Acid-sensing ion channel 4 (ASIC4) also known as amiloride-sensitive cation channel 4 (ACCN4) is a protein that in humans is encoded by the ASIC4 gene. The ASIC4 gene is one of the five paralogous genes that encode proteins that form trimeric acid-sensing ion channels (ASICs) in mammals.[5] The cDNA of this gene was first cloned in 2000.[6][7] The ASIC genes have splicing variants that encode different proteins that are called isoforms.
This gene encodes a member of the ASIC/ENaC superfamily of proteins.[9] The members of this family are amiloride-sensitive sodium channels that contain intracellular N and C termini, 2 hydrophobictransmembrane (TM) regions, and a large extracellular loop, which has many cysteine residues with conserved spacing. The TM regions are generally symbolized as TM1 (clone to N-terminus) and TM2 (close to C-terminus).
The pore of the channel through which ions selectively flow from the extracellular side into the cytoplasm is formed by the three TM2 regions of the trimer. [5]
Donier E, Rugiero F, Jacob C, Wood JN (2008). "Regulation of ASIC activity by ASIC4--new insights into ASIC channel function revealed by a yeast two-hybrid assay". Eur. J. Neurosci. 28 (1): 74–86. doi:10.1111/j.1460-9568.2008.06282.x. PMID18662336. S2CID29369987.