Figure 1. Assembly of Cx43 during its life cycle.

Cx43 is produced in the endoplasmic reticulum (ER) and is exported to the Golgi apparatus as a monomer. In the Golgi, Cx43 oligomerizes into hexamers and is exported to the plasma membrane, where it can exist as a closed (red channel) or open (green) hemichannel that can allow the regulated passage of specific small molecules (denoted by stars and ovals). Hemichannels from adjoining cells dock and form a head-to-head dodecameric structure (gap junction channel) to permit the regulated intercellular passage of small molecules and metabolites.