Transient Receptor Potential Family of Ion Channels

Definition

The mammalian transient receptor potential (TRP) ion channels are named after the role of these channels in Drosophilaphototransduction. They are encoded by at least 21 different channel genes. The TRP channel primary structures predict six transmembrane domains, with a pore domain between the fifth and sixth segments, and both the C- and N-termini are located intracellularly. The mammalian TRP channel family is comprised of three subfamilies, including TRPC, TRPV, and TRPM. The family members are at least 25 % homologous within their amino acid sequences. Most of the channels are nonselective to cations, allowing sodium and calcium to flow in and depolarize neurons. The most well-characterized TRP channels in DRG neurons are the vanilloid family of TRPV1–4 channels, which are activated by a range of heat and/or warm temperatures. TRPV1 is the prototype vanilloid channel and is activated by noxious heat, acidic pH, and the alkaloid irritant capsaicin. Additional TRP...