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Møller TC, Moo EV, Inoue A, Pedersen MF, Bräuner-Osborne H. Characterization of the real-time internalization of nine GPCRs reveals distinct dependence on arrestins and G proteins. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119584. [PMID: 37714305 DOI: 10.1016/j.bbamcr.2023.119584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 08/24/2023] [Accepted: 09/06/2023] [Indexed: 09/17/2023]
Abstract
G protein-coupled receptors (GPCRs) are seven transmembrane receptors that respond to external stimuli and undergo conformational changes to activate G proteins and modulate cellular processes leading to biological outcomes. To prevent overstimulation and prolonged exposure to stimuli, GPCRs are regulated by internalization. While the canonical GPCR internalization mechanism in mammalian cells is arrestin-dependent, clathrin-mediated endocytosis, more diverse GPCR internalization mechanisms have been described over the years. However, there is a lack of consistent methods used in the literature making it complicated to determine a receptor's internalization pathway. Here, we utilized a highly efficient time-resolved Förster resonance energy transfer (TR-FRET) internalization assay to determine the internalization profile of nine distinct GPCRs representing the GPCR classes A, B and C and with different G protein coupling profiles. This technique, coupled with clustered regularly interspaced palindromic repeats (CRISPR) engineered knockout cells allows us to effectively study the involvement of heterotrimeric G proteins and non-visual arrestins. We found that all the nine receptors internalized upon agonist stimulation in a concentration-dependent manner and six receptors showed basal internalization. Yet, there is no correlation between the receptor class and primary G protein coupling to the arrestin and G protein dependence for GPCR internalization. Overall, this study presents a platform for studying internalization that is applicable to most GPCRs and may even be extended to other membrane proteins. This method can be easily applicable to other endocytic machinery of interest and ultimately will lend itself towards the construction of comprehensive receptor internalization profiles.
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Affiliation(s)
- Thor C Møller
- Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Ee Von Moo
- Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark.
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Mie F Pedersen
- Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen, Denmark
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2
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Yoshida A, Ito A, Yasui N, Yamashita A. Direct binding of calmodulin to the cytosolic C-terminal regions of sweet/umami taste receptors. J Biochem 2023; 174:451-459. [PMID: 37527916 PMCID: PMC11033526 DOI: 10.1093/jb/mvad060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/15/2023] [Accepted: 07/26/2023] [Indexed: 08/03/2023] Open
Abstract
Sweet and umami taste receptors recognize chemicals such as sugars and amino acids on their extracellular side and transmit signals into the cytosol of the taste cell. In contrast to ligands that act on the extracellular side of these receptors, little is known regarding the molecules that regulate receptor functions within the cytosol. In this study, we analysed the interaction between sweet and umami taste receptors and calmodulin, a representative Ca2+-dependent cytosolic regulatory protein. High prediction scores for calmodulin binding were observed on the C-terminal cytosolic side of mouse taste receptor type 1 subunit 3 (T1r3), a subunit that is common to both sweet and umami taste receptors. Pull-down assay and surface plasmon resonance analyses showed different affinities of calmodulin to the C-terminal tails of distinct T1r subtypes. Furthermore, we found that T1r3 and T1r2 showed the highest and considerable binding to calmodulin, whereas T1r1 showed weaker binding affinity. Finally, the binding of calmodulin to T1rs was consistently higher in the presence of Ca2+ than in its absence. The results suggested a possibility of the Ca2+-dependent feedback regulation process of sweet and umami taste receptor signaling by calmodulin.
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Affiliation(s)
- Atsuki Yoshida
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Ayumi Ito
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Norihisa Yasui
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Atsuko Yamashita
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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Zheng R, Xu FX, Zhou L, Xu J, Shen Y, Hao K, Wang XT, Deng J. Ablation of KIF2C in Purkinje cells impairs metabotropic glutamate receptor trafficking and motor coordination in male mice. J Physiol 2023; 601:3905-3920. [PMID: 37431690 DOI: 10.1113/jp284214] [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: 12/19/2022] [Accepted: 06/27/2023] [Indexed: 07/12/2023] Open
Abstract
Kinesin family member 2C (KIF2C)/mitotic centromere-associated kinesin (MCAK), is thought to be oncogenic as it is involved in tumour progression and metastasis. Moreover, it also plays a part in neurodegenerative conditions like Alzheimer's disease and psychiatric disorders such as suicidal schizophrenia. Our previous study conducted on mice demonstrated that KIF2C is widely distributed in various regions of the brain, and is localized in synaptic spines. Additionally, it regulates microtubule dynamic properties through its own microtubule depolymerization activity, thereby affecting AMPA receptor transport and cognitive behaviour in mice. In this study, we show that KIF2C regulates the transport of mGlu1 receptors in Purkinje cells by binding to Rab8. KIF2C deficiency in Purkinje cells results in abnormal gait, reduced balance ability and motor incoordination in male mice. These data suggest that KIF2C is essential for maintaining normal transport and synaptic function of mGlu1 and motor coordination in mice. KEY POINTS: KIF2C is localized in synaptic spines of hippocampus neurons, and regulates excitatory transmission, synaptic plasticity and cognitive behaviour. KIF2C is extensively expressed in the cerebellum, and we investigated its functions in development and synaptic transmission of cerebellar Purkinje cells. KIF2C deficiency in Purkinje cells alters the expression of metabotropic glutamate receptor 1 (mGlu1) and the AMPA receptor GluA2 subunit at Purkinje cell synapses, and changes excitatory synaptic transmission, but not inhibitory transmission. KIF2C regulates the transport of mGlu1 receptors in Purkinje cells by binding to Rab8. KIF2C deficiency in Purkinje cells affects motor coordination, but not social behaviour in male mice.
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Affiliation(s)
- Rui Zheng
- Joint Centre of Translational Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, China
| | - Fang-Xiao Xu
- Zhejiang Key Laboratory of Organ Development and Regeneration, Institute of Life Sciences, Hangzhou Normal University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Ministry of Education Frontier Science Center for Brain Research and Brain Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Lin Zhou
- NHC and CAMS Key Laboratory of Medical Neurobiology, Ministry of Education Frontier Science Center for Brain Research and Brain Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Junyu Xu
- NHC and CAMS Key Laboratory of Medical Neurobiology, Ministry of Education Frontier Science Center for Brain Research and Brain Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Ying Shen
- Research Center of Blood Transfusion Medicine, Ministry of Education Key Laboratory of Laboratory Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Ke Hao
- Research Center of Blood Transfusion Medicine, Ministry of Education Key Laboratory of Laboratory Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Xin-Tai Wang
- Zhejiang Key Laboratory of Organ Development and Regeneration, Institute of Life Sciences, Hangzhou Normal University, Hangzhou, China
| | - Junjie Deng
- Joint Centre of Translational Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, China
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4
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Chetwynd SA, Andrews S, Inglesfield S, Delon C, Ktistakis NT, Welch HCE. Functions and mechanisms of the GPCR adaptor protein Norbin. Biochem Soc Trans 2023; 51:1545-1558. [PMID: 37503670 PMCID: PMC10586782 DOI: 10.1042/bst20221349] [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: 02/08/2023] [Revised: 06/27/2023] [Accepted: 07/07/2023] [Indexed: 07/29/2023]
Abstract
Norbin (Neurochondrin, NCDN) is a highly conserved 79 kDa adaptor protein that was first identified more than a quarter of a century ago as a gene up-regulated in rat hippocampus upon induction of long-term potentiation. Most research has focussed on the role of Norbin in the nervous system, where the protein is highly expressed. Norbin regulates neuronal morphology and synaptic plasticity, and is essential for normal brain development and homeostasis. Dysregulation of Norbin is linked to a variety of neurological conditions. Recently, Norbin was shown to be expressed in myeloid cells as well as neurons. Myeloid-cell specific deletion revealed an important role of Norbin as a suppressor of neutrophil-derived innate immunity. Norbin limits the ability of neutrophils to clear bacterial infections by curbing the responsiveness of these cells to inflammatory and infectious stimuli. Mechanistically, Norbin regulates cell responses through binding to its interactors, in particular to a wide range of G protein-coupled receptors (GPCRs). Norbin association with GPCRs controls GPCR trafficking and signalling. Other important Norbin interactors are the Rac guanine-nucleotide exchange factor P-Rex1 and protein kinase A. Downstream signalling pathways regulated by Norbin include ERK, Ca2+ and the small GTPase Rac. Here, we review the current understanding of Norbin structure, expression and its roles in health and disease. We also explore Norbin signalling through its interactors, with a particular focus on GPCR trafficking and signalling. Finally, we discuss avenues that could be pursued in the future to increase our understanding of Norbin biology.
