionotropic receptor delta type subunit 1 (GluD1), on puberty onset in female rats. Grid1 mRNA and protein expression was detected in the hypothalamus of female rats at prepuberty and puberty. The levels of Grid1 mRNA in the hypothalamus, the fluorescence intensity in the arcuate nucleus and paraventricular nucleus of the prepubertal rats was significantly lower than pubertal. Additionally, the expression of Grid1 was suppressed in primary hypothalamus cells and prepubertal rat. Finally, investigated the effect of Grid1 knockdown on puberty onset and reproductive performance. Treatment of hypothalamic neurons with LV-Grid1 decreased the level of Grid1 and Rfrp-3 (encoding RFamide-related peptide 3) mRNA expression, but increased the Gnrh (encoding gonadotropin-releasing hormone) mRNA levels. After an ICV injection, the time for the rat vaginal opening occurred earlier. Moreover, Gnrh mRNA expression was increased, whereas Rfrp-3 mRNA expression was decreased in the hypothalamus. The concentration of progesterone (P4) in the serum was significantly decreased compare with control group. Ovary hematoxylin-eosin staining revealed that the LV-Grid1 group mainly contained primary and secondary follicles. The reproductive performance of the rats was not affected by the Grid1 knockdown. Therefore, Grid1 may affect the onset of puberty in female rats by regulating the levels of Gnrh, and Rfrp-3 in the hypothalamus, as well as the concentrations of P4, but not reproduction performance.
Collapse
Affiliation(s)
- Jing YE
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| | - Xiaoqian LI
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| | - Zhihao PAN
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| | - Zhuoya WU
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| | - Yanyun ZHU
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| | - Wei ZHANG
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| | - Juntai LU
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| | - Shuangshuang XU
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| | - Ping QIN
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| | - Ya LIU
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| | - Yunsheng LI
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| | - Yinghui LING
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, Anhui, China
| | - Fugui FANG
- Anhui Provincial Laboratory of Animal Genetic Resources Protection and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Anhui,
China
- Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, Anhui, China
- Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, Anhui, China
| |
Collapse
|
2
|
Ung DC, Pietrancosta N, Badillo EB, Raux B, Tapken D, Zlatanovic A, Doridant A, Pode-Shakked B, Raas-Rothschild A, Elpeleg O, Abu-Libdeh B, Hamed N, Papon MA, Marouillat S, Thépault RA, Stevanin G, Elegheert J, Letellier M, Hollmann M, Lambolez B, Tricoire L, Toutain A, Hepp R, Laumonnier F. GRID1/GluD1 homozygous variants linked to intellectual disability and spastic paraplegia impair mGlu1/5 receptor signaling and excitatory synapses. Mol Psychiatry 2024; 29:1205-1215. [PMID: 38418578 PMCID: PMC11176079 DOI: 10.1038/s41380-024-02469-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 01/23/2024] [Accepted: 01/30/2024] [Indexed: 03/01/2024]
Abstract
The ionotropic glutamate delta receptor GluD1, encoded by the GRID1 gene, is involved in synapse formation, function, and plasticity. GluD1 does not bind glutamate, but instead cerebellin and D-serine, which allow the formation of trans-synaptic bridges, and trigger transmembrane signaling. Despite wide expression in the nervous system, pathogenic GRID1 variants have not been characterized in humans so far. We report homozygous missense GRID1 variants in five individuals from two unrelated consanguineous families presenting with intellectual disability and spastic paraplegia, without (p.Thr752Met) or with (p.Arg161His) diagnosis of glaucoma, a threefold phenotypic association whose genetic bases had not been elucidated previously. Molecular modeling and electrophysiological recordings indicated that Arg161His and Thr752Met mutations alter the hinge between GluD1 cerebellin and D-serine binding domains and the function of this latter domain, respectively. Expression, trafficking, physical interaction with metabotropic glutamate receptor mGlu1, and cerebellin binding of GluD1 mutants were not conspicuously altered. Conversely, upon expression in neurons of dissociated or organotypic slice cultures, we found that both GluD1 mutants hampered metabotropic glutamate receptor mGlu1/5 signaling via Ca2+ and the ERK pathway and impaired dendrite morphology and excitatory synapse density. These results show that the clinical phenotypes are distinct entities segregating in the families as an autosomal recessive trait, and caused by pathophysiological effects of GluD1 mutants involving metabotropic glutamate receptor signaling and neuronal connectivity. Our findings unravel the importance of GluD1 receptor signaling in sensory, cognitive and motor functions of the human nervous system.
Collapse
Affiliation(s)
- Dévina C Ung
- UMR 1253, iBrain, Université de Tours, Inserm, 37032, Tours, France
| | - Nicolas Pietrancosta
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
- Laboratoire des biomolécules, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | | | - Brigitt Raux
- Univ. Bordeaux, CNRS, IINS, UMR 5297, F-33000, Bordeaux, France
| | - Daniel Tapken
- Department of Biochemistry I - Receptor Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, D-44780, Bochum, Germany
| | - Andjela Zlatanovic
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
| | - Adrien Doridant
- Univ. Bordeaux, CNRS, IINS, UMR 5297, F-33000, Bordeaux, France
| | - Ben Pode-Shakked
- The Institute for Rare Diseases, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hahsomer, 5262000, Israel
- Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, 5262000, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - Annick Raas-Rothschild
- The Institute for Rare Diseases, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hahsomer, 5262000, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - Orly Elpeleg
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Bassam Abu-Libdeh
- Department of Pediatrics, Makassed Hospital and Faculty of Medicine, Al-Quds University, East Jerusalem, Jerusalem, Palestine
| | - Nasrin Hamed
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel
- Pediatric Neurology Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hahsomer, 5262000, Israel
| | | | | | | | - Giovanni Stevanin
- Univ. Bordeaux, INCIA, UMR 5287 CNRS EPHE, F-33000, Bordeaux, France
| | | | | | - Michael Hollmann
- Department of Biochemistry I - Receptor Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, D-44780, Bochum, Germany
| | - Bertrand Lambolez
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
| | - Ludovic Tricoire
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
| | - Annick Toutain
- UMR 1253, iBrain, Université de Tours, Inserm, 37032, Tours, France.
- Unité fonctionnelle de Génétique Médicale, Centre Hospitalier Universitaire, 37044, Tours, France.
| | - Régine Hepp
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France.
| | - Frédéric Laumonnier
- UMR 1253, iBrain, Université de Tours, Inserm, 37032, Tours, France.
- Service de Génétique, Centre Hospitalier Universitaire, 37044, Tours, France.
| |
Collapse
|
3
|
Allen JP, Garber KB, Perszyk R, Khayat CT, Kell SA, Kaneko M, Quindipan C, Saitta S, Ladda RL, Hewson S, Inbar-Feigenberg M, Prasad C, Prasad AN, Olewiler L, Mu W, Rosenthal LS, Scala M, Striano P, Zara F, McCullock TW, Jauss RT, Lemke JR, MacLean DM, Zhu C, Yuan H, Myers SJ, Traynelis SF. Clinical features, functional consequences, and rescue pharmacology of missense GRID1 and GRID2 human variants. Hum Mol Genet 2024; 33:355-373. [PMID: 37944084 PMCID: PMC10840383 DOI: 10.1093/hmg/ddad188] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/28/2023] [Accepted: 10/20/2023] [Indexed: 11/12/2023] Open
Abstract
GRID1 and GRID2 encode the enigmatic GluD1 and GluD2 proteins, which form tetrameric receptors that play important roles in synapse organization and development of the central nervous system. Variation in these genes has been implicated in neurodevelopmental phenotypes. We evaluated GRID1 and GRID2 human variants from the literature, ClinVar, and clinical laboratories and found that many of these variants reside in intolerant domains, including the amino terminal domain of both GRID1 and GRID2. Other conserved regions, such as the M3 transmembrane domain, show different intolerance between GRID1 and GRID2. We introduced these variants into GluD1 and GluD2 cDNA and performed electrophysiological and biochemical assays to investigate the mechanisms of dysfunction of GRID1/2 variants. One variant in the GRID1 distal amino terminal domain resides at a position predicted to interact with Cbln2/Cbln4, and the variant disrupts complex formation between GluD1 and Cbln2, which could perturb its role in synapse organization. We also discovered that, like the lurcher mutation (GluD2-A654T), other rare variants in the GRID2 M3 domain create constitutively active receptors that share similar pathogenic phenotypes. We also found that the SCHEMA schizophrenia M3 variant GluD1-A650T produced constitutively active receptors. We tested a variety of compounds for their ability to inhibit constitutive currents of GluD receptor variants and found that pentamidine potently inhibited GluD2-T649A constitutive channels (IC50 50 nM). These results identify regions of intolerance to variation in the GRID genes, illustrate the functional consequences of GRID1 and GRID2 variants, and suggest how these receptors function normally and in disease.
