GRM3 Gene
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">GRM3 — Glutamate Metabotropic Receptor 3</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>GRM3</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Glutamate Metabotropic Receptor 3</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>7q21.12</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>2915</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>604099</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000138821</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td>Q14832</td>
</tr>
<tr>
<td class="label">Pathway</td>
<td>Effect</td>
</tr>
<tr>
<td class="label">Gi/o → AC ↓</td>
<td>cAMP reduction</td>
</tr>
<tr>
<td class="label">Gβγ → ion channels</td>
<td>Modulates Ca²⁺, K⁺ channels</td>
</tr>
<tr>
<td class="label">MAPK/ERK</td>
<td>Cell survival</td>
</tr>
<tr>
<td class="label">PI3K/Akt</td>
<td>Neuroprotection</td>
</tr>
<tr>
<td class="label">[NF-κB](/entities/nf-kb)</td>
<td>Inflammation regulation</td>
</tr>
<tr>
<td class="label">Agent</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">LY341495</td>
<td>mGluR2/3 antagonist</td>
</tr>
<tr>
<td class="label">JP506</td>
<td>mGluR3 NAM</td>
</tr>
<tr>
<td class="label">VU0650786</td>
<td>mGluR3 NAM</td>
</tr>
<tr>
<td class="label">VU6000183</td>
<td>mGluR3 NAM</td>
</tr>
<tr>
...GRM3 Gene
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">GRM3 — Glutamate Metabotropic Receptor 3</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>GRM3</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Glutamate Metabotropic Receptor 3</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>7q21.12</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>2915</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>604099</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000138821</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td>Q14832</td>
</tr>
<tr>
<td class="label">Pathway</td>
<td>Effect</td>
</tr>
<tr>
<td class="label">Gi/o → AC ↓</td>
<td>cAMP reduction</td>
</tr>
<tr>
<td class="label">Gβγ → ion channels</td>
<td>Modulates Ca²⁺, K⁺ channels</td>
</tr>
<tr>
<td class="label">MAPK/ERK</td>
<td>Cell survival</td>
</tr>
<tr>
<td class="label">PI3K/Akt</td>
<td>Neuroprotection</td>
</tr>
<tr>
<td class="label">[NF-κB](/entities/nf-kb)</td>
<td>Inflammation regulation</td>
</tr>
<tr>
<td class="label">Agent</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">LY341495</td>
<td>mGluR2/3 antagonist</td>
</tr>
<tr>
<td class="label">JP506</td>
<td>mGluR3 NAM</td>
</tr>
<tr>
<td class="label">VU0650786</td>
<td>mGluR3 NAM</td>
</tr>
<tr>
<td class="label">VU6000183</td>
<td>mGluR3 NAM</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/bipolar" style="color:#ef9a9a">Bipolar</a>, <a href="/wiki/depression" style="color:#ef9a9a">Depression</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">70 edges</a></td>
</tr>
</table>
Introduction
Grm3 — Glutamate Metabotropic Receptor 3 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Overview
Mermaid diagram (expand to render)
GRM3 (Glutamate Metabotropic Receptor 3) encodes the metabotropic glutamate receptor 3 (mGluR3), a Group II metabotropic glutamate receptor that plays important roles in modulating glutamatergic and GABAergic neurotransmission.
Protein Encoding
The GRM3 gene encodes mGluR3, a 879 amino acid G protein-coupled receptor.
- UniProt ID: Q14832
- Molecular Weight: ~98 kDa
- Subcellular Localization: Presynaptic and postsynaptic membranes
- Protein Family: Class C GPCR, mGluR family
Structure
mGluR3 has characteristic GPCR structure:
Extracellular Domain
- Venus flytrap domain (VFT): Large bilobed ligand-binding domain
- Cysteine-rich domain (CRD): Connects VFT to transmembrane domain
Transmembrane Domain
- 7 transmembrane helices: Classic GPCR architecture
- G protein coupling: Gi/o family specificity
Intracellular Domain
- C-terminal tail: Contains phosphorylation sites
- Protein interactions: Scaffold and signaling partners
Normal Function
mGluR3 is a presynaptic autoreceptor and postsynaptic receptor that:
- Inhibits Adenylate Cyclase: Reduces cAMP production via Gi/o protein signaling
- Modulates Neurotransmission: Reduces glutamate and GABA release
- Neuroprotection: Activates neuroprotective signaling pathways
- Synaptic Plasticity: Involved in [LTP](/mechanisms/long-term-potentiation) and LTD mechanisms
- Gene Expression Regulation: Modulates transcription through various signaling cascades
Signaling Pathways
