Cold-Activated Protein Found in Skin Neurons

Investigators have identified an ion channel protein located in nerve endings in the skin that is inactive at room temperature but responds to cold temperatures below 15oC to send a pain signal to the brain.

The research group at the Scripps Research Institute (La Jolla, CA, USA) and the Genomics Institute of the Novartis Research Foundation (San Diego, CA, USA) had previously cloned the first sensory molecule, a type of transient receptor potential (TRP) channel called TRPV1 that became active above 42o C.

In the current study, published in the March 21, 2003, issue of Cell, the group described the ion channel protein ANKTM1, which is the first noxious (painful) cold receptor to be identified. ANKTM1 displayed a lower activation temperature than that of the cold and menthol receptor, TRPM8. ANKTM1 was shown to be a distant family member of TRP channels with very little amino acid similarity to TRPM8. ANKTM1 proteins are co-expressed with TRPV1 proteins on the same neurons, showing that hot and cold receptors do not require separate neurons.

"This protein may be an important therapeutic target,” said senior author Dr. Ardem Patapoutian, assistant professor of cell biology at the Scripps Research Institute, "because, like these other TRP channels, it may be involved in inflammation and pain-mediation.”




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Genomics Institute of the Novartis Research Foundation