Acid-sensing ion channel 4 (ASIC4) also known asamiloride-sensitive cation channel 4 (ACCN4) is aprotein that in humans is encoded by the ASIC4gene. The ASIC4 gene is one of the fiveparalogous genes that encode proteins that form trimericacid-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.
These genes are mainly expressed in the central and peripheral nervous system.
ASICs can form both homotrimeric (meaning composed of three identical subunits) and heterotrimeric channels.[8]
This gene encodes a member of the ASIC/ENaC superfamily of proteins.[9] The members of this family areamiloride-sensitivesodium channels that containintracellular N and C termini, 2hydrophobictransmembrane (TM) regions, and a largeextracellular loop, which has manycysteine 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 (Jul 2008). "Regulation of ASIC activity by ASIC4--new insights into ASIC channel function revealed by a yeast two-hybrid assay".The European Journal of Neuroscience.28 (1):74–86.doi:10.1111/j.1460-9568.2008.06282.x.PMID18662336.S2CID29369987.
