Transient receptor potential ankyrin 1 (TRPA1) is a polymodal ion channel sensitive to temperature and chemical stimuli. The importance of temperature and aversive chemical detection for survival has driven the evolutionary diversity of TRPA1 sensitivity. This diversity can be observed in the various roles of TRPA1 in different species, where it is proposed to act as a temperature-insensitive chemosensor, a heat transducer, a noxious cold transducer, or a detector of low-intensity heat for prey localization. Exploring the variation of TRPA1 functions among species provides evolutionary insight into molecular mechanisms that fine-tune thermal and chemical sensitivity, and offers an opportunity to address basic principles of temperature gating in ion channels. A decade of research has yielded a number of hypotheses describing physiological roles of TRPA1, modulators of its activity, and biophysical principles of gating. This review surveys the diversity of TRPA1 adaptations across evolutionary taxa and explores possible mechanisms of TRPA1 activation.
Keywords: AITC- allyl isothiocyanate; ANKTM1; ANKTM1- ankyrin-like with transmembrane domains protein 1; AR- ankyrin repeat; EC50- half maximal effective concentration; Ion channels; Keq- equillibrium constant; PH- pore helix; PI- phosphatidylinositol; Q10- temperature activation coefficient; S1-S6- transmembrane helices 1–6; TRP- Transient Receptor Potential; TRPA1; TRPA1- transient receptor potential ankyrin 1; TRPM8- transient receptor potential melastatin 8; TRPV1- transient receptor potential vanilloid 1; ThermoTRP; Thermosensation; ceTRPA1- Caenorhabditis elegans TRPA1; dTRPA1- Drosophila melanogaster TRPA1; hsTRPA1- hymenoptera-specific TRPA1; ΔCp -change in heat capacity.