Urokinase Recombinant Protein (RPPB2415)

Catalytic activity: Specific cleavage of Arg-|-Val bond in plasminogen to form plasmin.

Enzyme regulation: Inhibited by SERPINA5. Ref.17 Ref.22

Subunit structure: Found in high and low molecular mass forms. Each consists of two chains, A and B. The high molecular mass form contains a long chain A which is cleaved to yield a short chain A. Forms heterodimer with SERPINA5. Binds LRP1B; binding is followed by internalization and degradation. Interacts with MRC2. Interacts with PLAUR. Ref.20 Ref.21

Subcellular location: Secreted.

Tissue specificity: Expressed in the prostate gland and prostate cancers. Ref.23

Post-translational modification: Phosphorylation of Ser-158 and Ser-323 abolishes proadhesive ability but does not interfere with receptor binding.

Involvement in Disease: Quebec platelet disorder (QPD) [MIM:601709]: An autosomal dominant bleeding disorder due to a gain-of-function defect in fibrinolysis. Although affected individuals do not exhibit systemic fibrinolysis, they show delayed onset bleeding after challenge, such as surgery. The hallmark of the disorder is markedly increased PLAU levels within platelets, which causes intraplatelet plasmin generation and secondary degradation of alpha-granule proteins.Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.24

Pharmaceutical use: Available under the name Abbokinase (Abbott). Used in Pulmonary Embolism (PE) to initiate fibrinolysis. Clinically used for therapy of thrombolytic disorders.

Sequence similarities: Belongs to the peptidase S1 family.Contains 1 EGF-like domain.Contains 1 kringle domain.Contains 1 peptidase S1 domain.