This peptide activates human sensory neuron-specific G-protein coupled receptors MRGPRX1, but not mouse receptors (EC(50)=0.54 uM) (PubMed:30243794). Compared with the agonist chloroquine (anti-malaria drug), it is 600-fold more potent (PubMed:30243794). In vivo, induces itch sensation, since intradermal cheek injection into humanized transgenic mouse (mouse MRGPRX1 replaced by human MRGPRX1) induces scratching (PubMed:30243794). In vivo, treatment of zebrafish larvae with high doses (10 uM) induces hypoactivity at the beginning of the experiment during the dark phase and hyperactivity in the strobe phase after one hour, even after the removal of the toxin from the solution (PubMed:33764053). Expressed by the venom duct. The mature peptide does not contain cysteine residue. Belongs to the FARP (FMRFamide related peptide) family. Paths of discomfort - Issue 212 of March 2019