Figure 1. Assembly and breakdown of gap junctions emphasizing the genesis and trafficking of CxHcs.

Formation of CxHcs occurs early in the secretory pathway (Stage 1) and they are transported along the secretory pathway (Stages 2 and 3), implicating regions of the endoplasmic reticulum and the Golgi apparatus. A second assembly mechanism that is poorly characterized also operates with Cx26 and possibly other connexins has been reported which does not directly feature the Golgi apparatus. CxHcs, after insertion into the plasma membrane (Stage 4), dock with partners (Stage 5) located on an attached cell, and gate to an open configuration (Stage 6), a process that may occur concurrently with the aggregation of the gap junction channels into large adhesive plaques (Stage 7). Stages 7 and 8 involve internalization of gap junctions into one of the attached cells and break down by hydrolysis in lysosomes (Stage 9).