ASIC2a is a member of a family of Na⁺ channels that are activated by external protons. The family includes four additional members: ASIC1, ASIC3, ASIC4 and ASIC5. The ASICs are in fact part of a larger superfamily named degenerin/epithelial Na⁺ channels (DEG/ENaC) and share with it the same basic characteristics: two transmembrane spanning domains, a large extracellular domain and short intracellular N- and C-termini.

There are two recognized splice variants of the ASIC2 gene that differ on their N-termini, ASIC2a and ASIC2b that have different tissue distributions and functions. ASIC2a is highly expressed in the central nervous system (CNS) and is less expressed in the peripheral nervous system (PNS) while ASIC2b is prominently expressed in the latter.

The functional channel is composed of 4 subunits that can be assembled as homo- or heterotetramers with the other ASIC subunits. The ASIC2b splice variant does not appear to be functional when expressed alone but it can modify the properties of ASIC2a and ASIC3 when co-expressed.

The ASIC2 protein has been proposed to be involved in mechanosensation and sensory transduction.