– The receptor (u-PAR) for urokinase plasminogen activator (u-PA) is a three-domain protein, GPI-anchored to the cell surface, which focuses the enzymatic activity of u-PA, and allows the cell surface activation of plasminogen.Regulation of the activity of u-PA is also mediated by u-PAR. uPAR/PLAUR Protein, Human, Recombinant (His & Avi) is expressed in HEK293 mammalian cells with C-His-Avi tag. The predicted molecular weight is 34.36 kDa and the accession number is Q03405-1.