Functional diversity of bitter taste receptor TAS2R16 in primates

Hiroo Imai, Nami Suzuki, Yoshiro Ishimaru, Takanobu Sakurai, Lijie Yin, Wenshi Pan, Keiko Abe, Takumi Misaka and Hirohisa Hirai

In mammals, bitter taste is mediated by TAS2R genes, which belong to the large family of seven transmembrane G protein-coupled receptors. Because TAS2Rs are directly involved in the interaction between mammals and their dietary sources, it is likely that these genes evolved to reflect species-specific diets during mammalian evolution. Here, we investigated the sensitivities of TAS2R16s of various primates by using a cultured cell expression system, and found that the sensitivity of each primate species varied according to the ligand. Especially, the sensitivity of TAS2R16 of Japanese macaques to salicin was much lower than that of human TAS2R16, which was supported by behavioural tests. These results suggest the possibility that bitter-taste sensitivities evolved independently by replacing specific amino acid residues of TAS2Rs in different primate species to adapt to food items they use.

 This work was financially supported by Global COE A06 and by grants-in-aid from the MEXT (2137009, 22247036), and from the Ministry of the Environment (D-1007), Japan, and grants from the Takeda Foundation for Science and the Suzuken Memorial Foundation to H.I. 

Biology Letters, Published online before print March 7, 2012, doi: 10.1098/rsbl.2011.1251 

Full Text: http://rsbl.royalsocietypublishing.org/cgi/content/full/rsbl.2011.1251?ijkey=sACVi2Jd0xLEzas&keytype=ref

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