It's an old axiom that in life we have to "take the bitter with the sweet." A recent study has shown that humans, as well as rodents, are well equipped to do just that. Scientists have discovered a new family of taste receptors (T2Rs) that may comprise as many as 80 different members, which together help detect different forms of bitter. Why so many? In nature, bitter comes in many shapes, most often associated with poisons, so broad recognition of this taste perception can be critical to an animal's survival. Now that the molecular structure of these receptors is known, scientists may be able to use this knowledge to take the bite out of bitter.
Dr. Nicholas Ryba from the National Institute of Dental and Craniofacial Research (NIDCR) and Dr. Charles Zuker from the Howard Hughes Medical Institute and the University of California at San Diego have established a long-term collaboration to investigate the sense of taste. Last year, their groups reported the identification of the first two strong candidate taste receptors: TR1 and TR2. Their work describing and characterizing the new T2R taste receptors is reported in two articles in the March 17 issue of Cell.
According to Dr. Ryba, "We now have the means to really start to investigate how taste works, not just in the tongue but also what happens in the brain." Dr. Mark Hoon from the NIDCR, a co-author of the study, adds, "These results significantly enhance our understanding of bitter taste and provide clues about how the sensation of bitter might protect animals from many poisons." Drs. Zuker and Ryba are continuing their studies not only to dissect the basis of taste perception but also to identify compounds that might be used to modify the human sensation of bitter.
The investigators found the first of the bitter receptors by focusing on a region of human chromosome 5 that was known to affect the ability of certain individuals to detect a bitter compound. They found a gene that coded for a pro
Contact: Wayne Little
NIH/National Institute of Dental and Craniofacial Research