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Mao LM, Mathur N, Mahmood T, Rajan S, Chu XP, Wang JQ. Phosphorylation and regulation of group II metabotropic glutamate receptors (mGlu2/3) in neurons. Front Cell Dev Biol 2022; 10:1022544. [PMID: 36407098 PMCID: PMC9669598 DOI: 10.3389/fcell.2022.1022544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 10/18/2022] [Indexed: 11/05/2022] Open
Abstract
Group II metabotropic glutamate (mGlu) receptors (mGlu2/3) are Gαi/o-coupled receptors and are primarily located on presynaptic axonal terminals in the central nervous system. Like ionotropic glutamate receptors, group II mGlu receptors are subject to regulation by posttranslational phosphorylation. Pharmacological evidence suggests that several serine/threonine protein kinases possess the ability to regulate mGlu2/3 receptors. Detailed mapping of phosphorylation residues has revealed that protein kinase A (PKA) phosphorylates mGlu2/3 receptors at a specific serine site on their intracellular C-terminal tails in heterologous cells or neurons, which underlies physiological modulation of mGlu2/3 signaling. Casein kinases promote mGlu2 phosphorylation at a specific site. Tyrosine protein kinases also target group II receptors to induce robust phosphorylation. A protein phosphatase was found to specifically bind to mGlu3 receptors and dephosphorylate the receptor at a PKA-sensitive site. This review summarizes recent progress in research on group II receptor phosphorylation and the phosphorylation-dependent regulation of group II receptor functions. We further explore the potential linkage of mGlu2/3 phosphorylation to various neurological and neuropsychiatric disorders, and discuss future research aimed at analyzing novel biochemical and physiological properties of mGlu2/3 phosphorylation.
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Affiliation(s)
- Li-Min Mao
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Nirav Mathur
- Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Tayyibah Mahmood
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Sri Rajan
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Xiang-Ping Chu
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - John Q. Wang
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States,Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States,*Correspondence: John Q. Wang,
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Group I Metabotropic Glutamate Receptors and Interacting Partners: An Update. Int J Mol Sci 2022; 23:ijms23020840. [PMID: 35055030 PMCID: PMC8778124 DOI: 10.3390/ijms23020840] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/09/2022] [Accepted: 01/10/2022] [Indexed: 12/21/2022] Open
Abstract
Group I metabotropic glutamate (mGlu) receptors (mGlu1/5 subtypes) are G protein-coupled receptors and are broadly expressed in the mammalian brain. These receptors play key roles in the modulation of normal glutamatergic transmission and synaptic plasticity, and abnormal mGlu1/5 signaling is linked to the pathogenesis and symptomatology of various mental and neurological disorders. Group I mGlu receptors are noticeably regulated via a mechanism involving dynamic protein-protein interactions. Several synaptic protein kinases were recently found to directly bind to the intracellular domains of mGlu1/5 receptors and phosphorylate the receptors at distinct amino acid residues. A variety of scaffolding and adaptor proteins also interact with mGlu1/5. Constitutive or activity-dependent interactions between mGlu1/5 and their interacting partners modulate trafficking, anchoring, and expression of the receptors. The mGlu1/5-associated proteins also finetune the efficacy of mGlu1/5 postreceptor signaling and mGlu1/5-mediated synaptic plasticity. This review analyzes the data from recent studies and provides an update on the biochemical and physiological properties of a set of proteins or molecules that interact with and thus regulate mGlu1/5 receptors.
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The coming together of allosteric and phosphorylation mechanisms in the molecular integration of A2A heteroreceptor complexes in the dorsal and ventral striatal-pallidal GABA neurons. Pharmacol Rep 2021; 73:1096-1108. [PMID: 34426901 PMCID: PMC8413191 DOI: 10.1007/s43440-021-00314-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 07/12/2021] [Accepted: 07/20/2021] [Indexed: 11/13/2022]
Abstract
The role of adenosine A2A receptor (A2AR) and striatal-enriched protein tyrosine phosphatase (STEP) interactions in the striatal-pallidal GABA neurons was recently discussed in relation to A2AR overexpression and cocaine-induced increases of brain adenosine levels. As to phosphorylation, combined activation of A2AR and metabotropic glutamate receptor 5 (mGluR5) in the striatal-pallidal GABA neurons appears necessary for phosphorylation of the GluA1 unit of the AMPA receptor to take place. Robert Yasuda (J Neurochem 152: 270–272, 2020) focused on finding a general mechanism by which STEP activation is enhanced by increased A2AR transmission in striatal-pallidal GABA neurons expressing A2AR and dopamine D2 receptor. In his Editorial, he summarized in a clear way the significant effects of A2AR activation on STEP in the dorsal striatal-pallidal GABA neurons which involves a rise of intracellular levels of calcium causing STEP activation through its dephosphorylation. However, the presence of the A2AR in an A2AR-fibroblast growth factor receptor 1 (FGFR1) heteroreceptor complex can be required in the dorsal striatal-pallidal GABA neurons for the STEP activation. Furthermore, Won et al. (Proc Natl Acad Sci USA 116: 8028–8037, 2019) found in mass spectrometry experiments that the STEP splice variant STEP61 can bind to mGluR5 and inactivate it. In addition, A2AR overexpression can lead to increased formation of A2AR-mGluR5 heterocomplexes in ventral striatal-pallidal GABA neurons. It involves enhanced facilitatory allosteric interactions leading to increased Gq-mediated mGluR5 signaling activating STEP. The involvement of both A2AR and STEP in the actions of cocaine on synaptic downregulation was also demonstrated. The enhancement of mGluR5 protomer activity by the A2AR protomer in A2AR-mGluR5 heterocomplexes in the nucleus accumbens shell appears to have a novel significant role in STEP mechanisms by both enhancing the activation of STEP and being a target for STEP61.
