Work

Intracellular acidification is required for full activation of the sweet taste receptor by miraculin

Year: 2016

Type: article

Abstract: Acidification of the glycoprotein, miraculin (MCL), induces sweet taste in humans, but not in mice. The sweet taste induced by MCL is more intense when acidification occurs with weak acids as opposed to strong acids. MCL interacts with the human sweet receptor subunit hTAS1R2, but the mechanisms by which the acidification of MCL activates the sweet taste receptor remain largely unexplored. The work reported here speaks directly to this activation by utilizing a sweet receptor TAS1R2 + TAS1R3 assay. In accordance with previous data, MCL-applied cells displayed a pH dependence with citric acid (weak acid) being right shifted to that with hydrochloric acid (strong acid). When histidine residues in both the intracellular and extracellular region of hTAS1R2 were exchanged for alanine, taste-modifying effect of MCL was reduced or abolished. Stronger intracellular acidification of HEK293 cells was induced by citric acid than by HCl and taste-modifying effect of MCL was proportional to intracellular pH regardless of types of acids. These results suggest that intracellular acidity is required for full activation of the sweet taste receptor by MCL.

Source: Scientific Reports

DOI: 10.1038/srep22807

Authors: Keisuke Sanematsu, Masayuki Kitagawa, Ryusuke Yoshida, Satoru Nirasawa, Noriatsu Shigemura, Yuzo Ninomiya

Institutions: Kyushu University, Japan International Research Center for Agricultural Sciences

Language: English

Topic: Biochemical Analysis and Sensing Techniques

Subfield: Nutrition and Dietetics

Field: Nursing

Domain: Health Sciences

Open Access status: gold

Estimated APC paid: $2,690

Funder: Japan Society for the Promotion of Science