Trace amine-associated receptors (TAARs), sometimes referred to as trace amine receptors, are a class of G protein-coupled receptors that were discovered in 2001. TAAR1, the first of six functional human TAARs, has gained considerable interest in academic and proprietary pharmaceutical research due to its role as the endogenous receptor for the trace amines phenylethylamine, tyramine, and tryptamine – metabolic derivatives of the amino acids phenylalanine, tyrosine and tryptophan, respectively – ephedrine, as well as the synthetic psychostimulants, amphetamine, methamphetamine and methylenedioxymethamphetamine. In 2004, it was shown that mammalian TAAR1 is also a receptor for thyronamines, decarboxylated and deiodinated relatives of thyroid hormones. TAAR2–TAAR9 function as olfactory receptors for volatile amine odorants in vertebrates.
Trace amine-associated receptor 2 (TAAR2), formerly known as G protein-coupled receptor 58 (GPR58), is a protein that in humans is encoded by the TAAR2 gene. TAAR2 is coexpressed with Gα proteins; however, as of February 2017, its signal transduction mechanisms have not been determined.
Putative trace amine-associated receptor 3 (TAAR3) is a human pseudogene with the gene symbol TAAR3P. In other species such as mice, TAAR3 is a functional protein-coding gene that encodes a trace amine-associated receptor protein.
Probable G-protein coupled receptor 52 is a protein that in humans is encoded by the GPR52 gene.
Probable G-protein coupled receptor 87 is a protein that in humans is encoded by the GPR87 gene.
Probable G-protein coupled receptor 135 is a protein that in humans is encoded by the GPR135 gene.
Probable G-protein coupled receptor 115 is a protein that in humans is encoded by the GPR115 gene.
Probable G-protein coupled receptor 150 is a protein that in humans is encoded by the GPR150 gene.
Trace amine associated receptor 6, also known as TAAR6, is a protein which in humans is encoded by the TAAR6 gene.
Probable G-protein coupled receptor 141 is a protein that in humans is encoded by the GPR141 gene.
Probable G-protein coupled receptor 153 is a protein that in humans is encoded by the GPR153 gene.
Probable G-protein coupled receptor 151 is a protein that in humans is encoded by the GPR151 gene.
Probable G-protein coupled receptor 142 is a protein that in humans is encoded by the GPR142 gene.
Trace amine-associated receptor 5 is a protein that in humans is encoded by the TAAR5 gene. In vertebrates, TAAR5 is expressed in the olfactory epithelium.
Trace amine-associated receptor 1 (TAAR1) is a trace amine-associated receptor (TAAR) protein that in humans is encoded by the TAAR1 gene. TAAR1 is an intracellular amine-activated Gs-coupled and Gq-coupled G protein-coupled receptor (GPCR) that is primarily expressed in several peripheral organs and cells, astrocytes, and in the intracellular milieu within the presynaptic plasma membrane of monoamine neurons in the central nervous system (CNS). TAAR1 was discovered in 2001 by two independent groups of investigators, Borowski et al. and Bunzow et al. TAAR1 is one of six functional human trace amine-associated receptors, which are so named for their ability to bind endogenous amines that occur in tissues at trace concentrations. TAAR1 plays a significant role in regulating neurotransmission in dopamine, norepinephrine, and serotonin neurons in the CNS; it also affects immune system and neuroimmune system function through different mechanisms.
Trace amine-associated receptor 9 is a protein that in humans is encoded by the TAAR9 gene.
Olfactory receptor 10A5 (OR10A5) is a protein that in humans is encoded by the OR10A5 gene.
Olfactory receptor 10A4 is a protein that in humans is encoded by the OR10A4 gene.
DnaJ homolog subfamily C member 14 is a protein that in humans is encoded by the DNAJC14 gene.
Probable G-protein coupled receptor 61 is a protein that in humans is encoded by the GPR61 gene.
