Gap junctions and connexins?

Gap junctions are specialized intercellular channels that allow for direct communication and exchange of ions, small molecules, and signaling molecules between adjacent cells. These junctions are formed by connexin proteins, which come together to form a hexameric structure called a connexon. Connexons on neighboring cells align and dock together to create a continuous channel for communication.

There are over 20 different connexin proteins in humans, each with specific properties and functions. The specific connexins present in a gap junction determine the permeability and selectivity of the channel, as well as its regulation and modulation. Gap junctions play important roles in coordinating cellular activities, such as synchronizing contractions in cardiac muscle cells and coordinating cell growth and differentiation in development. Dysfunction of gap junctions and connexins has been linked to various diseases, including cardiac arrhythmias, deafness, and certain skin disorders.