ENTEROPATHOGENIC ESCHERICHIA-COLI (EPEC) TRANSFERS ITS RECEPTOR FOR INTIMATE ADHERENCE INTO MAMMALIAN-CELLS

Enteropathogenic E. coli (EPEC) belongs to a group of bacterial pathog ens that induce epithelial cell actin rearrangements resulting in pede stal formation beneath adherent bacteria. This requires the secretion of specific virulence proteins needed for signal transduction and inti mate adherence. EPEC interaction induces tyrosine phosphorylation of a protein in the host membrane, Hp90, which is the receptor for the EPE C outer membrane protein, intimin. Hp90-intimin interaction is essenti al for intimate attachment and pedestal formation. Here, we demonstrat e that Hp90 is actually a bacterial protein (Tir). Thus, this bacteria l pathogen inserts its own receptor into mammalian cell surfaces, to w hich it then adheres to trigger additional host signaling events and a ctin nucleation. It is also tyrosine-phosphorylated upon transfer into the host cell.