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.
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.
In 2004 it was shown that in mammals TAAR1 is probably also a receptor for thyronamines, decarboxylated and deiodinated metabolites of the thyroid hormones, while the mouse mTAAR2 â€" mTAAR9 receptors are most probably olfactory receptors for volatile amines.
Animal TAAR complement
The following is a list of the TAARs contained in selected animal genomes:
- Human â€" 6 genes genes (TAAR1, TAAR2, TAAR5, TAAR6, TAAR8, TAAR9), 2 pseudogenes (TAAR4P, TAAR7P), and one probable pseudogene (TAAR3)
- Chimpanzee â€" 3 genes and 6 pseudogenes
- Mouse â€" 15 genes and 1 pseudogene
- Rat â€" 17 genes and 2 pseudogenes
- Zebrafish â€" 112 genes and 4 pseudogenes
- Frog â€" 3 genes and 0 pseudogenes
- Medaka â€" 25 genes and 1 pseudogenes
- Stickleback â€" 25 genes and 1 pseudogenes
Receptor function and ligands
- †TAAR1 is not expressed in the human olfactory epithelium, but certain volatile odorants have been identified as agonists of hTAAR1; hence, it's not an olfactory receptor in spite of its capacity for odorant detection.
- ‡TAAR2 is inactive in a subset of the human population, as there is a polymorphism with a premature stop codon in 10â€"15% of Asians.
- ‡TAAR9 is a functional receptor in most of the population, but has a polymorphism with a premature stop codon in 10â€"30%, depending on the population group populations.
See also
- Receptor
- Olfactory receptor
- Odorant
- Trace amine
- Thyronamine
- Amphetamine
- Methamphetamine
- Psychostimulant
External links
- "Trace Amine Receptors". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology.Â