GJA8 is a an integral membrane protein that belongs to the connexin family, alpha-type (group II) subfamily. One gap junction consists of a cluster of closely packed pairs of transmembrane channels, the connexons, through which materials of low MW diffuse from one cell to a neighboring cell. A connexon is composed of a hexamer of connexins. This particular connexin only forms junctional channels. GJA8 is expressed in the eye lens, and defects in GJA8 are the cause of zonular pulverulent cataract type 1 (CZP1), a form of autosomal dominant congenital cataract.