TRPC channels form the subfamily of channels in human most closely related to drosophila TRP channels. Structurally, this family shares a number of similar characteristics. At the proximal C-terminus of this sub-family is a TRP box motif containing the invariant EWKFAR sequence and between 3 and 4 ankyrin repeats near the N-terminus. These channels are non-selectively permeable to cations, with a selectivity of calcium over sodium variable among the different members. Many of TRPC channel subunits are able to coassemble.
In general, TRPC channels can be activated by phospholipase C stimulation, with some members also activated by diacylglycerol. There is one at least one report that TRPC1 is also activated by stretching of the membrane. It has long been proposed that TRPC channels underlie the store-operated channels (SOC) observed in many cell types. These channels open due to the depletion of intracellular calcium stores. Two other proteins, stromal interaction molecules (STIMs) and the ORAIs, however, have more recently been implicated in this process. It should be noted that STIM1 and TRPC1 can coassemble, complicating the understanding of this phenomenon.