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Xu X, Wu K, Ma X, Wang W, Wang H, Huang M, Luo L, Su C, Yuan T, Shi H, Han J, Wang A, Xu T. mGluR5-Mediated eCB Signaling in the Nucleus Accumbens Controls Vulnerability to Depressive-Like Behaviors and Pain After Chronic Social Defeat Stress. Mol Neurobiol 2021; 58:4944-4958. [PMID: 34227060 DOI: 10.1007/s12035-021-02469-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/21/2021] [Indexed: 12/16/2022]
Abstract
Stress contributes to major depressive disorder (MDD) and chronic pain, which affect a significant portion of the global population, but researchers have not clearly determined how these conditions are initiated or amplified by stress. The chronic social defeat stress (CSDS) model is a mouse model of psychosocial stress that exhibits depressive-like behavior and chronic pain. We hypothesized that metabotropic glutamate receptor 5 (mGluR5) expressed in the nucleus accumbens (NAc) normalizes the depressive-like behaviors and pain following CSDS. Here, we show that CSDS induced both pain and social avoidance and that the level of mGluR5 decreased in susceptible mice. Overexpression of mGluR5 in the NAc shell and core prevented the development of depressive-like behaviors and pain in susceptible mice, respectively. Conversely, depression-like behaviors and pain were exacerbated in mice with mGluR5 knockdown in the NAc shell and core, respectively, compared to control mice subjected to 3 days of social defeat stress. Furthermore, (RS)-2-chloro-5-hydroxyphenylglycine (CHPG), an mGluR5 agonist, reversed the reduction in the level of the endocannabinoid (eCB) 2-arachidonoylglycerol (2-AG) in the NAc of susceptible mice, an effect that was blocked by 3-((2-methyl-1, 3-thiazol-4-yl) ethynyl) pyridine hydrochloride (MTEP), an mGluR5 antagonist. In addition, the injection of CHPG into the NAc shell and core normalized depressive-like behaviors and pain, respectively, and these effects were inhibited by AM251, a cannabinoid type 1 receptor (CB1R) antagonist. Based on these results, mGluR5-mediated eCB production in the NAc relieves stress-induced depressive-like behaviors and pain.
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Affiliation(s)
- Xiaotao Xu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Kaixuan Wu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Xiaqing Ma
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Wenying Wang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Haiyan Wang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Min Huang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Limin Luo
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China
| | - Chen Su
- Department of Anesthesiology and Pain Medicine, Hunan Cancer Hospital/The Affiliated Cancer Hospital of Xiangya School of Medicine, Changsha, 410013, People's Republic of China
| | - Tifei Yuan
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, People's Republic of China
| | - Haibo Shi
- Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, 200233, People's Republic of China
| | - Ji Han
- Internal medicine of TCM, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, No.164 Lanxi Road, Shanghai, 200062, China.
| | - Aizhong Wang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China.
| | - Tao Xu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, People's Republic of China. .,Department of Anesthesiology, Tongzhou People's Hospital, Nantong, 226300, China.
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Ledonne A, Mercuri NB. Insights on the Functional Interaction between Group 1 Metabotropic Glutamate Receptors (mGluRI) and ErbB Receptors. Int J Mol Sci 2020; 21:ijms21217913. [PMID: 33114459 PMCID: PMC7662933 DOI: 10.3390/ijms21217913] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/23/2020] [Accepted: 10/23/2020] [Indexed: 11/16/2022] Open
Abstract
It is well-appreciated that phosphorylation is an essential post-translational mechanism of regulation for several proteins, including group 1 metabotropic glutamate receptors (mGluRI), mGluR1, and mGluR5 subtypes. While contributions of various serine/threonine protein kinases on mGluRI modulation have been recognized, the functional role of tyrosine kinases (TKs) is less acknowledged. Here, while describing current evidence supporting that mGluRI are targets of TKs, we mainly focus on the modulatory roles of the ErbB tyrosine kinases receptors—activated by the neurotrophic factors neuregulins (NRGs)—on mGluRI function. Available evidence suggests that mGluRI activity is tightly dependent on ErbB signaling, and that ErbB’s modulation profoundly influences mGluRI-dependent effects on neurotransmission, neuronal excitability, synaptic plasticity, and learning and memory processes.
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Affiliation(s)
- Ada Ledonne
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
- Correspondence: ; Tel.: +39-06-50170-3160
| | - Nicola B. Mercuri
- Department of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
- Department of Systems Medicine, Università di Roma “Tor Vergata”, 00133 Rome, Italy;
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Wang HY, MacDonald ML, Borgmann-Winter KE, Banerjee A, Sleiman P, Tom A, Khan A, Lee KC, Roussos P, Siegel SJ, Hemby SE, Bilker WB, Gur RE, Hahn CG. mGluR5 hypofunction is integral to glutamatergic dysregulation in schizophrenia. Mol Psychiatry 2020; 25:750-760. [PMID: 30214040 PMCID: PMC7500805 DOI: 10.1038/s41380-018-0234-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 06/18/2018] [Accepted: 07/09/2018] [Indexed: 11/19/2022]
Abstract
Multiple lines of evidence point to glutamatergic signaling in the postsynaptic density (PSD) as a pathophysiologic mechanism in schizophrenia. Integral to PSD glutamatergic signaling is reciprocal interplay between GluN and mGluR5 signaling. We examined agonist-induced mGluR5 signaling in the postmortem dorsolateral prefrontal cortex (DLPFC) derived from 17 patients and age-matched and sex-matched controls. The patient group showed a striking reduction in mGluR5 signaling, manifested by decreases in Gq/11 coupling and association with PI3K and Homer compared to controls (p < 0.01 for all). This was accompanied by increases in serine and tyrosine phosphorylation of mGluR5, which can decrease mGluR5 activity via desensitization (p < 0.01). In addition, we find altered protein-protein interaction (PPI) of mGluR5 with RGS4, norbin, Preso 1 and tamalin, which can also attenuate mGluR5 activity. We previously reported molecular underpinnings of GluN hypofunction (decreased GluN2 phosphorylation) and here we show those of reduced mGluR5 signaling in schizophrenia. We find that reduced GluN2 phosphorylation can be precipitated by attenuated mGluR5 activity and that increased mGluR5 phosphorylation can result from decreased GluN function, suggesting a reciprocal interplay between the two pathways in schizophrenia. Interestingly, the patient group showed decreased mGluR5-GluN association (p < 0.01), a mechanistic basis for the reciprocal facilitation. In sum, we present the first direct evidence for mGluR5 hypoactivity, propose a reciprocal interplay between GluN and mGluR5 pathways as integral to glutamatergic dysregulation and suggest protein-protein interactions in mGluR5-GluN complexes as potential targets for intervention in schizophrenia.
