Acid-sensing ion channel subunit family member 4 (ASIC4)

Acid-sensing ion channel subunit family member 4 (ASIC4) is a member of the acid-sensing ion channel (ASIC) family, which belongs to the epithelial sodium channel/degenerin (ENaC/DEG) superfamily of voltage-independent, amiloride-sensitive ion channels. Unlike other ASICs, ASIC4 does not function as a proton-gated channel by itself and does not contribute to the formation of functional heteromeric acid-sensing ion channels currently known. It is mainly expressed in the central nervous system, especially in the pituitary gland, and is predominantly localized within intracellular endosomal compartments rather than at the plasma membrane. The precise biological function of ASIC4 remains unknown, although its gene has been mapped near loci implicated in certain movement disorders and has possible associations with epilepsy and neurodegeneration. As a protein, it displays the typical structure of ASICs with two transmembrane domains and a large cysteine-rich extracellular loop, but its gating and activation mechanisms differ substantially from canonical ASIC family members.

Other names

Acid-sensing ion channel 4ACCN4BNAC4Amiloride-sensitive cation channel 4Amiloride-sensitive cation channel 4, pituitaryacid-sensing (proton-gated) ion channel family member 4amiloride-sensitive cation channel family member 4, pituitarybrain sodium channel 4

Sodium channel blockade (generally for ASICs, via amiloride; ASIC4-specific pharmacology unclear)