[6][7] The ASIC genes have splicing variants that encode different proteins that are called isoforms.
ASICs can form both homotrimeric (meaning composed of three identical subunits) and heterotrimeric channels.
[9] The members of this family are amiloride-sensitive sodium channels that contain intracellular N and C termini, 2 hydrophobic transmembrane (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.