The term adherens junctions is a group of adherens (English: Adhering junctions ) summarized. They include the adherens junction ( Gürteldesmosom or Adhäsionsgürtel ), fascia adherens ( Streifendesmosom ) and punctum adherens ( Punktdesmosom ). Adherence connections establish a connection between the actin filaments of two cells and thereby strengthen them mechanically.
The typical adherence compound is present in epithelial cells, where often just below the tight junctions a Adhäsionsgürtel often forms ( adherens junction ) while in all other tissues only point-like compounds are seen. The proteins involved in adherence to all connections are cadherins (Ca2 -dependent transmembrane proteins that also play an important role in desmosomes ) which with various anchor proteins ( catenins, vinculin and α -actinin ) are connected to the actin cytoskeleton. Cadherins are dimers and are among the homotypic cell adhesion molecules, that have for the formation of cell-cell connection on the Extrazellularseite the plasma membrane of a specific amino acid sequence for binding of another cadherin another cell.
In this way, the actin filaments of many cells are combined to form a transcellular network that can contract using myosin motor proteins. It is believed that this is in the morphogenesis of animals ( particularly in the training of the neural tube ) plays a fundamental role.
Also it is assumed that an adherence connection is necessary to later form a tight junction.