Epithelial sodium channel, chordates (IPR004724)

Short name: ENaC_chordates

Overlapping homologous superfamilies


Family relationships


The epithelial Na+ channel (ENaC) proteins consist of sodium channels from animals and has no recognizable homologues in other eukaryotes or bacteria. The vertebrate ENaC proteins from epithelial cells cluster tightly together on the phylogenetic tree: voltage-insensitive ENaC homologues are also found in the brain. Eleven sequenced Caenorhabditis elegans proteins, including the degenerins (IPR004726), are distantly related to the vertebrate proteins as well as to each other.

At least some of the proteins in this group form part of a mechano-transducing complex for touch sensitivity. Others include the acid-sensing ion channels, ASIC1-3 that are homo- or hetero-oligomeric neuronal H+-gated channels that mediate pain sensation in response to tissue acidosis. Mammalian ENaC is important for the maintenance of Na+ balance and the regulation of blood pressure. Three homologous ENaC subunits, a, b and g, have been shown to assemble to form the highly Na+-selective channel.

GO terms

Biological Process

GO:0006814 sodium ion transport

Molecular Function

GO:0015280 ligand-gated sodium channel activity

Cellular Component

GO:0016021 integral component of membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.