Zinc irritates an ion channel

Researchers have discovered how the body reacts to the negative effects of zinc over exposure. A paper online in Nature Chemical Biology, reports that a previously known sensor for other chemicals, also acts as a mediator for the sensory symptoms associated with zinc toxicity, such as pain.

Zinc is one of the most commonly used metals in industrial settings. While being essential for the function of hundreds of proteins, high concentrations are toxic to cells. Overexposure by inhalation can cause symptoms such as nausea, gastric pain and inflammation.

Ardem Patapoutian and colleagues found that zinc acts as a messenger that enters somatosensory neurons through minimally active TRPA1 channels. It then further activates the channel through an interaction with several intracellular residues. TRPA1 had been previously implicated as a sensor for several pungent phytochemicals, such as mustard oil, as well as extreme cold.