Transient receptor potential channel

Transient receptor potential channels (TRP channels) are a group of ion channels located mostly on the plasma membrane of numerous animal cell types. There are about 30 TRP channels that share some structural similarity to each other. These are grouped into two broad groups: Group 1 includes TRPC ( 'C' for canonical), TRPV ('V' for vanilloid), TRPM ('M' for melastatin), TRPN ('N' for no mechanoreceptor potential C) , and TRPA ('A' for ankyrin). In group 2, there are TRPP ('P' for polycystic) and TRPML ('ML' for mucolipin). Many of these channels mediate a variety of sensations such as pain, temperature, different kinds of tastes, pressure, and vision. In the body, some TRP channels are thought to behave like microscopic thermometers and used in animals to sense hot or cold. Some TRP channels are activated by molecules found in spices like garlic (allicin), chili pepper (capsaicin), wasabi (allyl isothiocyanate); others are activated by menthol, camphor, peppermint, and cooling agents; yet others are activated by molecules found in cannabis (i.e., THC, CBD and CBN) or stevia. Some act as sensors of osmotic pressure, volume, stretch, and vibration. Transient receptor potential channels (TRP channels) are a group of ion channels located mostly on the plasma membrane of numerous animal cell types. There are about 30 TRP channels that share some structural similarity to each other. These are grouped into two broad groups: Group 1 includes TRPC ( 'C' for canonical), TRPV ('V' for vanilloid), TRPM ('M' for melastatin), TRPN ('N' for no mechanoreceptor potential C) , and TRPA ('A' for ankyrin). In group 2, there are TRPP ('P' for polycystic) and TRPML ('ML' for mucolipin). Many of these channels mediate a variety of sensations such as pain, temperature, different kinds of tastes, pressure, and vision. In the body, some TRP channels are thought to behave like microscopic thermometers and used in animals to sense hot or cold. Some TRP channels are activated by molecules found in spices like garlic (allicin), chili pepper (capsaicin), wasabi (allyl isothiocyanate); others are activated by menthol, camphor, peppermint, and cooling agents; yet others are activated by molecules found in cannabis (i.e., THC, CBD and CBN) or stevia. Some act as sensors of osmotic pressure, volume, stretch, and vibration. These ion channels have a relatively non-selective permeability to cations, including sodium, calcium and magnesium. TRP channels were initially discovered in trp-mutant strain of the fruit fly Drosophila. Later, TRP channels were found in vertebrates where they are ubiquitously expressed in many cell types and tissues. Most TRP channels are composed of 6 membrane-spanning helices with intracellular N- and C-termini. Mammalian TRP channels are activated and regulated by a wide variety of stimuli and are expressed throughout the body. In the TRP super-family there are currently 7 different sub-families split into two groups. Group one consists of TRPC, TRPV, TRPA, TRPM, and TRPN. While group two contains TRPP and TRPML. There is an eighth sub-family labeled TRPY that is not included in either of these groups because of its distant relation. All of these sub-families are similar in that they are molecular sensing, non-selective cation channels that have six transmembrane segments, however, each sub-family is very unique and shares little structural homology with one another. This uniqueness gives rise to the various sensory perception and regulation functions that TRP channels have throughout the body. Group one and group two vary in that both TRPP and TRPML of group two have a much longer extracellular loop between the S1 and S2 transmembrane segments. Another differentiating characteristic is that all the group one sub-families either contain a C-terminal, intracellular ankyrin repeat sequence, an N-terminal TRP domain sequence, or both—whereas both group two sub-families have neither. Below are members of the sub-families and a brief description of each: TRPC, C for 'canonical', is named for being the most closely related to TRP channels in drosophilia, sharing above 30% amino acid homology. There are actually only six TRPC channels expressed in humans because TRPC2 is found to be expressed solely in mice and is considered a pseudo-gene in humans; this is partly due to the role of TRPC2 in detecting pheromones, which mice have an increased ability compared to humans. Mutations in TRPC channels have been associated with respiratory diseases along with focal segmental glomerulosclerosis in the kidneys. All TRPC channels are activated either by phospholipase C (PLC) or diacyglycerol (DAG). TRPV, V for 'vanilloid', is named for the vanilloid chemicals that activate this channel, and are some of the most studied TRP channels. These channels have been made famous for their association with molecules such as capsaicin (a TRPV1 agonist), and its ability to produce heat sensation and act as a topical ointment for pain relief. TRPA, A for 'ankyrin', is named for the large amount of ankyrin repeats found near the N-terminus. TRPA is primarily found in afferent nociceptive nerve fibers and is associated with the amplification of pain signaling as well as cold pain hypersensitivity. These channels have been shown to be both mechanical receptors for pain and chemosensors activated by various chemical species, including isothiocyanates (pungent chemicals in substances such as mustard oil and wasabi), cannabinoids, general and local analgesics, and cinnamaldehyde. TRPM, M for 'melastatin', was found during a comparative genetic analysis between benign nevi and malignant nevi (melanoma). Mutatations within TRPM channels have been associated with hypomagnesemia with secondary hypocalcemia. TRPM channels have also become famous for their cold-sensing mechanisms, such is the case with TRPM8.