SCN3A

Pore-forming subunit of Nav1.3, a voltage-gated sodium (Nav) channel that directly mediates the depolarising phase of action potentials in excitable membranes. Navs, also called VGSCs (voltage-gated sodium channels) or VDSCs (voltage-dependent sodium channels), operate by switching between closed and open conformations depending on the voltage difference across the membrane. In the open conformation they allow Na(+) ions to selectively pass through the pore, along their electrochemical gradient. The influx of Na+ ions provokes membrane depolarisation, initiating the propagation of electrical signals throughout cells and tissues. In some secretory cell types, it also participates in cell excitability through membrane depolarisation and regulates cells responsiveness to stimuli triggering secretion. For instance, it controls the release of serotonin/5-hydroxytryptamine by enterochromaffin cells and is required for both glucagon- and glucose-induced insulin secretion in pancreatic endocrine cells. Location: Cell membrane; Basal cell membrane (UniProt). Locus 2q24.3 (HGNC).