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Affiliation(s)
- Hoau-Yan Wang
- Department of Physiology, Pharmacology and Neuroscience, City University of New York School of Medicine, New York, NY 10031,Department of Biology and Neuroscience, Graduate School of the City University of New York, NY 10016
| | - Mathew L. MacDonald
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Karin E. Borgmann-Winter
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403,Department of Child and Adolescent Psychiatry and Behavioral Sciences, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
| | - Anamika Banerjee
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Patrick Sleiman
- The Center for Applied Genomics, The Children’s Hospital of Philadelphia, and Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104
| | - Andrew Tom
- Department of Physiology, Pharmacology and Neuroscience, City University of New York School of Medicine, New York, NY 10031
| | - Amber Khan
- Department of Physiology, Pharmacology and Neuroscience, City University of New York School of Medicine, New York, NY 10031,Department of Biology and Neuroscience, Graduate School of the City University of New York, NY 10016
| | - Kuo-Chieh Lee
- Department of Physiology, Pharmacology and Neuroscience, City University of New York School of Medicine, New York, NY 10031
| | - Panos Roussos
- Department of Psychiatry, Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029
| | - Steven J. Siegel
- Department of Psychiatry and the Behavioral Sciences, University of Southern California, Los Angeles, CA, 90007
| | - Scott E Hemby
- Department of Basic Pharmaceutical Sciences, High Point University, High Point, NC, 27106
| | - Warren B. Bilker
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA 19104
| | - Raquel E. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104-3403
| | - Chang-Gyu Hahn
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, 19104-3403, USA.
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7
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Mao LM, Wang JQ. Linkage of Non-receptor Tyrosine Kinase Fyn to mGlu5 Receptors in Striatal Neurons in a Depression Model. Neuroscience 2020; 433:11-20. [PMID: 32145272 DOI: 10.1016/j.neuroscience.2020.02.048] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 12/22/2022]
Abstract
The Src family kinase (SFK) is a subfamily of non-receptor tyrosine kinases. The SFK member Fyn is enriched at synaptic sites in the limbic reward circuit and plays a pivotal role in the regulation of glutamate receptors. In this study, we investigated changes in phosphorylation and function of the two key SFK members (Fyn and Src) and SFK interactions with a metabotropic glutamate (mGlu) receptor in the limbic striatum of adult rats in response to chronic passive stress, i.e., prolonged social isolation which is a pre-validated animal paradigm modeling depression in adulthood. In rats that showed typical anhedonic/depression-like behavior after chronic social isolation, phosphorylation of SFKs at a conserved and activation-associated autophosphorylation site (Y416) was not altered in the two subdivisions of the striatum, the nucleus accumbens and caudate putamen. The total level of phosphorylation and kinase activity of individual Fyn and Src immunopurified from the striatum also remained stable after social isolation. Noticeably, Fyn and Src were found to interact with a Gαq-coupled mGlu5 receptor in striatal neurons. The interaction of Fyn with mGlu5 receptors was selectively elevated in socially isolated rats. Moreover, social isolation induced an increase in surface expression of striatal mGlu5 receptors, which was reduced by an SFK inhibitor. These results indicate that Fyn interacts with mGlu5 receptors in striatal neurons. Adulthood social isolation in rats enhances the Fyn-mGlu5 interaction, which appears to be critical for the upregulation of surface mGlu5 receptor expression in striatal neurons.
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Affiliation(s)
- Li-Min Mao
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - John Q Wang
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA; Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA.
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8
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Mao LM, Wang JQ. Antagonism of Dopamine D2 Receptors Alters Phosphorylation of Fyn in the Rat Medial Prefrontal Cortex. J Mol Neurosci 2017; 61:524-530. [PMID: 28176147 DOI: 10.1007/s12031-017-0894-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 01/27/2017] [Indexed: 02/06/2023]
Abstract
Several Src family kinase (SFK) members are expressed in the mammalian brain and serve as key kinases in the regulation of a variety of cellular and synaptic events. These SFKs may be subject to the modulation by dopamine, although this topic has been investigated incompletely. In this study, we explored whether dopamine D2 receptors (D2Rs) regulate SFKs in adult rat brains in vivo. We investigated the role of D2Rs in two forebrain areas, the medial prefrontal cortex (mPFC) and hippocampus, since dopamine plays a pivotal role in regulating activity of mPFC and hippocampal neurons and D2Rs are expressed in these regions. We found that a systemic injection of a D2R selective antagonist eticlopride elevated phosphorylation of SFKs at a conserved autophosphorylation site, an event correlated with activation of SFKs, in the mPFC. Similarly, antagonism of D2Rs by haloperidol increased SFK phosphorylation. In contrast, eticlopride and haloperidol did not alter SFK phosphorylation in the hippocampus. The effect of eticlopride was time-dependent and relatively delayed. Among two common SFK members enriched at synaptic sites, eticlopride selectively altered phosphorylation of Fyn but not Src. Our data suggest that D2Rs exert an inhibitory effect on the activity-related phosphorylation of Fyn in the mPFC under normal conditions.
