BBA - Biomembranes
Apical Junctional Complexes Part II
Edited by J.-C. Hervé
Volume 1788, Issue 4, Pages 753-910 (April 2009)

In multicellular organisms, epithelial barriers, which promote organ homeostasis by restricting the flow of ions and solutes between cells, are fundamental to the physiology of organ systems. Epithelia form diffusion barriers between cellular compartments of very different fluid and solute composition through both asymmetrically distributed transcellular transport mechanisms (transcellular pathway) and also by structures that regulate the diffusion of ions and small, noncharged solutes through the paracellular pathway. At the apical end of the paracellular space, adjacent cell membranes are indeed in close apposition, a site that was termed by early anatomists as the “terminal bar.” These intercellular junctional complexes are composed of the tight junctions or zonula occludens, the adherens junctions or zonula adherens, and desmosomes or macular adherens, whereas gap junctions provide for intercellular communication.

The present issue of Biochimica et Biophysica Acta “Biomembranes” and the companion issue “The apical junctional complexes Part 1, composition, structure and characteristics” (Biochim. Biophys. Acta   Volume 1778, Issue 3, 2008) were designed to summarize the main aspects of the state of the art on the characteristics, composition, structure, and roles of the apical junctional complexes as well as some of the consequences of their dysfunctions.