desmogleïnes

Desmogleins are a family of transmembrane proteins belonging to the cadherin superfamily, playing a critical role in cell-cell adhesion within epithelial tissues. They are key components of desmosomes, specialized junctions that provide mechanical strength and structural integrity to tissues subjected to mechanical stress, such as the skin, heart, and gastrointestinal tract. The name "desmoglein" is derived from the Greek words *desmos* (meaning bond) and *glyco-* (referring to their glycosylated nature).

There are four known desmoglein isoforms in humans, designated as desmoglein 1 (DSG1), desmoglein 2 (DSG2), desmoglein 3 (DSG3), and desmoglein 4 (DSG4). DSG1 and DSG2 are primarily expressed in suprabasal epidermal layers and cardiac muscle, respectively, while DSG3 is localized to the basal layers of the epidermis and mucosal surfaces. DSG4 has a more limited distribution, found in certain epithelial tissues. These proteins mediate calcium-dependent adhesion by interacting with other cadherins, such as desmocollins, and linking to the cytoskeletal intermediate filament protein, keratin, via plaque proteins like plakoglobin and desmoplakin.

Mutations or dysfunction in desmogleins are associated with several blistering disorders, collectively known as pemphigus. For example, autoimmune attacks on DSG3 (pemphigus vulgaris) or DSG1 (pemphigus foliaceus) disrupt cell adhesion, leading to intraepidermal blistering and skin fragility. Genetic defects in desmogleins have also been linked to arrhythmogenic right ventricular cardiomyopathy (ARVC), a heart condition characterized by weakened cardiac tissue due to impaired desmosomal function.

Structurally, desmogleins consist of an extracellular domain containing cadherin repeats responsible for homophilic binding, a single transmembrane segment, and a short cytoplasmic tail. Their precise regulation and interaction with neighboring proteins are essential for maintaining tissue cohesion and overall organ function. Research into desmogleins continues to advance understanding of cellular adhesion mechanisms and potential therapeutic targets for related diseases.