Molecular characterization and localization of human metabotropic glutamate receptor type 4

doi:10.1016/0169-328X(95)00321-I

Molecular Brain Research

Volume 37, Issues 1–2, April 1996, Pages 239-248

https://doi.org/10.1016/0169-328X(95)00321-I Get rights and content

Abstract

Oligonucleotides of consensus sequences from rat metabotropic glutamate receptor (mGluR) genes were synthesized and used to amplify human DNA by the polymerase chain reaction (PCR). Five unique human sequences homologous to these rat receptor genes were isolated including mGluR4. A human cerebellum cDNA library was screened using this amplified mGluR4 sequence as a probe and yielded clones which between them contained the complete coding sequence for human mGluR4. The coding sequence is very similar to the equivalent rat gene (90% DNA sequence identity and 97% predicted protein sequence identity). The mGluR4 cDNA was transfected in Chinese hamster ovary (CHO) cells and stable clonal cell lines were isolated. Stimulation of the expressed receptor by l-2-amino-4-phosphonobutyrate (L-AP4), l-glutamate or (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) resulted in a reduction of forskolin-stimulated cyclic AMP (cAMP) with EC₅₀ values of 0.2, 13 and 90 μM respectively. Quisqualate had little effect at concentrations up to 1 mM. In Northern blots mGluR4 mRNA appears to be brain-specific, and shows a distinct distribution (excluding the cerebellum), being expressed in the thalamus, hypothalamus and caudate nucleus. In situ hybridization studies on human brain sections confirmed this general pattern of distribution. The strongest mGluR4 mRNA signal was found in the cerebellar granule cells consistent with the reported distribution of mGluR4 in the rat brain. The major difference from the rat brain is the presence in the human brain of mGluR4 mRNA in the caudate nucleus and putamen.

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Cited by (47)

