[1] Tight junctions may also serve as leaky pathways by forming selective channels for small cations, anions, or water.

Each strand is formed from a row of transmembrane proteins embedded in both plasma membranes, with extracellular domains joining one another directly.

In one study for paracellular transport across the tight junction in kidney proximal tubule, a dual pathway model was proposed, consisting of large slit breaks formed by infrequent discontinuities in the tight junction complex and numerous small circular pores.

Occludin is able to interact with signaling pathways controlling cellular differentiation, and has been shown to travel to the nucleus of cells in which the tight junction has been disrupted.

[8] Claudins, and angulins, like ZO-1, have been shown to interact with several important transcription factors influencing cellular migration and proliferation.