Desmosomes at a glance.

Desmosomes are one of four intercellular junctions present on the lateral side of neighboring polarized epithelial cells. Tight junctions and adherens junctions (AJs) are restricted to the apical domain, where they form the epithelial barrier and organize cortical actin, respectively. Desmosomes are found subjacent to the AJs and are more widely distributed along the lateral membranes. By tethering the intermediate filament (IF) cytoskeleton to the plasma membrane, these strongly adhesive junctions further enhance their force-resisting mechanical properties (see Poster, panels 1 and 3). Interspersed among desmosomes are ‘communicating’ or gap junctions that chemically and electrically couple cells. Desmosomes confer stability to tissues that experience mechanical stress such as the epidermis and heart, and are also found in more specialized junctions of the meninges and lymphatic endothelial cells (reviewed by Getsios et al., 2004; Green and Simpson, 2007; Holthofer et al., 2007). It has recently emerged that desmosomal cadherins and their associated proteins play a role in instructing the development and differentiation of complex tissues in vertebrates. In addition, they are frequently mutated in inherited diseases of the skin and heart and are targeted by autoimmune antibodies and bacterial toxins, the latter of which can result in blistering of complex epithelia (McGrath, 2005; Waschke, 2008). This Cell Science at a Glance article and its accompanying poster highlight key aspects of desmosome structure, function and regulation, and relate this knowledge to recent advances in our understanding of the role of desmosomes in human disease. Interested readers are referred to more comprehensive recent reviews for further details (Bazzi and Christiano, 2007; Dusek et al., 2007; Garrod and Chidgey, 2008; Getsios et al., 2004; Green and Simpson, 2007; Holthofer et al., 2007; Huber, 2003; McGrath, 2005; Schmidt and Koch, 2007; Waschke, 2008).