Collapse
Affiliation(s)
- James P Allen
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
| | - Kathryn B Garber
- Department of Human Genetics, Emory University School of Medicine, 615 Michael St., Atlanta GA 30322, United States
- EGL Genetics, 2460 Mountain Industrial Blvd., Tucker, GA 30084, United States
| | - Riley Perszyk
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
| | - Cara T Khayat
- Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Drive, Atlanta, GA 30332, United States
| | - Steven A Kell
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Department of Chemistry, Emory University School of Medicine, 1515 Dickey Dr, Atlanta, GA 30322, United States
| | - Maki Kaneko
- Division of Genomic Medicine, Department of Pathology, Children’s Hospital Los Angeles, 4650 Sunset Blvd, Los Angeles, CA 90027, United States
- Center for Personalized Medicine, Children’s Hospital Los Angeles, 4650 Sunset Blvd, Los Angeles, CA 90027, United States
| | - Catherine Quindipan
- Center for Personalized Medicine, Children’s Hospital Los Angeles, 4650 Sunset Blvd, Los Angeles, CA 90027, United States
| | - Sulagna Saitta
- Division of Clinical Genetics, Departments of Human Genetics, OBGYN and Pediatrics, David Geffen School of Medicine at UCLA, 200 Medical Plaza, Los Angeles, CA 90095, United States
| | - Roger L Ladda
- Division of Human Genetics, Department of Pediatrics, Penn State College of Medicine, 600 University Dr, Hershey, PA 17033, United States
| | - Stacy Hewson
- Department of Genetic Counselling, The Hospital for Sick Children and Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5G 1X8, Canada
| | - Michal Inbar-Feigenberg
- Division of Clinical & Metabolic Genetics, The Hospital for Sick Children and Pediatrics, University of Toronto, 555 University Avenue, Toronto ON M5G 1X8, Canada
| | - Chitra Prasad
- Department of Pediatrics (Section of Genetics and Metabolism), Western University and Schulich School of Medicine and Dentistry, Children’s Hospital LHSC, 800 Commissioners Road East, London, ON N6A5W9, Canada
| | - Asuri N Prasad
- Division of Pediatric Neurology, Department of Pediatrics and Clinical Neurological Sciences, Western University and Schulich School of Medicine and Dentistry, Children’s Hospital LHSC, 800 Commissioners Road East, London, ON N6A5W9, Canada
| | - Leah Olewiler
- Department of Pediatrics, Division of Medical Genetics, University of Mississippi Medical Center, 2500 N. State St., Jackson, MS 39216, United States
| | - Weiyi Mu
- Department of Genetic Medicine, Johns Hopkins University, 600 N. Wolfe St., Baltimore MD 21287, United States
| | - Liana S Rosenthal
- Department of Neurology, Johns Hopkins University, 601 N. Caroline St., Baltimore MD 21287, United States
| | - Marcello Scala
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università Degli Studi di Genova, Largo Paolo Daneo, 3, 16132 Genova GE, Italy
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Pavilion 16, Via Gerolamo Gaslini, 516147 Genoa GE, Italy
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università Degli Studi di Genova, Largo Paolo Daneo, 3, 16132 Genova GE, Italy
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Pavilion 16, Via Gerolamo Gaslini, 516147 Genoa GE, Italy
| | - Federico Zara
- Medical Genetics Unit, IRCCS Istituto Giannina Gaslini, Pavilion 20, Via Gerolamo Gaslini, 516147 Genoa GE, Italy
| | - Tyler W McCullock
- Department Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester NY, 14642, United States
| | - Robin-Tobias Jauss
- Institute of Human Genetics, University of Leipzig Medical Center, Philipp-Rosenthal-Str. 55, Haus W, Leipzig 04103, Germany
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Philipp-Rosenthal-Str. 55, Haus W, Leipzig 04103, Germany
| | - David M MacLean
- Department Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester NY, 14642, United States
| | - Cheng Zhu
- Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Drive, Atlanta, GA 30332, United States
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
| | - Scott J Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322, United States
- Emory Neurodegenerative Disease Center, 615 Michael St., Emory University School of Medicine, Atlanta, GA 30322, United States
| |
Collapse
|
4
|
Kumar J, Popescu GK, Gantz SC. GluD receptors are functional ion channels. Biophys J 2023; 122:2383-2395. [PMID: 37177782 PMCID: PMC10323023 DOI: 10.1016/j.bpj.2023.05.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/27/2023] [Accepted: 05/09/2023] [Indexed: 05/15/2023] Open
Abstract
In this article, we review contemporary evidence that GluD receptors are functional ion channels whose depolarizing currents contribute to their biological functions, akin to all other members of the ionotropic glutamate receptor (iGluR) family.
Collapse
Affiliation(s)
- Janesh Kumar
- Laboratory of Membrane Protein Biology, Council of Scientific and Industrial Research (CSIR)-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Gabriela K Popescu
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, SUNY, Buffalo, New York
| | - Stephanie C Gantz
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, Iowa; Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa.
| |
Collapse
|
5
|
Koh K, Shimazaki H, Ogawa M, Takiyama Y. A heterozygous GRID2 mutation in autosomal dominant cerebellar ataxia. Hum Genome Var 2022; 9:27. [PMID: 35882834 PMCID: PMC9325744 DOI: 10.1038/s41439-022-00204-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 06/14/2022] [Accepted: 06/30/2022] [Indexed: 01/12/2023] Open
Abstract
A heterozygous mutation in GRID2 that causes SCAR18 was first reported in an Algerian family with autosomal dominant cerebellar ataxia (ADCA). We identified the second ADCA family with a heterozygous GRID2 mutation. The Algerian family had cognitive impairment and hearing loss associated with cerebellar ataxia. However, the Japanese family presented here showed pure cerebellar ataxia. Therefore, we should also screen for the GRID2 mutation in ADCA families with pure cerebellar ataxia.
Collapse
Affiliation(s)
- Kishin Koh
- grid.267500.60000 0001 0291 3581Department of Neurology, Graduate School of Medical Sciences, University of Yamanashi, Yamanashi, 409-3898 Japan
| | - Haruo Shimazaki
- grid.410802.f0000 0001 2216 2631Faculty of Health & Medical Care, Saitama Medical University, Saitama, 350-1241 Japan
| | | | - Yoshihisa Takiyama
- grid.267500.60000 0001 0291 3581Department of Neurology, Graduate School of Medical Sciences, University of Yamanashi, Yamanashi, 409-3898 Japan
| |
Collapse
|
6
|
Abbott JA, Popescu GK. Homecoming of the estranged GluD channels. Trends Neurosci 2022; 45:499-501. [PMID: 35490056 PMCID: PMC9308142 DOI: 10.1016/j.tins.2022.04.001] [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: 02/17/2022] [Accepted: 04/01/2022] [Indexed: 10/18/2022]
Abstract
A recent paper by Carrillo and colleagues demonstrates that GluD proteins form bona fide ligand-gated ion channels when their intrinsic flexibility is constrained by interactions with protein partners. Therefore, Delta receptors resemble all other members of the ionotropic glutamate receptor family not only by sequence and structural homology, but also by functional dynamics.
