324
Cell Junctions, Structure, Function, and Regulation
2.4
Desmosomal Cadherins and Desmosomes
356
2.4.1
Extracellular Domain of Desmoglein and Desmocollin
357
2.4.2
Cytoplasmic Tail, Plaque Proteins, and Attachment to the
Cytoskeleton
358
2.4.3
Functions of Desmosomes
361
2.5
Tight Junctions
361
2.5.1
Claudins and Other TJ Transmembrane Proteins
362
2.5.2
Plaque Proteins of Tight Junctions
365
2.5.3
Regulation of Tight Junction Assembly/Disassembly
366
3
Summary and Future Directions
368
Bibliography
370
Books and Reviews
370
Primary Literature
371
Keywords
Adherens Junction
Cadherin-mediated cell–cell junction that attaches to the actin cytoskeleton thereby
providing strength to the junction and allowing the cells to act as a single structure.
Cadherins
A family of single pass transmembrane proteins possessing ±ve homologous domains
in the extracellular region. Cadherins on adjacent cells bind in a homophilic,
calcium-dependent manner to form a cell–cell junction.
Desmosome
A ‘‘spot weld’’-like cell–cell junction characterized by a dense plaque on the
cytoplasmic face of the plasma membrane into which intermediate ±laments attach.
Mediated by members of the cadherin family, this specialized junction has tremendous
cell–cell adhesion strength and is found in tissues that require strong cell–cell
attachment such as the heart and skin.
Extracellular Matrix
An insoluble meshwork of cell-secreted macromolecules (including polysaccharides,
such as glycosaminoglycans and large proteins, such as collagen and ±bronectin) that
holds cells together in tissues, and tissues together in organs, and also provides an
adhesive substrate for cells that regulates cell behavior.
Focal Adhesion
A specialized cell-ECM junction where there is tight association between the cell and
an ECM protein, such as ±bronectin. Adhesion is mediated by the direct binding of
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