PLAU

PLAU, or urokinase-type plasminogen activator, is a human gene that encodes a secreted serine protease involved in the activation of plasminogen to plasmin. Plasmin is a broad-spectrum protease that degrades fibrin and other components of the extracellular matrix, contributing to tissue remodeling and cell migration.

The enzyme is produced as a single-chain zymogen, pro-uPA, which is activated by proteolytic cleavage to active two-chain uPA. Active uPA can bind to the cell-surface receptor uPAR, concentrating proteolysis at the pericellular environment. The uPA-uPAR interaction also influences signaling and adhesion through associations with integrins and other surface molecules.

uPA activity is tightly regulated by inhibitors, most notably plasminogen activator inhibitors PAI-1 and PAI-2, which limit plasmin generation. The plasminogen activation system participates in normal physiological processes such as wound healing, embryogenesis, and angiogenesis, and in pathological conditions including cancer invasion and metastasis, fibrosis, and thrombotic disorders.

Expression of PLAU is widespread, with higher levels observed in several cancer types where elevated uPA activity correlates with invasive behavior and poorer prognosis. Because of its role in pericellular proteolysis and tissue remodeling, components of the PLAU system have been explored as prognostic markers and therapeutic targets. Strategies under investigation include small-molecule inhibitors, monoclonal antibodies, and receptor-based approaches aimed at reducing pericellular proteolysis and tumor invasion.

In summary, PLAU encodes urokinase-type plasminogen activator, a key enzyme in plasmin generation and pericellular proteolysis, functioning within a network that includes the receptor PLAUR and inhibitors such as PAI-1 and PAI-2.