FIGURE 4.

Testing truncation mutants of mouse Sdc4 ectodomain for inhibitory motif. A, wound healing assay is conducted with HaCat cells in the presence or absence of 10 ng/ml EGF, thrombin (2 units/mg) and added mouse GST-S4ED fusion protein (10 μm). Note that neither thrombin nor 10 μm GST has an effect on migration. However, GST-S4ED79–132 fusion protein, in which GST is close to the active site, requires the removal of GST for activity. B, concentration range of thrombin-cleaved GST-S4ED fusion protein or truncation mutants are tested for inhibition of MCF10A cell migration in response to 10 ng/ml EGF in a wound healing assay. C, schematic showing fusion proteins with the putative binding site (amino acids 88–132) highlighted and estimated IC₅₀.