Gap junctions allow the exchange of ions, second messengers, and small metabolites
between adjacent cells and are formed by two unrelated protein families, the pannexins and
connexins. Mutations in connexin genes cause a variety of genetic disorders, implicating a
critical role in tissue homeostasis. Association of congenital skin disorders to mutations in
different connexins has underscored the importance of gap junctional communication in the
skin and its appendages. Here, we discuss the basic structure of gap junction channels and …

Adherens and tight junctions are intercellular junctions crucial for epithelial adhesion and
barrier function in a wide variety of tissues and organisms. In stratifying epithelia, such as the
epidermis, the role of adherens and tight junctions was considered less important owing to
the abundance of desmosomes, mediating firm mechanical stability between the cells, and
to the barrier function of the stratum corneum, respectively. This view has changed in recent
years because of different studies that showed the importance of these structures for proper …