TRPC Channels in the SOCE Scenario.

Transient receptor potential (TRP) proteins form non-selective Ca permeable channels that contribute to the modulation of a number of physiological functions in a variety of cell types. Since the identification of TRP proteins in , it is well known that these channels are activated by stimuli that induce PIP hydrolysis. The canonical TRP (TRPC) channels have long been suggested to be constituents of the store-operated Ca (SOC) channels; however, none of the TRPC channels generate Ca currents that resemble . STIM1 and Orai1 have been identified as the components of the Ca release-activated Ca (CRAC) channels and there is a body of evidence supporting that STIM1 is able to gate Orai1 and TRPC1 in order to mediate non-selective cation currents named . STIM1 has been found to interact to and activate Orai1 and TRPC1 by different mechanisms and the involvement of TRPC1 in store-operated Ca entry requires both STIM1 and Orai1. In addition to the participation of TRPC1 in the currents, TRPC1 and other TRPC proteins might play a relevant role modulating Orai1 channel function. This review summarizes the functional role of TRPC channels in the STIM1-Orai1 scenario.