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.
| Attribute | Value | [@aghajanian1995] |-----------|-------| [@meltzer1998] | Protein Name | Serotonin Receptor 2A | [@nichols2016] | Gene Symbol | [htr2a](/proteins/htr2a-protein) | | UniProt ID | [P28223](https://www.uniprot.org/uniprot/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 |
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Overview
The Serotonin Receptor 2A (HTR2A) is a Gq-coupled GPCR encoded by the [HTR2A](/proteins/htr2a-protein) 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.
Structure
HTR2A features the characteristic GPCR fold with unique elements:
Long C-terminal tail: Contains serine/threonine residues for phosphorylation and desensitization
Differential splicing: Generates multiple isoforms with distinct coupling properties
Palmitoylation sites: In the C-tail for membrane anchoring
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Serotonin Receptor 2A Protein
Introduction
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.
| Attribute | Value | [@aghajanian1995] |-----------|-------| [@meltzer1998] | Protein Name | Serotonin Receptor 2A | [@nichols2016] | Gene Symbol | [htr2a](/proteins/htr2a-protein) | | UniProt ID | [P28223](https://www.uniprot.org/uniprot/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 |
</div>}
Overview
The Serotonin Receptor 2A (HTR2A) is a Gq-coupled GPCR encoded by the [HTR2A](/proteins/htr2a-protein) 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.
Structure
HTR2A features the characteristic GPCR fold with unique elements:
Long C-terminal tail: Contains serine/threonine residues for phosphorylation and desensitization
Differential splicing: Generates multiple isoforms with distinct coupling properties
Palmitoylation sites: In the C-tail for membrane anchoring
The receptor binds tryptamines (serotonin, psilocybin), phenethylamines (DOI), and ergolines (lysergic acid).
Normal Function
HTR2A mediates diverse central nervous system functions:
Phospholipase C activation: Increases IP3 and DAG, raising intracellular calcium
Pyramidal neuron modulation: Excitatory effects in prefrontal [cortex](/brain-regions/cortex)
Smooth muscle contraction: Vascular and gastrointestinal effects
Dreaming and consciousness: HTR2A activity correlates with REM sleep
Role in Neurodegeneration
Alzheimer's Disease
HTR2A expression is altered in AD brains, particularly in cortical regions. The receptor interacts with [amyloid-beta](/proteins/amyloid-beta) and may contribute to synaptic dysfunction. 5-HT2A agonists have shown promise in improving cognition in animal models.
Parkinson's Disease
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.
Schizophrenia
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.
Depression
Chronic SSRI treatment downregulates HTR2A, which may contribute to antidepressant effects. Some novel antidepressants (trazodone, vilazodone) directly target HTR2A.
Therapeutic Targeting
| 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 |
Research Directions
5-HT2A-selective partial agonists for treatment-resistant depression
Understanding psychedelic mechanisms through HTR2A signaling
Development of non-hallucinogenic 5-HT2A agonists for cognitive enhancement
Background
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.