Figure 2

Activated phosphoinositide 3-kinase (PI3K) is recruited to lipid rafts in response to infection, independent of the type III secretion system and Shiga-like toxins 1 and 2. Western blots of PI3K from ultracentrifugation fractions of whole-cell (HEp-2) extracts. PI3K recruitment in EHEC mutant (CVD 451 and 85-170)-infected cells indicates that signaling is independent of the type III secretion system and Shiga-like toxins 1 and 2 (a). Cells treated with the PI3K inhibitor LY294002 before EHEC O157:H7 infection had reduced amounts of PI3K recruited to lipid rafts, compared with the amount of PI3K recruited in cells treated with the inactive analog, LY303511, before EHEC infection (b).