Gap Junctions

Gap junctions consist of Connexins (Cx), a family of proteins that form channels linking the cytoplasm of adjacent cells. All Connexin molecules have four membrane-spanning domains, two extracellular domains, and a cytoplasmic carboxy-terminal tail of varying length that has an important role in the regulation of the gating properties of the channel. Interestingly Connexin 43 also known as gap junction alpha-1 protein is one of the most abundant gap-junction protein.

Connexin 43/GJA1 is a member of the connexin gene family and the most abundant protein component found within gap junctions. Gap junctions are the cell-to-cell contacts that provide direct intercellular communication between cells by regulating back and forth diffusion of low molecular weight molecules. As such, they regulate quite an extensive range of key cellular processes.