Acid-sensing ion channel subunit family member 5 (ASIC5)

Acid-sensing ion channel subunit family member 5 (ASIC5) is a member of the degenerin/epithelial sodium channel (DEG/ENaC) superfamily of amiloride-sensitive sodium channels. While most acid-sensing ion channels in this family act as proton-gated sodium channels responding to drops in extracellular pH, ASIC5 functions distinctively as a sodium channel gated by bile acids in epithelial tissue, particularly in bile ducts and small intestine, and is not significantly activated by acid. ASIC5 is also selectively and highly expressed in a subset of interneurons—unipolar brush cells—in the vestibulocerebellum, where it may play a role in motor coordination and balance. Though its precise physiological roles and mechanisms remain incompletely understood, ASIC5 is implicated in sodium ion transport in both neuronal and epithelial tissues, with potential but not yet well-defined relevance in disease and pharmacology[2][3][4].

Other names

Bile acid-sensitive ion channelACCN5BASICHINaCINACAmiloride-sensitive cation channel 5 (intestinal)Human intestine Na(+) channelBLINaCbile acid-sensitive ion channelacid sensing (proton gated) ion channel family member 5acid-sensing ion channel 5human intestine Na(+) channel

Sodium channel blockade (via amiloride or structurally related inhibitors), modulation of channel function by bile acids (indirect gating)[4]