desmosomy

Desmosomy, commonly referred to in English as desmosomes, are intercellular junctions that provide strong adhesion between neighboring cells. They are especially abundant in tissues subjected to mechanical stress, such as the epidermis and cardiac muscle, where they help resist shear forces and maintain tissue integrity. Desmosomy mediate cell–cell adhesion by linking the cytoskeletons of adjacent cells through transmembrane cadherin proteins and cytoplasmic plaque components.

The core structure of a desmosom consists of extracellular cadherin domains of desmogleins and desmocollins, which form adhesive Bonds with cadherins on neighboring cells in a calcium-dependent manner. The intracellular plaque is composed of plakoglobin (gamma-catenin), beta-catenin family proteins, and plakophilins, which associate with desmoplakin. Desmoplakin then anchors to intermediate filaments, such as keratin in epithelia or desmin in cardiac muscle, providing mechanical linkage to the cytoskeleton.

Desmosome assembly is dynamic and regulated by calcium levels and signaling pathways. They function not only as structural anchors but also engage in signaling interactions that can influence cell behavior. Components of the desmosomal plaque can participate in pathways such as Wnt signaling, and various kinases modulate junction assembly and turnover.

Clinical relevance includes inherited and autoimmune conditions. Mutations in desmosomal proteins are linked to arrhythmogenic right ventricular cardiomyopathy and related cardiomyopathies, while autoimmune diseases such as pemphigus vulgaris and pemphigus foliaceus target desmosomal cadherins (desmogleins), leading to blistering of the skin and mucous membranes.