Htr2A Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
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| Attribute | Value |
|---|---|
| Protein Name | Serotonin Receptor 2A |
| Gene Symbol | htr2a |
| UniProt ID | P28223 |
| Molecular Weight | ~55-60 kDa |
| Subcellular Localization | Plasma membrane, dendritic shafts, postsynaptic densities |
| Protein Family | 5-HT2 family (GPCR) |
| Signal Transduction | Gq protein-coupled, activates phospholipase C |
The Serotonin Receptor 2A (HTR2A) is a Gq-coupled GPCR encoded by the HTR2A gene. It is the primary target for classic hallucinogens (psychedelics), atypical antipsychotics, and plays crucial roles in perception, cognition, and emotion. HTR2A dysfunction is implicated in schizophrenia, depression, and neurodegenerative disorders.
HTR2A features the characteristic GPCR fold with unique elements:
The receptor binds tryptamines (serotonin, psilocybin), phenethylamines (DOI), and ergolines (lysergic acid).
HTR2A mediates diverse central nervous system functions:
HTR2A expression is altered in AD brains, particularly in cortical regions. The receptor interacts with amyloid-beta and may contribute to synaptic dysfunction. 5-HT2A agonists have shown promise in improving cognition in animal models.
HTR2A dysfunction contributes to levodopa-induced dyskinesias. Post-mortem studies show increased HTR2A binding in the striatum of PD patients with dyskinesias. 5-HT2A antagonists may reduce dyskinesia severity.
HTR2A is a key target for atypical antipsychotics (clozapine, risperidone). The A-1438G polymorphism affects treatment response. HTR2A agonists (psychedelics) can induce psychotic-like experiences.
Chronic SSRI treatment downregulates HTR2A, which may contribute to antidepressant effects. Some novel antidepressants (trazodone, vilazodone) directly target HTR2A.
| Drug Class | Examples | Mechanism | Status |
|---|---|---|---|
| Atypical Antipsychotics | Clozapine, Risperidone | HTR2A antagonism | FDA approved |
| Antidepressants | Trazodone, Vilazodone | 5-HT2A antagonism | FDA approved |
| Hallucinogens | Psilocybin, LSD | HTR2A agonism | Research/Clinical trials |
| Research | Ketanserin, M100907 | Selective antagonists | Preclinical |
The study of Htr2A Protein 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.
[1] Glennon RA, et al. (1986). Binding of phenylisothiocyanate to 5-HT2 receptors. European Journal of Pharmacology. PMID:3005158
[2] Marek GJ, et al. (1992). Metabotropic glutamate (mGlu)2/3 receptors and 5-HT2A receptors. Brain Research. PMID:1284238
[3] Aghajanian GK, et al. (1995). Serotonin and hallucinogens. Neuropsychopharmacology. PMID:7606283
[4] Meltzer HY, et al. (1998). The role of 5-HT2A receptors in antipsychotic drug action. Neuropsychopharmacology. PMID:9880095
[5] Nichols DE, et al. (2016). Psychedelics as medicines. Current Topics in Medicinal Chemistry. PMID:27486156