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Affiliation(s)
- Li-Min Mao
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO, 64108, USA
| | - John Q Wang
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO, 64108, USA. .,Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, 64108, USA.
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9
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VPS26A-SNX27 Interaction-Dependent mGluR5 Recycling in Dorsal Horn Neurons Mediates Neuropathic Pain in Rats. J Neurosci 2016; 35:14943-55. [PMID: 26538661 DOI: 10.1523/jneurosci.2587-15.2015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED Retromer, which crucially contributes to endosomal sorting machinery through the retrieval and recycling of signaling receptors away from degradation, has been identified as a critical element for glutamatergic-receptor-dependent neural plasticity at excitatory synapses. We observed it accompanied by behavioral allodynia; neuropathic injury time-dependently enhanced VPS26A and SNX27 expression; VPS26A-SNX27 coprecipitation; and VPS26A-positive, SNX27-positive, and VPS26A-SNX27 double-labeled immunoreactivity in the dorsal horn of Sprague Dawley rats that were all sufficiently ameliorated through the focal knock-down of spinal VPS26A expression. Although the knock-down of spinal SNX27 expression exhibited similar effects, spinal nerve ligation (SNL)-enhanced VPS26A expression remained unaffected. Moreover, SNL also increased membrane-bound and total mGluR5 abundance, VPS26A-bound SNX27 and mGluR5 and mGluR5-bound VPS26A and SNX27 coprecipitation, and mGluR5-positive and VPS26A/SNX27/mGluR5 triple-labeled immunoreactivity in the dorsal horn, and these effects were all attenuated through the focal knock-down of spinal VPS26A and SNX27 expression. Although administration with MPEP adequately ameliorated SNL-associated allodynia, mGluR5 expression, and membrane insertion, SNL-enhanced VPS26A and SNX27 expression were unaffected. Together, these results suggested a role of spinal VPS26A-SNX27-dependent mGluR5 recycling in the development of neuropathic pain. This is the first study that links retromer-associated sorting machinery with the spinal plasticity underlying pain hypersensitivity and proposes the possible pathophysiological relevance of endocytic recycling in pain pathophysiology through the modification of glutamatergic mGluR5 recycling. SIGNIFICANCE STATEMENT VPS26A-SNX27-dependent mGluR5 recycling plays a role in the development of neuropathic pain. The regulation of the VPS26A-SNX27 interaction that modifies mGluR5 trafficking and expression in the dorsal horn provides a novel therapeutic strategy for pain relief.
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10
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Mao LM, Wang JQ. Dopamine D2 receptors are involved in the regulation of Fyn and metabotropic glutamate receptor 5 phosphorylation in the rat striatum in vivo. J Neurosci Res 2016; 94:329-38. [PMID: 26777117 DOI: 10.1002/jnr.23713] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 12/22/2015] [Accepted: 01/04/2016] [Indexed: 12/12/2022]
Abstract
Fyn, a major Src family kinase (SFK) member that is densely expressed in striatal neurons, is actively involved in the regulation of cellular and synaptic activities in local neurons. This SFK member is likely regulated by dopamine signaling through a receptor mechanism involving dopamine D2 receptors (D2Rs). This study characterizes the D2R-dependent regulation of Fyn in the rat striatum in vivo. Moreover, we explore whether D2Rs regulate metabotropic glutamate receptor 5 (mGluR5) in its tyrosine phosphorylation and whether the D2R-SFK pathway modulates trafficking of mGluR5. We found that blockade of D2Rs by systemic administration of a D2R antagonist, eticlopride, substantially increased SFK phosphorylation in the striatum. This increase was a transient and reversible event. The eticlopride-induced SFK phosphorylation occurred predominantly in immunopurified Fyn but not in another SFK member, Src. Eticlopride also elevated tyrosine phosphorylation of mGluR5. In parallel, eticlopride enhanced synaptic delivery of active Fyn and mGluR5. Pretreatment with an SFK inhibitor blocked the eticlopride-induced tyrosine phosphorylation and synaptic trafficking of mGluR5. These results indicate that D2Rs inhibit SFK (mainly Fyn) phosphorylation in the striatum. D2Rs also inhibit tyrosine phosphorylation and synaptic recruitment of mGluR5 through a signaling mechanism likely involving Fyn.
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Affiliation(s)
- Li-Min Mao
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri
| | - John Q Wang
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri.,Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri
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11
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Krishnan N, Tonks NK. Anxious moments for the protein tyrosine phosphatase PTP1B. Trends Neurosci 2015; 38:462-5. [PMID: 26166619 DOI: 10.1016/j.tins.2015.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 06/26/2015] [Accepted: 06/29/2015] [Indexed: 11/16/2022]
Abstract
Chronic stress can lead to the development of anxiety and mood disorders. Thus, novel therapies for preventing adverse effects of stress are vitally important. Recently, the protein tyrosine phosphatase PTP1B was identified as a novel regulator of stress-induced anxiety. This opens up exciting opportunities to exploit PTP1B inhibitors as anxiolytics.
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Affiliation(s)
- Navasona Krishnan
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA
| | - Nicholas K Tonks
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA.
