TRP channels are a large family (about 28 genes) of plasma membrane, non-selective cationic channels that are either specifically or ubiquitously expressed in excitable and non-excitable cells. The TRP channels have putative six-transmembrane domains (TM) with a pore domain between the fifth and the sixth TM, and all assemble as tetramers. Both the N- and the C-terminus of all TRPs are intracellular.
According to IUPHAR, the TRP family is comprised of three main subfamilies on the basis of sequence homology; TRPC, TRPM and TRPV (to date, three additional subfamilies are also considered to belong to the TRP family: the TRPA, TRPML, and TRPP). The TRPV subfamily consists of six members, TRPV.