In an article appearing in the journal Science, a group led by Ardem Patapoutian of TSRI and Stuart Bevan of Novartis describes the protein the gene makes, a type of transient receptor potential (TRP) channel called "TRPV3." This membrane protein opens when it senses a certain temperature and allows ions to pass through and cause an electrical potential that signals the brain.
"This protein may be an important target for drugs," says Patapoutian, "because, like other TRP channels, it may be involved in inflammation and pain-mediation."
Significantly, TRPV3 is the first temperature-sensing molecule identified that becomes activated at warm and hot temperatures, 33 C (91.5 F) and above. And it is the first temperature-sensing channel found in keratinocytes, which are the major type of cell in the skin.
Previously, scientists had known that humans and other vertebrate animals use specialized neurons located in the spinal column that are connected to the skin and organs through long axons to sense temperature, pressure, and other physical stimuli. Expressed on these axons are the same sort of TRP channels as the one in the current study, and in the last few years scientists have identified them as the "molecular thermometers" that detect hot and cold temperatures in the skin and relay that information back to the brain.
Earlier this year, the TSRI and GNF group identified and cloned the genecalled TRPM8 that codes for the first-known signaling molecule that helps the body sense cold temperatures and the cooling compound, menthol. That led them in part to the current molecule.
They knew that TRPM8 detects cold. And another set of channels in the spinal cord were known to detect noxious hea
Contact: Robin B. Clark
Scripps Research Institute