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12
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Qin Z, Zhou X, Pandey NR, Vecchiarelli HA, Stewart CA, Zhang X, Lagace DC, Brunel JM, Béïque JC, Stewart AFR, Hill MN, Chen HH. Chronic stress induces anxiety via an amygdalar intracellular cascade that impairs endocannabinoid signaling. Neuron 2015; 85:1319-31. [PMID: 25754825 DOI: 10.1016/j.neuron.2015.02.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 01/09/2015] [Accepted: 02/03/2015] [Indexed: 01/27/2023]
Abstract
Collapse of endocannabinoid (eCB) signaling in the amygdala contributes to stress-induced anxiety, but the mechanisms of this effect remain unclear. eCB production is tied to the function of the glutamate receptor mGluR5, itself dependent on tyrosine phosphorylation. Herein, we identify a novel pathway linking eCB regulation of anxiety through phosphorylation of mGluR5. Mice lacking LMO4, an endogenous inhibitor of the tyrosine phosphatase PTP1B, display reduced mGluR5 phosphorylation, eCB signaling, and profound anxiety that is reversed by genetic or pharmacological suppression of amygdalar PTP1B. Chronically stressed mice exhibited elevated plasma corticosterone, decreased LMO4 palmitoylation, elevated PTP1B activity, reduced amygdalar eCB levels, and anxiety behaviors that were restored by PTP1B inhibition or by glucocorticoid receptor antagonism. Consistently, corticosterone decreased palmitoylation of LMO4 and its inhibition of PTP1B in neuronal cells. Collectively, these data reveal a stress-responsive corticosterone-LMO4-PTP1B-mGluR5 cascade that impairs amygdalar eCB signaling and contributes to the development of anxiety.
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Affiliation(s)
- Zhaohong Qin
- Ottawa Hospital Research Institute, Ottawa, ON K1H8M5, Canada
| | - Xun Zhou
- Ottawa Hospital Research Institute, Ottawa, ON K1H8M5, Canada
| | - Nihar R Pandey
- Ottawa Hospital Research Institute, Ottawa, ON K1H8M5, Canada
| | - Haley A Vecchiarelli
- Hotchkiss Brain Institute and Mathison Centre for Mental Health Research and Education, Departments of Cell Biology and Anatomy & Psychiatry, University of Calgary, Calgary, AB T2N4N1, Canada
| | - Chloe A Stewart
- Ottawa Hospital Research Institute, Ottawa, ON K1H8M5, Canada
| | - Xia Zhang
- Royal Ottawa Mental Health Centre, Ottawa, ON K1Z7K4, Canada; Department of Cellular and Molecular Medicine, Ottawa, ON K1H8M5, Canada
| | - Diane C Lagace
- Department of Cellular and Molecular Medicine, Ottawa, ON K1H8M5, Canada
| | - Jean Michel Brunel
- Centre de Recherche en Cancérologie de Marseille, Laboratory of Integrative Structural & Chemical Biology (iSCB), Aix-Marseille Université, 13385 Marseille Cedex 5, France
| | - Jean-Claude Béïque
- Department of Cellular and Molecular Medicine, Ottawa, ON K1H8M5, Canada
| | - Alexandre F R Stewart
- Department of Biochemistry, Microbiology and Immunology, Ottawa, ON K1H8M5, Canada; University of Ottawa Heart Institute, Ottawa, ON K1Y4W7, Canada; Department of Medicine, University of Ottawa, Ottawa, ON K1H8M5, Canada
| | - Matthew N Hill
- Hotchkiss Brain Institute and Mathison Centre for Mental Health Research and Education, Departments of Cell Biology and Anatomy & Psychiatry, University of Calgary, Calgary, AB T2N4N1, Canada
| | - Hsiao-Huei Chen
- Ottawa Hospital Research Institute, Ottawa, ON K1H8M5, Canada; Department of Cellular and Molecular Medicine, Ottawa, ON K1H8M5, Canada; Department of Medicine, University of Ottawa, Ottawa, ON K1H8M5, Canada.
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13
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Ayala R, Kett LR, Leach TL, Young AB, Dunah AW, Orlando LR. Metabotropic glutamate receptor 1 (mGluR1): antibody specificity and receptor expression in cultured primary neurons. J Neurosci Methods 2011; 204:221-6. [PMID: 22155385 DOI: 10.1016/j.jneumeth.2011.11.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 11/04/2011] [Accepted: 11/08/2011] [Indexed: 11/30/2022]
Abstract
The availability of high quality, well-characterized antibodies for molecular and cellular neuroscience studies is important. However, not all available antibodies are rigorously evaluated, nor are limitations of particular antibodies often reported. We have examined a panel of currently available mGluR1 antibodies and have identified which ones are selective for use by western blots and immunocytochemistry. We have also specifically determined whether the antibodies cross-react to recognize mGluR5, by examining (1) tissue from both mGluR1 and mGluR5 knock-out mice and (2) primary cortical cultures, in which mGluR5 is widely expressed but mGluR1 is not. Together, these data provide a baseline characterization of antibodies that can and cannot be reliably used in these types of studies, and will hopefully facilitate and positively impact the research efforts of others studying mGluR1.
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Affiliation(s)
- Ramses Ayala
- Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, 114 16th Street B114-2000, Boston, MA 02129, United States
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14
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Mao LM, Guo ML, Jin DZ, Fibuch EE, Choe ES, Wang JQ. Post-translational modification biology of glutamate receptors and drug addiction. Front Neuroanat 2011; 5:19. [PMID: 21441996 PMCID: PMC3062099 DOI: 10.3389/fnana.2011.00019] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 03/03/2011] [Indexed: 01/26/2023] Open
Abstract
Post-translational covalent modifications of glutamate receptors remain a hot topic. Early studies have established that this family of receptors, including almost all ionotropic and metabotropic glutamate receptor subtypes, undergoes active phosphorylation at serine, threonine, or tyrosine residues in their intracellular domains. Recent evidence identifies several glutamate receptor subtypes to be direct substrates for palmitoylation at cysteine residues. Other modifications such as ubiquitination and sumoylation at lysine residues also occur to certain glutamate receptors. These modifications are dynamic and reversible in nature and are regulatable by changing synaptic inputs. The regulated modifications significantly impact the receptor in many ways, including interrelated changes in biochemistry (synthesis, subunit assembling, and protein–protein interactions), subcellular redistribution (trafficking, endocytosis, synaptic delivery, and clustering), and physiology, usually associated with changes in synaptic plasticity. Glutamate receptors are enriched in the striatum and cooperate closely with dopamine to regulate striatal signaling. Emerging evidence shows that modification processes of striatal glutamate receptors are sensitive to addictive drugs, such as psychostimulants (cocaine and amphetamine). Altered modifications are believed to be directly linked to enduring receptor/synaptic plasticity and drug-seeking. This review summarizes several major types of modifications of glutamate receptors and analyzes the role of these modifications in striatal signaling and in the pathogenesis of psychostimulant addiction.
