HTR4 Gene
Introduction
Htr4 Gene 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
flowchart TD
HTR4["HTR4"] -->|"regulates"| ALS["ALS"]
HTR4["HTR4"] -->|"regulates"| Inflammation["Inflammation"]
HTR4["HTR4"] -->|"regulates"| Amyotrophic_Lateral_Sclerosis["Amyotrophic Lateral Sclerosis"]
HTR4["HTR4"] -->|"regulates"| Neuroinflammation["Neuroinflammation"]
HTR4["HTR4"] -->|"expressed in"| Neuron["Neuron"]
SOD1["SOD1"] -->|"regulates"| HTR4["HTR4"]
style HTR4 fill:#4fc3f7,stroke:#333,color:#000
The HTR4 gene encodes the 5-hydroxytryptamine receptor 4 (5-HT4), a G-protein coupled receptor that mediates the effects of serotonin in the central nervous system and peripheral tissues. The 5-HT4 receptor plays important roles in learning, memory, mood regulation, and gastrointestinal motility. [@lucas2010]
Key points: [@maillet2015]
- Located on chromosome 5q31.3
- Encodes 5-HT4 receptor (GPCR)
- Expressed in hippocampus, basal ganglia, and cortex
- Implicated in Alzheimer's disease, Parkinson's disease, and mood disorders
5-Hydroxytryptamine Receptor 4
...HTR4 Gene
Introduction
Htr4 Gene 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)
The HTR4 gene encodes the 5-hydroxytryptamine receptor 4 (5-HT4), a G-protein coupled receptor that mediates the effects of serotonin in the central nervous system and peripheral tissues. The 5-HT4 receptor plays important roles in learning, memory, mood regulation, and gastrointestinal motility. [@lucas2010]
Key points: [@maillet2015]
- Located on chromosome 5q31.3
- Encodes 5-HT4 receptor (GPCR)
- Expressed in hippocampus, basal ganglia, and cortex
- Implicated in Alzheimer's disease, Parkinson's disease, and mood disorders
5-Hydroxytryptamine Receptor 4
<div class="infobox infobox-gene">
<div class="header">Gene Information</div>
<table>
<tr><td><b>Symbol</b></td><td>HTR4</td></tr>
<tr><td><b>Full Name</b></td><td>5-Hydroxytryptamine Receptor 4</td></tr>
<tr><td><b>Chromosome</b></td><td>5q31-q33</td></tr>
<tr><td><b>NCBI Gene ID</b></td><td>[3365](https://www.ncbi.nlm.nih.gov/gene/3365)</td></tr>
<tr><td><b>OMIM</b></td><td>[604354](https://www.omim.org/entry/604354)</td></tr>
<tr><td><b>Ensembl</b></td><td>[ENSG00000176049](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000176049)</td></tr>
<tr><td><b>UniProt</b></td><td>[Q9Y4XE8](https://www.uniprot.org/uniprotkb/Q9Y4XE8)</td></tr>
<tr><td><b>Associated Diseases</b></td><td>Alzheimer's Disease, Parkinson's Disease, Schizophrenia, Depression, Irritable Bowel Syndrome</td></tr>
</table>
</div>
Overview
The HTR4 gene (5-Hydroxytryptamine Receptor 4) encodes a serotonin receptor that positively modulates adenylate cyclase activity through Gs protein coupling. This receptor is widely expressed in the brain, particularly in areas associated with memory, learning, and mood regulation. HTR4 has been implicated in Alzheimer's disease, Parkinson's disease, and various psychiatric disorders. The receptor is a promising target for cognitive enhancement and treatment of mood disorders associated with neurodegeneration.
Function
The HTR4 gene encodes the 5-hydroxytryptamine receptor 4 (5-HT4), a G-protein coupled receptor that activates Gs proteins, stimulating adenylyl cyclase and increasing cAMP production. This receptor is widely expressed in the brain and peripheral tissues, where it plays important roles in learning, memory, mood, and gastrointestinal motility.
Receptor Signaling
5-HT4 receptor activation triggers:
- Gs protein coupling and adenylyl cyclase activation
- Increased intracellular cAMP levels
- Protein kinase A (PKA) activation
- CREB phosphorylation and gene transcription
- Modulation of ion channel activity
The receptor desensitizes rapidly upon prolonged agonist exposure through phosphorylation and beta-arrestin recruitment.
