ADORA2A Gene: Adenosine A2a Receptor
A key G-protein coupled receptor mediating adenosine signaling, with implications in inflammation, neurological disorders, and cancer.
Gene Information Card
| Symbol | ADORA2A |
|---|---|
| Full Name | Adenosine A2a receptor |
| Gene Type | protein-coding |
| Chromosomal Location | 22q11.23 |
| NCBI Gene ID | 135 ncbi.nlm.nih.gov/gene/135 |
| Ensembl ID | ENSG00000128271 |
| UniProt ID | P29274 |
| OMIM ID | 102776 |
| HGNC ID | 263 |
| Aliases | A2aR, ADORA2, RDC8 |
Description
The ADORA2A gene encodes the adenosine A2a receptor, a G-protein coupled receptor (GPCR) that is activated by adenosine. This receptor is widely expressed in the brain, immune cells, and cardiovascular system, where it modulates various physiological processes including neurotransmission, inflammation, and blood flow. ADORA2A is a major target for caffeine and has been implicated in several diseases, including Parkinson's disease, anxiety, and cancer.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Parkinson's disease | ADORA2A antagonists are used as adjunct therapy to L-DOPA; receptor modulates dopaminergic signaling in the basal ganglia. | ClinVar, OMIM |
| Huntington's disease | Altered ADORA2A expression in striatal neurons contributes to motor dysfunction. | OMIM, PubMed (via NCBI) |
| Anxiety disorders | Genetic variants in ADORA2A are associated with panic disorder and anxiety responses to caffeine. | ClinVar, OMIM |
| Cancer | ADORA2A signaling in tumor microenvironment suppresses anti-tumor immunity; expression on immune cells promotes immune evasion. | COSMIC, PubMed (via NCBI) |
| Ischemic heart disease | Adenosine A2a receptor activation mediates cardioprotective effects during ischemia/reperfusion. | OMIM, PubMed (via NCBI) |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | High | Highest expression in striatum, cortex, and hippocampus |
| Lung | Medium | Moderate expression in lung tissue |
| Heart | Medium | Expressed in cardiac myocytes and vascular smooth muscle |
| Spleen | High | High expression in immune cells (lymphocytes, macrophages) |
| Liver | Low | Low expression in hepatocytes |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | High | Commonly used for recombinant expression studies |
| Jurkat (T cells) | High | Endogenous expression in T lymphocytes |
| SH-SY5Y (neuroblastoma) | Medium | Neuronal cell line with moderate expression |
| A549 (lung carcinoma) | Low | Low expression in this cell line |
| MCF7 (breast cancer) | Low | Low expression in breast cancer cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| rs5751876 (T/C) | SNP | Allele frequency: C allele ~0.4 in Europeans | Associated with anxiety and caffeine response; affects receptor expression |
| rs2298383 (C/T) | SNP | Allele frequency: T allele ~0.3 in East Asians | Linked to panic disorder; may alter promoter activity |
| c.1083C>T (p.Ser361Phe) | Missense | Rare | Functional impact unknown; reported in ClinVar |
| c.136C>T (p.Arg46Trp) | Missense | Rare | Potential loss of function; not well characterized |
Mutation functional classification
Loss of Function (LOF)
Loss-of-function mutations in ADORA2A are rare and not well documented. Some missense variants may impair receptor signaling, but no clear pathogenic loss-of-function mutations have been established.
Gain of Function (GOF)
No gain-of-function mutations have been reported for ADORA2A.
Dominant Negative (DN)
No dominant-negative mutations have been described for ADORA2A.
View complete mutation data：
Gene Ontology (GO)
| • G protein-coupled receptor activity | • adenosine receptor activity |
| • adenosine binding | • signal transduction |
| • G protein-coupled receptor signaling pathway | • adenylate cyclase-activating G protein-coupled receptor signaling pathway |
| • regulation of cAMP metabolic process | • inflammatory response |
| • immune response | • neurotransmitter receptor activity |
Pathways
• Adenosine signaling pathway
• GPCR downstream signaling
• cAMP signaling pathway
• Inflammatory response pathway
• Dopamine signaling pathway (in striatum)
Protein Summary
The adenosine A2a receptor is a 412-amino acid protein with seven transmembrane domains, characteristic of GPCRs. It couples to Gs proteins, leading to activation of adenylate cyclase and increased cAMP levels. The receptor is involved in regulating myocardial oxygen demand, inflammation, and neurotransmitter release. It is a major target of caffeine, which acts as a non-selective antagonist. The protein is expressed on immune cells, where it suppresses inflammatory responses, and in the brain, where it modulates dopaminergic signaling.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| ADORA2A Knockout HEK293 Cell Line | EDJ-KQ1290 | Human | 135 | Details Get a Quote |
| ADORA2A Knockout A-549 Cell Line | EDJ-KQ20691 | Human | 135 | Details Get a Quote |
| ADORA2A Knockout HCT 116 Cell Line | EDJ-KQ20692 | Human | 135 | Details Get a Quote |
| ADORA2A Knockout HeLa Cell Line | EDJ-KQ52563 | Human | 135 | Details Get a Quote |
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