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Affiliation(s)
| | - Simon Andrews
- Bioinformatics Facility, Babraham Institute, Cambridge, U.K
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Ramsakha N, Ojha P, Pal S, Routh S, Citri A, Bhattacharyya S. A vital role for PICK1 in the differential regulation of metabotropic glutamate receptor internalization and synaptic AMPA receptor endocytosis. J Biol Chem 2023:104837. [PMID: 37209824 DOI: 10.1016/j.jbc.2023.104837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 04/19/2023] [Accepted: 05/12/2023] [Indexed: 05/22/2023] Open
Abstract
Group I metabotropic glutamate receptors (mGluRs) play important roles in many neuronal processes and are believed to be involved in synaptic plasticity underlying the encoding of experience, including classic paradigms of learning and memory. These receptors have also been implicated in various neurodevelopmental disorders, such as Fragile X syndrome and autism. Internalization and recycling of these receptors in the neuron are important mechanisms to regulate the activity of the receptor and control the precise spatio-temporal localization of these receptors. Applying a "molecular replacement" approach in hippocampal neurons derived from mice, we demonstrate a critical role for protein interacting with C kinase 1 (PICK1) in regulating the agonist-induced internalization of mGluR1. We show that PICK1 specifically regulates the internalization of mGluR1 but it does not play any role in the internalization of the other member of group I mGluR family, mGluR5. Various regions of PICK1 viz., the N-terminal acidic motif, PDZ domain and BAR domain play important roles in the agonist-mediated internalization of mGluR1. Finally, we demonstrate that PICK1-mediated internalization of mGluR1 is critical for the resensitization of the receptor. Upon knockdown of endogenous PICK1, mGluR1s stayed on the cell membrane as inactive receptors, incapable of triggering the MAP-kinase signaling. They also could not induce AMPAR endocytosis, a cellular correlate for mGluR-dependent synaptic plasticity. Thus, this study unravels a novel role for PICK1 in the agonist-mediated internalization of mGluR1 and mGluR1-mediated AMPAR endocytosis that might contribute to the function of mGluR1 in neuropsychiatric disorders.
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Affiliation(s)
- Namrata Ramsakha
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Knowledge city, Sector - 81, SAS Nagar, PO: 140306, Punjab, India
| | - Prachi Ojha
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Knowledge city, Sector - 81, SAS Nagar, PO: 140306, Punjab, India
| | - Subhajit Pal
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Knowledge city, Sector - 81, SAS Nagar, PO: 140306, Punjab, India
| | - Sanjeev Routh
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Knowledge city, Sector - 81, SAS Nagar, PO: 140306, Punjab, India
| | - Ami Citri
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem; Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel 91904; Institute of Life Sciences, The Hebrew University of Jerusalem; Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel 91904; Program in Child and Brain Development, Canadian Institute for Advanced Research; MaRS Centre, West Tower, 661 University Ave, Suite 505, Toronto, Ontario, Canada M5G 1M1
| | - Samarjit Bhattacharyya
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Knowledge city, Sector - 81, SAS Nagar, PO: 140306, Punjab, India.
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Koda S, Hu J, Ju X, Sun G, Shao S, Tang RX, Zheng KY, Yan J. The role of glutamate receptors in the regulation of the tumor microenvironment. Front Immunol 2023; 14:1123841. [PMID: 36817470 PMCID: PMC9929049 DOI: 10.3389/fimmu.2023.1123841] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 01/20/2023] [Indexed: 02/04/2023] Open
Abstract
Glutamate, as one of the most important carbon sources in the TCA cycle, is central in metabolic processes that will subsequently influence tumor progression. Several factors can affect the expression of glutamate receptors, playing either a tumor-promoting or tumor-suppressor role in cancer. Thus, the activation of glutamate receptors by the ligand could play a role in tumor development as ample studies have demonstrated the expression of glutamate receptors in a broad range of tumor cells. Glutamate and its receptors are involved in the regulation of different immune cells' development and function, as suggested by the receptor expression in immune cells. The activation of glutamate receptors can enhance the effectiveness of the effector's T cells, or decrease the cytokine production in immunosuppressive myeloid-derived suppressor cells, increasing the antitumor immune response. These receptors are essential for the interaction between tumor and immune cells within the tumor microenvironment (TME) and the regulation of antitumor immune responses. Although the role of glutamate in the TCA cycle has been well studied, few studies have deeply investigated the role of glutamate receptors in the regulation of cancer and immune cells within the TME. Here, by a systematic review of the available data, we will critically assess the physiopathological relevance of glutamate receptors in the regulation of cancer and immune cells in the TME and provide some unifying hypotheses for futures research on the role of glutamate receptors in the immune modulation of the tumor.
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Affiliation(s)
- Stephane Koda
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, National Experimental Demonstration Center for Basic Medicine Education, Xuzhou Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Jing Hu
- Department of Bioinformatics, School of Life Science, Xuzhou Medical University, Xuzhou, Jiangsu, China,Department of Genetics, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Xiaoman Ju
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, National Experimental Demonstration Center for Basic Medicine Education, Xuzhou Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Guowei Sun
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, National Experimental Demonstration Center for Basic Medicine Education, Xuzhou Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Simin Shao
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, National Experimental Demonstration Center for Basic Medicine Education, Xuzhou Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Ren-Xian Tang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, National Experimental Demonstration Center for Basic Medicine Education, Xuzhou Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Kui-Yang Zheng
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, National Experimental Demonstration Center for Basic Medicine Education, Xuzhou Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, Jiangsu, China,*Correspondence: Juming Yan, ; Kui-Yang Zheng,
| | - Juming Yan
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, National Experimental Demonstration Center for Basic Medicine Education, Xuzhou Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, Jiangsu, China,*Correspondence: Juming Yan, ; Kui-Yang Zheng,
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7
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Yadav P, Podia M, Kumari SP, Mani I. Glutamate receptor endocytosis and signaling in neurological conditions. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 196:167-207. [PMID: 36813358 DOI: 10.1016/bs.pmbts.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The non-essential amino acid glutamate acts as a major excitatory neurotransmitter and plays a significant role in the central nervous system (CNS). It binds with two different types of receptors, ionotropic glutamate receptors (iGluRs) and metabotropic glutamate receptors (mGluRs), responsible for the postsynaptic excitation of neurons. They are important for memory, neural development and communication, and learning. Endocytosis and subcellular trafficking of the receptor are essential for the regulation of receptor expression on the cell membrane and excitation of the cells. The endocytosis and trafficking of the receptor are dependent on its type, ligand, agonist, and antagonist present. This chapter discusses the types of glutamate receptors, their subtypes, and the regulation of their internalization and trafficking. The roles of glutamate receptors in neurological diseases are also briefly discussed.
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Affiliation(s)
- Prerna Yadav
- Department of Microbiology, University of Delhi, New Delhi, India
| | - Mansi Podia
- Department of Microbiology, University of Delhi, New Delhi, India
| | - Shashi Prabha Kumari
- Department of Microbiology, Ram Lal Anand College, University of Delhi, New Delhi, India
| | - Indra Mani
- Department of Microbiology, Gargi College, University of Delhi, New Delhi, India.
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8
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Pronot M, Poupon G, Pizzamiglio L, Prieto M, Chato-Astrain I, Lacagne I, Schorova L, Folci A, Brau F, Martin S. Bidirectional regulation of synaptic SUMOylation by Group 1 metabotropic glutamate receptors. Cell Mol Life Sci 2022; 79:378. [PMID: 35739402 PMCID: PMC9226087 DOI: 10.1007/s00018-022-04405-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/19/2022] [Accepted: 05/24/2022] [Indexed: 11/27/2022]
Abstract
SUMOylation is a post-translational modification essential to cell homeostasis. A tightly controlled equilibrium between SUMOylation and deSUMOylation processes is also critical to the neuronal function including neurotransmitter release and synaptic transmission and plasticity. Disruption of the SUMOylation homeostasis in neurons is associated with several neurological disorders. The balance between the SUMOylation and deSUMOylation of substrate proteins is maintained by a group of deSUMOylation enzymes called SENPs. We previously showed that the activation of type 5 metabotropic glutamate receptors (mGlu5R) first triggers a rapid increase in synaptic SUMOylation and then upon the sustained activation of these receptors, the deSUMOylase activity of SENP1 allows the increased synaptic SUMOylation to get back to basal levels. Here, we combined the use of pharmacological tools with subcellular fractionation and live-cell imaging of individual hippocampal dendritic spines to demonstrate that the synaptic accumulation of the deSUMOylation enzyme SENP1 is bidirectionally controlled by the activation of type 1 mGlu1 and mGlu5 receptors. Indeed, the pharmacological blockade of mGlu1R activation during type 1 mGluR stimulation leads to a faster and greater accumulation of SENP1 at synapses indicating that mGlu1R acts as a brake to the mGlu5R-dependent deSUMOylation process at the post-synapse. Altogether, our findings reveal that type 1 mGluRs work in opposition to dynamically tune the homeostasis of SUMOylation at the mammalian synapse.
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Affiliation(s)
- Marie Pronot
- Université Côte d'Azur, CNRS, IPMC, Valbonne, France
| | | | | | - Marta Prieto
- Université Côte d'Azur, CNRS, IPMC, Valbonne, France
| | | | | | | | | | - Frédéric Brau
- Université Côte d'Azur, CNRS, IPMC, Valbonne, France
| | - Stéphane Martin
- Université Côte d'Azur, INSERM, CNRS, IPMC, Valbonne, France.
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275, Centre National de la Recherche Scientifique, Université Côte d'Azur, 660 route des lucioles, 06560, Valbonne, France.
