Tuesday 29 June 2004
Definition: Specialized cell-cell junctions that are formed by cadherins and additional associated proteins into which actin filaments are inserted (also known as zonula adherens).
Adherens junctions (AJs), also called the zonula adherens, are critical for the establishment and maintenance of epithelial layers, such as those lining organ surfaces.
AJs mediate adhesion between cells, communicate a signal that neighboring cells are present, and anchor the actin cytoskeleton.
In serving these roles, AJs regulate normal cell growth and behavior.
At several stages of embryogenesis, wound healing, and tumor cell metastasis, cells form and leave epithelia. This process, which involves the disruption and reestablishment of epithelial cell-cell contacts, may be regulated by the disassembly and assembly of AJs.
AJs may also function in the transmission of the ’contact inhibition’ signal, which instructs cells to stop dividing once an epithelial sheet is complete.