Hemidesmosomes are adhesive structures between cells and the extracellular matrix. They play a role in anchoring intermediate fibers to the extracellular basement membrane. Structurally, hemidesmosomes occur in two forms: Type I and Type II. Type I hemidesmosomes develop in stratified epithelia such as the epidermis. Its main components include the intracellular linker proteins Plectin and BPAG1, the adhesion receptor integrin α6β4 and collagen type BP180/XVII. Type II hemidesmosomes occur in blood vessels, Schwann cells, and digestive tract epithelia as a simplified form of Type I hemidesmosomes, consisting only plectin and integrin α6β4. The hemidesmosomal adhesion receptor is normally associated with Laminin 5 in the basement membrane. Furthermore, Laminin 5 (of which Laminin gamma 2 is a subunit) is linked to collagen fibers in the dermis via type VII collagen. Genetic deletion of hemidesmosome-related proteins causes various forms of epidermolysis bullosa, highlighting their importance in promoting adhesion between the epidermis and the basement membrane.

Unlike most collagens, collagen XVII is a transmembrane protein. Collagen XVII is a structural component of hemidesmosomes, multiprotein complexes at the dermal-epidermal basement membrane zone that mediate adhesion of keratinocytes to the underlying membrane. Mutations in this gene are associated with both generalized atrophic benign and junctional epidermolysis bullosa.

References:
1) Yamauchi T., et al. J. Dermatol. Sci., 76:25-33 (2014).
2) Hirako Y., et al. Exp. Cell Res., 324:172-182 (2014).
3) Hirako Y., et al. J. Baiol. Chem., 273:9711-9717 (1998).

Hemidesmosomes are adhesive structures between cells and the extracellular matrix. They play a role in anchoring intermediate fibers to the extracellular basement membrane. Structurally, hemidesmosomes occur in two forms: Type I and Type II. Type I hemidesmosomes develop in stratified epithelia such as the epidermis. Its main components include the intracellular linker proteins Plectin and BPAG1, the adhesion receptor integrin α6β4 and collagen type BP180/XVII. Type II hemidesmosomes occur in blood vessels, Schwann cells, and digestive tract epithelia as a simplified form of Type I hemidesmosomes, consisting only plectin and integrin α6β4. The hemidesmosomal adhesion receptor is normally associated with Laminin 5 in the basement membrane. Furthermore, Laminin 5 (of which Laminin gamma 2 is a subunit) is linked to collagen fibers in the dermis via type VII collagen. Genetic deletion of hemidesmosome-related proteins causes various forms of epidermolysis bullosa, highlighting their importance in promoting adhesion between the epidermis and the basement membrane.

Unlike most collagens, collagen XVII is a transmembrane protein. Collagen XVII is a structural component of hemidesmosomes, multiprotein complexes at the dermal-epidermal basement membrane zone that mediate adhesion of keratinocytes to the underlying membrane. Mutations in this gene are associated with both generalized atrophic benign and junctional epidermolysis bullosa.

References:
1) Yamauchi T., et al. J. Dermatol. Sci., 76:25-33 (2014).
2) Hirako Y., et al. Exp. Cell Res., 324:172-182 (2014).
3) Hirako Y., et al. J. Baiol. Chem., 273:9711-9717 (1998).