SPLTRAK Abstract Submission
TMC6: A Novel Salt Taste Receptor in Mice
Takami Maekawa1, Koki Kamiya2, Tooru Takahashi1,3, Kentaro Kaji1,3, Yukio Tezuka1,3, Toshihisa Osaki2, Shoji Takeuchi2,4, Takashi Kondoh1
1Ajinomoto Co., Inc., Kawasaki, Japan
2Kanagawa Institute of Industrial Science and Technology, Kawasaki, Japan
3WDB Co., Ltd., Tokyo, Japan
4Institute of Industrial Science, The University of Tokyo, Tokyo, Japan

Mechanism of amiloride-insensitive salt taste perception remains unclear. To find novel salt taste receptors, we investigated gene and protein expression in taste cells. Among them, it was found that transmembrane channel-like 6 (TMC6), a protein with unknown functions, was expressed in taste cells by single cell PCR and immunohistochemistry analysis. To perform functional analysis of TMC6, we generated Tmc6 knockout mice with C57BL/6J background and found that NaCl preference of the Tmc6 (-/-) mice, in the presence of amiloride, was largely decreased compared to the wild-type mice. Interestingly, the Tmc6 (-/-) mice showed normal preferences to sweet, sour, bitter and umami solutions. The results suggested that Tmc6 gene relates specifically to salt taste perception. By calcium imaging of CHO-K1 cells transfected withTmc6 gene, we found that the cells responded to NaCl stimulus. Finally, we embedded a purified TMC6 protein in an artificial lipid bilayer membrane and observed single ion channel-like currents under NaCl application. These results suggest that TMC6 is a novel ion channel that functions as a novel salt taste receptor in mouse taste cells.