Collapse
Affiliation(s)
- Jamie A Abbott
- Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, 955 Main Street, Buffalo, NY 14203, USA
| | - Gabriela K Popescu
- Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, 955 Main Street, Buffalo, NY 14203, USA.
| |
Collapse
|
7
|
Carrillo E, Gonzalez CU, Berka V, Jayaraman V. Delta glutamate receptors are functional glycine- and ᴅ-serine-gated cation channels in situ. SCIENCE ADVANCES 2021; 7:eabk2200. [PMID: 34936451 PMCID: PMC8694607 DOI: 10.1126/sciadv.abk2200] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Delta receptors are members of the ionotropic glutamate receptor superfamily and form trans-synaptic connections by interacting with the extracellular scaffolding protein cerebellin-1 and presynaptic transmembrane protein neurexin-1β. Unlike other family members, however, direct agonist-gated ion channel activity has not been recorded in delta receptors. Here, we show that the GluD2 subtype of delta receptor forms cation-selective channels when bound to cerebellin-1 and neurexin-1β. Using fluorescence lifetime measurements and chemical cross-linking, we reveal that tight packing of the amino-terminal domains of GluD2 permits glycine- and d-serine–induced channel openings. Thus, cerebellin-1 and neurexin-1β act as biological cross-linkers to stabilize the extracellular domains of GluD2 receptors, allowing them to function as ionotropic excitatory neurotransmitter receptors in synapses.
Collapse
Affiliation(s)
- Elisa Carrillo
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Cuauhtemoc U. Gonzalez
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Vladimir Berka
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - Vasanthi Jayaraman
- Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
- Corresponding author.
| |
Collapse
|
8
|
Burada AP, Vinnakota R, Lambolez B, Tricoire L, Kumar J. Structural biology of ionotropic glutamate delta receptors and their crosstalk with metabotropic glutamate receptors. Neuropharmacology 2021; 196:108683. [PMID: 34181979 DOI: 10.1016/j.neuropharm.2021.108683] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/31/2021] [Accepted: 06/17/2021] [Indexed: 10/21/2022]
Abstract
Enigmatic orphan glutamate delta receptors (GluD) are one of the four classes of the ionotropic glutamate receptors (iGluRs) that play key roles in synaptic transmission and plasticity. While members of other iGluR families viz AMPA, NMDA, and kainate receptors are gated by glutamate, the GluD receptors neither bind glutamate nor evoke ligand-induced currents upon binding of glycine and D-serine. Thus, the GluD receptors were considered to function as structural proteins that facilitate the formation, maturation, and maintenance of synapses in the hippocampus and cerebellum. Recent work has revealed that GluD receptors have extensive crosstalk with metabotropic glutamate receptors (mGlus) and are also gated by their activation. The latest development of a novel optopharamcological tool and the cryoEM structures of GluD receptors would help define the molecular and chemical basis of the GluD receptor's role in synaptic physiology. This article is part of the special Issue on "Glutamate Receptors - Orphan iGluRs".
Collapse
Affiliation(s)
- Ananth Prasad Burada
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, 411007, India
| | - Rajesh Vinnakota
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, 411007, India
| | - Bertrand Lambolez
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), CNRS, INSERM, Sorbonne Université, Paris, France
| | - Ludovic Tricoire
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), CNRS, INSERM, Sorbonne Université, Paris, France.
| | - Janesh Kumar
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, 411007, India.
| |
Collapse
|
9
|
Essiz S, Gencel M, Aktolun M, Demir A, Carpenter TS, Servili B. Correlated conformational dynamics of the human GluN1-GluN2A type N-methyl-D-aspartate (NMDA) receptor. J Mol Model 2021; 27:162. [PMID: 33969428 DOI: 10.1007/s00894-021-04755-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 04/15/2021] [Indexed: 11/30/2022]
Abstract
N-Methyl-D-aspartate receptors (NMDARs) are glutamate-gated ion channels found in the nerve cell membranes. As a result of overexcitation of NMDARs, neuronal death occurs and may lead to diseases such as epilepsy, stroke, Alzheimer's disease, and Parkinson's disease. In this study, human GluN1- GluN2A type NMDAR structure is modeled based on the X-ray structure of the Xenopus laevis template and missing loops are added by ab-initio loop modeling. The final structure is chosen according to two different model assessment scores. To be able to observe the structural changes upon ligand binding, glycine and glutamate molecules are docked into the corresponding binding sites of the receptor. Subsequently, molecular dynamics simulations of 1.3 μs are performed for both apo and ligand-bound structures. Structural parameters, which have been considered to show functionally important changes in previous NMDAR studies, are monitored as conformational rulers to understand the dynamics of the conformational changes. Moreover, principal component analysis (PCA) is performed for the equilibrated part of the simulations. From these analyses, the differences in between apo and ligand-bound simulations can be summarized as the following: The girdle right at the beginning of the pore loop, which connects M2 and M3 helices of the ion channel, partially opens. Ligands act like an adhesive for the ligand-binding domain (LBD) by keeping the bi-lobed structure together and consequently this is reflected to the overall dynamics of the protein as an increased correlation of the LBD with especially the amino-terminal domain (ATD) of the protein.
Collapse
Affiliation(s)
- Sebnem Essiz
- Bioinformatics and Genetics Department, Faculty of Engineering and Natural Sciences, Kadir Has University, 34083 Fatih, Istanbul, Turkey.
| | - Melis Gencel
- Bioinformatics and Genetics Department, Faculty of Engineering and Natural Sciences, Kadir Has University, 34083 Fatih, Istanbul, Turkey
| | - Muhammed Aktolun
- Bioinformatics and Genetics Department, Faculty of Engineering and Natural Sciences, Kadir Has University, 34083 Fatih, Istanbul, Turkey
| | - Ayhan Demir
- Bioinformatics and Genetics Department, Faculty of Engineering and Natural Sciences, Kadir Has University, 34083 Fatih, Istanbul, Turkey
| | - Timothy S Carpenter
- Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Burak Servili
- Bioinformatics and Genetics Department, Faculty of Engineering and Natural Sciences, Kadir Has University, 34083 Fatih, Istanbul, Turkey
| |
Collapse
|
10
|
Lemoine D, Mondoloni S, Tange J, Lambolez B, Faure P, Taly A, Tricoire L, Mourot A. Probing the ionotropic activity of glutamate GluD2 receptor in HEK cells with genetically-engineered photopharmacology. eLife 2020; 9:59026. [PMID: 33112237 PMCID: PMC7679134 DOI: 10.7554/elife.59026] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/27/2020] [Indexed: 12/13/2022] Open
Abstract
Glutamate delta (GluD) receptors belong to the ionotropic glutamate receptor family, yet they don’t bind glutamate and are considered orphan. Progress in defining the ion channel function of GluDs in neurons has been hindered by a lack of pharmacological tools. Here, we used a chemo-genetic approach to engineer specific and photo-reversible pharmacology in GluD2 receptor. We incorporated a cysteine mutation in the cavity located above the putative ion channel pore, for site-specific conjugation with a photoswitchable pore blocker. In the constitutively open GluD2 Lurcher mutant, current could be rapidly and reversibly decreased with light. We then transposed the cysteine mutation to the native receptor, to demonstrate with high pharmacological specificity that metabotropic glutamate receptor signaling triggers opening of GluD2. Our results assess the functional relevance of GluD2 ion channel and introduce an optogenetic tool that will provide a novel and powerful means for probing GluD2 ionotropic contribution to neuronal physiology. Neurotransmitters are chemicals released by the body that trigger activity in neurons. Receptors on the surface of neurons detect these neurotransmitters, providing a link between the inside and the outside of the cell. Glutamate is one of the major neurotransmitters and is involved in virtually all brain functions. Glutamate binds to two different types of receptors in neurons. Ionotropic receptors have pores known as ion channels, which open when glutamate binds. This is a fast-acting response that allows sodium ions to flow into the neuron, triggering an electrical signal. Metabotropic receptors, on the other hand, trigger a series of events inside the cell that lead to a response. Metabotropic receptors take more time than ionotropic receptors to elicit a response in the cell, but their effects last much longer. One type of receptor, known as the GluD family, is very similar to ionotropic glutamate receptors but does not directly respond to glutamate. Instead, the ion channel of GluD receptors opens after being activated by glutamate metabotropic receptors. GluD receptors are produced throughout the brain and play roles in synapse formation and activity, but the way they work remains unclear. An obstacle to understanding how GluD receptors work is the lack of molecules that can specifically block these receptors’ ion channel activity. Lemoine et al. have developed a tool that enables control of the ion channel in GluD receptors using light. Human cells grown in the lab were genetically modified to produce a version of GluD2 (a member of the GluD family) with a light-sensitive molecule attached. In darkness or under green light, the light-sensitive molecule blocks the channel and prevents ions from passing through. Under violet light, the molecule twists, and ions can flow through the channel. With this control over the GluD2 ion channel activity, Lemoine et al. were able to validate previous research showing that the activation of metabotropic glutamate receptors can trigger GluD2 to open. The next step will be to test this approach in neurons. This will help researchers to understand what role GluD ion channels play in neuron to neuron communication.
