Trace amine-associated receptor

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]


  • 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]

Receptor function and ligands

HumanTAARs and their ligands
Group Naming
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)
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 TAAR4 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)
Group 3 TAAR6 Chemoreceptor for volatile odorants [15][17]
Group 3 TAAR7 Not present in humans [15][17]
Group 3 TAAR8 TA5, TRAR5,
TAR5, GPR102
Chemoreceptor for volatile odorants
(Note: only known Gi/o-coupled TAAR)
Group 3 TAAR9 TA3, TRAR3,
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

External links


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