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Membrane trafficking and positioning of mGluRs at presynaptic and postsynaptic sites of excitatory synapses. Neuropharmacology 2021; 200:108799. [PMID: 34592242 DOI: 10.1016/j.neuropharm.2021.108799] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 08/31/2021] [Accepted: 09/17/2021] [Indexed: 01/21/2023]
Abstract
The plethora of functions of glutamate in the brain are mediated by the complementary actions of ionotropic and metabotropic glutamate receptors (mGluRs). The ionotropic glutamate receptors carry most of the fast excitatory transmission, while mGluRs modulate transmission on longer timescales by triggering multiple intracellular signaling pathways. As such, mGluRs mediate critical aspects of synaptic transmission and plasticity. Interestingly, at synapses, mGluRs operate at both sides of the cleft, and thus bidirectionally exert the effects of glutamate. At postsynaptic sites, group I mGluRs act to modulate excitability and plasticity. At presynaptic sites, group II and III mGluRs act as auto-receptors, modulating release properties in an activity-dependent manner. Thus, synaptic mGluRs are essential signal integrators that functionally couple presynaptic and postsynaptic mechanisms of transmission and plasticity. Understanding how these receptors reach the membrane and are positioned relative to the presynaptic glutamate release site are therefore important aspects of synapse biology. In this review, we will discuss the currently known mechanisms underlying the trafficking and positioning of mGluRs at and around synapses, and how these mechanisms contribute to synaptic functioning. We will highlight outstanding questions and present an outlook on how recent technological developments will move this exciting research field forward.
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10
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Hámor PU, Schwendt M. Metabotropic Glutamate Receptor Trafficking and its Role in Drug-Induced Neurobehavioral Plasticity. Brain Plast 2021; 7:61-76. [PMID: 34868874 PMCID: PMC8609495 DOI: 10.3233/bpl-210120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/06/2021] [Indexed: 12/18/2022] Open
Abstract
Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system that guides developmental and experience-dependent changes in many cellular substrates and brain circuits, through the process collectively referred to as neurobehavioral plasticity. Regulation of cell surface expression and membrane trafficking of glutamate receptors represents an important mechanism that assures optimal excitatory transmission, and at the same time, also allows for fine-tuning neuronal responses to glutamate. On the other hand, there is growing evidence implicating dysregulated glutamate receptor trafficking in the pathophysiology of several neuropsychiatric disorders. This review provides up-to-date information on the molecular determinants regulating trafficking and surface expression of metabotropic glutamate (mGlu) receptors in the rodent and human brain and discusses the role of mGluR trafficking in maladaptive synaptic plasticity produced by addictive drugs. As substantial evidence links glutamatergic dysfunction to the progression and the severity of drug addiction, advances in our understanding of mGluR trafficking may provide opportunities for the development of novel pharmacotherapies of addiction and other neuropsychiatric disorders.
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Affiliation(s)
- Peter U. Hámor
- Department of Psychology, University of Florida, Gainesville, FL, USA
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
| | - Marek Schwendt
- Department of Psychology, University of Florida, Gainesville, FL, USA
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
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11
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Historical perspective and progress on protein ubiquitination at glutamatergic synapses. Neuropharmacology 2021; 196:108690. [PMID: 34197891 DOI: 10.1016/j.neuropharm.2021.108690] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/07/2021] [Accepted: 06/22/2021] [Indexed: 12/23/2022]
Abstract
Transcription-translation coupling leads to the production of proteins that are key for controlling essential neuronal processes that include neuronal development and changes in synaptic strength. Although these events have been a prevailing theme in neuroscience, the regulation of proteins via posttranslational signaling pathways are equally relevant for these neuronal processes. Ubiquitin is one type of posttranslational modification that covalently attaches to its targets/substrates. Ubiquitination of proteins play a key role in multiple signaling pathways, the predominant being removal of its substrates by a large molecular machine called the proteasome. Here, I review 40 years of progress on ubiquitination in the nervous system at glutamatergic synapses focusing on axon pathfinding, synapse formation, presynaptic release, dendritic spine formation, and regulation of postsynaptic glutamate receptors. Finally, I elucidate emerging themes in ubiquitin biology that may challenge our current understanding of ubiquitin signaling in the nervous system.
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12
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Scheefhals N, Catsburg LAE, Westerveld ML, Blanpied TA, Hoogenraad CC, MacGillavry HD. Shank Proteins Couple the Endocytic Zone to the Postsynaptic Density to Control Trafficking and Signaling of Metabotropic Glutamate Receptor 5. Cell Rep 2020; 29:258-269.e8. [PMID: 31597090 PMCID: PMC6815225 DOI: 10.1016/j.celrep.2019.08.102] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 07/25/2019] [Accepted: 08/29/2019] [Indexed: 12/17/2022] Open
Abstract
Activation of postsynaptic metabotropic glutamate receptors (mGluRs) modulates neuronal excitability and synaptic plasticity, while deregulation of mGluR signaling has been implicated in neurodevelopmental disorders. Overstimulation of mGluRs is restricted by the rapid endocytosis of receptors after activation. However, how membrane trafficking of mGluRs at synapses is controlled remains poorly defined. We find that in hippocampal neurons, the agonist-induced receptor internalization of synaptic mGluR5 is significantly reduced in Shank knockdown neurons. This is rescued by the re-expression of wild-type Shanks, but not by mutants unable to bind Homer1b/c, Dynamin2, or Cortactin. These effects are paralleled by a reduction in synapses associated with an endocytic zone. Moreover, a mutation in SHANK2 found in autism spectrum disorders (ASDs) similarly disrupts these processes. On the basis of these findings, we propose that synaptic Shank scaffolds anchor the endocytic machinery to govern the efficient trafficking of mGluR5 and to balance the surface expression of mGluRs to efficiently modulate neuronal functioning. Receptor activation triggers efficient internalization of mGluR5 in spines Shank proteins control mGluR5 trafficking and signaling Shanks link essential components of the endocytic zone to the postsynaptic density Mutation in SHANK2 found in ASD disrupt these processes
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Affiliation(s)
- Nicky Scheefhals
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Lisa A E Catsburg
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Margriet L Westerveld
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Thomas A Blanpied
- Department of Physiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Casper C Hoogenraad
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Harold D MacGillavry
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands.
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13
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Structure-based discovery and development of metabotropic glutamate receptor 5 negative allosteric modulators. ADVANCES IN PHARMACOLOGY 2020; 88:35-58. [PMID: 32416871 DOI: 10.1016/bs.apha.2020.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
The metabotropic glutamate (mGlu) receptors are a family of eight class C G protein-coupled receptors (GPCRs) which modulate cell signaling and synaptic transmission to the major excitatory neurotransmitter l-glutamate (l-glutamic acid). Due to their role in modulating glutamate response, their widespread distribution in the central nervous system (CNS) and some evidence of dysregulation in disease, the mGlu receptors have become attractive pharmacological targets. As the orthosteric (glutamate) binding site is highly conserved across the eight mGlu receptors, it is difficult not only to generate ligands with subtype selectivity but, due to the nature of the binding site, with suitable drug-like properties to allow oral bioavailability and CNS penetration. Selective pharmacological targeting of a single receptor subtype can be achieved by targeting alternative (allosteric) binding sites. The nature of the allosteric binding pockets allows ligands to be developed that have good physical chemical properties as evidenced by several allosteric modulators of mGlu receptors entering clinical trials. The first negative allosteric modulators of the metabotropic glutamate 5 (mGlu5) receptor were discovered from high throughput screening activities. An alternative approach to drug discovery is to use structural knowledge to enable structure-based drug design (SBDD), which allows the design of molecules in a more rational, rather than empirical, fashion. Here we will describe the process of SBDD in the discovery of the mGlu5 negative allosteric modulator HTL0014242 and describe how knowledge of receptor structure can also be used to gain insights into the receptor activation mechanisms.
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14
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Pandey S, Ramsakha N, Sharma R, Gulia R, Ojha P, Lu W, Bhattacharyya S. The post-synaptic scaffolding protein tamalin regulates ligand-mediated trafficking of metabotropic glutamate receptors. J Biol Chem 2020; 295:8575-8588. [PMID: 32376687 DOI: 10.1074/jbc.ra119.011979] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 05/04/2020] [Indexed: 11/06/2022] Open
Abstract
Group I metabotropic glutamate receptors (mGluRs) play important roles in various neuronal functions and have also been implicated in multiple neuropsychiatric disorders like fragile X syndrome, autism, and others. mGluR trafficking not only plays important roles in controlling the spatiotemporal localization of these receptors in the cell but also regulates the activity of these receptors. Despite this obvious significance, the cellular machineries that control the trafficking of group I metabotropic glutamate receptors in the central nervous system have not been studied in detail. The post-synaptic scaffolding protein tamalin has been shown to interact with group I mGluRs and also with many other proteins involved in protein trafficking in neurons. Using a molecular replacement approach in mouse hippocampal neurons, we show here that tamalin plays a critical role in the ligand-dependent internalization of mGluR1 and mGluR5, members of the group I mGluR family. Specifically, knockdown of endogenous tamalin inhibited the ligand-dependent internalization of these two receptors. Both N-terminal and C-terminal regions of tamalin played critical roles in mGluR1 endocytosis. Furthermore, we found that tamalin regulates mGluR1 internalization by interacting with S-SCAM, a protein that has been implicated in vesicular trafficking. Finally, we demonstrate that tamalin plays a critical role in mGluR-mediated internalization of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, a process believed to be the cellular correlate for mGluR-dependent synaptic plasticity. Taken together, these findings reveal a mechanistic role of tamalin in the trafficking of group I mGluRs and suggest its physiological implications in the brain.
