cell junction assembly

Definition

Target type: biologicalprocess

A cellular process that results in the aggregation, arrangement and bonding together of a set of components to form a cell junction. [GOC:mah]

Cell junction assembly is a complex and highly regulated process that involves the coordinated action of multiple proteins and signaling pathways. It is essential for maintaining tissue integrity, cell polarity, and proper cell function. The process begins with the formation of initial contacts between cells, which can be mediated by various adhesion molecules, such as cadherins, integrins, and immunoglobulin superfamily proteins. Once these initial contacts are established, they are further stabilized and elaborated into specialized junctions, such as adherens junctions, tight junctions, and gap junctions.

Adherens junctions are the primary junctions responsible for cell-cell adhesion and are characterized by the presence of cadherin proteins. Cadherins are transmembrane proteins that bind to each other in a calcium-dependent manner, forming strong adhesive contacts between cells. Adherens junctions also serve as anchoring points for the actin cytoskeleton, which provides structural support and allows for the transmission of mechanical forces.

Tight junctions are specialized junctions that seal the space between epithelial cells, preventing the passage of fluids and solutes. Tight junctions are composed of transmembrane proteins called claudins and occludins, which form a network of strands that encircle the apical region of epithelial cells. Tight junctions play a crucial role in maintaining epithelial barrier function and regulating the passage of molecules between the apical and basolateral compartments of epithelial cells.

Gap junctions are channels that allow for direct communication between adjacent cells. Gap junctions are composed of connexin proteins, which form hexameric structures called connexons. Connexons from adjacent cells align to form a channel that allows for the passage of small molecules, including ions, nutrients, and signaling molecules. Gap junctions are essential for coordinating cell behavior and allowing cells to communicate with each other.

The assembly of cell junctions is tightly regulated by a variety of signaling pathways, including the Rho GTPase signaling pathway, the Wnt signaling pathway, and the TGF-beta signaling pathway. These signaling pathways control the expression, localization, and activity of junctional proteins, ensuring that cell junctions are properly assembled and maintained.

In addition to the above-mentioned processes, cell junction assembly also involves the recruitment of various adaptor proteins, scaffolding proteins, and signaling molecules. These proteins play critical roles in regulating the assembly, stability, and function of cell junctions.

Dysregulation of cell junction assembly can lead to a variety of diseases, including cancer, developmental defects, and inflammatory diseases. For example, mutations in genes encoding junctional proteins have been implicated in the development of certain cancers. Additionally, defects in cell junction assembly can lead to increased permeability of epithelial barriers, which can contribute to inflammation and infection.'
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Proteins (2)

Compounds (8)