Sodium channel

Protein which is part of a cation channel permeable for sodium found in the plasma membrane and in intracellular membranes. Sodium channels have been classified according to their gating mechanisms, which may depend on changes in the transmembrane electric field (voltage-gated sodium channels) or not (non-voltage-gated sodium channels, e.g. degenerins which are permeable also to lithium and potassium). Voltage-gated sodium channels, by opening in response to membrane depolarization, allow sodium entry and thus the propagation of depolarization along the plasma membrane of nerve, muscle and other electrically excitable cells. They play a role in different processes such as sensation, emotions, thought and movement. Another class of sodium channel is the degenerin/epithelial sodium channel (ENaC) superfamily, which is a group of proteins involved in diverse biological processes, including sodium homeostasis, salt taste, nociception, pain transduction, touch sensation and mechanotransduction.

Source:http://purl.uniprot.org/keywords/894