Referenced in: none

Automatically associated channels: Nav1.6

Title: Resurgent current and voltage sensor trapping enhanced activation by a beta-scorpion toxin solely in Nav1.6 channel. Significance in mice Purkinje neurons.

Authors: Emanuele Schiavon, Tiziana Sacco, Rita Restano Cassulini, Georgina Gurrola, Filippo Tempia, Lourival D Possani, Enzo Wanke

Journal, date & volume: J. Biol. Chem., 2006 Jul 21 , 281, 20326-37

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/16702217

Abstract
Resurgent currents are functionally crucial in sustaining the high frequency firing of cerebellar Purkinje neurons expressing Na(v)1.6 channels. Beta-scorpion toxins, such as CssIV, induce a left shift in the voltage-dependent activation of Na(v)1.2 channels by "trapping" the IIS4 voltage sensor segment. We found that the dangerous Cn2 beta-scorpion peptide induces both the left shift voltage-dependent activation and a transient resurgent current only in human Na(v)1.6 channels (among 1.1-1.7), whereas CssIV did not induce the resurgent current. Cn2 also produced both actions in mouse Purkinje cells. These findings suggest that only distinct beta-toxins produce resurgent currents. We suggest that the novel and unique selectivity of Cn2 could make it a model drug to replace deep brain stimulation of the subthalamic nucleus in patients with Parkinson disease.