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Affiliation(s)
- Saurabh Pandey
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, SAS Nagar, Punjab, India
| | - Namrata Ramsakha
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, SAS Nagar, Punjab, India
| | - Rohan Sharma
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, SAS Nagar, Punjab, India
| | - Ravinder Gulia
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, SAS Nagar, Punjab, India
| | - Prachi Ojha
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, SAS Nagar, Punjab, India
| | - Wei Lu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Samarjit Bhattacharyya
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, SAS Nagar, Punjab, India
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15
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Raynaud F, Homburger V, Seveno M, Vigy O, Moutin E, Fagni L, Perroy J. SNAP23-Kif5 complex controls mGlu1 receptor trafficking. J Mol Cell Biol 2019; 10:423-436. [PMID: 29762713 DOI: 10.1093/jmcb/mjy031] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 05/11/2018] [Indexed: 11/13/2022] Open
Abstract
Metabotropic glutamate receptors are expressed at excitatory synapses and control synaptic transmission in mammalian brain. These receptors are involved in numerous patho-physiological functions. However, little is known about the molecular determinants responsible for their intracellular transport and membrane targeting. Here we investigated the nature of the molecular motor and adaptor protein responsible for trafficking and membrane localization of the group I metabotropic glutamate mGlu1 postsynaptic receptor in cultured hippocampal neurons. In proteomic studies, we identified the synaptosome-associated protein 23 (SNAP23) and the molecular motor Kif5 kinesin as proteins interacting with mGlu1 receptor. We showed that SNAP23, but not Kif5, directly interacts with mGlu1 receptor carboxyl terminus. Using a recombination approach to impair or enhance the interaction between SNAP23 and Kif5, we found that the SNAP23-Kif5 complex controls the trafficking of mGlu1 receptor along microtubules. Additional fluorescence recovery after cleavage experiments allowed us to identify a role of the complex in the receptor cell surface targeting. In conclusion, our study indicates that along dendritic processes Kif5-SNAP23 complex contributes to proper mGlu1 receptor trafficking and cell surface expression.
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Affiliation(s)
| | | | - Martial Seveno
- BioCampus Montpellier, CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Oana Vigy
- IGF, CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Enora Moutin
- IGF, CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Laurent Fagni
- IGF, CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Julie Perroy
- IGF, CNRS, INSERM, Univ. Montpellier, Montpellier, France
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16
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Marks CR, Shonesy BC, Wang X, Stephenson JR, Niswender CM, Colbran RJ. Activated CaMKII α Binds to the mGlu 5 Metabotropic Glutamate Receptor and Modulates Calcium Mobilization. Mol Pharmacol 2018; 94:1352-1362. [PMID: 30282777 DOI: 10.1124/mol.118.113142] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 09/19/2018] [Indexed: 01/03/2023] Open
Abstract
Ca2+/calmodulin-dependent protein kinase II (CaMKII) and metabotropic glutamate receptor 5 (mGlu5) are critical signaling molecules in synaptic plasticity and learning/memory. Here, we demonstrate that mGlu5 is present in CaMKIIα complexes isolated from mouse forebrain. Further in vitro characterization showed that the membrane-proximal region of the C-terminal domain (CTD) of mGlu5a directly interacts with purified Thr286-autophosphorylated (activated) CaMKIIα However, the binding of CaMKIIα to this CTD fragment is reduced by the addition of excess Ca2+/calmodulin or by additional CaMKIIα autophosphorylation at non-Thr286 sites. Furthermore, in vitro binding of CaMKIIα is dependent on a tribasic residue motif Lys-Arg-Arg (KRR) at residues 866-868 of the mGlu5a-CTD, and mutation of this motif decreases the coimmunoprecipitation of CaMKIIα with full-length mGlu5a expressed in heterologous cells by about 50%. The KRR motif is required for two novel functional effects of coexpressing constitutively active CaMKIIα with mGlu5a in heterologous cells. First, cell-surface biotinylation studies showed that CaMKIIα increases the surface expression of mGlu5a Second, using Ca2+ fluorimetry and single-cell Ca2+ imaging, we found that CaMKIIα reduces the initial peak of mGlu5a-mediated Ca2+ mobilization by about 25% while doubling the relative duration of the Ca2+ signal. These findings provide new insights into the physical and functional coupling of these key regulators of postsynaptic signaling.
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Affiliation(s)
- Christian R Marks
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Brian C Shonesy
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Xiaohan Wang
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jason R Stephenson
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Colleen M Niswender
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Roger J Colbran
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
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17
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Sharma R, Gulia R, Bhattacharyya S. Analysis of ubiquitination and ligand-dependent trafficking of group I mGluRs. Methods Cell Biol 2018; 149:107-130. [PMID: 30616814 DOI: 10.1016/bs.mcb.2018.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Group I metabotropic glutamate receptors (mGluRs) are G-protein coupled receptors (GPCRs). They have been implicated in multiple forms of synaptic plasticity, as well as in various neuropsychiatric disorders. The signaling of these receptors is governed by the mechanisms of desensitization, internalization and resensitization of these receptors. Various post-translational modifications determine the signaling as well as trafficking of these receptors. Ubiquitination is a post-translational modification that has emerged as an essential regulatory process which governs group I mGluR trafficking. In this chapter, we have discussed the strategies to investigate the ubiquitination and the ligand-mediated trafficking of group I mGluRs in HEK293T cells and in primary hippocampal neurons, respectively. We have illustrated the protocols of (i) maintenance and transient transfection in HEK293T cells and primary hippocampal neurons, (ii) immunoprecipitation and western blot analysis to identify the ubiquitination of group I mGluRs, (iii) endocytosis and recycling assay and (iv) image acquisition and analysis.
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Affiliation(s)
- Rohan Sharma
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Ravinder Gulia
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Samarjit Bhattacharyya
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India.
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18
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A Critical Role for Sorting Nexin 1 in the Trafficking of Metabotropic Glutamate Receptors. J Neurosci 2018; 38:8605-8620. [PMID: 30143569 DOI: 10.1523/jneurosci.0454-18.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 07/22/2018] [Accepted: 08/16/2018] [Indexed: 11/21/2022] Open
Abstract
Group I metabotropic glutamate receptors (mGluRs) function as modulators of neuronal physiology and they have also been implicated in various neuropsychiatric disorders. Trafficking of mGluRs plays important roles in controlling the precise localization of these receptors at specific region of the cell, as well as it regulates the activity of these receptors. Despite this obvious significance, we know very little about the cellular machineries that control the trafficking of these receptors in the CNS. Sorting nexin 1 (SNX1) has been shown to regulate the endosomal sorting of few cell surface receptors either to lysosomes where they are downregulated or back to the cell surface. Using "molecular replacement" approach in hippocampal neurons derived from mice of both sexes, we show here that SNX1 plays critical role in the trafficking of mGluR1, a member of the group I mGluR family. Overexpression of dominant-negative SNX1 or knockdown of endogenous SNX1 resulted in the rapid recycling of the receptor. Importantly, recycling via the rapid recycling route, did not allow the resensitization of the receptors. Our data suggest that both, N-terminal and C-terminal region of SNX1 play critical role in the normal trafficking of the receptor. In addition, we also show here that SNX1 regulates the trafficking of mGluR1 through the interaction with Hrs (hepatocyte growth factor-regulated tyrosine kinase substrate), a protein that has been implicated in both signaling and vesicular trafficking. Thus, these studies reveal a mechanistic role of SNX1 in the trafficking of group I mGluRs and its physiological implications.SIGNIFICANCE STATEMENT Group I mGluRs are activated by the neurotransmitter glutamate in the CNS, and play various important roles in the brain. Similar to many other receptors, trafficking plays crucial roles in controlling the precise localization as well as activity of these receptors. Despite this obvious significance very little is known about the cellular machineries that control the trafficking of these receptors. We demonstrate here, that SNX1 plays a critical role in the trafficking of mGluR1, a member of the group I mGluR family. SNX1-mediated trafficking is critical for the resensitization of the receptor. SNX1 controls the trafficking of the receptor through the interaction with another protein, Hrs. The results suggest a role for SNX1 in the regulation of group I mGluRs.
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19
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Wang N, Cai XY, Gao W, Shen Y. Numb-p72, but not Numb-p65, contributes to the trafficking of group I metabotropic glutamate receptors. Neuroreport 2018; 29:902-906. [PMID: 29762249 DOI: 10.1097/wnr.0000000000001051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The protein Numb localizes to clathrin-coated vesicles and participates in the trafficking of transmembrane receptors. We previous reported that Numb promotes the presence of metabotropic glutamate receptor 1 (mGlu1) on neuronal membrane, and Numb deficiency impairs synaptic expression of mGlu1. However, the actions of different Numb isoforms on mGlu1 trafficking are unknown. Here, we found that Numb-p72 and Numb-p65 are distinctly expressed in HEK293T cells. Interestingly, Numb-p72, but not Numb-p65, binds to mGlu1α and promotes the membrane expression of mGlu1α by antagonizing its internalization. We hypothesize that the incomplete structure of Numb-p65 does not act in the same way as Numb-p72 on mGlu1 trafficking.
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Affiliation(s)
- Na Wang
- School of Medicine, Zhejiang University City College
| | - Xin-Yu Cai
- Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China
| | - Wei Gao
- School of Medicine, Zhejiang University City College
| | - Ying Shen
- Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China
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20
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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.
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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.
