Signaling and invasin-promoted uptake via integrin receptors.

The invasin protein encoded by enteropathogenic Yersinia allows entry of bacteria into intestinal M cells by binding to integrin receptors. In cultured cells, invasin-mediated uptake requires proteins involved in endocytosis and signaling to the cell cytoskeleton. At least four different factors have been demonstrated to play a role in regulating the efficiency of invasin-promoted uptake. These include receptor-ligand affinity, receptor clustering, signaling through focal adhesion kinase, and stimulation of cytoskeletal rearrangements by small GTP binding proteins.