Collapse
Affiliation(s)
- Damien Lemoine
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), CNRS, INSERM, Sorbonne Université, Paris, France
| | - Sarah Mondoloni
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), CNRS, INSERM, Sorbonne Université, Paris, France
| | - Jérome Tange
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), CNRS, INSERM, Sorbonne Université, Paris, France
| | - Bertrand Lambolez
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), CNRS, INSERM, Sorbonne Université, Paris, France
| | - Philippe Faure
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), CNRS, INSERM, Sorbonne Université, Paris, France
| | - Antoine Taly
- CNRS, Université de Paris, UPR 9080, Laboratoire de Biochimie Théorique, Paris, France.,Institut de Biologie Physico-Chimique-Fondation Edmond de Rothschild, PSL Research University, Paris, France
| | - Ludovic Tricoire
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), CNRS, INSERM, Sorbonne Université, Paris, France
| | - Alexandre Mourot
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), CNRS, INSERM, Sorbonne Université, Paris, France
| |
Collapse
|
11
|
Gantz SC, Moussawi K, Hake HS. Delta glutamate receptor conductance drives excitation of mouse dorsal raphe neurons. eLife 2020; 9:e56054. [PMID: 32234214 PMCID: PMC7180053 DOI: 10.7554/elife.56054] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/01/2020] [Indexed: 01/04/2023] Open
Abstract
The dorsal raphe nucleus is the predominant source of central serotonin, where neuronal activity regulates complex emotional behaviors. Action potential firing of serotonin dorsal raphe neurons is driven via α1-adrenergic receptors (α1-AR) activation. Despite this crucial role, the ion channels responsible for α1-AR-mediated depolarization are unknown. Here, we show in mouse brain slices that α1-AR-mediated excitatory synaptic transmission is mediated by the ionotropic glutamate receptor homolog cation channel, delta glutamate receptor 1 (GluD1). GluD1R-channels are constitutively active under basal conditions carrying tonic inward current and synaptic activation of α1-ARs augments tonic GluD1R-channel current. Further, loss of dorsal raphe GluD1R-channels produces an anxiogenic phenotype. Thus, GluD1R-channels are responsible for α1-AR-dependent induction of persistent pacemaker-type firing of dorsal raphe neurons and regulate dorsal raphe-related behavior. Given the widespread distribution of these channels, ion channel function of GluD1R as a regulator of neuronal excitability is proposed to be widespread in the nervous system.
Collapse
Affiliation(s)
- Stephanie C Gantz
- National Institute on Drug Abuse Intramural Research Program, National Institutes of HealthBaltimoreUnited States
- Center on Compulsive Behaviors, National Institutes of HealthBethesdaUnited States
| | - Khaled Moussawi
- National Institute on Drug Abuse Intramural Research Program, National Institutes of HealthBaltimoreUnited States
- Johns Hopkins Medicine, Neurology DepartmentBaltimoreUnited States
| | - Holly S Hake
- National Institute on Drug Abuse Intramural Research Program, National Institutes of HealthBaltimoreUnited States
| |
Collapse
|
12
|
Burada AP, Vinnakota R, Kumar J. Cryo-EM structures of the ionotropic glutamate receptor GluD1 reveal a non-swapped architecture. Nat Struct Mol Biol 2020; 27:84-91. [PMID: 31925409 PMCID: PMC7025878 DOI: 10.1038/s41594-019-0359-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 11/27/2019] [Indexed: 01/06/2023]
Abstract
Ionotropic orphan delta receptors (GluD) are not gated by glutamate or
any other endogenous ligand but are grouped with ionotropic glutamate receptors
based on sequence similarity. GluD1 receptors play critical roles in
synaptogenesis, synapse maintenance and have been implicated in neuronal
disorders including schizophrenia, cognitive deficits, and cerebral ataxia. Here
we report cryo-electron microscopy structures of the rat GluD1 receptor
complexed with calcium and the ligand 7-chlorokynurenic acid, elucidating
molecular architecture and principles of receptor assembly. The structures
reveal a non-swapped architecture at the extracellular amino-terminal (ATD) and
ligand-binding domain (LBD) interface. This is in contrast to other families of
ionotropic glutamate receptors (iGluRs) where the dimer partners between the ATD
and LBD layers are swapped. Our results demonstrate that principles of
architecture and symmetry are not conserved between delta receptors and other
iGluRs and provide a molecular blueprint for understanding the functions of the
“orphan” class of iGluRs.
Collapse
Affiliation(s)
- Ananth Prasad Burada
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, India
| | - Rajesh Vinnakota
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, India
| | - Janesh Kumar
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University, Pune, Maharashtra, India.
| |
Collapse
|
13
|
Prestori F, Moccia F, D’Angelo E. Disrupted Calcium Signaling in Animal Models of Human Spinocerebellar Ataxia (SCA). Int J Mol Sci 2019; 21:ijms21010216. [PMID: 31892274 PMCID: PMC6981692 DOI: 10.3390/ijms21010216] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 12/22/2019] [Accepted: 12/24/2019] [Indexed: 12/12/2022] Open
Abstract
Spinocerebellar ataxias (SCAs) constitute a heterogeneous group of more than 40 autosomal-dominant genetic and neurodegenerative diseases characterized by loss of balance and motor coordination due to dysfunction of the cerebellum and its efferent connections. Despite a well-described clinical and pathological phenotype, the molecular and cellular events that underlie neurodegeneration are still poorly undaerstood. Emerging research suggests that mutations in SCA genes cause disruptions in multiple cellular pathways but the characteristic SCA pathogenesis does not begin until calcium signaling pathways are disrupted in cerebellar Purkinje cells. Ca2+ signaling in Purkinje cells is important for normal cellular function as these neurons express a variety of Ca2+ channels, Ca2+-dependent kinases and phosphatases, and Ca2+-binding proteins to tightly maintain Ca2+ homeostasis and regulate physiological Ca2+-dependent processes. Abnormal Ca2+ levels can activate toxic cascades leading to characteristic death of Purkinje cells, cerebellar atrophy, and ataxia that occur in many SCAs. The output of the cerebellar cortex is conveyed to the deep cerebellar nuclei (DCN) by Purkinje cells via inhibitory signals; thus, Purkinje cell dysfunction or degeneration would partially or completely impair the cerebellar output in SCAs. In the absence of the inhibitory signal emanating from Purkinje cells, DCN will become more excitable, thereby affecting the motor areas receiving DCN input and resulting in uncoordinated movements. An outstanding advantage in studying the pathogenesis of SCAs is represented by the availability of a large number of animal models which mimic the phenotype observed in humans. By mainly focusing on mouse models displaying mutations or deletions in genes which encode for Ca2+ signaling-related proteins, in this review we will discuss the several pathogenic mechanisms related to deranged Ca2+ homeostasis that leads to significant Purkinje cell degeneration and dysfunction.
