Figure 4

Biological activity of YopM-InlB and of YopM-InlB-fl. (A) The ability of the YopM-InlB to induce ERK phosphorylation was tested in Vero cells. Hepatocyte growth factor/scatter factor (HGF/SF) was used as positive control. InlB₂₄₁ was used as negative control. The controls and reference in this figure (lane 1–6) are the same as those shown in a previously published experiment with InlB₃₂₁ with an additional LRR inserted (Figure five c in [21]) as the experiments with both InlB cap variants (YopM-InlB and InlB₃₂₁ + 1LRRa) were carried out in parallel. (B) The ability of YopM-InlB-fl to induce cell motility was tested in an MDCK cell colony scatter assay. HGF/SF was used as positive control, medium without ligand as negative control. YopM-InlB-fl stimulated colony dispersal at a concentration of 1 nM but showed no activity at 100 pM. The wild type protein was active at 10-fold lower concentration