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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, USA
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15
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Xiao MY, Gustafsson B, Niu YP. Metabotropic glutamate receptors in the trafficking of ionotropic glutamate and GABA(A) receptors at central synapses. Curr Neuropharmacol 2010; 4:77-86. [PMID: 18615134 DOI: 10.2174/157015906775202986] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Revised: 08/23/2005] [Accepted: 09/30/2005] [Indexed: 01/08/2023] Open
Abstract
The trafficking of ionotropic glutamate (AMPA, NMDA and kainate) and GABA(A) receptors in and out of, or laterally along, the postsynaptic membrane has recently emerged as an important mechanism in the regulation of synaptic function, both under physiological and pathological conditions, such as information processing, learning and memory formation, neuronal development, and neurodegenerative diseases. Non-ionotropic glutamate receptors, primarily group I metabotropic glutamate receptors (mGluRs), co-exist with the postsynaptic ionotropic glutamate and GABA(A) receptors. The ability of mGluRs to regulate postsynaptic phosphorylation and Ca(2+) concentration, as well as their interactions with postsynaptic scaffolding/signaling proteins, makes them well suited to influence the trafficking of ionotropic glutamate and GABA(A) receptors. Recent studies have provided insights into how mGluRs may impose such an influence at central synapses, and thus how they may affect synaptic signaling and the maintenance of long-term synaptic plasticity. In this review we will discuss some of the recent progress in this area: i) long-term synaptic plasticity and the involvement of mGluRs; ii) ionotropic glutamate receptor trafficking and long-term synaptic plasticity; iii) the involvement of postsynaptic group I mGluRs in regulating ionotropic glutamate receptor trafficking; iv) involvement of postsynaptic group I mGluRs in regulating GABA(A) receptor trafficking; v) and the trafficking of postsynaptic group I mGluRs themselves.
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Affiliation(s)
- Min-Yi Xiao
- Institute of Physiology and Pharmacology, Göteborg University, Box 432, 405 30 Göteborg, Sweden.
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16
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Orlando LR, Ayala R, Kett LR, Curley AA, Duffner J, Bragg DC, Tsai LH, Dunah AW, Young AB. Phosphorylation of the homer-binding domain of group I metabotropic glutamate receptors by cyclin-dependent kinase 5. J Neurochem 2009; 110:557-69. [PMID: 19457112 DOI: 10.1111/j.1471-4159.2009.06139.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Phosphorylation of neurotransmitter receptors can modify their activity and regulate neuronal excitability. Cyclin-dependent kinase 5 (cdk5) is a proline-directed serine/threonine kinase involved not only in neuronal development, but also in synaptic function and plasticity. Here we demonstrate that group I metabotropic glutamate receptors (mGluRs), which modulate post-synaptic signaling by coupling to intracellular signal transduction pathways, are phosphorylated by cdk5. In vitro kinase assays reveal that cdk5 phosphorylates mGluR5 within the domain of the receptor that interacts with the scaffolding protein homer. Using a novel phosphospecific mGluR antibody, we show that the homer-binding domain of both mGluR1 and mGluR5 are phosphorylated in vivo, and that inhibition of cdk5 with siRNA decreases the amount of phosphorylated receptor. Furthermore, kinetic binding analysis, by surface plasmon resonance, indicates that phosphorylation of mGluR5 enhances its association with homer. Homer protein complexes in the post-synaptic density, and their disruption by an activity-dependent short homer 1a isoform, have been shown to regulate the trafficking and signaling of the mGluRs and impact many neuroadaptive processes. Phosphorylation of the mGluR homer-binding domain, in contrast to homer 1a induction, provides a novel mechanism for potentially regulating a subset of homer interactions.
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Affiliation(s)
- Lianna R Orlando
- Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Boston, 02129, USA
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17
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Mao LM, Liu XY, Zhang GC, Chu XP, Fibuch EE, Wang LS, Liu Z, Wang JQ. Phosphorylation of group I metabotropic glutamate receptors (mGluR1/5) in vitro and in vivo. Neuropharmacology 2008; 55:403-8. [PMID: 18585398 DOI: 10.1016/j.neuropharm.2008.05.034] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 05/28/2008] [Accepted: 05/30/2008] [Indexed: 02/05/2023]
Abstract
Group I metabotropic glutamate receptors (mGluR1 and mGluR5 subtypes) are densely expressed in mammalian brain. They are actively involved in the regulation of normal cellular activity and synaptic plasticity, and are frequently linked to the pathogenesis of various mental illnesses. Like ionotropic glutamate receptors, group I mGluRs are subject to the regulation by protein phosphorylation. Accumulative data demonstrate sufficient phosphorylation of the intracellular mGluR1/5 domains at specific serine/threonine sites by protein kinase C in heterologous cells or neurons, which serves as an important mechanism for regulating the receptor signaling and desensitization. Emerging evidence also shows the significant involvements of G protein-coupled receptor kinases, Ca2+/calmodulin-dependent protein kinase II, tyrosine kinases, and protein phosphatases in controlling the phosphorylation status of group I mGluRs. This review analyzes the recent data concerning group I mGluR phosphorylation and the phosphorylation-dependent regulation of group I mGluR function. Future research directions in this area with newly available high throughput and proteomic approaches are also discussed in the end.
