6ofa
From Proteopedia
Wasabi Receptor Toxin
Structural highlights
FunctionKKX1U_UROMN Cell-penetrating peptide (CPP) with defensive purpose that induces pain by specifically activating mammalian sensory neuron TRPA1 channels. It non-covalently binds to the same region than other TRPA1 agonists (irritants), but acts via a distinct biochemical mechanism. Its binding stabilizes the TRPA1 open state and diminishes calcium-permeability. Consequently, it produces pain and pain hypersensitivity, but fails to trigger efferent release of neuropeptides (CGRP) and neurogenic inflammation typically produced by noxious electrophiles. Is not active on voltage-gated potassium channels and other TRP channels.[1] Publication Abstract from PubMedTRPA1 is a chemosensory ion channel that functions as a sentinel for structurally diverse electrophilic irritants. Channel activation occurs through an unusual mechanism involving covalent modification of cysteine residues clustered within an amino-terminal cytoplasmic domain. Here, we describe a peptidergic scorpion toxin (WaTx) that activates TRPA1 by penetrating the plasma membrane to access the same intracellular site modified by reactive electrophiles. WaTx stabilizes TRPA1 in a biophysically distinct active state characterized by prolonged channel openings and low Ca(2+) permeability. Consequently, WaTx elicits acute pain and pain hypersensitivity but fails to trigger efferent release of neuropeptides and neurogenic inflammation typically produced by noxious electrophiles. These findings provide a striking example of convergent evolution whereby chemically disparate animal- and plant-derived irritants target the same key allosteric regulatory site to differentially modulate channel activity. WaTx is a unique pharmacological probe for dissecting TRPA1 function and its contribution to acute and persistent pain. A Cell-Penetrating Scorpion Toxin Enables Mode-Specific Modulation of TRPA1 and Pain.,Lin King JV, Emrick JJ, Kelly MJS, Herzig V, King GF, Medzihradszky KF, Julius D Cell. 2019 Sep 5;178(6):1362-1374.e16. doi: 10.1016/j.cell.2019.07.014. Epub 2019, Aug 22. PMID:31447178[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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