Biomedical subjects

J Chandrashekar

Publications and source records attributed to J Chandrashekar.

3 recordsLinked to original sources

PubMed2001

Mammalian sweet taste receptors.

The sense of taste provides animals with valuable information about the quality and nutritional value of food. Previously, we identified a large family of mammalian taste receptors involved in bitter taste perception (the T2Rs). We now report the characterization of mammalian sweet taste receptors. First, transgenic rescue experiments prove that the Sac locus encodes T1R3, a member of the T1R family of candidate taste receptors. Second, using a heterologous expression system, we demonstrate that T1R2 and T1R3 combine to function as a sweet receptor, recognizing sweet-tasting molecules as diverse as sucrose, saccharin, dulcin, and acesulfame-K. Finally, we present a detailed analysis of the patterns of expression of T1Rs and T2Rs, thus providing a view of the representation of sweet and bitter taste at the periphery.

Animals↗

PubMed2000

A novel family of mammalian taste receptors.

In mammals, taste perception is a major mode of sensory input. We have identified a novel family of 40-80 human and rodent G protein-coupled receptors expressed in subsets of taste receptor cells of the tongue and palate epithelia. These candidate taste receptors (T2Rs) are organized in the genome in clusters and are genetically linked to loci that influence bitter perception in mice and humans. Notably, a single taste receptor cell expresses a large repertoire of T2Rs, suggesting that each cell may be capable of recognizing multiple tastants. T2Rs are exclusively expressed in taste receptor cells that contain the G protein alpha subunit gustducin, implying that they function as gustducin-linked receptors. In the accompanying paper, we demonstrate that T2Rs couple to gustducin in vitro, and respond to bitter tastants in a functional expression assay.

Animals↗

PubMed2000

T2Rs function as bitter taste receptors.

Bitter taste perception provides animals with critical protection against ingestion of poisonous compounds. In the accompanying paper, we report the characterization of a large family of putative mammalian taste receptors (T2Rs). Here we use a heterologous expression system to show that specific T2Rs function as bitter taste receptors. A mouse T2R (mT2R-5) responds to the bitter tastant cycloheximide, and a human and a mouse receptor (hT2R-4 and mT2R-8) responded to denatonium and 6-n-propyl-2-thiouracil. Mice strains deficient in their ability to detect cycloheximide have amino acid substitutions in the mT2R-5 gene; these changes render the receptor significantly less responsive to cycloheximide. We also expressed mT2R-5 in insect cells and demonstrate specific tastant-dependent activation of gustducin, a G protein implicated in bitter signaling. Since a single taste receptor cell expresses a large repertoire of T2Rs, these findings provide a plausible explanation for the uniform bitter taste that is evoked by many structurally unrelated toxic compounds.

Afferent Pathways↗