title: Gating pore currents are defects in common with two Nav1.5 mutations in patients with mixed arrhythmias and dilated cardiomyopathy.
abstract: The gating pore current, also called omega current, consists of a cation leak through the typically nonconductive voltage-sensor domain (VSD) of voltage-gated ion channels. Although the study of gating pore currents has refined our knowledge of the structure and the function of voltage-gated ion channels, their implication in cardiac disorders has not been established. Two Na(v)1.5 mutations (R222Q and R225W) located in the VSD are associated with atypical clinical phenotypes involving complex arrhythmias and dilated cardiomyopathy. Using the patch-clamp technique, in silico mutagenesis, and molecular dynamic simulations, we tested the hypothesis that these two mutations may generate gating pore currents, potentially accounting for their clinical phenotypes. Our findings suggest that the gating pore current generated by the R222Q and R225W mutations could constitute the underlying pathological mechanism that links Na(v)1.5 VSD mutations with human cardiac arrhythmias and dilatation of cardiac chambers.
authors.affiliation: Centre de Recherche de L'Institut Universitaire en Santé Mentale de Québec, Québec City, Québec G1J 2G3, Canada.
authors.forename: Adrien
authors.initials: A
authors.lastname: Moreau
authors.affiliation: Centre de Recherche de L'Institut Universitaire en Santé Mentale de Québec, Québec City, Québec G1J 2G3, Canada.
authors.forename: Pascal
authors.initials: P
authors.lastname: Gosselin-Badaroudine
authors.affiliation: Institute of Computational Molecular Science, Temple University, Philadelphia, PA 19122.
authors.forename: Lucie
authors.initials: L
authors.lastname: Delemotte
authors.affiliation: Institute of Computational Molecular Science, Temple University, Philadelphia, PA 19122.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Klein
authors.affiliation: Centre de Recherche de L'Institut Universitaire en Santé Mentale de Québec, Québec City, Québec G1J 2G3, Canada Department of Medicine, Université Laval, Québec City, Québec G1K 7P4, Canada mohamed.chahine@phc.ulaval.ca.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Chahine
mesh_terms: D000595:Amino Acid Sequence; D001145:Arrhythmias, Cardiac / Q000235:genetics* / Q000378:metabolism; D002311:Cardiomyopathy, Dilated / Q000235:genetics* / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D015640:Ion Channel Gating; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D062554:NAV1.5 Voltage-Gated Sodium Channel / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D062554:NAV1.5 Voltage-Gated Sodium Channel