Structural component of the gap junctions and the hemichannels. Forms PANX1/PANX2-heteromeric intercellular channels on coexpression in paired Xenopus oocytes. Does not form homomeric channels. Expressed in the eye, thyroid, prostate, kidney and liver. Abundantly expressed in the CNS, including hippocampus, olfactory bulb, cortex, cerebellum. Not detected in the white matter. Belongs to the pannexin family. Truncated N-terminus.