Taste receptor cells share comm...( Although sweet bitter and umami (monos...)

The identification of a common pathway runs counter to widespread belief among some researchers in the taste field who have long held the view that the different tastes require distinct machinery within the cell to transduce their signals to the brain, which is responsible for processing taste perceptions.

The discovery also opens the way for more precise genetic manipulation of taste sensations in laboratory animals to discover how different tastes are perceived in the brain, according to Howard Hughes Medical Institute investigator Charles Zuker, who is at the University of California, San Diego. Zuker, Nicholas Ryba of the National Institute of Dental and Craniofacial Research of the National Institutes of Health and their colleagues reported their findings in the February 7, 2003, issue of the journal Cell.

The research team reported that two enzymes found in the same signaling pathway in the cell were necessary for mice to process sweet, bitter and umami tastes. Umami is the taste of monosodium glutamate.

According to Zuker, the effort to identify common components of the cell machinery involved in taste was driven by two goals. "One, is that we wanted to be able to manipulate the function of the various taste modalities, to understand taste processing," he said. "We might normally seek to knock out the receptors themselves, which is feasible with sweet receptors, since there are only a couple. But there are thirty bitter-taste receptors, which would be practically impossible to eliminate.

"Our other goal was to make sense of the extraordinary complexity in the scientific understanding of the signaling pathways involved in t
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Contact: Jim Keeley
keeleyj@hhmi.org
301-215-8858
Howard Hughes Medical Institute
6-Feb-2003