Trace amine-associated receptor
Trace amine-associated receptors, abbreviated TAAR and otherwise known as trace amine receptors, abbreviated TAR or TA, are a class of G protein-coupled receptors identified in 2001.[1][2][3]
TAAR1 has gained considerable interest in academic and pharmaceutical industry research as endogenous receptors for trace amines, which are non-classical metabolic derivatives of phenylalanine and tryptophan and the psychostimulants amphetamine and methamphetamine.[3][4][5][6][7][8]
In 2004 it was shown that in mammals TAAR1 is probably also a receptor for thyronamines, decarboxylated and deiodinated metabolites of the thyroid hormones,[4] while the mouse mTAAR2 – mTAAR9 receptors are most probably olfactory receptors for volatile amines.[9][10]
Contents
- Animal TAAR complement 1
- Receptor function and ligands 2
- See also 3
- External links 4
- References 5
Animal TAAR complement
The following is a list of the TAARs contained in selected animal genomes:[1][11]
- Human — 6 genes (TAAR1, TAAR2, TAAR5, TAAR6, TAAR8, TAAR9), 2 pseudogenes (TAAR4P, TAAR7P), and one probable pseudogene (TAAR3)[12]
- Chimpanzee — 3 genes and 6 pseudogenes
- Mouse — 15 genes and 1 pseudogene
- Rat — 17 genes and 2 pseudogenes
- Zebrafish — 112 genes and 4 pseudogenes
- Frog — 3 genes and 0 pseudogenes
- Medaka — 25 genes and 1 pseudogenes
- Stickleback — 25 genes and 1 pseudogenes
Receptor function and ligands
Group |
Naming convention |
Prior names | Known or putative function in humans[13] | Known ligands | References |
---|---|---|---|---|---|
Group 1 | TAAR1 | TA1 |
• Neuromodulation of biogenic amines in the CNS • Chemotaxis of leukocytes • Chemoreceptor for volatile odorants† |
• Trace amines (e.g., phenethylamine, N-methylphenethylamine) • Classical monoamines (e.g., dopamine, serotonin, histamine) • Substituted amphetamines (e.g., amphetamine) |
[14][15][16] |
Group 1 | TAAR2‡ | GPR58 |
• Chemotaxis of leukocytes • Chemoreceptor for volatile odorants |
phenethylamine, tyramine, 3-iodothyronamine | [15][16] |
Group 1 | TAAR3 | GPR57, GPR57P | Probably a pseudogene | [12][15] | |
Group 1 |
|
– | Not present in humans | [15][17] | |
Group 2 | TAAR5 | PNR | Chemoreceptor for volatile and foul odorants |
trimethylamine, N,N-dimethylethylamine (agonists) 3-iodothyronamine (inverse agonist) |
[15][17][18][19][20] |
Group 3 | TAAR6 | – | Chemoreceptor for volatile odorants | [15][17] | |
Group 3 |
|
– | Not present in humans | [15][17] | |
Group 3 | TAAR8 |
TA5, TRAR5, TAR5, GPR102 |
Chemoreceptor for volatile odorants (Note: only known Gi/o-coupled TAAR) |
[15][17][21] | |
Group 3 | TAAR9‡ |
TA3, TRAR3, TAR3 |
Chemoreceptor for volatile odorants | [15][17] |
- †TAAR1 is not expressed in the human olfactory epithelium, but certain volatile odorants have been identified as agonists of hTAAR1;[22] hence, it's not an olfactory receptor in spite of its capacity for odorant detection.[22]
- ‡TAAR2 is inactive in a subset of the human population, as there is a polymorphism with a premature stop codon in 10–15% of Asians.[12]
- ‡TAAR9 is a functional receptor in most of the population, but has a polymorphism with a premature stop codon in 10–30%, depending on the population subgroup.[12]
See also
- Receptor
- Olfactory receptor
- Odorant
- Trace amine
- Thyronamine
- Amphetamine
- Methamphetamine
- Psychostimulant
External links
References
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