Forms a channel through the mitochondrial outer membrane that allows diffusion of small hydrophilic molecules (By similarity). The channel adopts an open conformation at low or zero membrane potential and a closed conformation at potentials above 30-40 mV (By similarity). The open state has a weak anion selectivity whereas the closed state is cation-selective (By similarity). Binds various lipids, including the sphingolipid ceramide, the phospholipid phosphatidylcholine, and the sterol cholesterol . Binding of ceramide promotes the mitochondrial outer membrane permeabilization (MOMP) apoptotic pathway .
Subcellular locations: Mitochondrion outer membrane, Membrane
May localize to non-mitochondrial membranes.
Expressed in erythrocytes (at protein level) . Expressed in all tissues examined .