Modulatory effect of auxiliary β1 subunit on Nav1.3 voltage-gated sodium channel expressed in Xenopus oocyte

Abstract

homologous and form single transmembrane glycoproteins with short intracellular loops and immunoglobulin-like extracellular segments. The association of the various α subtypes with different combinations of auxiliary β subunits creates the possibility of additional molecular and functional complexity for neuronal sodium channels. Nav1.1, Nav1.2, Nav1.3 and Nav1.6 are predominantly expressed in the central nervous system while Nav1.7, Nav1.8 and Nav1.9 are principally found in the peripheral nervous system. 2 The Nav1.3 α subtype has attracted interest recently because its expression is dramatically up-regulated in nociceptive sensory neurons after peripheral nerve damage, perhaps contributing to the pathophysiology of neuropathic pain. 3 Theoretically, no matter how the expression of the Nav1.3 α subunit is changed in neuropathic pain, the function of the Nav1.3 α subtype should be modulated by β subunits. The aim of this study was to examine the effects of cloned rat β1 subunit on Nav1.3 function.