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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, USA
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18
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Kim CH, Lee J, Lee JY, Roche KW. Metabotropic glutamate receptors: phosphorylation and receptor signaling. J Neurosci Res 2008; 86:1-10. [PMID: 17663464 DOI: 10.1002/jnr.21437] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Metabotropic glutamate receptors (mGluRs) play important roles in neurotransmission, neuronal development, synaptic plasticity, and neurological disorders. Recent studies have revealed a sophisticated interplay between mGluRs and protein kinases: activation of mGluRs regulates the activity of a number of kinases, and direct phosphorylation of mGluRs affects receptor signaling, trafficking, and desensitization. Here we review the emerging literature on mGluR phosphorylation, signaling, and synaptic function.
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Affiliation(s)
- Chul Hoon Kim
- Department of Pharmacology, Brain Research Institute, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
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19
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Lea PM, Faden AI. Metabotropic glutamate receptor subtype 5 antagonists MPEP and MTEP. CNS DRUG REVIEWS 2006; 12:149-66. [PMID: 16958988 PMCID: PMC6494124 DOI: 10.1111/j.1527-3458.2006.00149.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Glutamate regulates the function of central nervous system (CNS), in part, through the cAMP and/or IP3/DAG second messenger-associated metabotropic glutamate receptors (mGluRs). The mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) has been extensively used to elucidate potential physiological and pathophysiological functions of mGluR5. Unfortunately, recent evidence indicates significant non-specific actions of MPEP, including inhibition of NMDA receptors. In contrast, in vivo and in vitro characterization of the newer mGluR5 antagonist 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) indicates that it is more highly selective for mGluR5 over mGluR1, has no effect on other mGluR subtypes, and has fewer off-target effects than MPEP. This article reviews literature on both of these mGluR5 antagonists, which suggests their possible utility in neurodegeneration, addiction, anxiety and pain management.
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Affiliation(s)
| | - Alan I. Faden
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC, USA
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20
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Giuffrida R, Musumeci S, D'Antoni S, Bonaccorso CM, Giuffrida-Stella AM, Oostra BA, Catania MV. A reduced number of metabotropic glutamate subtype 5 receptors are associated with constitutive homer proteins in a mouse model of fragile X syndrome. J Neurosci 2006; 25:8908-16. [PMID: 16192381 PMCID: PMC6725593 DOI: 10.1523/jneurosci.0932-05.2005] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Fragile X (FRAX) syndrome is a common inherited form of mental retardation resulting from the lack of fragile X mental retardation protein (FMRP) expression. The consequences of FMRP absence in the mechanism underlying mental retardation are unknown. Here, we tested the hypothesis that glutamate receptor (GluR) expression might be altered in FRAX syndrome. Initial in situ hybridization and Western blotting experiments did not reveal differences in mRNA levels and protein expression of AMPA and NMDA subunits and metabotropic glutamate subtype 5 (mGlu5) receptors between control and Fmr1 knock-out (KO) mice during postnatal development. However, a detergent treatment (1% Triton X-100) revealed a selective reduction of mGlu5 receptor expression in the detergent-insoluble fraction of synaptic plasma membranes (SPMs) from KO mice, with no difference in the expression of NR2A, GluR1, GluR2/3, GluR4, and Homer proteins. mGlu5 receptor expression was also lower in Homer immunoprecipitates from Fmr1 KO SPMs. Homer, but not NR2A, mGlu5, and GluR1, was found to be less tyrosine phosphorylated in Fmr1 KO than control mice. Our data indicate that, in FRAX syndrome, a reduced number of mGlu5 receptors are tightly linked to the constituents of postsynaptic density and, in particular, to the constitutive forms of Homer proteins, with possible consequent alterations in synaptic plasticity.
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Affiliation(s)
- Raffaella Giuffrida
- Department of Chemical Sciences, University of Catania, 95125 Catania, Italy
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21
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von Arnim CAF, Kinoshita A, Peltan ID, Tangredi MM, Herl L, Lee BM, Spoelgen R, Hshieh TT, Ranganathan S, Battey FD, Liu CX, Bacskai BJ, Sever S, Irizarry MC, Strickland DK, Hyman BT. The low density lipoprotein receptor-related protein (LRP) is a novel beta-secretase (BACE1) substrate. J Biol Chem 2005; 280:17777-85. [PMID: 15749709 DOI: 10.1074/jbc.m414248200] [Citation(s) in RCA: 196] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BACE is a transmembrane protease with beta-secretase activity that cleaves the amyloid precursor protein (APP). After BACE cleavage, APP becomes a substrate for gamma-secretase, leading to release of amyloid-beta peptide (Abeta), which accumulates in senile plaques in Alzheimer disease. APP and BACE are co-internalized from the cell surface to early endosomes. APP is also known to interact at the cell surface and be internalized by the low density lipoprotein receptor-related protein (LRP), a multifunctional endocytic and signaling receptor. Using a new fluorescence resonance energy transfer (FRET)-based assay of protein proximity, fluorescence lifetime imaging (FLIM), and co-immunoprecipitation we demonstrate that the light chain of LRP interacts with BACE on the cell surface in association with lipid rafts. Surprisingly, the BACE-LRP interaction leads to an increase in LRP C-terminal fragment, release of secreted LRP in the media and subsequent release of the LRP intracellular domain from the membrane. Taken together, these data suggest that there is a close interaction between BACE and LRP on the cell surface, and that LRP is a novel BACE substrate.
