Desmosomes are the most common type of intercellular junction in vertebrate epithelial cells. They are characterized by 2 forms of interaction with other cellular structures.

First, they form membrane anchorage sites for intermediate-size filaments, which are seen as electron-dense plaques evident beneath the plasma membrane.

Second, a specific membrane core domain interacts with a corresponding domain of the plasma membrane of an adjacent cell, apparently mediating intercellular adhesion in a stable way.

The desmosome intermediate filament complex is thought to impart tensile strength and resilience to the epithelium.

Desmosomal proteins can be divided into 2 groups based on whether they fractionate with the urea-insoluble 'core' or the urea-soluble 'plaque' components. Desmoglein (MIM.125670) is, for example, a protein of the core. The main proteins of the plaque comprise the desmoplakins and plakoglobin (MIM.173325).

Components

 cadherin superfamily (desmosomal cadherins)(MIM.114020)

• desmogleins (MIM.125670)
• desmocollins (MIM.125643)

 plakin family (MIM.125647)

• armadillo repeat protein family (MIM.602269)
• plakophilin

 pinin (MIM.603154)

 desmoplakins (desmoplakin-1 and desmoplakin-2)(MIM.125647)

Molecular pathology of desmosomes

 pemphigus foliaceum: inactivation of desmoglein-1 by an autoantibody
 type I striate palmoplantaris keratosis: inactivation of desmoglein-1 by genic mutation
 pemphigus vulgaris: inactivation of desmoglein-3 by an autoantibody
 localized autosomal recessive hypotrichosis (LAH): inactivation of desmoglein-4 by genic mutation in (MIM.607903)
 type II striate palmoplantaris keratosis: inactivation of desmoplakin by genic mutation
 generalized striate keratoderma particularly affecting the palmoplantar epidermis, woolly hair, and a dilated left ventricular cardiomyopathy: inactivation of desmoplakin by genic mutation
 skin fragility-woolly hair syndrome (MIM.607655): inactivation of desmoplakin by genic mutation
 arrhythmogenic right ventricular dysplasia mapping to 6p24 (MIM.607450): inactivation of desmoplakin by genic mutation

References

 Huber O. Structure and function of desmosomal proteins and their role in development and disease. Cell Mol Life Sci. 2003 Sep;60(9):1872-90. PMID: #14523549#

 Green KJ, Gaudry CA. Are desmosomes more than tethers for intermediate filaments? Nat Rev Mol Cell Biol. 2000 Dec;1(3):208-16. PMID: #11252896#

 Cozzani E, Cacciapuoti M, Parodi A, Ghohestani R, Rebora A. Desmosomes and their autoimmune pathologies. Eur J Dermatol. 2000 Jun;10(4):255-61. PMID: #10846249#

 Kowalczyk AP, Bornslaeger EA, Norvell SM, Palka HL, Green KJ. Desmosomes: intercellular adhesive junctions specialized for attachment of intermediate filaments. Int Rev Cytol. 1999;185:237-302. PMID: #9750269#

 Garrod DR. Desmosomes and hemidesmosomes. Curr Opin Cell Biol. 1993 Feb;5(1):30-40. PMID: #8448028#