adherensjunction

Adherens junctions are a type of cell junction that provide mechanical strength and help cells to stick together. They are part of the adherens system, a network of proteins that spans the cell membrane and connects the actin cytoskeleton of one cell to the actin cytoskeleton of an adjacent cell. Adherens junctions are typically found in epithelial and endothelial cells, where they play a crucial role in maintaining tissue integrity and shape.

The structure of an adherens junction involves several key proteins. Cadherins, a family of transmembrane proteins, are the primary adhesion molecules. They engage in homophilic binding, meaning cadherins from one cell bind to cadherins on neighboring cells. Inside the cell, cadherins are linked to the actin cytoskeleton through a complex of adapter proteins, including catenins (alpha-catenin, beta-catenin, and p120-catenin). This linkage is essential for transmitting mechanical forces and coordinating cytoskeletal organization.

Adherens junctions are dynamic structures that can be assembled and disassembled in response to cellular signals. They are involved in various biological processes, such as cell migration, tissue morphogenesis, and wound healing. The precise arrangement and type of cadherins expressed can influence the strength and specificity of cell-cell adhesion. Disruptions in adherens junction function are associated with diseases, including cancer, where loss of cell adhesion can contribute to tumor invasion and metastasis.