Collapse
Affiliation(s)
- Francesca Prestori
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
- Correspondence:
| | - Francesco Moccia
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy;
| | - Egidio D’Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
- IRCCS Mondino Foundation, 27100 Pavia, Italy
| |
Collapse
|
14
|
Ionotropic glutamate receptors (iGluRs) of the delta family (GluD1 and GluD2) and synaptogenesis. ALEXANDRIA JOURNAL OF MEDICINE 2019. [DOI: 10.1016/j.ajme.2016.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
15
|
Cahill EN, Milton AL. Neurochemical and molecular mechanisms underlying the retrieval-extinction effect. Psychopharmacology (Berl) 2019; 236:111-132. [PMID: 30656364 PMCID: PMC6373198 DOI: 10.1007/s00213-018-5121-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 11/12/2018] [Indexed: 12/26/2022]
Abstract
Extinction within the reconsolidation window, or 'retrieval-extinction', has received much research interest as a possible technique for targeting the reconsolidation of maladaptive memories with a behavioural intervention. However, it remains to be determined whether the retrieval-extinction effect-a long-term reduction in fear behaviour, which appears resistant to spontaneous recovery, renewal and reinstatement-depends specifically on destabilisation of the original memory (the 'reconsolidation-update' account) or represents facilitation of an extinction memory (the 'extinction-facilitation' account). We propose that comparing the neurotransmitter systems, receptors and intracellular signalling pathways recruited by reconsolidation, extinction and retrieval-extinction will provide a way of distinguishing between these accounts.
Collapse
Affiliation(s)
- Emma N Cahill
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3EG, UK
| | - Amy L Milton
- Department of Psychology, University of Cambridge, Downing Site, Cambridge, CB2 3EB, UK.
- Behavioural and Clinical Neuroscience Institute, Cambridge, CB2 3EB, UK.
| |
Collapse
|
16
|
Pre- and postsynaptic ionotropic glutamate receptors in the auditory system of mammals. Hear Res 2018; 362:1-13. [DOI: 10.1016/j.heares.2018.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 02/16/2018] [Accepted: 02/21/2018] [Indexed: 01/22/2023]
|
17
|
Suh YH, Chang K, Roche KW. Metabotropic glutamate receptor trafficking. Mol Cell Neurosci 2018; 91:10-24. [PMID: 29604330 DOI: 10.1016/j.mcn.2018.03.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/07/2018] [Accepted: 03/26/2018] [Indexed: 01/14/2023] Open
Abstract
The metabotropic glutamate receptors (mGlu receptors) are G protein-coupled receptors that bind to the excitatory neurotransmitter glutamate and are important in the modulation of neuronal excitability, synaptic transmission, and plasticity in the central nervous system. Trafficking of mGlu receptors in and out of the synaptic plasma membrane is a fundamental mechanism modulating excitatory synaptic function through regulation of receptor abundance, desensitization, and signaling profiles. In this review, we cover the regulatory mechanisms determining surface expression and endocytosis of mGlu receptors, with particular focus on post-translational modifications and receptor-protein interactions. The literature we review broadens our insight into the precise events defining the expression of functional mGlu receptors at synapses, and will likely contribute to the successful development of novel therapeutic targets for a variety of developmental, neurological, and psychiatric disorders.
Collapse
Affiliation(s)
- Young Ho Suh
- Department of Biomedical Sciences, Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080, South Korea.
| | - Kai Chang
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
18
|
GluD1, linked to schizophrenia, controls the burst firing of dopamine neurons. Mol Psychiatry 2018; 23:691-700. [PMID: 28696429 PMCID: PMC5822454 DOI: 10.1038/mp.2017.137] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Revised: 05/11/2017] [Accepted: 05/15/2017] [Indexed: 01/08/2023]
Abstract
Human mutations of the GRID1 gene encoding the orphan delta1 glutamate receptor-channel (GluD1) are associated with schizophrenia but the explicit role of GluD1 in brain circuits is unknown. Based on the known function of its paralog GluD2 in cerebellum, we searched for a role of GluD1 in slow glutamatergic transmission mediated by metabotropic receptor mGlu1 in midbrain dopamine neurons, whose dysfunction is a hallmark of schizophrenia. We found that an mGlu1 agonist elicits a slow depolarizing current in HEK cells co-expressing mGlu1 and GluD1, but not in cells expressing mGlu1 or GluD1 alone. This current is abolished by additional co-expression of a dominant-negative GluD1 dead pore mutant. We then characterized mGlu1-dependent currents in dopamine neurons from midbrain slices. Both the agonist-evoked and the slow postsynaptic currents are abolished by expression of the dominant-negative GluD1 mutant, pointing to the involvement of native GluD1 channels in these currents. Likewise, both mGlu1-dependent currents are suppressed in GRID1 knockout mice, which reportedly display endophenotypes relevant for schizophrenia. It is known that mGlu1 activation triggers the transition from tonic to burst firing of dopamine neurons, which signals salient stimuli and encodes reward prediction. In vivo recordings of dopamine neurons showed that their spontaneous burst firing is abolished in GRID1 knockout mice or upon targeted expression of the dominant-negative GluD1 mutant in wild-type mice. Our results de-orphanize GluD1, unravel its key role in slow glutamatergic transmission and provide insights into how GRID1 gene alterations can lead to dopaminergic dysfunctions in schizophrenia.
Collapse
|
19
|
Hansen KB, Yi F, Perszyk RE, Menniti FS, Traynelis SF. NMDA Receptors in the Central Nervous System. Methods Mol Biol 2017; 1677:1-80. [PMID: 28986865 DOI: 10.1007/978-1-4939-7321-7_1] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
NMDA-type glutamate receptors are ligand-gated ion channels that mediate a major component of excitatory neurotransmission in the central nervous system (CNS). They are widely distributed at all stages of development and are critically involved in normal brain functions, including neuronal development and synaptic plasticity. NMDA receptors are also implicated in the pathophysiology of numerous neurological and psychiatric disorders, such as ischemic stroke, traumatic brain injury, Alzheimer's disease, epilepsy, mood disorders, and schizophrenia. For these reasons, NMDA receptors have been intensively studied in the past several decades to elucidate their physiological roles and to advance them as therapeutic targets. Seven NMDA receptor subunits exist that assemble into a diverse array of tetrameric receptor complexes, which are differently regulated, have distinct regional and developmental expression, and possess a wide range of functional and pharmacological properties. The diversity in subunit composition creates NMDA receptor subtypes with distinct physiological roles across neuronal cell types and brain regions, and enables precise tuning of synaptic transmission. Here, we will review the relationship between NMDA receptor structure and function, the diversity and significance of NMDA receptor subtypes in the CNS, as well as principles and rules by which NMDA receptors operate in the CNS under normal and pathological conditions.
