Characterization of the Sweet Taste Receptor Tas1r2 from an Old World Monkey Species Rhesus Monkey and Species-Dependent Activation of the Monomeric Receptor by an Intense Sweetener Perillartine.

Chenggu Cai,Bo Liu,Tianming Liu,Hua Jiang,Xuejie Song,Lei Li,Maik Behrens

doi:10.1371/journal.pone.0160079

Chenggu Cai, Bo Liu + Show 5 more

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https://doi.org/10.1371/journal.pone.0160079

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Journal: PloS one	Publication Date: Aug 1, 2016
Citations: 13	License type: CC BY 4.0

Affiliation: Qilu University of Technology, Shandong University

Abstract

Sweet state is a basic physiological sensation of humans and other mammals which is mediated by the broadly acting sweet taste receptor-the heterodimer of Tas1r2 (taste receptor type 1 member 2) and Tas1r3 (taste receptor type 1 member 3). Various sweeteners interact with either Tas1r2 or Tas1r3 and then activate the receptor. In this study, we cloned, expressed and functionally characterized the taste receptor Tas1r2 from a species of Old World monkeys, the rhesus monkey. Paired with the human TAS1R3, it was shown that the rhesus monkey Tas1r2 could respond to natural sugars, amino acids and their derivates. Furthermore, similar to human TAS1R2, rhesus monkey Tas1r2 could respond to artificial sweeteners and sweet-tasting proteins. However, the responses induced by rhesus monkey Tas1r2 could not be inhibited by the sweet inhibitor amiloride. Moreover, we found a species-dependent activation of the Tas1r2 monomeric receptors of human, rhesus monkey and squirrel monkey but not mouse by an intense sweetener perillartine. Molecular modeling and sequence analysis indicate that the receptor has the conserved domains and ligand-specific interactive residues, which have been identified in the characterized sweet taste receptors up to now. This is the first report of the functional characterization of sweet taste receptors from an Old World monkey species.

Highlights

Sweet taste is a prime sense that is essential for humans and other mammals to discern and ingest sweet-tasting nutritious foods and reject environmental toxins [1]
The rhesus monkey Tas1r2 responds to natural sugars and amino acids and their derivates
It was shown that rhTas1r2/hTAS1R3 could respond to natural sugars sucrose, glucose and trehalose, and the representative sweet amino acid D-tryptophan

Summary

Introduction

Sweet taste is a prime sense that is essential for humans and other mammals to discern and ingest sweet-tasting nutritious foods and reject environmental toxins [1]. Various sweeteners including natural sugars, sweet amino acids, artificial sweeteners and sweet-tasting proteins can interact with the receptor induce the receptor activation and downstream signal transduction [2]. Many behavioral and physiological studies have shown that the natural sugars, some amino acids, artificial sweeteners aspartame, neotame and cyclamate and sweet-tasting proteins can be perceived by catarrhines (humans, apes and Old World monkeys), but not by plathyrrhines (New World monkeys) and rodents [3,4,5,6,7]. We cloned and functionally characterized the first sweet taste receptor Tas1r2 from an Old World monkey species, rhesus monkey

Materials and Methods

Results and Discussion

Conclusions