5-HT2A receptor

HTR2A
Identifiers
Aliases	HTR2A, 5-HT2A, HTR2, 5-hydroxytryptamine receptor 2A
External IDs	OMIM: 182135; MGI: 109521; HomoloGene: 68073; GeneCards: HTR2A; OMA:HTR2A - orthologs
Gene location (Human) Chr. Chromosome 13 (human)[1] Band 13q14.2 Start 46,831,546 bp[1] End 46,897,076 bp[1]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in buccal mucosa cell middle temporal gyrus frontal pole Brodmann area 23 Brodmann area 10 Brodmann area 46 endothelial cell orbitofrontal cortex superior frontal gyrus primary visual cortex n/a More reference expression data BioGPS More reference expression data
Gene ontology Molecular function 1-(4-iodo-2,5-dimethoxyphenyl)propan-2-amine binding G protein-coupled receptor activity virus receptor activity signal transducer activity G-protein alpha-subunit binding G protein-coupled serotonin receptor activity serotonin binding neurotransmitter receptor activity protein binding protein-containing complex binding Cellular component cytoplasm integral component of membrane cytosol cell projection membrane cell body fiber integral component of plasma membrane dendritic shaft axon soma caveola cytoplasmic vesicle plasma membrane dendrite glutamatergic synapse integral component of postsynaptic membrane integral component of presynaptic membrane Biological process detection of mechanical stimulus involved in sensory perception of pain release of sequestered calcium ion into cytosol regulation of dopamine secretion phospholipase C-activating serotonin receptor signaling pathway urinary bladder smooth muscle contraction positive regulation of MAP kinase activity behavioral response to cocaine positive regulation of cytosolic calcium ion concentration positive regulation of kinase activity positive regulation of phosphatidylinositol biosynthetic process ageing cellular calcium ion homeostasis cell death memory activation of phospholipase C activity detection of temperature stimulus involved in sensory perception of pain protein localization to cytoskeleton sleep positive regulation of vasoconstriction positive regulation of cell population proliferation negative regulation of potassium ion transport positive regulation of ERK1 and ERK2 cascade artery smooth muscle contraction positive regulation of peptidyl-tyrosine phosphorylation viral entry into host cell phosphatidylinositol 3-kinase signaling sensory perception of pain temperature homeostasis viral process positive regulation of fat cell differentiation positive regulation of glycolytic process negative regulation of synaptic transmission, glutamatergic signal transduction chemical synaptic transmission serotonin receptor signaling pathway phospholipase C-activating G protein-coupled receptor signaling pathway G protein-coupled receptor signaling pathway animal behavior regulation of synaptic vesicle exocytosis G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 3356 15558 Ensembl ENSG00000102468 ENSMUSG00000034997 UniProt P28223 P35363 RefSeq (mRNA) NM_001165947 NM_000621 NM_001378924 NM_172812 RefSeq (protein) NP_000612 NP_001159419 NP_001365853 NP_766400 Location (UCSC) Chr 13: 46.83 – 46.9 Mb n/a PubMed search [2] [3]
Wikidata
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The 5-HT_2A receptor is a subtype of the 5-HT₂ receptor that belongs to the serotonin receptor family and functions as a G protein-coupled receptor (GPCR).^[4] It is a cell surface receptor^[5] that activates multiple intracellular signalling cascades.^[6] Like all 5-HT₂ receptors, the 5-HT_2A receptor is coupled to the G_q/G₁₁ signaling pathway. It is the primary excitatory receptor subtype among the serotonin-responsive GPCRs. The 5-HT_2A receptor was initially noted for its central role as the primary target of serotonergic psychedelic drugs such as LSD and psilocybin mushrooms. It later regained research prominence when found to mediate, at least in part, the effects of many antipsychotic drugs, particularly atypical antipsychotics.

Downregulation of post-synaptic 5-HT_2A receptors is an adaptive response triggered by chronic administration of selective serotonin reuptake inhibitors (SSRIs) and atypical antipsychotics. Elevated 5-HT_2A receptor density has been observed in suicidal and otherwise depressed patients, suggesting that post-synaptic 5-HT_2A receptor overexpression may contribute to the pathogenesis of depression.^[7] Paradoxically, several 5-HT_2A receptor antagonists can also induce receptor downregulation.^[8] This effect may lead to reverse tolerance, rather than the expected development of tolerance. However, at least one antagonist has been shown to upregulate 5-HT_2A receptor expression,^[8][9] and a few others appear to have no effect on receptor levels.^[10] Nonetheless, such upregulation remains the exception rather than the rule.

Importantly, neither tolerance nor rebound has been observed in humans in relation to the slow-wave sleep (SWS)-promoting effects of 5-HT_2A antagonists.^[11]