'Warm to the touch' gene found

A group of researchers has identified and cloned the first known gene that makes skin cells able to sense warm temperatures.

The protein which the gene makes is 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 Ardem Patapoutian of The Scripps Research Institute, "because, like other TRP channels, it may be involved in inflammation and pain mediation."

TRPV3 is the first temperature-sensing molecule identified that becomes activated at warm and hot temperatures - 33 degrees C and above. It is also the first temperature-sensing channel found in keratinocytes, which are the major type of cell in the skin.

"We have shown for the first time that skin cells are capable of detecting heat through molecules similar to those in heat-sensing neurons," says Patapoutian.

It is not known how the electrical potential signal is communicated to the brain, since keratinocytes, unlike neurons, have no direct link with the central nervous system. Keratinocytes do, however, touch nerve fibres, and it may be through these contacts that the temperatures are communicated.

The channel's similarity to another temperature-sensing ion channel, VR1, suggestst that TRPV3 may be a target for pain therapeutics. VR1 is involved in inflammation and in communicating pain to the brain. Several compounds which block its action are currently under investigation for chronic pain indications.

Item provided courtesy of The Scripps Research Institute