Definition: Specialized adhesive structure at the basal surface of epithelial cells that functions to attach the cells to the underlying basement membrane. The hemidesmosome contains a dense plaque on the inner surface of the plasma membrane, with keratin containing filaments coursing out into the cytoplasm
Hemidesmosome anchor epithelial cells to a basement membrane
- Similar to desmosomes but totally different molecular structure
- Cell matrix adhesions –attach cells to basal lamina
Molecular Structure of Hemidesmosomes
- Composed of integrins (outside) that bind to type XVII collagen and laminin -5
- Cytosolic side consists of a plague composed of adaptor proteins (plectin) attaching integrins to keratin filaments.