Collapse
Affiliation(s)
- Kasper B Hansen
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, USA. .,Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT, USA.
| | - Feng Yi
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, USA
| | - Riley E Perszyk
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Frank S Menniti
- MindImmune Therapeutics, Inc., George & Anne Ryan Institute for Neuroscience, Kingston, RI, USA
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| |
Collapse
|
20
|
Hadzic M, Jack A, Wahle P. Ionotropic glutamate receptors: Which ones, when, and where in the mammalian neocortex. J Comp Neurol 2016; 525:976-1033. [PMID: 27560295 DOI: 10.1002/cne.24103] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 08/09/2016] [Accepted: 08/15/2016] [Indexed: 12/14/2022]
Abstract
A multitude of 18 iGluR receptor subunits, many of which are diversified by splicing and RNA editing, localize to >20 excitatory and inhibitory neocortical neuron types defined by physiology, morphology, and transcriptome in addition to various types of glial, endothelial, and blood cells. Here we have compiled the published expression of iGluR subunits in the areas and cell types of developing and adult cortex of rat, mouse, carnivore, bovine, monkey, and human as determined with antibody- and mRNA-based techniques. iGluRs are differentially expressed in the cortical areas and in the species, and all have a unique developmental pattern. Differences are quantitative rather than a mere absence/presence of expression. iGluR are too ubiquitously expressed and of limited use as markers for areas or layers. A focus has been the iGluR profile of cortical interneuron types. For instance, GluK1 and GluN3A are enriched in, but not specific for, interneurons; moreover, the interneurons expressing these subunits belong to different types. Adressing the types is still a major hurdle because type-specific markers are lacking, and the frequently used neuropeptide/CaBP signatures are subject to regulation by age and activity and vary as well between species and areas. RNA-seq reveals almost all subunits in the two morphofunctionally characterized interneuron types of adult cortical layer I, suggesting a fairly broad expression at the RNA level. It remains to be determined whether all proteins are synthesized, to which pre- or postsynaptic subdomains in a given neuron type they localize, and whether all are involved in synaptic transmission. J. Comp. Neurol. 525:976-1033, 2017. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Minela Hadzic
- Developmental Neurobiology, Faculty for Biology and Biotechnology ND 6/72, Ruhr University Bochum, 44801, Bochum, Germany
| | - Alexander Jack
- Developmental Neurobiology, Faculty for Biology and Biotechnology ND 6/72, Ruhr University Bochum, 44801, Bochum, Germany
| | - Petra Wahle
- Developmental Neurobiology, Faculty for Biology and Biotechnology ND 6/72, Ruhr University Bochum, 44801, Bochum, Germany
| |
Collapse
|
21
|
Jin Z, Bhandage AK, Bazov I, Kononenko O, Bakalkin G, Korpi ER, Birnir B. Expression of specific ionotropic glutamate and GABA-A receptor subunits is decreased in central amygdala of alcoholics. Front Cell Neurosci 2014; 8:288. [PMID: 25278838 PMCID: PMC4165314 DOI: 10.3389/fncel.2014.00288] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 08/29/2014] [Indexed: 01/20/2023] Open
Abstract
The central amygdala (CeA) has a role for mediating fear and anxiety responses. It is also involved in emotional imbalance caused by alcohol abuse and dependence and in regulating relapse to alcohol abuse. Growing evidences suggest that excitatory glutamatergic and inhibitory γ-aminobutyric acid-ergic (GABAergic) transmissions in the CeA are affected by chronic alcohol exposure. Human post-mortem CeA samples from male alcoholics (n = 9) and matched controls (n = 9) were assayed for the expression level of ionotropic glutamate and GABA-A receptors subunit mRNAs using quantitative real-time reverse transcription-PCR (RT-qPCR). Our data revealed that out of the 16 ionotropic glutamate receptor subunits, mRNAs encoding two AMPA [2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl)propanoic acid] receptor subunits GluA1 and GluA4; one kainate receptor subunit GluK2; one NMDA (N-methyl-D-aspartate) receptor subunit GluN2D and one delta receptor subunit GluD2 were significantly decreased in the CeA of alcoholics. In contrast, of the 19 GABA-A receptor subunits, only the mRNA encoding the α2 subunit was significantly down-regulated in the CeA of the alcoholics as compared with control subjects. Our findings imply that the down-regulation of specific ionotropic glutamate and GABA-A receptor subunits in the CeA of alcoholics may represent one of the molecular substrates underlying the new balance between excitatory and inhibitory neurotransmission in alcohol dependence.
Collapse
Affiliation(s)
- Zhe Jin
- Molecular Physiology and Neuroscience Unit, Neuroscience, Biomedical Center, Uppsala University Uppsala, Sweden
| | - Amol K Bhandage
- Molecular Physiology and Neuroscience Unit, Neuroscience, Biomedical Center, Uppsala University Uppsala, Sweden
| | - Igor Bazov
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University Uppsala, Sweden
| | - Olga Kononenko
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University Uppsala, Sweden
| | - Georgy Bakalkin
- Division of Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, Uppsala University Uppsala, Sweden
| | - Esa R Korpi
- Pharmacology, Institute of Biomedicine, University of Helsinki Helsinki, Finland
| | - Bryndis Birnir
- Molecular Physiology and Neuroscience Unit, Neuroscience, Biomedical Center, Uppsala University Uppsala, Sweden
| |
Collapse
|
22
|
Glutamate receptors of the delta family are widely expressed in the adult brain. Brain Struct Funct 2014; 220:2797-815. [DOI: 10.1007/s00429-014-0827-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 06/17/2014] [Indexed: 10/25/2022]
|
23
|
Ady V, Perroy J, Tricoire L, Piochon C, Dadak S, Chen X, Dusart I, Fagni L, Lambolez B, Levenes C. Type 1 metabotropic glutamate receptors (mGlu1) trigger the gating of GluD2 delta glutamate receptors. EMBO Rep 2013; 15:103-9. [PMID: 24357660 DOI: 10.1002/embr.201337371] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The orphan GluD2 receptor belongs to the ionotropic glutamate receptor family but does not bind glutamate. Ligand-gated GluD2 currents have never been evidenced, and whether GluD2 operates as an ion channel has been a long-standing question. Here, we show that GluD2 gating is triggered by type 1 metabotropic glutamate receptors, both in a heterologous expression system and in Purkinje cells. Thus, GluD2 is not only an adhesion molecule at synapses but also works as a channel. This gating mechanism reveals new properties of glutamate receptors that emerge from their interaction and opens unexpected perspectives regarding synaptic transmission and plasticity.
Collapse
Affiliation(s)
- Visou Ady
- Centre National de la Recherche Scientifique (CNRS) UMR 8119 Neurophysics and Physiology Laboratory, Université Paris Descartes, Paris, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Searcy JL, Phelps JT, Pancani T, Kadish I, Popovic J, Anderson KL, Beckett TL, Murphy MP, Chen KC, Blalock EM, Landfield PW, Porter NM, Thibault O. Long-term pioglitazone treatment improves learning and attenuates pathological markers in a mouse model of Alzheimer's disease. J Alzheimers Dis 2013; 30:943-61. [PMID: 22495349 DOI: 10.3233/jad-2012-111661] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Thiazolidinediones (TZDs) are agonists at peroxisome proliferator-activated gamma-type (PPAR-γ) receptors and are used clinically for the treatment of type 2 diabetes where they have been shown to reestablish insulin sensitivity, improve lipid profiles, and reduce inflammation. Recent work also suggests that TZDs may be beneficial in Alzheimer's disease (AD), ameliorating cognitive decline early in the disease process. However, there have been only a few studies identifying mechanisms through which cognitive benefits may be exerted. Starting at 10 months of age, the triple transgenic mouse model of AD (3xTg-AD) with accelerated amyloid-β (Aβ) deposition and tau pathology was treated with the TZD pioglitazone (PIO-Actos) at 18 mg/Kg body weight/day. After four months, PIO-treated animals showed multiple beneficial effects, including improved learning on the active avoidance task, reduced serum cholesterol, decreased hippocampal amyloid-β and tau deposits, and enhanced short- and long-term plasticity. Electrophysiological membrane properties and post-treatment blood glucose levels were unchanged by PIO. Gene microarray analyses of hippocampal tissue identified predicted transcriptional responses following TZD treatment as well as potentially novel targets of TZDs, including facilitation of estrogenic processes and decreases in glutamatergic and lipid metabolic/cholesterol dependent processes. Taken together, these results confirm prior animal studies showing that TZDs can ameliorate cognitive deficits associated with AD-related pathology, but also extend these findings by pointing to novel molecular targets in the brain.
