Trace Amine-associated Receptor (TAAR)

Trace amine associated-receptors (TAARs) are a class of G protein-coupled receptors that were discovered in 2001. Humans possess six functional isoforms (TAAR1, TAAR2, TAAR5, TAAR6, TAAR8, and TAAR9), whereas some fish species express over 100. It acts as an endogenous receptor for the trace amines. Trace amines are endogenous compounds classically regarded as comprising β-phenylethyalmine, p-tyramine, tryptamine, p-octopamine, and some of their metabolites.

Although all other TAARs serve predominantly or exclusively as chemosensory receptors in the main olfactory system, TAAR 1 has been demonstrated to be a novel modulator of dopaminergic, serotonergic and glutamatergic activity in the brain. And TAAR 1 has been identified as a novel therapeutic target for schizophrenia, depression, and addiction. In the periphery, TAAR1 regulates nutrient-induced hormone secretion, suggesting its potential as a novel therapeutic target for diabetes and obesity. TAAR1 may also regulate immune responses by regulating leukocyte differentiation and activation.