The developmental expression of metabotropic glutamate receptor 4 in prenatal human frontal lobe and neurogenesis regions
2019, Brain and Development
Citation Excerpt :
A growing body of evidence suggests that mGluR4 is expressed in postnatal rodent or human brain. The mRNA and protein expression for mGluR4 could be detected at birth, then increase gradually and in adult preferentially express in cerebellum, hippocampus, basal ganglia and thalamus, etc [27–31]. However, so far the data about the expression of mGluR4 in prenatal brain are very hard to be found.
Metabotropic glutamate receptors, besides ionotropic receptors, mediate the complicated effect of glutamate on neurogenesis. Previous studies showed that metabotropic glutamate receptor 4 (mGluR4) regulated the proliferation and differentiation of neural stem/progenitor cells in vitro. However, little is known about the expression pattern of mGluR4 on prenatal central nervous system in vivo, especially the human being.
The normal brain tissues of human fetus were collected and divided into 4 groups according to the gestational age: 9–11 W, 14–16 W, 22–24 W and 32–36 W. Then the expression of mGluR4 was evaluated at mRNA and protein levels by means of PCR or immunohistochemistry method, respectively. The type of cell expressing mGluR4 was further investigated using double-labeling immunofluorescence.
RT-PCR showed that the mRNA of mGluR4 could be detected in frontal lobe from 9 W to 32 W and real-time PCR quantificationally demonstrated the mRNA increased with development. Similarly, immnoreactivity was found in all layers of frontal lobe, VZ/SVZ. The intensity scores analysis showed that the staining became stronger and the range extended gradually with development. The double-labeling immunofluorescence showed that mGluR4 was present in neural stem/progenitor cells (nestin-positive cells after 9 W), young neurons (DCX-positive cells after 9 W), mature neurons (NeuN-positive cells in cortex after 32 W), as well as typical astrocytes (GFAP-positive cells in medulla after 32 W).
These results supply an important evidence that mGluR4 is expressed in prenatal human cerebrum, and main kinds of cells related to neurogenesis are involved in its expression.
Regulation of the brain-gut axis by group III metabotropic glutamate receptors
2013, European Journal of Pharmacology
Citation Excerpt :
Here we present a summary of the localisation of group III mGlu receptors within the CNS. mGlu4 receptor is expressed in cerebellum, olfactory bulb, entorhinal cortex, globus pallidus, substantia nigra, hippocampus, lateral septum, amygdala, striatum, dorsal horn, retina, nucleus tractus solitarius in the medulla oblongata and in pontine, thalamic and mammillary nuclei (Bradley et al., 1996; Corti et al., 2002; Ferraguti and Shigemoto, 2006; Kinoshita et al., 1996; Makoff et al., 1996; Ohishi et al., 1995). Although mGlu4 receptor is mostly located presynaptically, it has also been found postsynaptically in hippocampal neurons (Bradley et al., 1996).
l-glutamate is produced by a great variety of peripheral tissues in both health and disease. Like other components of the glutamatergic system, metabotropic glutamate (mGlu) receptors also have a widespread distribution outside the central nervous system (CNS). In particular, group III mGlu receptors have been recently found in human stomach and colon revealing an extraordinary potential for these receptors in the treatment of peripheral disorders, including gastrointestinal dysfunction. The significance of these findings is that pharmacological tools originally designed for mGlu receptors in the CNS may also be directed towards new disease targets in the periphery. Targeting mGlu receptors can also be beneficial in the treatment of disorders involving central components together with gastrointestinal dysfunction, such as irritable bowel syndrome, which can be co-morbid with anxiety and depression. Conversely, the development of more specific therapeutic approaches for mGlu ligands both centrally as in the gut will depend on the elucidation of tissue-specific elements in mGlu receptor signalling.
Positive allosteric modulation of metabotropic glutamate 4 (mGlu4) receptors enhances spontaneous and evoked absence seizures
2008, Neuropharmacology
Citation Excerpt :
This suggests that the regulation of absence seizures by mGlu4 receptors is mainly exerted at the level of RTN (see below). High mGlu4 receptor mRNA and protein levels are found in rodent and human thalamic relay nuclei (Ohishi et al., 1995; Makoff et al., 1996; Thomsen and Hampson, 1999; Lourenco Neto et al., 2000; Corti et al., 2002), whereas low mRNA and low-to-moderate mGlu4 protein levels are found in primary somatosensory cortex, and, particularly, in the outer cortical layers (Ohishi et al., 1995; Corti et al., 2002). Because no mGlu4 receptor mRNA is detectable in the RTN (Ohishi et al., 1995; Lourenco Neto et al., 2000; Shigemoto and Mizuno, 2000; and present data), the mGlu4 receptor protein found in the RTN must be present on extrinsic inputs.
