Non-essential component of the volume-regulated anion channel (VRAC, also named VSOAC channel), an anion channel required to maintain a constant cell volume in response to extracellular or intracellular osmotic changes. The VRAC channel conducts iodide better than chloride and can also conduct organic osmolytes like taurine. Plays a redundant role in the efflux of amino acids, such as aspartate and glutamate, in response to osmotic stress. The VRAC channel also mediates transport of immunoreactive cyclic dinucleotide GMP-AMP (2'-3'-cGAMP), an immune messenger produced in response to DNA virus in the cytosol. Channel activity requires LRRC8A plus at least one other family member (LRRC8B, LRRC8C, LRRC8D or LRRC8E); channel characteristics depend on the precise subunit composition. chloride(in) = chloride(out) iodide(out) = iodide(in) taurine(out) = taurine(in) 2',3'-cGAMP(out) = 2',3'-cGAMP(in) Heterooligomer; heterooligomerizes with other LRRC8 proteins (LRRC8A, LRRC8B, LRRC8D and/or LRRC8E), possibly to form a heterohexamer. In vivo, the subunit composition may depend primarily on expression levels, and heterooligomeric channels containing various proportions of the different LRRC8 proteins may coexist. In the absence of LRRC8A, resides primarily in a cytoplasmic compartment, probably the endoplasmic reticulum. Requires LRRC8A for expression at the cell membrane. The volume-regulated anion channel (VRAC) channel forms a trimer of dimers, with symmetry mismatch between the pore-forming domain and the cytosolic LRR repeats, a topology similar to gap junction proteins. The cytoplasmic N-terminus preceding the first transmembrane (residues 1-22) regulates volume-regulated anion channel (VRAC) conductance, ion permeability and inactivation gating. Belongs to the LRRC8 family.