Desmosomes

Synonyms

Macula adherens; Maculae adherentes

Definition

Desmosomes are intercellular junctions that mediate cellular adhesion and maintain tissue integrity. They are found in epithelial cells, myocardial and Purkinje fiber cells of the heart, arachnoid cells of brain meninges, and follicular dendritic cells of lymph nodes.

Characteristics

Desmosomes are localized at sites of close cell-cell contact (Fig. 1a). They are less than 1 μm in diameter, have a highly organized structure at the ultrastructural level, and act as anchoring points for intermediate filaments of the cell cytoskeleton (Fig. 1b). By linking intermediate filaments of adjacent cells, desmosomes confer structural continuity and mechanical strength on tissues. Desmosomes are particularly prevalent in tissues, such as the epidermis and heart, that experience mechanical stress. The proteins that form desmosomes belong to three families, the desmosomal cadherins, the armadillo family, and the plakin family of cytolinkers.

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