Individual metabotropic glutamate (mGlu) receptor subtypes have been implicated in the pathophysiology of epileptic seizures, and are potential targets for novel antiepileptic drugs. Here, we examined the role of the mGlu4 receptor subtype in absence seizures using as models: (i) WAG/Rij rats, which develop spontaneous absence seizures after 2–3 months of age; and (ii) mice treated with pentylentetrazole (PTZ, 30 mg/kg, s.c.). Expression of mGlu4 receptors was enhanced in the reticular thalamic nucleus (RTN) of symptomatic WAG/Rij rats as compared with age-matched controls, as assessed by immunoblotting and immunohistochemistry. No changes were found in other regions of WAG/Rij rats including ventrobasal thalamic nuclei, somatosensory cortex, and hippocampus. Electron microscopy and in situ hybridization data suggested that mGlu4 receptors in the RTN are localized on excitatory cortical afferents. Systemic injection of the selective mGlu4 receptor positive allosteric modulator, N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen1a-carboxamide (PHCCC, 10 mg/kg, s.c.), substantially enhanced the number of spike-and-wave discharges (SWDs) in WAG/Rij rats. Injection of PHCCC also enhanced absence-like seizures in PTZ-treated mice, whereas it was totally inactive in mGlu4 receptor knockout mice, which were intrinsically resistant to PTZ-induced seizures, as expected. This data supports the hypothesis that activation of mGlu4 receptors participates in the generation of absence seizures which can be exacerbated with the use of a positive allosteric modulator.
Mglu4 metabotropic glutamate receptor
2007, xPharm: The Comprehensive Pharmacology Reference
Distribution and synaptic localisation of the metabotropic glutamate receptor 4 (mGluR4) in the rodent CNS
2002, Neuroscience
Group III metabotropic glutamate receptors (mGluRs) are selectively activated by L-2-amino-4-phosphonobutyrate (L-AP4), which produces depression of synaptic transmission. The relative contribution of different group III mGluRs to the effects of L-AP4 remains to be clarified. Here, we assessed the distribution of mGluR4 in the rat and mouse brain using affinity-purified antibodies raised against its entire C-terminal domain. The antibodies reacted specifically with mGluR4 and not with other mGluRs in transfected COS 7 cells. No immunoreactivity was detected in brains of mice with gene-targeted deletion of mGluR4. Pre-embedding immunocytochemistry for light and electron microscopy showed the most intense labelling in the cerebellar cortex, basal ganglia, the sensory relay nuclei of the thalamus, and some hippocampal areas. Immunolabelling was most intense in presynaptic active zones. In the basal ganglia, both the direct and indirect striatal output pathways showed immunolabelled terminals forming mostly type II synapses on dendritic shafts. The localisation of mGluR4 on GABAergic terminals of striatal projection neurones suggests a role as a presynaptic heteroreceptor. In the cerebellar cortex and hippocampus, mGluR4 was also localised in terminals establishing type I synapses, where it probably operates as an autoreceptor. In the hippocampus, mGluR4 labelling was prominent in the dentate molecular layer and CA1–3 strata lacunosum moleculare and oriens. Somatodendritic profiles of some stratum oriens/alveus interneurones were richly decorated with mGluR4-labelled axon terminals making either type I or II synapses. This differential localisation suggests a regulation of synaptic transmission via a target cell-dependent synaptic segregation of mGluR4.
Our results demonstrate that, like other group III mGluRs, presynaptic mGluR4 is highly enriched in the active zone of boutons innervating specific classes of neurones. In addition, the question of alternatively spliced mGluR4 isoforms is discussed.
Chapter III Metabotropic glutamate receptors - immunocytochemical and in situ hybridization analyses
2000, Handbook of Chemical Neuroanatomy
This chapter focuses on metabotropic glutamate receptors (mGluRs). These receptors are linked to several intracellular signal transduction mechanisms via G-protein and are implicated in diverse functions of the mammalian central nervous system (CNS). These functions include mediation of slow excitatory and inhibitory responses; regulation of calcium channels, potassium channels, and non-selective cation channels; inhibition and facilitation of transmitter release; induction of long-term potentiation and long-term depression; and regulation of neuronal development. Functional diversity of the metabotropic glutamate receptor is reflected in molecular diversity of receptor subtypes. The sites of action of mGluRs are widely found throughout different membrane compartments of neuronal and glial cells. The chapter reviews the differential subcellular localization of metabotropic glutamate receptors in relation to transmitter release sites. Patterns of subcellular localization of mGluRs are different among three subgroups: group I and III mGluRs are mainly localized to somatodendritic and axonal domains of neurons, respectively, while group II mGluRs are extensively localized to both domains as well as to glial cell processes.

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^☆: The nucleotide sequence reported in this paper has been submitted to the EMBL Data Bank with accession number X80818.

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Research reportMolecular characterization and localization of human metabotropic glutamate receptor type 4☆

Abstract

J. Biol. Chem.

Neuroscience

Neuropharmacology

Cell

Neurosci. Lett.

Biochem. Biophys. Res. Commun.

J. Biol. Chem.

Neuron

Cell

J. Biol. Chem.

J. Biol. Chem.

Eur. J. Pharmacol.

Brain Res.

Signal transduction and pharmacological characteristics of a metabotropic glutamate receptor, mGluR1, in transfected CHO cells

Neuron

Eukaryotic start and stop translation sites

Nucleic Acids Res.

Research report
Molecular characterization and localization of human metabotropic glutamate receptor type 4☆