Trace amine associated receptor 5 (TAAR5) is an olfactory receptor specific for trimethylamine, a trace amine. It is also activated at lower level by dimethylethylamine. Trimethylamine is a bacterial metabolite found in some animal odors, and to humans it has a repulsive odor associated with bad breath and spoiled food. TAAR5 is mediated by the G(s)-class of G-proteins which activate adenylate cyclase. In immunohistochemistry, TAAR5 has membranous positivity in neurons in the thalamus, tuberomammillary nucleus, and subsets of cells in the caudate, medulla and pituitary. It is also positivie in endothelial cells in many tissues throughout the body, including the spleen, liver, smooth muscle, immune tissues, plasma, ovaries, thyroid, and prostate. In cancer, it is moderately positive in melanomas and has low levels of expression in glioblastoma and many other tumour types.
References: The UniProt Consortium. Nucleic Acids Res. 47: D506-515 (2019); Nucleic Acids Res. 2016 Jan 4;44(D1):D733-45, PMID:26553804