Collapse
Affiliation(s)
- James L Searcy
- Department of Molecular and Biomedical Pharmacology, University of Kentucky Medical Center, Lexington, KY 40536-0084, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Yadav R, Hillman BG, Gupta SC, Suryavanshi P, Bhatt JM, Pavuluri R, Stairs DJ, Dravid SM. Deletion of glutamate delta-1 receptor in mouse leads to enhanced working memory and deficit in fear conditioning. PLoS One 2013; 8:e60785. [PMID: 23560106 PMCID: PMC3616134 DOI: 10.1371/journal.pone.0060785] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 03/02/2013] [Indexed: 11/18/2022] Open
Abstract
Glutamate delta-1 (GluD1) receptors are expressed throughout the forebrain during development with high levels in the hippocampus during adulthood. We have recently shown that deletion of GluD1 receptor results in aberrant emotional and social behaviors such as hyperaggression and depression-like behaviors and social interaction deficits. Additionally, abnormal expression of synaptic proteins was observed in amygdala and prefrontal cortex of GluD1 knockout mice (GluD1 KO). However the role of GluD1 in learning and memory paradigms remains unknown. In the present study we evaluated GluD1 KO in learning and memory tests. In the eight-arm radial maze GluD1 KO mice committed fewer working memory errors compared to wildtype mice but had normal reference memory. Enhanced working memory in GluD1 KO was also evident by greater percent alternation in the spontaneous Y-maze test. No difference was observed in object recognition memory in the GluD1 KO mice. In the Morris water maze test GluD1 KO mice showed no difference in acquisition but had longer latency to find the platform in the reversal learning task. GluD1 KO mice showed a deficit in contextual and cue fear conditioning but had normal latent inhibition. The deficit in contextual fear conditioning was reversed by D-Cycloserine (DCS) treatment. GluD1 KO mice were also found to be more sensitive to foot-shock compared to wildtype. We further studied molecular changes in the hippocampus, where we found lower levels of GluA1, GluA2 and GluK2 subunits while a contrasting higher level of GluN2B in GluD1 KO. Additionally, we found higher postsynaptic density protein 95 (PSD95) and lower glutamate decarboxylase 67 (GAD67) expression in GluD1 KO. We propose that GluD1 is crucial for normal functioning of synapses and absence of GluD1 leads to specific abnormalities in learning and memory. These findings provide novel insights into the role of GluD1 receptors in the central nervous system.
Collapse
Affiliation(s)
- Roopali Yadav
- Department of Pharmacology, Creighton University, Omaha, Nebraska, United States of America
| | - Brandon G. Hillman
- Department of Pharmacology, Creighton University, Omaha, Nebraska, United States of America
| | - Subhash C. Gupta
- Department of Pharmacology, Creighton University, Omaha, Nebraska, United States of America
| | - Pratyush Suryavanshi
- Department of Pharmacology, Creighton University, Omaha, Nebraska, United States of America
| | - Jay M. Bhatt
- Department of Pharmacology, Creighton University, Omaha, Nebraska, United States of America
| | - Ratnamala Pavuluri
- Department of Pharmacology, Creighton University, Omaha, Nebraska, United States of America
| | - Dustin J. Stairs
- Department of Psychology, Creighton University, Omaha, Nebraska, United States of America
| | - Shashank M. Dravid
- Department of Pharmacology, Creighton University, Omaha, Nebraska, United States of America
| |
Collapse
|
26
|
Orth A, Tapken D, Hollmann M. The delta subfamily of glutamate receptors: characterization of receptor chimeras and mutants. Eur J Neurosci 2013; 37:1620-30. [DOI: 10.1111/ejn.12193] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 02/08/2013] [Accepted: 02/20/2013] [Indexed: 12/14/2022]
|
27
|
Glutamate receptor δ2 associates with metabotropic glutamate receptor 1 (mGluR1), protein kinase Cγ, and canonical transient receptor potential 3 and regulates mGluR1-mediated synaptic transmission in cerebellar Purkinje neurons. J Neurosci 2013; 32:15296-308. [PMID: 23115168 DOI: 10.1523/jneurosci.0705-12.2012] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cerebellar motor coordination and cerebellar Purkinje cell synaptic function require metabotropic glutamate receptor 1 (mGluR1, Grm1). We used an unbiased proteomic approach to identify protein partners for mGluR1 in cerebellum and discovered glutamate receptor δ2 (GluRδ2, Grid2, GluΔ2) and protein kinase Cγ (PKCγ) as major interactors. We also found canonical transient receptor potential 3 (TRPC3), which is also needed for mGluR1-dependent slow EPSCs and motor coordination and associates with mGluR1, GluRδ2, and PKCγ. Mutation of GluRδ2 changes subcellular fractionation of mGluR1 and TRPC3 to increase their surface expression. Fitting with this, mGluR1-evoked inward currents are increased in GluRδ2 mutant mice. Moreover, loss of GluRδ2 disrupts the time course of mGluR1-dependent synaptic transmission at parallel fiber-Purkinje cells synapses. Thus, GluRδ2 is part of the mGluR1 signaling complex needed for cerebellar synaptic function and motor coordination, explaining the shared cerebellar motor phenotype that manifests in mutants of the mGluR1 and GluRδ2 signaling pathways.
Collapse
|
28
|
Nenadic I, Maitra R, Scherpiet S, Gaser C, Schultz CC, Schachtzabel C, Smesny S, Reichenbach JR, Treutlein J, Mühleisen TW, Deufel T, Cichon S, Rietschel M, Nöthen MM, Sauer H, Schlösser RGM. Glutamate receptor δ 1 (GRID1) genetic variation and brain structure in schizophrenia. J Psychiatr Res 2012; 46:1531-9. [PMID: 23017809 DOI: 10.1016/j.jpsychires.2012.08.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 08/23/2012] [Accepted: 08/24/2012] [Indexed: 01/28/2023]
Abstract
Common genetic variation in the promoter region of the glutamate receptor delta 1 (GRID1) gene has recently been shown to confer increased risk for schizophrenia in several independent large samples. We analysed high-resolution magnetic resonance imaging (MRI) data from 62 patients with schizophrenia and 54 healthy controls using voxel-based morphometry (VBM) to assess the effect of single nucleotide polymorphism rs3814614 (located in the GRID1 promoter region), of which the T allele was identified as a risk factor in a previous association study. There were no effects of genotype or group × genotype interactions on total brain grey matter or white matter, but on regional grey matter. In healthy subjects, we identified a significant effect of rs3814614 genotype in the anterior thalamus (bilaterally), superior prefrontal cortex, and orbitofrontal cortex - in all cases with the homozygous risk genotype TT resulting in higher grey matter density. We did not find this association within the schizophrenia sample, where rs3814614 variation was only associated with grey matter reduction in TT homozygous subjects in medial parietal cortex and increased grey matter in right medial cerebellum. For white matter, we did not find significant genotype effects in healthy controls, and only minor effects within schizophrenia patients in the posterior temporal lobe white matter. Our data indicate that GRID1 rs3814614 genotype is related to grey matter variation in prefrontal and anterior thalamic brain areas in healthy subjects, but not in patients indicating a potential role of this schizophrenia candidate gene in thalamo-cortical functioning.
Collapse
Affiliation(s)
- Igor Nenadic
- Department of Psychiatry and Psychotherapy, Jena University Hospital, Philosophenweg 3, 07743 Jena, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
For neurons to communicate, signals must cross the cell-to-cell distance at their points of contact. At the predominant cell-cell contact in the central nervous system, the chemical synapse, the synaptic cleft spans roughly 20 nanometers. To signal across this distance, the presynaptic neuron secretes a diffusible neurotransmitter, which is detected by receptors on the postsynaptic neuron. Although this signaling mechanism has become common knowledge, it remains unclear how synapses are maintained when they are not in immediate use. New evidence reveals how Nature solved this problem at a particular type of synapse in the cerebellum: Three old acquaintances bridge the cleft. The ionotropic glutamate receptor GluD2 constitutes the postsynaptic anchor that indirectly interacts with the presynaptic anchor neurexin through a presynaptically secreted soluble factor, a member of the C1q protein family named Cbln1. This trio collaborates to align pre- and postsynaptic sides.
