Fig. 4.

The uPA-TEM8 interaction at the cell surface. a The HMW-tcuPA protein was incubated with TEM8-Fc at different ratios, or with anti-uPA polyclonal antibody as a positive control. The fibrinolytic activity of TEM8-bound uPA was assayed on human plasminogen-rich fibrinogen agarose plates. The linearity of the plot, in the absence of TEM8-Fc, is shown in the insert. b & c Cells with wild-type or down-regulated TEM8 and/or uPAR were cultured in 96-well cell culture plates until they reached 90% confluence. The cells were fixed and treated with acidified buffer to remove endogenous uPA, then human HMW-tcuPA was added and cell surface-based fibrinolytic activity was measured