Proteases from Entamoeba spp. and Pathogenic Free-Living Amoebae as Virulence Factors
EhPCP5 stimulates NFκB-mediated proinflammatory responses. Attached to E. histolytica surface or secreted, EhPCP5 binds to α(V)β(3) integrin through the RGD motif and triggers PI3K-mediated ILK activation. ILK phosphorylates Akt-473, which binds and induces the ubiquitination of NEMO. This activates the IKKα-IKKβ complex that phosphorylate IκBα. This phosphorylation event signals IκBα ubiquitin-mediated degradation and, thereby, the release of NF-κB into the nucleus, where it activates proinflammatory gene expression.