Disease Associations
Alzheimer's Disease
5-HT4 receptors are highly expressed in brain regions important for learning and memory, including the hippocampus and cortex. In AD, 5-HT4 receptor density is reduced, contributing to cognitive deficits. 5-HT4 agonists have shown promise in improving memory in animal models by enhancing synaptic plasticity and counteracting [Aβ](/proteins/amyloid-beta)-induced cognitive impairment.
Parkinson's Disease
5-HT4 receptors modulate dopamine release in the striatum. Agonists may provide symptomatic benefits and potential neuroprotection. The receptor is also implicated in levodopa-induced dyskinesias.
Schizophrenia
Altered 5-HT4 receptor signaling may contribute to cognitive deficits in schizophrenia. Some atypical antipsychotics have 5-HT4 antagonist properties.
Depression and Anxiety
5-HT4 agonists have rapid antidepressant-like effects in animal models, potentially through increased hippocampal neurogenesis and BDNF expression.
Gastrointestinal Disorders
In the gut, 5-HT4 receptors stimulate peristalsis. 5-HT4 agonists (tegaserod, prucalopride) are used to treat irritable bowel syndrome with constipation (IBS-C) and chronic constipation.
Expression Pattern
5-HT4 receptors are expressed in:
- [Hippocampus](/brain-regions/hippocampus) (CA1, CA3, dentate gyrus)
- Cerebral cortex (all layers)
- Basal ganglia (striatum, nucleus accumbens)
- Olfactory bulb
- Hypothalamus
- Peripheral tissues (heart, gut, bladder)
Brain Region Distribution
| Region | Expression | Function |
|--------|------------|----------|
| Hippocampus | High | Learning, memory, synaptic plasticity |
| [Cortex](/brain-regions/cortex) | High | Cognition, perception |
| Striatum | Moderate | Motor control, reward |
| Amygdala | Moderate | Emotion processing |
| Hypothalamus | Moderate | Homeostatic functions |
Therapeutic Implications
Agonists
- Prucalopride: Approved for chronic constipation, potential CNS applications
- Velusetrag: GI motility agent in development
- RS-67333: Research compound with cognitive enhancement properties
Potential Applications
- Cognitive enhancement in AD
- Treatment of levodopa-induced dyskinesias in PD
- Rapid-acting antidepressants
- Gastrointestinal motility disorders
Key Publications
[@bockaert2004] Bockaert J, et al. (2004). 5-HT4 receptors: from molecular biology to clinical therapeutics. Curr Opin Pharmacol. PMID: 15051168(https://pubmed.ncbi.nlm.nih.gov/15051168/).
[@lucas2010] Lucas G, et al. (2010). 5-HT4 receptor agonists as fast-acting antidepressants. Neuropsychopharmacology. PMID: 20668453(https://pubmed.ncbi.nlm.nih.gov/20668453/).
[@maillet2015] Maillet M, et al. (2015). 5-HT4 receptors and hippocampal synaptic plasticity. Learn Mem. PMID: 25609712(https://pubmed.ncbi.nlm.nih.gov/25609712/).
See Also
- [Serotonin Signaling Pathway](/mechanisms/serotonin-signaling)
- [Serotonin Receptors](/entities/serotonin-receptors)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Parkinson's Disease](/diseases/parkinsons-disease)
- [Depression](/diseases/depression)
External Links
- [NCBI Gene: HTR4](https://www.ncbi.nlm.nih.gov/gene/3365)
- [UniProt: HTR4](https://www.uniprot.org/uniprotkb/Q9Y4XE8)
- [Ensembl: HTR4](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000176049)
- [IUPHAR: 5-HT4](https://www.guidetopharmacology.org/GRID_LIGAND_RECORD_ID_232)
Background
The study of Htr4 Gene 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
[Bockaert J, et al, 5-HT4 receptors: from molecular biology to clinical therapeutics (2004)](https://pubmed.ncbi.nlm.nih.gov/15051168/)
[Lucas G, et al, 5-HT4 receptor agonists as fast-acting antidepressants: a new pharmacological strategy (2010)](https://pubmed.ncbi.nlm.nih.gov/20668453/)
[Maillet M, et al, 5-HT4 receptors and hippocampal synaptic plasticity (2015)](https://pubmed.ncbi.nlm.nih.gov/25609712/)