| First Author | Mühlhaus J | Year | 2014 |
| Journal | Int J Mol Sci | Volume | 15 |
| Issue | 11 | Pages | 20638-55 |
| PubMed ID | 25391046 | Mgi Jnum | J:345351 |
| Mgi Id | MGI:6880361 | Doi | 10.3390/ijms151120638 |
| Citation | Muhlhaus J, et al. (2014) Analysis of human TAAR8 and murine Taar8b mediated signaling pathways and expression profile. Int J Mol Sci 15(11):20638-55 |
| abstractText | The thyroid hormone derivative 3-iodothyronamine (3-T1AM) exerts metabolic effects in vivo that contradict known effects of thyroid hormones. 3-T1AM acts as a trace amine-associated receptor 1 (TAAR1) agonist and activates G(s) signaling in vitro. Interestingly, 3-T1AM-meditated in vivo effects persist in Taar1 knockout-mice indicating that further targets of 3-T1AM might exist. Here, we investigated another member of the TAAR family, the only scarcely studied mouse and human trace-amine-associated receptor 8 (Taar8b, TAAR8). By RT-qPCR and locked-nucleic-acid (LNA) in situ hybridization, Taar8b expression in different mouse tissues was analyzed. Functionally, we characterized TAAR8 and Taar8b with regard to cell surface expression and signaling via different G-protein-mediated pathways. Cell surface expression was verified by ELISA, and cAMP accumulation was quantified by AlphaScreen for detection of G(s) and/or G(i/o) signaling. Activation of G-proteins G(q/11) and G(12/13) was analyzed by reporter gene assays. Expression analyses revealed at most marginal Taar8b expression and no gender differences for almost all analyzed tissues. In heart, LNA-in situ hybridization demonstrated the absence of Taar8b expression. We could not identify 3-T1AM as a ligand for TAAR8 and Taar8b, but both receptors were characterized by a basal G(i/o) signaling activity, a so far unknown signaling pathway for TAARs. |
