A Johns Hopkins team has identified a protein in sensory cells on the "tongues" of fruit flies that allows them to detect a noxious chemical and, ultimately, influences their decision about what to eat and what to avoid.
A report on the work, appearing April 19 in the online Early Edition of the Proceedings of the National Academy of Sciences (PNAS), raises the possibility that the protein TRPA1 is a new molecular target for controlling insect pests.
"We're interested in how TRPA1 and a whole family of so-called TRP channels affect not just the senses, like taste, but also behavior," says Craig Montell, Ph.D., a professor of biological chemistry and member of the Center for Sensory Biology in Johns Hopkins' Institute for Basic Biomedical Sciences.
Montell notes that when his team knocked out the TRPA1 sensor, the behavior change an alteration in food preference was stark. "This is the first TRP channel in insects that responds to a naturally occurring plant chemical known as an antifeedant, so now we have a target for finding more effective chemicals to protect plants from destruction by insect pests."
Montell discovered TRP (pronounced "trip") channels in 1989 in flies and, a handful of years later, in humans, noting their abundance on sensory cells that communicate with the outside world. The job of these pore-like proteins activated by a bright light, a chilly breeze or a hot chili pepper is to excite cells to signal each other and ultimately alert the brain by controlling the flux of atoms of calcium and sodium that carry electrical charges. Montell's lab and others have tallied 28 TRP channels in mammals and 13 in flies, improving understanding about how animals detect a broad range of sensory stimuli, including the most subtle changes in temperature.
"We already knew that TRP channels have these broad sensory roles, having previously discovered that the insect TRPA1 had a role in helping flies
|Contact: Maryalice Yakutchik|
Johns Hopkins Medical Institutions