What underlies tight junctions to provide strength?

Tight junctions are critical components of the cell's architecture, particularly in epithelial tissues, where they play a key role in maintaining the integrity of the cell layer and regulating paracellular transport. The strength of tight junctions is fundamentally underpinned by their association with adhering junctions, which connect adjacent cells and help maintain the structural stability of the tissue.

Adhering junctions, through their links to the cytoskeleton, assist in distributing mechanical forces and provide reinforcement to the areas where tight junctions are present. This connection ensures that tight junctions are not only functional in sealing gaps between cells but also structurally secure, preventing cells from separating under stress and maintaining the barrier function of epithelia. Overall, this interplay ensures tight junctions can effectively perform their roles in maintaining tissue cohesion and regulating the movement of substances between cells.