Type XVII collagen

Type XVII collagen, also known as 180kD bullous pemphigoid antigen (BP180), is a type II transmembrane collagen. It is expressed in epithelial hemidesmosomes of skin, colonic mucosa, cornea, brain, kidney, and placenta and has a number of binding partners. The intracellular domain binds to integrin α6β4, bullous pemphigoid antigen, and plectin, while the extracellular domain binds to laminin-332. The putative function of type XVII collagen is to stabilize adhesion of epithelial cells to the surrounding extracellular matrix. Mutations in type XVII collagen can cause junctional epidermolysis bullosa, with skin blistering and epithelial recurrent erosion dystrophy disease with recurrent corneal erosions. Mouse knockout model displays similar skin symptoms to humans, such as blisters and erosions. Enamel hypoplasia is also found in this model, suggesting that type XVII collagen also has important roles in tooth formation. Recent studies have demonstrated a potential role for type XVII collagen in multiple cancers in relation to, for example, migration, proliferation, and overall survival of the patients. There are currently no biomarkers for type XVII collagen.