Disease Associations
Schizophrenia
Strong genetic associations:
- GWAS hits in GRM3 gene
- Altered mGluR3 expression in schizophrenia brains
- Risk variants affect receptor function
- mGluR3 modulators as potential antipsychotics
Therapeutic implications:
- mGluR3 NAMs (negative allosteric modulators) may reduce negative symptoms
- mGluR3 PAMs (positive allosteric modulators) may improve cognition
Alzheimer's Disease
mGluR3 signaling affected in AD:
- Altered expression in AD brains
- Potential role in amyloid processing
- Neuroprotective effects via mGluR3 signaling
- May modulate [tau](/proteins/tau) pathology
Parkinson's Disease
Altered striatal mGluR3 signaling:
- Changes in basal ganglia circuitry
- Motor function modulation
- Potential for dyskinesia treatment
Depression and Anxiety
mGluR3 involved in mood regulation:
- Antidepressant effects of mGluR3 blockade
- Modulation of GABAergic tone
- Interaction with monoamine systems
Addiction
mGluR3 modulates reward pathways:
- Involved in cocaine and alcohol reinforcement
- Potential treatment target
Expression Pattern
High expression in:
- Cerebral [cortex](/brain-regions/cortex) (prefrontal cortex)
- [Hippocampus](/brain-regions/hippocampus) (CA1, dentate gyrus)
- Basal ganglia (striatum, globus pallidus)
- [Thalamus](/brain-regions/thalamus)
- [Amygdala](/brain-regions/amygdala)
- [Cerebellum](/brain-regions/cerebellum)
Cellular localization:
- Presynaptic terminals (axon terminals)
- Postsynaptic membranes
- Glial cells ([astrocytes](/entities/astrocytes), microglia)
Therapeutic Targeting
Drug Development
Clinical Applications
- Schizophrenia: mGluR3 modulators for cognitive symptoms
- AD: Neuroprotective strategies
- Depression: Rapid-acting antidepressants
- PD: Motor complications
Animal Models
Knockout Studies
- GRM3-/- mice show:
- Enhanced basal glutamatergic transmission
- Impaired working memory
- Increased anxiety-like behavior
Transgenic Models
- Overexpression of mutant GRM3:
- Schizophrenia-related behaviors
- Cognitive deficits
Key Publications
Conn PJ, et al. (2009). Pharmacology and functions of metabotropic glutamate receptors. Annu Rev Pharmacol Toxicol.<sup>[1]</sup>
Corti C, et al. (2007). Metabotropic glutamate receptors as therapeutic targets for cognitive disorders. Neuropharmacology.<sup>[2]</sup>
Moghaddam B. (2004). Targeting metabotropic glutamate receptors for antipsychotic drug development. Psychopharmacology.<sup>[3]</sup>
Nicoletti F, et al. (2011). Group-I metabotropic glutamate receptors: hypotheses to explain how the mind works. Neuropharmacology.<sup>[4]</sup>
Li ML, et al. (2015). Metabotropic glutamate receptor 3 and risk for schizophrenia. Mol Psychiatry.<sup>[5]</sup>See Also
- [mGluR3 Protein](/proteins/grm3-protein)
- [GRM2 Gene](/grm2-gene)
- [Glutamate Receptors](/entities/glutamate-receptors)
- [Schizophrenia](/diseases/schizophrenia)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Parkinson's Disease](/diseases/parkinsons-disease)
- [GABA](/entities/gaba)
- [Glutamate Signaling](/mechanisms/synaptic-dysfunction-pathway)
External Links
- [NCBI Gene: GRM3](https://www.ncbi.nlm.nih.gov/gene/2915)
- [UniProt: Q14832](https://www.uniprot.org/uniprot/Q14832)
- [Ensembl: GRM3](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000138821)
- [GeneCards: GRM3](https://www.genecards.org/cgi-bin/carddisp.pl?gene=GRM3)
- [IUPHAR: mGluR3](https://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=56)
Background
The study of Grm3 — Glutamate Metabotropic Receptor 3 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
References
<sup>[1]</sup> Conn PJ, et al. Pharmacology and functions of metabotropic glutamate receptors. Annu Rev Pharmacol Toxicol. 2009;49:291-322.
<sup>[2]</sup> Corti C, et al. Metabotropic glutamate receptors as therapeutic targets for cognitive disorders. Neuropharmacology. 2007;53(3):363-375.
<sup>[3]</sup> Moghaddam B. Targeting metabotropic glutamate receptors for antipsychotic drug development. Psychopharmacology. 2004;174(1):39-44.
<sup>[4]</sup> Nicoletti F, et al. Group-I metabotropic glutamate receptors: hypotheses to explain how the mind works. Neuropharmacology. 2011;60(7-8):1017-1041.
<sup>[5]</sup> Li ML, et al. Metabotropic glutamate receptor 3 and risk for schizophrenia. Mol Psychiatry. 2015;20(10):1236-1246.
Pathway Diagram
The following diagram shows the key molecular relationships involving GRM3 — Glutamate Metabotropic Receptor 3 discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)