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. Plays an essential role in gap junction communication in the ventricles. A connexon is composed of a hexamer of connexins. Interacts with TMEM65. Localizes at the intercalated disk (ICD) in cardiomyocytes and proper localization at ICD is dependent on TMEM65. Expressed in most tissues. Highest levels found in eye and brain. Appears during organogenesis. Belongs to the connexin family. Alpha-type (group II) subfamily.