Editing Transient receptor potential channel (section)

===TRPA===
{| class="wikitable"
!Family
!Sub-Family
!Known Taxa<ref>{{cite journal | vauthors = Kang K, Pulver SR, Panzano VC, Chang EC, Griffith LC, Theobald DL, Garrity PA | title = Analysis of Drosophila TRPA1 reveals an ancient origin for human chemical nociception | journal = Nature | volume = 464 | issue = 7288 | pages = 597–600 | date = March 2010 | pmid = 20237474 | pmc = 2845738 | doi = 10.1038/nature08848 | bibcode = 2010Natur.464..597K }}</ref><ref name="Drosophila menthol sensitivity">{{cite journal | vauthors = Himmel NJ, Letcher JM, Sakurai A, Gray TR, Benson MN, Cox DN | title = ''Drosophila'' menthol sensitivity and the Precambrian origins of transient receptor potential-dependent chemosensation | journal = Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences | volume = 374 | issue = 1785 | pages = 20190369 | date = November 2019 | pmid = 31544603 | pmc = 6790378 | doi = 10.1098/rstb.2019.0369 }}</ref><ref name="Peng">{{cite journal | vauthors = Peng G, Shi X, Kadowaki T | title = Evolution of TRP channels inferred by their classification in diverse animal species | journal = Molecular Phylogenetics and Evolution | volume = 84 | pages = 145–57 | date = March 2015 | pmid = 24981559 | doi = 10.1016/j.ympev.2014.06.016 | bibcode = 2015MolPE..84..145P }}</ref>
|-
|rowspan="7" |TRPA
|[[TRPA1]]
|[[Vertebrates]], [[arthropods]], and [[molluscs]]
|-
|TRPA-like
|[[Choanoflagellates]], [[cnidarians]], [[nematodes]], arthropods (only crustaceans and myriapods), molluscs, and [[echinoderms]]
|-
|TRPA5
|rowspan="4" |Arthropods (only crustaceans and insects)
|-
|painless
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|pyrexia
|-
|waterwitch
|-
|HsTRPA
|Specific to [[hymenopteran]] insects
|}
TRPA, A for "ankyrin", is named for the large amount of ankyrin repeats found near the N-terminus.<ref name=":4">{{cite journal | vauthors = Moran MM, McAlexander MA, Bíró T, Szallasi A | title = Transient receptor potential channels as therapeutic targets | journal = Nature Reviews. Drug Discovery | volume = 10 | issue = 8 | pages = 601–20 | date = August 2011 | pmid = 21804597 | doi = 10.1038/nrd3456 | s2cid = 8809131 }}</ref> 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.<ref name=":3" />

While TRPA1 is expressed in a wide variety of animals, a variety of other TRPA channels exist outside of vertebrates.  TRPA5, painless, pyrexia, and waterwitch are distinct phylogenetic branches within the TRPA clade, and are only evidenced to be expressed in crustaceans and insects,<ref name="Kadowaki_evodyn"/> while HsTRPA arose as a Hymenoptera-specific duplication of waterwitch.<ref>{{cite journal | vauthors = Kohno K, Sokabe T, Tominaga M, Kadowaki T | title = Honey bee thermal/chemical sensor, AmHsTRPA, reveals neofunctionalization and loss of transient receptor potential channel genes | journal = The Journal of Neuroscience | volume = 30 | issue = 37 | pages = 12219–29 | date = September 2010 | pmid = 20844118 | pmc = 6633439 | doi = 10.1523/JNEUROSCI.2001-10.2010 }}</ref> Like TRPA1 and other TRP channels, these function as ion channels in a number of sensory systems. TRPA- or TRPA1-like channels also exists in a variety of species as a phylogenetically distinct clade, but these are less well understood.<ref name="Drosophila menthol sensitivity"/>