Transient Receptor Potential channel, Vanilloid subfamily (TRPV)The vanilloid TRP subfamily (TRPV), named after the vanilloid receptor 1 (TRPV1), consists of six members: four thermo-sensing channels (TRPV1, TRPV2, TRPV3, and TRPV4) and two Ca2+ selective channels (TRPV5 and TRPV6). The calcium-selective channels TRPV5 and TRPV6 can be heterotetramers and are important for general Ca2+ homeostasis. All four channels within the TRPV1-4 group show temperature-invoked currents when expressed in heterologous cell systems, ranging from activation at ~25C for TRPV4 to ~52C for TRPV2. The structure of TRPV shows the typical topology features of all Transient Receptor Potential (TRP) ion channel family members, such as six transmembrane regions, a short hydrophobic stretch between transmembrane segments 5 and 6 and large intracellular N- and C-terminal domains. The TRP family consists of membrane proteins that function as ion channels that communicate between the cell and its environment, by a vast array of physical or chemical stimuli, including radiation (in the form of temperature, infrared ,or light) and pressure (osmotic or mechanical). TRP channels are formed by a tetrameric complex of channel subunits. Based on sequence identity, the mammalian TRP channel family is classified into six subfamilies, with significant sequence similarity within the transmembrane domains, but very low similarity in their N- and C-terminal cytoplasmic regions. The six subfamilies are named based on their first member: TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPA (ankyrin), TRPML (mucolipin), and TRPP (polycystic).