TRPA is a family oftransient receptor potentialion channels. The TRPA family is made up of 7 subfamilies: TRPA1, TRPA- or TRPA1-like, TRPA5, painless, pyrexia, waterwitch, and HsTRPA. TRPA1 is the only subfamily widely expressed across animals, while the other subfamilies (collectively referred to as the basal clade) are largely absent indeuterostomes (and in the case of HsTRPA, only expressed inhymenopteran insects).^[2][1][3][4]

TRPA1s have been the most extensively studied subfamily; they typically contain 14 N-terminalankyrin repeats and are believed to function as mechanical stress, temperature, and chemical sensors. TRPA1 is known to be activated by compounds such asisothiocyanate (which are the pungent chemicals in substances such asmustard oil andwasabi) andMichael acceptors (e.g.cinnamaldehyde). These compounds are capable of forming covalent chemical bonds with the protein'scysteins.^[5] Non-covalent activators of TRPA1 also exists, such asmethyl salicylate,menthol, and the synthetic compoundPF-4840154.^[6][1][7]

The thermal sensitivity of TRPAs varies by species. For example, TRPA1 functions as a high-temperature sensor in insects and snakes, but as a cold sensor in mammals.^[8] The basal TRPAs have evolved some degree of thermal sensitivity as well: painless and pyrexia function in high-temperature sensing inDrosophila melanogaster, and the honey bee HsTRPA underwentneofunctionalization following its divergence from waterwitch, gaining function as a high-temperature sensor.^[9]

TRPA1s promiscuity with respect to sensory modality has been the source of controversy, particularly when considering its ability to detect cold.^[10] More recent work has alternatively (or additionally) proposed thatreactive oxygen species activate TRPA1, across species.^[11][12]

• TRPA1+protein,+human at the U.S. National Library of MedicineMedical Subject Headings (MeSH)
• "TRIP Database".a manually curated database of protein-protein interactions for mammalian TRP channels.

• Genes on human chromosome 8
• Membrane proteins
• Ion channels

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• Short description matches Wikidata
• Protein pages needing a picture