Editing Transient receptor potential channel (section)

== Structure ==
TRP channels are composed of 6 [[Cell membrane|membrane]]-spanning helices (S1-S6) with intracellular [[N-terminus|N-]] and [[C terminus|C-termini]]. Mammalian TRP channels are activated and regulated by a wide variety of stimuli including many post-transcriptional mechanisms like [[phosphorylation]], [[G protein-coupled receptor|G-protein receptor coupling]], ligand-gating, and [[ubiquitin]]ation. The receptors are found in almost all cell types and are largely localized in cell and organelle membranes, modulating ion entry.

Most TRP channels form homo- or heterotetramers when completely functional. The ion selectivity filter, pore, is formed by the complex combination of p-loops in the tetrameric protein, which are situated in the extracellular domain between the S5 and S6 transmembrane segments. As with most cation channels, TRP channels have negatively charged residues within the pore to attract the positively charged ions.<ref>{{Cite book|title=Ion channels of excitable membranes| vauthors = Hille B |date=2001|publisher=Sinauer|isbn=978-0878933211|edition= 3rd|location=Sunderland, Mass.|oclc=46858498}}</ref>

=== Group 1 Characteristics ===
Each channel in this group is structurally unique, which adds to the diversity of functions that TRP channels possess, however, there are some commonalities that distinguish this group from others. Starting from the intracellular N-terminus there are varying lengths of ankryin repeats (except in TRPM) that aid with membrane anchoring and other protein interactions. Shortly following S6 on the C-terminal end, there is a highly conserved TRP domain (except in TRPA) which is involved with gating modulation and channel multimerization. Other C-terminal modifications such as alpha-kinase domains in TRPM7 and M8 have been seen as well in this group.<ref name="Kadowaki_evodyn"/><ref name=":3" /><ref name=":4" />

=== Group 2 Characteristics ===
Group two most distinguishable trait is the long extracellular span between the S1 and S2 transmembrane segments. Members of group two are also lacking in ankryin repeats and a TRP domain. They have been shown, however, to have endoplasmic reticulum (ER) retention sequences towards on the C-terminal end illustrating possible interactions with the ER.<ref name="Kadowaki_evodyn"/><ref name=":3" /><ref name=":4" />