Figure 3.

Salmonella Activation of Arf1 during Invasion

(A and B) Activation of Arf1 by Salmonella. HeLa cells expressing Arf1^HA (Arf1) were lysed with detergent and the soluble fractions were incubated with ^GSTGAT (GAT), then Arf1^HA was immunoprecipitated. The fraction of GTP-bound Arf1^HA was determined by immunoblotting for coprecipitated GAT with anti-GST antibody and anti-HA as control. In (A), HeLa cells expressing Arf1^HA alone (-) or together with ARNO (+) are shown. (B) shows HeLa cells expressing Arf1^HA either noninfected (-) or infected (15 min) with wild-type (WT), ΔinvG, or ΔE/E2 strains of Salmonella.

(C and D) Localization of ^CFPGAT (C) or Arf1^RFP (D) in HeLa cells infected for 15 min with wild-type (WT), ΔinvG, or ΔE/E2 strains of Salmonella (bacteria). Alexa Fluor 488-phalloidin was used to visualize actin in (C). Insets show magnified area. Scale bar 8 μm.