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Affiliation(s)
- Christine A F von Arnim
- Alzheimer Disease Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
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22
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Bonsi P, Cuomo D, De Persis C, Centonze D, Bernardi G, Calabresi P, Pisani A. Modulatory action of metabotropic glutamate receptor (mGluR) 5 on mGluR1 function in striatal cholinergic interneurons. Neuropharmacology 2005; 49 Suppl 1:104-13. [PMID: 16005029 DOI: 10.1016/j.neuropharm.2005.05.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2005] [Revised: 05/12/2005] [Accepted: 05/12/2005] [Indexed: 11/21/2022]
Abstract
Within basal ganglia, group I metabotropic glutamate receptor subtypes (mGluR1 and 5) frequently co-localize in the same neuron. However, little is known about how these receptors functionally interact. We addressed this issue by means of electrophysiological recordings of striatal cholinergic interneurons, a neuronal subtype that co-express both group I mGluRs. The group I non-selective agonist 3,5-DHPG induced a membrane depolarization/inward current that was prevented by co-application of LY 367385, a selective mGluR1 antagonist, and SIB 1757 or MPEP, blockers of mGluR5 subtype. The reversal potential for the response to 3,5-DHPG was close to the equilibrium potential for potassium channels. Repeated bath or focal applications of 3,5-DHPG induced a progressive decline in the amplitude of the membrane depolarization, suggesting that group I mGluRs undergo receptor desensitization. Interestingly, in the presence of the mGluR5 blocker, SIB 1757, this event was not observed, whereas it occurred in LY 367385. PKC blockers chelerythrine and calphostin C mimicked the inhibitory effect of SIB 1757. In a subset of interneurons, in MPEP or SIB 1757, 3,5-DHPG induced a 0.5-1 Hz oscillatory response, that was prevented by L-type Ca2+ channel blockers, and by the tyrosine kinase inhibitors genistein and lavendustin. Together, these data suggest that mGluR5 modulates mGluR1 activity to shape cell excitability.
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Affiliation(s)
- P Bonsi
- Laboratorio di Neurofisiologia, Fondazione Santa Lucia, C.E.R.C., Rome, Italy
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23
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Ireland DR, Guevremont D, Williams JM, Abraham WC. Metabotropic Glutamate Receptor-Mediated Depression of the Slow Afterhyperpolarization Is Gated by Tyrosine Phosphatases in Hippocampal CA1 Pyramidal Neurons. J Neurophysiol 2004; 92:2811-9. [PMID: 15240770 DOI: 10.1152/jn.01236.2003] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Group I metabotropic glutamate receptor (mGluR) agonists increase the excitability of hippocampal CAl pyramidal neurons via depression of the postspike afterhyperpolarization. In adult rats, this is mediated by both mGluR1 and -5, but the signal transduction processes involved are unknown. In this study, we investigated whether altered levels of tyrosine phosphorylation of proteins are involved in the depression of the slow-duration afterhyperpolarization (sAHP) by the Group I mGluR agonist (RS)-3,5-dihydroxyphenylglycine (DHPG) in CA1 pyramidal neurons of rat hippocampal slices. Preincubation with the tyrosine kinase inhibitors lavendustin A or genistein, or the Src-specific inhibitor 3-(4-chlorophenyl) 1-(1,1-dimethylethyl)-1 H-pyrazolo[3,4-d]pyrimidin-4-amine (PP2), did not inhibit the DHPG-mediated depression of the sAHP. However, preincubation with the tyrosine phosphatase inhibitor orthovanadate reduced the effects of DHPG. This effect of orthovanadate was prevented by simultaneous inhibition of tyrosine kinases with lavendustin A. Selective activation of either mGluR1 or -5 by application of DHPG plus either the mGluR5 antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) or the mGluR1 antagonist (S)-(+)-α-amino-4-carboxy-2-methylbenzeneacetic acid (LY367385) demonstrated that the effect of inhibiting tyrosine phosphatases is not specific to either subtype of mGluR. These results suggest that the depression of the sAHP induced by activation of mGluR1 and -5 is gated by a balance between tyrosine phosphorylation and dephosphorylation.
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Affiliation(s)
- David R Ireland
- Department of Psychology, University of Otago, PO Box 56, Dunedin, New Zealand.
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24
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von Arnim CAF, Tangredi MM, Peltan ID, Lee BM, Irizarry MC, Kinoshita A, Hyman BT. Demonstration of BACE (beta-secretase) phosphorylation and its interaction with GGA1 in cells by fluorescence-lifetime imaging microscopy. J Cell Sci 2004; 117:5437-45. [PMID: 15466887 DOI: 10.1242/jcs.01422] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
beta-Secretase (BACE) carries out the first of two proteolysis steps to generate the amyloid-beta peptides that accumulate in the senile plaques in Alzheimer's disease (AD). Because most BACE activity occurs in endosomes, signals regulating its trafficking to these compartments are important to an understanding of AD pathogenesis. A DISLL sequence near the BACE C-terminus mediates binding of BACE to the VHS domains of Golgi-localized gamma-ear-containing ARF-binding (GGA) proteins, which are involved in the sorting of proteins to endosomes. Phosphorylation of the motif's serine residue regulates BACE recycling back to the cell surface from early endosomes and enhances the interaction of BACE with GGA proteins in isolated protein assays. We found that BACE phosphorylation influences BACE-GGA interactions in cells using a new fluorescence-resonance-energy-transfer-based assay of protein proximity, fluorescence lifetime imaging. Although serine-phosphorylated BACE was distributed throughout the cell, interaction of GGA1 with the wild-type protein occurred in juxtanuclear compartments. Pseudo-phosphorylated and non-phosphorylated BACE mutants remained localized with GGA1 in the Golgi body, but the latter mutation diminished the two proteins' FRET signal. Because BACE phosphorylated at serine residues can be identified in human brain, these data suggest that serine phosphorylation of BACE is a physiologically relevant post-translational modification that regulates trafficking in the juxtanuclear compartment by interaction with GGA1.
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Affiliation(s)
- Christine A F von Arnim
- Alzheimer Disease Research Laboratory, Massachusetts General Hospital, Harvard Medical School, 114 16th Street, Charlestown, MA 02129, USA
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25
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Age-related changes in synaptic phosphorylation and dephosphorylation. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/s1566-3124(04)16006-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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