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21
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Goniotaki D, Lakkaraju AKK, Shrivastava AN, Bakirci P, Sorce S, Senatore A, Marpakwar R, Hornemann S, Gasparini F, Triller A, Aguzzi A. Inhibition of group-I metabotropic glutamate receptors protects against prion toxicity. PLoS Pathog 2017; 13:e1006733. [PMID: 29176838 PMCID: PMC5720820 DOI: 10.1371/journal.ppat.1006733] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 12/07/2017] [Accepted: 11/04/2017] [Indexed: 12/29/2022] Open
Abstract
Prion infections cause inexorable, progressive neurological dysfunction and neurodegeneration. Expression of the cellular prion protein PrPC is required for toxicity, suggesting the existence of deleterious PrPC-dependent signaling cascades. Because group-I metabotropic glutamate receptors (mGluR1 and mGluR5) can form complexes with the cellular prion protein (PrPC), we investigated the impact of mGluR1 and mGluR5 inhibition on prion toxicity ex vivo and in vivo. We found that pharmacological inhibition of mGluR1 and mGluR5 antagonized dose-dependently the neurotoxicity triggered by prion infection and by prion-mimetic anti-PrPC antibodies in organotypic brain slices. Prion-mimetic antibodies increased mGluR5 clustering around dendritic spines, mimicking the toxicity of Aβ oligomers. Oral treatment with the mGluR5 inhibitor, MPEP, delayed the onset of motor deficits and moderately prolonged survival of prion-infected mice. Although group-I mGluR inhibition was not curative, these results suggest that it may alleviate the neurological dysfunctions induced by prion diseases.
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Affiliation(s)
| | | | - Amulya N. Shrivastava
- École Normale Supérieure, Institut de Biologie de l'ENS (IBENS) INSERM CNRS PSL Research University, Paris, France
- Paris-Saclay Institute of Neuroscience, CNRS, Gif-sur-Yvette, France
| | - Pamela Bakirci
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Silvia Sorce
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - Assunta Senatore
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | | | - Simone Hornemann
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | | | - Antoine Triller
- École Normale Supérieure, Institut de Biologie de l'ENS (IBENS) INSERM CNRS PSL Research University, Paris, France
| | - Adriano Aguzzi
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
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22
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Ablation of TFR1 in Purkinje Cells Inhibits mGlu1 Trafficking and Impairs Motor Coordination, But Not Autistic-Like Behaviors. J Neurosci 2017; 37:11335-11352. [PMID: 29054881 DOI: 10.1523/jneurosci.1223-17.2017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/28/2017] [Accepted: 10/06/2017] [Indexed: 11/21/2022] Open
Abstract
Group 1 metabotropic glutamate receptors (mGlu1/5s) are critical to synapse formation and participate in synaptic LTP and LTD in the brain. mGlu1/5 signaling alterations have been documented in cognitive impairment, neurodegenerative disorders, and psychiatric diseases, but underlying mechanisms for its modulation are not clear. Here, we report that transferrin receptor 1 (TFR1), a transmembrane protein of the clathrin complex, modulates the trafficking of mGlu1 in cerebellar Purkinje cells (PCs) from male mice. We show that conditional knock-out of TFR1 in PCs does not affect the cytoarchitecture of PCs, but reduces mGlu1 expression at synapses. This regulation by TFR1 acts in concert with that by Rab8 and Rab11, which modulate the internalization and recycling of mGlu1, respectively. TFR1 can bind to Rab proteins and facilitate their expression at synapses. PC ablation of TFR1 inhibits parallel fiber-PC LTD, whereas parallel fiber-LTP and PC intrinsic excitability are not affected. Finally, we demonstrate that PC ablation of TFR1 impairs motor coordination, but does not affect social behaviors in mice. Together, these findings underscore the importance of TFR1 in regulating mGlu1 trafficking and suggest that mGlu1- and mGlu1-dependent parallel fiber-LTD are associated with regulation of motor coordination, but not autistic behaviors.SIGNIFICANCE STATEMENT Group 1 metabotropic glutamate receptor (mGlu1/5) signaling alterations have been documented in cognitive impairment, neurodegenerative disorders, and psychiatric diseases. Recent work suggests that altered mGlu1 signaling in Purkinje cells (PCs) may be involved in not only motor learning, but also autistic-like behaviors. We find that conditional knock-out of transferrin receptor 1 (TFR1) in PCs reduces synaptic mGlu1 by tethering Rab8 and Rab11 in the cytosol. PC ablation of TFR1 inhibits parallel fiber-PC LTD, whereas parallel fiber-PC LTP and PC intrinsic excitability are intact. Motor coordination is impaired, but social behaviors are normal in TFR1flox/flox;pCP2-cre mice. Our data reveal a new regulator for trafficking and synaptic expression of mGlu1 and suggest that mGlu1-dependent LTD is associated with motor coordination, but not autistic-like behaviors.
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23
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Kalinowska M, Francesconi A. Group I Metabotropic Glutamate Receptor Interacting Proteins: Fine-Tuning Receptor Functions in Health and Disease. Curr Neuropharmacol 2017; 14:494-503. [PMID: 27296642 PMCID: PMC4983749 DOI: 10.2174/1570159x13666150515234434] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 04/24/2015] [Accepted: 05/12/2015] [Indexed: 11/22/2022] Open
Abstract
Group I metabotropic glutamate receptors mediate slow excitatory neurotransmission in the central nervous system and are critical to activity-dependent synaptic plasticity, a cellular substrate of learning and memory. Dysregulated receptor signaling is implicated in neuropsychiatric conditions ranging from neurodevelopmental to neurodegenerative disorders. Importantly, group I metabotropic glutamate receptor signaling functions can be modulated by interacting proteins that mediate receptor trafficking, expression and coupling efficiency to signaling effectors. These interactions afford cell- or pathway-specific modulation to fine-tune receptor function, thus representing a potential target for pharmacological interventions in pathological conditions.
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Affiliation(s)
| | - Anna Francesconi
- Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Center, Room 706, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
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24
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Pin JP, Bettler B. Organization and functions of mGlu and GABAB receptor complexes. Nature 2016; 540:60-68. [DOI: 10.1038/nature20566] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 10/21/2016] [Indexed: 02/08/2023]
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25
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Chang K, Roche KW. Structural and molecular determinants regulating mGluR5 surface expression. Neuropharmacology 2016; 115:10-19. [PMID: 27211252 DOI: 10.1016/j.neuropharm.2016.04.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 02/29/2016] [Accepted: 04/26/2016] [Indexed: 01/29/2023]
Abstract
Trafficking of G protein-coupled receptors (GPCRs) to the plasma membrane is a pivotal process to fulfill their biological functions. Metabotropic glutamate receptors (mGluRs; mGluR1-8) are expressed throughout the CNS and are important for modulating synaptic transmission and plasticity. Group I mGluRs, including mGluR1 and mGluR5, have long intracellular C-terminal tails containing multiple protein binding domains and sites for phosphorylation and ER retention. We have now investigated some of the structural determinants for mGluR5 trafficking to the plasma membrane by studying a series of truncations and ligand binding mutants. We also take advantage of dimer formation between the extracellular domain (ECD) of mGluR5 and design an ECD based surface-binding assay to evaluate dimerization and surface expression of mGluR5 containing various truncations or point mutations. We found that the C terminus is not essential for mGluR5 surface expression. In contrast, the 7th transmembrane domain (TM7) plays a critical role in its surface expression in both heterologous cells and neurons. Furthermore, a ligand binding mutation within the ECD of mGluR5 (Y64A/T174A) that blocks ligand binding impairs both surface expression and dimerization of mGluR5 in neurons. The integrity of both the whole 7TM domain and the C- terminal tail of mGluR5 are also important for stabilizing dimerization with the ECD. Thus multiple domains regulate dimerization and trafficking of mGluR5. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
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Affiliation(s)
- Kai Chang
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 35, Room 2C903, Bethesda, MD 20892, USA
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 35, Room 2C903, Bethesda, MD 20892, USA.
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26
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Bhattacharyya S. Inside story of Group I Metabotropic Glutamate Receptors (mGluRs). Int J Biochem Cell Biol 2016; 77:205-12. [PMID: 26987586 DOI: 10.1016/j.biocel.2016.03.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/10/2016] [Accepted: 03/11/2016] [Indexed: 12/31/2022]
Abstract
Metabotropic glutamate receptors (mGluRs) are G-protein coupled receptors (GPCRs) that are activated by the neurotransmitter glutamate in the central nervous system. Among the eight subtypes, mGluR1 and mGluR5 belong to the group I family. These receptors play important roles in the brain and are believed to be involved in multiple forms of experience dependent synaptic plasticity including learning and memory. In addition, group I mGluRs also have been implicated in various neuropsychiatric disorders like Fragile X syndrome, autism etc. The normal signaling depends on the precise location of these receptors in specific region of the neuron and the process of receptor trafficking plays a crucial role in controlling this localization. Intracellular trafficking could also regulate the desensitization, resensitization, down-regulation and intracellular signaling of these receptors. In this review I focus on the current understanding of group I mGluR regulation in the central nervous system and also their role in neuropsychiatric disorders.
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Affiliation(s)
- Samarjit Bhattacharyya
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge city, Sector-81, SAS Nagar, PO: 140306, Punjab, India.
