Bitter taste

The ability to detect bitter tastes is thought to help us avoid eating toxic substances. In an Advanced Online Publication in Nature Genetics, Bernd Bufe and colleagues describe the characterization of a human bitter taste receptor (Nature Genetics, doi:10.1038/ng1014, 15 October 2002).

Bufe et al. mined human genome sequence information and found 24 intron-less genes encoding potential TAS2R taste receptors. They expressed each of them in HEK293/15 cells and recorded calcium transients using a fluorescence imaging plate reader. They identified a receptor, TAS2R16, that recognized the bitter tastes of beta-glycopyranoside phytonutrients such as salicin — an extract from willow bark that is used as an analgesic. TAS2R16 is expressed in human taste buds of the villate papillae. In addition they found evidence for receptor desensitization upon repeated exposure and adaptation. Compounds recognized by TAS2R16 have a common chemical structure, which could explain the breadth of taste perception.

These...