Collapse
Affiliation(s)
- Sabine M Schmid
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94143, USA
| | | |
Collapse
|
30
|
Bukiya AN, Vaithianathan T, Toro L, Dopico AM. Channel beta2-4 subunits fail to substitute for beta1 in sensitizing BK channels to lithocholate. Biochem Biophys Res Commun 2009; 390:995-1000. [PMID: 19852931 DOI: 10.1016/j.bbrc.2009.10.091] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2009] [Accepted: 10/19/2009] [Indexed: 12/20/2022]
Abstract
Large conductance, calcium- and voltage-gated potassium (BK) channels regulate numerous physiological processes. While most basic functional characteristics of native BK channels are reproduced by BK alpha (slo1) subunit homotetramers, key biophysical and pharmacological properties are drastically modified by the presence of auxiliary beta subunits (encoded by KCNMB1-4). Numerous physiological steroids, including sex hormones, gluco- and mineralocorticoids, activate beta subunit-containing BK channels, yet these steroids appear to be sensed by different types of beta subunits, with some steroids being sensed by homomeric slo1 channels as well. We recently showed that beta1 sensitizes the BK channel to microM concentrations of lithocholate (LC). Following expression of rat cerebral artery myocyte slo1 subunits ("cbv1") with beta1, beta2, beta3 or beta4 in Xenopus laevis oocytes we now demonstrate that BK beta2, beta3 and beta4 subunits fail to substitute for beta1 in providing LC-sensitivity (150 microM) to the BK channel. These findings document for the first time a rather selective steroid activation of BK channels via a particular channel accessory subunit. In addition, LC routinely activated native BK channels in myocytes freshly isolated from rat cerebral artery smooth muscle, where BK beta1 is highly expressed, while failing to do so in skeletal (flexor digitorum brevis) muscle, where BK beta1 expression is negligible. This indicates that the native environment of the BK channel sustains the LC-sensitivity distinctly provided to the BK channel by beta1 subunits. Our study indicates that LC represents a unique tool to probe the presence of functional beta1-subunits and selectively activate BK channels in tissues that highly express KCNMB1.
Collapse
Affiliation(s)
- Anna N Bukiya
- Department of Pharmacology, University of Tennessee HSC, 874 Union Ave, Memphis, TN 38163, USA
| | | | | | | |
Collapse
|
31
|
Fiorentini M, Nielsen AK, Kristensen O, Kastrup JS, Gajhede M. Structure of the first PDZ domain of human PSD-93. Acta Crystallogr Sect F Struct Biol Cryst Commun 2009; 65:1254-7. [PMID: 20054121 PMCID: PMC2802873 DOI: 10.1107/s1744309109043267] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Accepted: 10/20/2009] [Indexed: 11/10/2022]
Abstract
The crystal structure of the PDZ1 domain of human PSD-93 has been determined to 2.0 A resolution. The PDZ1 domain forms a crystallographic trimer that is also predicted to be stable in solution. The main contributions to the stabilization of the trimer seem to arise from interactions involving the PDZ1-PDZ2 linker region at the extreme C-terminus of PDZ1, implying that the oligomerization that is observed is not of biological significance in full-length PSD-93. Comparison of the structures of the binding cleft of PSD-93 PDZ1 with the previously reported structures of PSD-93 PDZ2 and PDZ3 as well as of the closely related human PSD-95 PDZ1 shows that they are very similar in terms of amino-acid composition. However, the cleft is significantly narrower in PSD-95. This could be part of the basis of peptide selectivity between PSD-93 PDZ1 and PSD-95 PDZ1.
Collapse
Affiliation(s)
- Monica Fiorentini
- Biostructural Research, Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Ann Kallehauge Nielsen
- Biostructural Research, Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Ole Kristensen
- Biostructural Research, Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Jette S. Kastrup
- Biostructural Research, Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Michael Gajhede
- Biostructural Research, Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| |
Collapse
|
32
|
The delta2 glutamate-like receptor undergoes similar conformational changes as other ionotropic glutamate receptors. J Neurosci 2009; 29:6767-8. [PMID: 19474303 DOI: 10.1523/jneurosci.1456-09.2009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
33
|
Schmid SM, Kott S, Sager C, Huelsken T, Hollmann M. The glutamate receptor subunit delta2 is capable of gating its intrinsic ion channel as revealed by ligand binding domain transplantation. Proc Natl Acad Sci U S A 2009; 106:10320-5. [PMID: 19506248 PMCID: PMC2700928 DOI: 10.1073/pnas.0900329106] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Indexed: 11/18/2022] Open
Abstract
The family of ionotropic glutamate receptors includes 2 subunits, delta1 and delta2, the physiological relevance of which remains poorly understood. Both are nonfunctional in heterologous expression systems, although the isolated, crystallized ligand binding domain (LBD) of delta2 is capable of binding D-serine. To investigate these seemingly contradictory observations we tested whether delta receptors can be ligand gated at all. We used a strategy that replaced the native LBD of delta2 by a proven glutamate-binding LBD. Test transplantations between alpha-amino-3-hydroxy-5-methylisoxazole propionate (AMPA) and kainate receptors (GluR1 and GluR6, respectively) showed that this approach can produce functional chimeras even if only one part of the bipartite LBD is swapped. Upon outfitting delta2 with the LBD of GluR6, the chimera formed glutamate-gated ion channels with low Ca(2+) permeability and unique rectification properties. Ligand-induced conformational changes can thus gate delta2, suggesting that the LBD of this receptor works fundamentally differently from that of other ionotropic glutamate receptors.
Collapse
Affiliation(s)
- Sabine M. Schmid
- Department of Biochemistry I–Receptor Biochemistry
- International Graduate School of Neuroscience
| | - Sabine Kott
- Department of Biochemistry I–Receptor Biochemistry
| | - Charlotte Sager
- Department of Biochemistry I–Receptor Biochemistry
- Ruhr University Research School, Ruhr University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | | | - Michael Hollmann
- Department of Biochemistry I–Receptor Biochemistry
- International Graduate School of Neuroscience
| |
Collapse
|
34
|
Modulation of the dimer interface at ionotropic glutamate-like receptor delta2 by D-serine and extracellular calcium. J Neurosci 2009; 29:907-17. [PMID: 19176800 DOI: 10.1523/jneurosci.4081-08.2009] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
GluRdelta2 is a member of the iGluR family, but despite a prominent role in cerebellar synaptic plasticity, this receptor does not appear to function as an ion channel. Endogenous ligands that modulate the activity of native GluRdelta2 in the cerebellum have not been identified, but two candidate modulators are d-serine and extracellular calcium. Taking advantage of known crystal structures and spontaneously active GluRdelta2 receptors containing the lurcher mutation (GluRdelta2(Lc)), we investigated the mechanism by which calcium and d-serine regulate the activity of GluRdelta2(Lc). Our data suggest that calcium binding stabilizes the dimer interface formed between two agonist-binding domains and increases GluRdelta2(Lc) currents. The data further suggest that d-serine binding induces rearrangements at the dimer interface to diminish GluRdelta2(Lc) currents by a mechanism that resembles desensitization at AMPA and kainate receptors. Thus, we propose that calcium and d-serine binding have opposing effects on the stability of the dimer interface. Furthermore, the effects of calcium are observed at concentrations that are within the physiological range, suggesting that the ability of native GluRdelta2 to respond to ligand binding may be modulated by extracellular calcium. These findings place GluRdelta2 among AMPA and kainate receptors, where the dimer interface is not only a biologically important site for functional regulation, but also an important target for exogenous and endogenous ligands that modulate receptor function.
Collapse
|