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.¹ The TRP channels have putative six-transmembrane domains (TM) with a pore domain between the fifth and the six TM, and all assemble as tetramers. Both the N- and the C-terminus of all TRPs are intracellular.³

According to IUPHAR the TRP family comprises of three main subfamilies on the basis of sequence homology; TRPC (canonical), TRPV (vanilloid) and TRPM (melastatin). To date, three extra subfamilies are also considered to belong to the TRP family; the TRPA, TRPML, and the TRPP.^1-4

The TRPM subfamily consists of eight members, TRPM1 to TRPM8, which also can be further subdivided into four subgroups based on their sequence homology: (1)TRPM1 and TRPM3 (2) TRPM6 and TRPM7 (3) TRPM4 and TRPM5 (4) TRPM2 and TRPM8.⁵