HTR2A
5-hydroxytryptamine receptor 2A
Gene summary
A protein-coding gene on chromosome 13 (neurotransmission). Encodes one of the receptors for serotonin, a neurotransmitter with many roles. Mutations in this gene are associated with susceptibility to schizophrenia and obsessive-compulsive disorder, and are also associated with response to the antidepressant citalopram in patients with major depressive disorder (MDD).
Source: NCBI Gene, accessed 2026-10-07.
Protein reference (UniProt)
- Protein
5-hydroxytryptamine receptor 2A
- Function (excerpt)
G protein-coupled receptor for 5-hydroxytryptamine (serotonin). Also functions as a receptor for various drugs and psychoactive substances, including mescaline, psilocybin, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) and lysergic acid diethylamide (LSD). Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors. HTR2A is coupled to G(q)/G(11) G alpha proteins and activates phospholipase C-beta, releasing diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) second messengers that modulate the activity of phosphatidylinositol 3-kinase and promote the release of Ca(2+) ions from intracellular stores, respectively. Beta-arrestin family members inhibit signaling via G proteins and mediate activation of alternative signaling pathways. Affects neural activity, perception, cognition and mood.
- Subcellular location
Cell membrane; Cell projection, dendrite; Cell projection, axon; Cytoplasmic vesicle; Membrane, caveola; Presynapse.
- Tissue specificity
Detected in brain cortex (at protein level). Detected in blood platelets.
Source: UniProtKB/Swiss-Prot P28223, release 2026_03, licensed CC BY 4.0. This is the protein’s normal biology, not evidence about post-drug syndromes; associated conditions are inherited disorders of the gene, not PFS, PSSD or PRSD.
Why its pathway is in the library
Monoamine, GABA, glutamate, and cholinergic systems are the direct pharmacologic targets of SSRIs/SNRIs (PSSD) and the downstream effectors of neurosteroid signaling (PFS).
Written for the whole neurotransmission family, not for HTR2A specifically.
Mentioned in 1 corpus record
- Peer-reviewed paper
Serotonin 2A -1438 G/A and G-Protein Beta3 Subunit C825T Polymorphisms in Patients with Depression and SSRI-Associated Sexual Side-Effects
Jeffrey R. Bishop, Jessica Moline, Vicki L. Ellingrod, Susan K. Schultz, Anita H. Clayton · Neuropsychopharmacology
In 81 outpatients treated with citalopram, escitalopram, fluoxetine, paroxetine, or sertraline, sexual dysfunction was measured with the Changes in Sexual Function Questionnaire as a primary outcome. The HTR2A -1438 G/G genotype was associated with…
GNB3HTR2AMECH-0372006PSSDSystems review · Oct 2026
Also in neurotransmission
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solute carrier family 6 member 4
chr 17· Drug transporters· 10 records - HTR1A
5-hydroxytryptamine receptor 1A
chr 5· Neurotransmission· 6 records - COMT
catechol-O-methyltransferase
chr 22· Drug metabolism· 4 records - HTR2C
5-hydroxytryptamine receptor 2C
chr X· Neurotransmission· 4 records - DBH
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chr 9· Neurotransmission· 3 records - BDNF
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chr 11· Neurotransmission· 2 records - DRD1
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chr 5· Neurotransmission· 1 record - DRD2
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chr 11· Neurotransmission· 1 record
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