Crucial in the assembly, expression, and functional modulation of the heterotrimeric complex of the sodium channel. The subunit beta-2 causes an increase in the plasma membrane surface area and in its folding into microvilli. Interacts with TNR may play a crucial role in clustering and regulation of activity of sodium channels at nodes of Ranvier (By similarity)
Voltage-gated sodium channels (NaV) are responsible for action potential initiation and propagation in excitable cells, including nerve, muscle, and neuroendocrine cell types. They are also expressed at low levels in non-excitable cells, where their physiological role is unclear. Structurally, Nav channels are composed of one pore-forming alpha-subunit, which may be associated with either one or more beta-subunits. alpha-subunits are composed for four homologous domains, each of which contains six transmembrane segments. The fourth transmembrane loop (S4) acts as the 'voltage sensor' and is activated by changes in membranepotential. S4 is also involved in channel gating.