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Alteration by p11 of mGluR5 localization regulates depression-like behaviors. Mol Psychiatry 2015; 20:1546-56. [PMID: 26370144 PMCID: PMC4907335 DOI: 10.1038/mp.2015.132] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 05/26/2015] [Accepted: 06/16/2015] [Indexed: 12/19/2022]
Abstract
Mood disorders and antidepressant therapy involve alterations of monoaminergic and glutamatergic transmission. The protein S100A10 (p11) was identified as a regulator of serotonin receptors, and it has been implicated in the etiology of depression and in mediating the antidepressant actions of selective serotonin reuptake inhibitors. Here we report that p11 can also regulate depression-like behaviors via regulation of a glutamatergic receptor in mice. p11 directly binds to the cytoplasmic tail of metabotropic glutamate receptor 5 (mGluR5). p11 and mGluR5 mutually facilitate their accumulation at the plasma membrane, and p11 increases cell surface availability of the receptor. Whereas p11 overexpression potentiates mGluR5 agonist-induced calcium responses, overexpression of mGluR5 mutant, which does not interact with p11, diminishes the calcium responses in cultured cells. Knockout of mGluR5 or p11 specifically in glutamatergic neurons in mice causes depression-like behaviors. Conversely, knockout of mGluR5 or p11 in GABAergic neurons causes antidepressant-like behaviors. Inhibition of mGluR5 with an antagonist, 2-methyl-6-(phenylethynyl)pyridine (MPEP), induces antidepressant-like behaviors in a p11-dependent manner. Notably, the antidepressant-like action of MPEP is mediated by parvalbumin-positive GABAergic interneurons, resulting in a decrease of inhibitory neuronal firing with a resultant increase of excitatory neuronal firing. These results identify a molecular and cellular basis by which mGluR5 antagonism achieves its antidepressant-like activity.
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Numb deficiency in cerebellar Purkinje cells impairs synaptic expression of metabotropic glutamate receptor and motor coordination. Proc Natl Acad Sci U S A 2015; 112:15474-9. [PMID: 26621723 DOI: 10.1073/pnas.1512915112] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Protein Numb, first identified as a cell-fate determinant in Drosophila, has been shown to promote the development of neurites in mammals and to be cotransported with endocytic receptors in clathrin-coated vesicles in vitro. Nevertheless, its function in mature neurons has not yet been elucidated. Here we show that cerebellar Purkinje cells (PCs) express high levels of Numb during adulthood and that conditional deletion of Numb in PCs is sufficient to impair motor coordination despite maintenance of a normal cerebellar cyto-architecture. Numb proved to be critical for internalization and recycling of metabotropic glutamate 1 receptor (mGlu1) in PCs. A significant decrease of mGlu1 and an inhibition of long-term depression at the parallel fiber-PC synapse were observed in conditional Numb knockout mice. Indeed, the trafficking of mGlu1 induced by agonists was inhibited significantly in these mutants, but the expression of ionotropic glutamate receptor subunits and of mGlu1-associated proteins was not affected by the loss of Numb. Moreover, transient and persistent forms of mGlu1 plasticity were robustly induced in mutant PCs, suggesting that they do not require mGlu1 trafficking. Together, our data demonstrate that Numb is a regulator for constitutive expression and dynamic transport of mGlu1.
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Sengmany K, Gregory KJ. Metabotropic glutamate receptor subtype 5: molecular pharmacology, allosteric modulation and stimulus bias. Br J Pharmacol 2015; 173:3001-17. [PMID: 26276909 DOI: 10.1111/bph.13281] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/30/2015] [Accepted: 07/26/2015] [Indexed: 12/12/2022] Open
Abstract
The metabotropic glutamate receptor subtype 5 (mGlu5 ) is a family C GPCR that has been implicated in various neuronal processes and, consequently, in several CNS disorders. Over the past few decades, GPCR-based drug discovery, including that for mGlu5 receptors, has turned considerable attention to targeting allosteric binding sites. Modulation of endogenous agonists by allosteric ligands offers the advantages of spatial and temporal fine-tuning of receptor activity, increased selectivity and reduced adverse effects with the potential to elicit improved clinical outcomes. Further, with greater appreciation of the multifaceted nature of the transduction of mGlu5 receptor signalling, it is increasingly apparent that drug discovery must take into consideration unique receptor conformations and the potential for stimulus-bias. This novel paradigm proposes that different ligands may differentially modulate distinct signalling pathways arising from the same receptor. We review our current understanding of the complexities of mGlu5 receptor signalling and regulation, and how these relate to allosteric ligands. Ultimately, a deeper appreciation of these relationships will provide the foundation for targeted drug design of compounds with increased selectivity, not only for the desired receptor but also for the desired signalling outcome from the receptor. Linked Articles This article is part of a themed section on Molecular Pharmacology of G Protein-Coupled Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v173.20/issuetoc.
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Affiliation(s)
- K Sengmany
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, VIC, Australia
| | - K J Gregory
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, VIC, Australia.
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Mahato P, Pandey S, Bhattacharyya S. Differential effects of protein phosphatases in the recycling of metabotropic glutamate receptor 5. Neuroscience 2015; 306:138-50. [DOI: 10.1016/j.neuroscience.2015.08.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 07/28/2015] [Accepted: 08/14/2015] [Indexed: 10/23/2022]
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Shifting towards a model of mGluR5 dysregulation in schizophrenia: Consequences for future schizophrenia treatment. Neuropharmacology 2015; 115:73-91. [PMID: 26349010 DOI: 10.1016/j.neuropharm.2015.08.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 08/02/2015] [Accepted: 08/03/2015] [Indexed: 12/22/2022]
Abstract
Metabotropic glutamate receptor subtype 5 (mGluR5), encoded by the GRM5 gene, represents a compelling novel drug target for the treatment of schizophrenia. mGluR5 is a postsynaptic G-protein coupled glutamate receptor strongly linked with several critical cellular processes that are reported to be disrupted in schizophrenia. Accordingly, mGluR5 positive allosteric modulators show encouraging therapeutic potential in preclinical schizophrenia models, particularly for the treatment of cognitive dysfunctions against which currently available therapeutics are largely ineffective. More work is required to support the progression of mGluR5-targeting drugs into the clinic for schizophrenia treatment, although some obstacles may be overcome by comprehensively understanding how mGluR5 itself is involved in the neurobiology of the disorder. Several processes that are necessary for the regulation of mGluR5 activity have been identified, but not examined, in the context of schizophrenia. These processes include protein-protein interactions, dimerisation, subcellular trafficking, the impact of genetic variability or mutations on protein function, as well as epigenetic, post-transcriptional and post-translational processes. It is essential to understand these aspects of mGluR5 to determine whether they are affected in schizophrenia pathology, and to assess the consequences of mGluR5 dysfunction for the future use of mGluR5-based drugs. Here, we summarise the known processes that regulate mGluR5 and those that have already been studied in schizophrenia, and discuss the consequences of this dysregulation for current mGluR5 pharmacological strategies. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
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Jong YJI, Sergin I, Purgert CA, O'Malley KL. Location-dependent signaling of the group 1 metabotropic glutamate receptor mGlu5. Mol Pharmacol 2014; 86:774-85. [PMID: 25326002 DOI: 10.1124/mol.114.094763] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although G protein-coupled receptors are primarily known for converting extracellular signals into intracellular responses, some receptors, such as the group 1 metabotropic glutamate receptor, mGlu5, are also localized on intracellular membranes where they can mediate both overlapping and unique signaling effects. Thus, besides "ligand bias," whereby a receptor's signaling modality can shift from G protein dependence to independence, canonical mGlu5 receptor signaling can also be influenced by "location bias" (i.e., the particular membrane and/or cell type from which it signals). Because mGlu5 receptors play important roles in both normal development and in disorders such as Fragile X syndrome, autism, epilepsy, addiction, anxiety, schizophrenia, pain, dyskinesias, and melanoma, a large number of drugs are being developed to allosterically target this receptor. Therefore, it is critical to understand how such drugs might be affecting mGlu5 receptor function on different membranes and in different brain regions. Further elucidation of the site(s) of action of these drugs may determine which signal pathways mediate therapeutic efficacy.
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Affiliation(s)
- Yuh-Jiin I Jong
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
| | - Ismail Sergin
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
| | - Carolyn A Purgert
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
| | - Karen L O'Malley
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
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Pandey S, Mahato PK, Bhattacharyya S. Metabotropic glutamate receptor 1 recycles to the cell surface in protein phosphatase 2A-dependent manner in non-neuronal and neuronal cell lines. J Neurochem 2014; 131:602-14. [DOI: 10.1111/jnc.12930] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/30/2014] [Accepted: 08/08/2014] [Indexed: 02/03/2023]
Affiliation(s)
- Saurabh Pandey
- Department of Biological Sciences; Indian Institute of Science Education and Research (IISER) Mohali; Punjab India
| | - Prabhat Kumar Mahato
- Department of Biological Sciences; Indian Institute of Science Education and Research (IISER) Mohali; Punjab India
| | - Samarjit Bhattacharyya
- Department of Biological Sciences; Indian Institute of Science Education and Research (IISER) Mohali; Punjab India
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Mao LM, Jin DZ, Xue B, Chu XP, Wang JQ. Phosphorylation and regulation of glutamate receptors by CaMKII. SHENG LI XUE BAO : [ACTA PHYSIOLOGICA SINICA] 2014; 66:365-372. [PMID: 24964855 PMCID: PMC4435801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) is the most abundant kinase within excitatory synapses in the mammalian brain. It interacts with and phosphorylates a large number of synaptic proteins, including major ionotropic glutamate receptors (iGluRs) and group I metabotropic glutamate receptors (mGluRs), to constitutively and/or activity-dependently regulate trafficking, subsynaptic localization, and function of the receptors. Among iGluRs, the N-methyl-D-aspartate receptor (NMDAR) is a direct target of CaMKII. By directly binding to an intracellular C-terminal (CT) region of NMDAR GluN2B subunits, CaMKII phosphorylates a serine residue (S1303) in the GluN2B CT. CaMKII also phosphorylates a serine site (S831) in the CT of α-amino-3-hydroxy-5- methylisoxazole-4-propionic acid receptors. This phosphorylation enhances channel conductance and is critical for synaptic plasticity. In addition to iGluRs, CaMKII binds to the proximal CT region of mGluR1a, which enables the kinase to phosphorylate threonine 871. Agonist stimulation of mGluR1a triggers a CaMKII-mediated negative feedback to facilitate endocytosis and desensitization of the receptor. CaMKII also binds to the mGluR5 CT. This binding seems to anchor and accumulate inactive CaMKII at synaptic sites. Active CaMKII dissociates from mGluR5 and may then bind to adjacent GluN2B to mediate the mGluR5-NMDAR coupling. Together, glutamate receptors serve as direct substrates of CaMKII. By phosphorylating these receptors, CaMKII plays a central role in controlling the number and activity of the modified receptors and determining the strength of excitatory synaptic transmission.
