Research Progress of Ectopic Olfactory Trace Amine-associated Receptors

Trace amine-associated receptors (TAARs) are a class of G-protein-coupled receptors, and with the exception of TAAR1, the remaining TAARs, like the olfactory receptors, are expressed in the olfactory epithelium and function to sense odorants. In recent years, the high expression of TAARs has been found in non-olfactory tissues, suggesting that TAARs may have important ectopic physiological functions. Recent studies have confirmed that endogenous and exogenous specific trace amines regulate a variety of physiological functions in non-olfactory tissues by acting on different TAARs, indicating that TAARs have the potential to become a new diagnostic and therapeutic target. This paper systematically introduces the expression of ectopic olfactory TAARs, endogenous and exogenous ligands, biogenic amines in food, ectopic olfactory TAARs-mediated signal pathways, and physiological and pathological functions. On the one hand, it provides new ideas for the future drug target development, physiological and pathological research, on the other hand, it also provides new research ideas for the biological activity of biogenic amines in food.