Formation and Function of Epithelial Tricellular Junctions

We investigate the assembly and function of epithelial barriers. Tight junctions in vertebrates and septate junctions in invertebrates form diffusion barriers by sealing the paracellular space between plasma membranes of neighboring cells. Junctions between two adjacent cells (bicellular junctions) have been intensely studied and most of their components are known. However, sealing the epithelium at sites of contact between three cells requires specialized tricellular junctions (TCJs). Despite their fundamental role in epithelial biology, TCJs have received little attention and are poorly described in terms of their structure, composition, and the dynamics of their assembly and maintenance. We characterized Anakonda (Aka), a new TCJ protein with an unusual triple-repeat structure, which plays a key role in TCJ assembly and function (Byri et al. 2015).