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Affiliation(s)
- Li-Min Mao
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA.
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Jiang S, Su J, Yao S, Zhang Y, Cao F, Wang F, Wang H, Li J, Xi S. Fluoride and arsenic exposure impairs learning and memory and decreases mGluR5 expression in the hippocampus and cortex in rats. PLoS One 2014; 9:e96041. [PMID: 24759735 PMCID: PMC3997496 DOI: 10.1371/journal.pone.0096041] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 04/02/2014] [Indexed: 11/18/2022] Open
Abstract
Fluoride and arsenic are two common inorganic contaminants in drinking water that are associated with impairment in child development and retarded intelligence. The present study was conducted to explore the effects on spatial learning, memory, glutamate levels, and group I metabotropic glutamate receptors (mGluRs) expression in the hippocampus and cortex after subchronic exposure to fluoride, arsenic, and a fluoride and arsenic combination in rats. Weaned male Sprague-Dawley rats were assigned to four groups. The control rats drank tap water. Rats in the three exposure groups drank water with sodium fluoride (120 mg/L), sodium arsenite (70 mg/L), and a sodium fluoride (120 mg/L) and sodium arsenite (70 mg/L) combination for 3 months. Spatial learning and memory was measured in Morris water maze. mGluR1 and mGluR5 mRNA and protein expression in the hippocampus and cortex was detected using RT-PCR and Western blot, respectively. Compared with controls, learning and memory ability declined in rats that were exposed to fluoride and arsenic both alone and combined. Combined fluoride and arsenic exposure did not have a more pronounced effect on spatial learning and memory compared with arsenic and fluoride exposure alone. Compared with controls, glutamate levels decreased in the hippocampus and cortex of rats exposed to fluoride and combined fluoride and arsenic, and in cortex of arsenic-exposed rats. mGluR5 mRNA and protein expressions in the hippocampus and mGluR5 protein expression in the cortex decreased in rats exposed to arsenic alone. Interestingly, compared with fluoride and arsenic exposure alone, fluoride and arsenic combination decreased mGluR5 mRNA expression in the cortex and protein expression in the hippocampus, suggesting a synergistic effect of fluoride and arsenic. These data indicate that fluoride and arsenic, either alone or combined, can decrease learning and memory ability in rats. The mechanism may be associated with changes of glutamate level and mGluR5 expression in cortex and hippocampus.
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Affiliation(s)
- Shoufang Jiang
- Department of Occupational and Environmental Health, Liaoning Provincial Key Lab of Arsenic Biological Effect and Poisoning, School of Public Health, China Medical University, Shenyang, Liaoning, P. R. China
- Department of Occupational and Environmental Health, Hebei Province Key Laboratory of Occupational Health and Safety for Coal Industry, School of Public Health, Hebei United University, Tangshan, Hebei, P. R. China
| | - Jing Su
- Department of Occupational and Environmental Health, Hebei Province Key Laboratory of Occupational Health and Safety for Coal Industry, School of Public Health, Hebei United University, Tangshan, Hebei, P. R. China
| | - Sanqiao Yao
- Department of Occupational and Environmental Health, Hebei Province Key Laboratory of Occupational Health and Safety for Coal Industry, School of Public Health, Hebei United University, Tangshan, Hebei, P. R. China
| | - Yanshu Zhang
- Department of Occupational and Environmental Health, Hebei Province Key Laboratory of Occupational Health and Safety for Coal Industry, School of Public Health, Hebei United University, Tangshan, Hebei, P. R. China
| | - Fuyuan Cao
- Laboratory Animal Center, Hebei United University, Tangshan, Hebei, P. R. China
| | - Fei Wang
- Department of Occupational and Environmental Health, Liaoning Provincial Key Lab of Arsenic Biological Effect and Poisoning, School of Public Health, China Medical University, Shenyang, Liaoning, P. R. China
| | - Huihui Wang
- Department of Occupational and Environmental Health, Liaoning Provincial Key Lab of Arsenic Biological Effect and Poisoning, School of Public Health, China Medical University, Shenyang, Liaoning, P. R. China
| | - Jun Li
- Department of Occupational and Environmental Health, Hebei Province Key Laboratory of Occupational Health and Safety for Coal Industry, School of Public Health, Hebei United University, Tangshan, Hebei, P. R. China
| | - Shuhua Xi
- Department of Occupational and Environmental Health, Liaoning Provincial Key Lab of Arsenic Biological Effect and Poisoning, School of Public Health, China Medical University, Shenyang, Liaoning, P. R. China
- * E-mail:
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Um JW, Kaufman AC, Kostylev M, Heiss JK, Stagi M, Takahashi H, Kerrisk ME, Vortmeyer A, Wisniewski T, Koleske AJ, Gunther EC, Nygaard HB, Strittmatter SM. Metabotropic glutamate receptor 5 is a coreceptor for Alzheimer aβ oligomer bound to cellular prion protein. Neuron 2013; 79:887-902. [PMID: 24012003 DOI: 10.1016/j.neuron.2013.06.036] [Citation(s) in RCA: 435] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2013] [Indexed: 02/07/2023]
Abstract
Soluble amyloid-β oligomers (Aβo) trigger Alzheimer's disease (AD) pathophysiology and bind with high affinity to cellular prion protein (PrP(C)). At the postsynaptic density (PSD), extracellular Aβo bound to lipid-anchored PrP(C) activates intracellular Fyn kinase to disrupt synapses. Here, we screened transmembrane PSD proteins heterologously for the ability to couple Aβo-PrP(C) with Fyn. Only coexpression of the metabotropic glutamate receptor, mGluR5, allowed PrP(C)-bound Aβo to activate Fyn. PrP(C) and mGluR5 interact physically, and cytoplasmic Fyn forms a complex with mGluR5. Aβo-PrP(C) generates mGluR5-mediated increases of intracellular calcium in Xenopus oocytes and in neurons, and the latter is also driven by human AD brain extracts. In addition, signaling by Aβo-PrP(C)-mGluR5 complexes mediates eEF2 phosphorylation and dendritic spine loss. For mice expressing familial AD transgenes, mGluR5 antagonism reverses deficits in learning, memory, and synapse density. Thus, Aβo-PrP(C) complexes at the neuronal surface activate mGluR5 to disrupt neuronal function.
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Affiliation(s)
- Ji Won Um
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neurobiology, Yale University School of Medicine, New Haven, CT 06536, USA
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Jin DZ, Guo ML, Xue B, Mao LM, Wang JQ. Differential regulation of CaMKIIα interactions with mGluR5 and NMDA receptors by Ca(2+) in neurons. J Neurochem 2013; 127:620-31. [PMID: 24032403 DOI: 10.1111/jnc.12434] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 08/05/2013] [Accepted: 08/21/2013] [Indexed: 11/29/2022]
Abstract
Two glutamate receptors, metabotropic glutamate receptor 5 (mGluR5), and ionotropic NMDA receptors (NMDAR), functionally interact with each other to regulate excitatory synaptic transmission in the mammalian brain. In exploring molecular mechanisms underlying their interactions, we found that Ca(2+) /calmodulin-dependent protein kinase IIα (CaMKIIα) may play a central role. The synapse-enriched CaMKIIα directly binds to the proximal region of intracellular C terminal tails of mGluR5 in vitro. This binding is state-dependent: inactive CaMKIIα binds to mGluR5 at a high level whereas the active form of the kinase (following Ca(2+) /calmodulin binding and activation) loses its affinity for the receptor. Ca(2+) also promotes calmodulin to bind to mGluR5 at a region overlapping with the CaMKIIα-binding site, resulting in a competitive inhibition of CaMKIIα binding to mGluR5. In rat striatal neurons, inactive CaMKIIα constitutively binds to mGluR5. Activation of mGluR5 Ca(2+) -dependently dissociates CaMKIIα from the receptor and simultaneously promotes CaMKIIα to bind to the adjacent NMDAR GluN2B subunit, which enables CaMKIIα to phosphorylate GluN2B at a CaMKIIα-sensitive site. Together, the long intracellular C-terminal tail of mGluR5 seems to serve as a scaffolding domain to recruit and store CaMKIIα within synapses. The mGluR5-dependent Ca(2+) transients differentially regulate CaMKIIα interactions with mGluR5 and GluN2B in striatal neurons, which may contribute to cross-talk between the two receptors. We show that activation of mGluR5 with a selective agonist triggers intracellular Ca(2+) release in striatal neurons. Released Ca(2+) dissociates preformed CaMKIIα from mGluR5 and meanwhile promotes active CaMKIIα to bind to the adjacent NMDAR GluN2B subunit, which enables CaMKIIα to phosphorylate GluN2B at a CaMKIIα-sensitive site. This agonist-induced cascade seems to mediate crosstalk between mGluR5 and NMDA receptors in neurons.
