Can insert into membranes and form chloride ion channels. Channel activity depends on the pH. Membrane insertion seems to be redox-regulated and may occur only under oxydizing conditions. Involved in regulation of the cell cycle. Monomer. Homodimer (in vitro). Interacts with TRAPPC2. Dimerization requires a conformation change that leads to the exposure of a large hydrophobic surface. In vivo, this may lead to membrane insertion. Interacts with AKAP9. Mostly in the nucleus including in the nuclear membrane (PubMed:9139710, PubMed:12681486). Small amount in the cytoplasm and the plasma membrane (PubMed:9139710). Exists both as soluble cytoplasmic protein and as membrane protein with probably a single transmembrane domain (PubMed:11940526, PubMed:11551966, PubMed:14613939). Expression is prominent in heart, placenta, liver, kidney and pancreas. Members of this family may change from a globular, soluble state to a state where the N-terminal domain is inserted into the membrane and functions as chloride channel. A conformation change of the N-terminal domain is thought to expose hydrophobic surfaces that trigger membrane insertion. Hydrogen peroxide treatment causes a conformation change, leading to dimerization and formation of an intramolecular disulfide bond between Cys-24 and Cys-59. The protein seems to have very low affinity for glutathione, even though glutathione binding was observed in protein crystals. Belongs to the chloride channel CLIC family.