New Research on Taste Receptors
April 2000
The taste system has the remarkable capacity to distinguish the sweet, salty, sour and bitter
components of foods. The detection of bitter-tasting compounds is of special importance because
strongly bitter substances are often poisonous and need to be avoided. Recent studies in the
laboratories of John R. Carlson, Charles S. Zuker and Robert F. Magolskee, with funding from the
NIDCD, have made tremendous progress in increasing our understanding about the genetic bases of
bitter taste sensitivity. This is an important first step in clarifying how the taste system
responds in a more general way to a variety of chemical compounds that range from sweet to sour.
These researchers have shown that both insect and mammalian systems possess several genes that
define a large, diverse family of 40 - 80 putative G protein-coupled taste receptors. This family
of taste receptors shares many of the signal transduction properties of the receptors found in
the olfactory system and appears conserved in the two sensory systems that respond to a variety
of chemical compounds in the environment. Taste receptors are often coupled in the same receptor
cell to a unique G protein called gustducin, supporting previous evidence that bitter taste
involves a signal transduction cascade involving gustducin. The existence of this large family
of taste receptors helps to explain why so many structurally dissimilar compounds have a bitter
taste.
NIDCD, one of the institutes of the National Institutes of Health, is the nation's focal
point for research in human communication. NIDCD conducts and supports biomedical and behavioral
research and research training on normal mechanisms as well as diseases and disorders of hearing,
balance, smell, taste, voice, speech, and language.
For further reading, the following articles are
suggested:
Adler E, et al.
A novel family of mammalian taste receptors. Cell.2000 Mar 17;100(6):693-702.
Clyne PJ, et al.
Candidate taste receptors in Drosophila. Science.2000 Mar 10;287(5459):1830-40.
Chandrashekar J, et al.
T2Rs function as bitter taste receptors. Cell.2000 Mar 17;100(6):703-11.
Wong GT, et al.
Transduction of bitter and sweet taste by gustducin. Nature.1996 Jun 27;381(6585):796-800.
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