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Affiliation(s)
- Dao-Zhong Jin
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, USA
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Two distinct calmodulin binding sites in the third intracellular loop and carboxyl tail of angiotensin II (AT(1A)) receptor. PLoS One 2013; 8:e65266. [PMID: 23755207 PMCID: PMC3673938 DOI: 10.1371/journal.pone.0065266] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 04/24/2013] [Indexed: 11/25/2022] Open
Abstract
In this study, we present data that support the presence of two distinct calmodulin binding sites within the angiotensin II receptor (AT1A), at juxtamembrane regions of the N-terminus of the third intracellular loop (i3, amino acids 214–231) and carboxyl tail of the receptor (ct, 302–317). We used bioluminescence resonance energy transfer assays to document interactions of calmodulin with the AT1A holo-receptor and GST-fusion protein pull-downs to demonstrate that i3 and ct interact with calmodulin in a Ca2+-dependent fashion. The former is a 1–12 motif and the latter belongs to 1-5-10 calmodulin binding motif. The apparent Kd of calmodulin for i3 is 177.0±9.1 nM, and for ct is 79.4±7.9 nM as assessed by dansyl-calmodulin fluorescence. Replacement of the tryptophan (W219) for alanine in i3, and phenylalanine (F309 or F313) for alanine in ct reduced their binding affinities for calmodulin, as predicted by computer docking simulations. Exogenously applied calmodulin attenuated interactions between G protein βγ subunits and i3 and ct, somewhat more so for ct than i3. Mutations W219A, F309A, and F313A did not alter Gβγ binding, but reduced the ability of calmodulin to compete with Gβγ, suggesting that calmodulin and Gβγ have overlapping, but not identical, binding requirements for i3 and ct. Calmodulin interference with the Gβγ binding to i3 and ct regions of the AT1A receptor strongly suggests that calmodulin plays critical roles in regulating Gβγ-dependent signaling of the receptor.
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Phosphorylation and feedback regulation of metabotropic glutamate receptor 1 by calcium/calmodulin-dependent protein kinase II. J Neurosci 2013; 33:3402-12. [PMID: 23426668 DOI: 10.1523/jneurosci.3192-12.2013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The metabotropic glutamate receptor 1 (mGluR1) is a Gα(q)-protein-coupled receptor and is distributed in broad regions of the mammalian brain. As a key element in excitatory synaptic transmission, the receptor regulates a wide range of cellular and synaptic activities. In addition to regulating its targets, the receptor itself is believed to be actively regulated by intracellular signals, although underlying mechanisms are essentially unknown. Here we found that a synapse-enriched protein kinase, Ca²⁺/calmodulin-dependent protein kinase IIα (CaMKIIα), directly binds to the intracellular C terminus (CT) of mGluR1a. This binding is augmented by Ca²⁺ in vitro. The direct interaction promotes CaMKIIα to phosphorylate mGluR1a at a specific threonine site (T871). In rat striatal neurons, the mGluR1 agonist triggers the receptor-associated phosphoinositide signaling pathway to induce Ca²⁺-dependent recruitment of CaMKIIα to mGluR1a-CT. This enables the kinase to inhibit the response of the receptor to subsequent agonist exposure. Our data identify an agonist-induced and Ca²⁺-dependent protein-protein interaction between a synaptic kinase and mGluR1, which constitutes a feedback loop facilitating desensitization of mGluR1a.
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Trivedi RR, Bhattacharyya S. Constitutive internalization and recycling of metabotropic glutamate receptor 5 (mGluR5). Biochem Biophys Res Commun 2012; 427:185-90. [DOI: 10.1016/j.bbrc.2012.09.040] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 09/07/2012] [Indexed: 12/11/2022]
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Bellone C, Mameli M. mGluR-Dependent Synaptic Plasticity in Drug-Seeking. Front Pharmacol 2012; 3:159. [PMID: 22969723 PMCID: PMC3428011 DOI: 10.3389/fphar.2012.00159] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 08/09/2012] [Indexed: 11/13/2022] Open
Abstract
A primary feature of drug addiction is the compulsive use despite negative consequences. A general consensus is emerging on the capacity of addictive substances to co-opt synaptic transmission and synaptic plasticity in brain circuits which are involved in reinforcement and reward processing. A current hypothesis is that drug-driven neuroadaptations during learning and memory processes divert the functions of these brain circuits, eventually leading to addictive behaviors. Metabotropic glutamate receptors (mGluRs) not only lead to long-term modulation of synaptic transmission but they have been implicated in drug-evoked synaptic plasticity and drug-seeking behaviors in two important ways. mGluR-dependent modulation of synaptic transmission is impaired by drug experience but interestingly their activation has been indicated as a strategy to restore baseline transmission after drug-evoked synaptic plasticity. Here we focus on the cellular mechanisms underlying mGluR-dependent long-term changes of excitatory synapses, and review results implicating these receptors in drug-evoked synaptic plasticity.
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Affiliation(s)
- Camilla Bellone
- Department of Basic Neuroscience, University of Geneva Geneva, Switzerland
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Rossi PIA, Musante I, Summa M, Pittaluga A, Emionite L, Ikehata M, Rastaldi MP, Ravazzolo R, Puliti A. Compensatory molecular and functional mechanisms in nervous system of the Grm1(crv4) mouse lacking the mGlu1 receptor: a model for motor coordination deficits. ACTA ACUST UNITED AC 2012; 23:2179-89. [PMID: 22791805 DOI: 10.1093/cercor/bhs200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The metabotropic glutamate type 1 (mGlu1) and type 5 (mGlu5) receptors, the only members of group I mGlu receptors, are implicated in synaptic plasticity and mechanisms of feedback control of glutamate release. They exhibit nearly complementary distributions throughout the central nervous system, well evident in the cerebellum, where mGlu1 receptor is most intensely expressed while mGlu5 receptor is not. Despite their different distribution, they show a similar subcellular localization and use common transducing pathways. We recently described the Grm1(crv4) mouse with motor coordination deficits and renal anomalies caused by a spontaneous mutation inactivating the mGlu1 receptor. To define the neuropathological mechanisms in these mice, we evaluated expression and function of the mGlu5 receptor in cerebral and cerebellar cortices. Western blot and immunofluorescence analyses showed mGlu5 receptor overexpression. Quantitative reverse transcriptase-polymerase chain reaction results indicated that the up-regulation is already evident at RNA level. Functional studies confirmed an enhanced glutamate release from cortical cerebral and cerebellar synaptosomes when compared with wild-type that is abolished by the mGlu5 receptor-specific inhibitor, 2-methyl-6-(phenylethynyl) pyridine hydrochloride (MPEP). Finally, acute MPEP treatment of Grm1(crv4/crv4) mice induced an evident although incomplete improvement of motor coordination, suggesting that mGlu5 receptors enhanced activity worsens, instead of improving, the motor-coordination defects in the Grm1(crv4/crv4) mice.
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Expression of the metabotropic glutamate receptor 5 (mGluR5) induces melanoma in transgenic mice. Proc Natl Acad Sci U S A 2011; 108:15219-24. [PMID: 21896768 DOI: 10.1073/pnas.1107304108] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Glutamate is the major excitatory neurotransmitter in the mammalian CNS and mediates fast synaptic transmission upon activation of glutamate-gated ion channels. In addition, glutamate modulates a variety of other synaptic responses and intracellular signaling by activating metabotropic glutamate receptors (mGluRs), which are G protein-coupled receptors. The mGluRs are also expressed in nonneuronal tissues and are implicated in a variety of normal biological functions as well as diseases. To study mGluR-activated calcium signaling in neurons, we generated mGluR5 transgenic animals using a Thy1 promoter to drive expression in the forebrain, and one founder unexpectedly developed melanoma. To directly investigate the role of mGluR5 in melanoma formation, we generated mGluR5 transgenic lines under a melanocyte-specific promoter, tyrosinase-related protein 1. A majority of the founders showed a severe phenotype with early onset. Hyperpigmentation of the pinnae and tail could be detected as early as 3-5 d after birth for most of the mGluR5 transgene-positive mice. There was 100% penetrance in the progeny from the tyrosinase-related protein 1-mGluR5 lines generated from founders that developed melanoma. Expression of mGluR5 was detected in melanoma samples by RT-PCR, immunoblotting, and immunohistochemistry. We evaluated the expression of several cancer-related proteins in tumor samples and observed a dramatic increase in the phosphorylation of ERK, implicating ERK as a downstream effector of mGluR5 signaling in tumors. Our findings show that mGluR5-mediated glutamatergic signaling can trigger melanoma in vivo. The aggressive growth and severe phenotype make these mouse lines unique and a potentially powerful tool for therapeutic studies.
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