A desmosome, also known as a macula adherens, is a cell structure specialized for cell-to-cell adhesion. A type of junctional complex, they are localized spot-like adhesions randomly arranged on the lateral sides of plasma membranes. Desmosomes are one of the stronger cell-to-cell adhesion types and are found in tissue that experience intense mechanical stress, such as cardiac muscle tissue, bladder tissue, gastrointestinal mucosa, and epithelia.
Keratin, type I cytoskeletal 4 also known as cytokeratin-4 (CK-4) or keratin-4 (K4) is a protein that in humans is encoded by the KRT4 gene.
Keratin 18 is a type I cytokeratin. It is, together with its filament partner keratin 8, perhaps the most commonly found products of the intermediate filament gene family. They are expressed in single layer epithelial tissues of the body. Mutations in this gene have been linked to cryptogenic cirrhosis. Two transcript variants encoding the same protein have been found for this gene.
The desmogleins are a family of desmosomal cadherins consisting of proteins DSG1, DSG2, DSG3, and DSG4. They play a role in the formation of desmosomes that join cells to one another.
Desmoglein-1 is a protein that in humans is encoded by the DSG1 gene. Desmoglein-1 is expressed everywhere in the skin epidermis, but mainly it is expressed in the superficial upper layers of the skin epidermis.
Desmoglein-3 is a protein that in humans is encoded by the DSG3 gene. In the skin epidermis Desmoglein-3 is expressed in the basal lower layers of the epidermis, and dominates in terms of expression on mucosal surfaces compared to Desmoglein-1.
Desmoglein-2 is a protein that in humans is encoded by the DSG2 gene. Desmoglein-2 is highly expressed in epithelial cells and cardiomyocytes. Desmoglein-2 is localized to desmosome structures at regions of cell-cell contact and functions to structurally adhere adjacent cells together. In cardiac muscle, these regions are specialized regions known as intercalated discs. Mutations in desmoglein-2 have been associated with arrhythmogenic right ventricular cardiomyopathy and familial dilated cardiomyopathy.
Desmoplakin is a protein in humans that is encoded by the DSP gene. Desmoplakin is a critical component of desmosome structures in cardiac muscle and epidermal cells, which function to maintain the structural integrity at adjacent cell contacts. In cardiac muscle, desmoplakin is localized to intercalated discs which mechanically couple cardiac cells to function in a coordinated syncytial structure. Mutations in desmoplakin have been shown to play a role in dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy, where it may present with acute myocardial injury; striate palmoplantar keratoderma, Carvajal syndrome and paraneoplastic pemphigus.
Plakoglobin, also known as junction plakoglobin or gamma-catenin, is a protein that in humans is encoded by the JUP gene. Plakoglobin is a member of the catenin protein family and homologous to β-catenin. Plakoglobin is a cytoplasmic component of desmosomes and adherens junctions structures located within intercalated discs of cardiac muscle that function to anchor sarcomeres and join adjacent cells in cardiac muscle. Mutations in plakoglobin are associated with arrhythmogenic right ventricular dysplasia.
p120 catenin, or simply p120, also called catenin delta-1, is a protein that in humans is encoded by the CTNND1 gene.
Cadherin-3, also known as P-Cadherin, is a protein that in humans is encoded by the CDH3 gene.
Desmocollin-2 is a protein that in humans is encoded by the DSC2 gene. Desmocollin-2 is a cadherin-type protein that functions to link adjacent cells together in specialized regions known as desmosomes. Desmocollin-2 is widely expressed, and is the only desmocollin isoform expressed in cardiac muscle, where it localizes to intercalated discs. Mutations in DSC2 have been causally linked to arrhythmogenic right ventricular cardiomyopathy.
Periplakin is a protein that in humans is encoded by the PPL gene.
Plakophilin-1 is a protein that in humans is encoded by the PKP1 gene.
Desmocollin-3 is a protein that in humans is encoded by the DSC3 gene.
Plakophilin-2 is a protein that in humans is encoded by the PKP2 gene. Plakophilin 2 is expressed in skin and cardiac muscle, where it functions to link cadherins to intermediate filaments in the cytoskeleton. In cardiac muscle, plakophilin-2 is found in desmosome structures located within intercalated discs. Mutations in PKP2 have been shown to be causal in arrhythmogenic right ventricular cardiomyopathy.
Envoplakin is a protein that in humans is encoded by the EVPL gene.
Cadherin-4 is a protein that in humans is encoded by the CDH4 gene.
Plakophilin-3 is a protein that in humans is encoded by the PKP3 gene.
Desmocollins are a subfamily of desmosomal cadherins, the transmembrane constituents of desmosomes. They are co-expressed with desmogleins to link adjacent cells by extracellular adhesion. There are seven desmosomal cadherins in humans, three desmocollins and four desmogleins. Desmosomal cadherins allow desmosomes to contribute to the integrity of tissue structure in multicellular living organisms.
