Trimeric intracellular cation-specific (TRIC) channels are critical for proper management of intracellular stores. TRIC-A and TRIC-B both belong to this family and are both permeable to monovalent ions with a preference for K+. Both channels are localized to the ER/SR membrane. Each TRIC subunit contains three transmembrane domains, a cytoplasmic C-terminus and a luminal N-terminus. Functional entities are formed by homotrimerizarion. The activity of TRIC-A is regulated by voltage whereas that of TRIC-B can be regulated by different mechanisms.