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 (By similarity). 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 (By similarity). Mostly in the nucleus including in the nuclear membrane. Small amount in the cytoplasm and the plasma membrane. Exists both as soluble cytoplasmic protein and as membrane protein with probably a single transmembrane domain (By similarity). 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 (By similarity). Belongs to the chloride channel CLIC family.