The research group, led by Prof Makoto Tominaga and Dr Takaaki Sokabe, National Institute for Physiological Sciences (NIPS), Japan, identified the receptor's function during the study of a small fly, drosophila.
The 'painless' protein had been predicted as one type of ionic TRP (transient receptor potential) channels.
The researchers found that the channel could sense noxious heat directly. The channel activity was modulated by intracellular calcium to maintain optimal sensitivity. Camphor, a moth repellent, did block the activity of this channel.
"This is the first report to show that flies can sense hazardous heat by a specific sensor, namely 'Painless'. This finding may help designing new anti-fly substance," Dr. Sokabe said.
The study has been published in the Journal of Neuroscience on Oct 1, 2008.