Salmonella Typhimurium effector SseI inhibits chemotaxis and increases host cell survival by deamidation of heterotrimeric Gi proteins
Fig 6
Effects of G protein deamidation on chemotaxis.
(A) Wild type (wt)-, Gnai2-/-—and Gnai3-/-—DCs were infected with wt-Salmonella (wt S. Tm) (MOI = 30; 30 min) and the chemotactic indices were determined from at least n = 34 cells for each condition from 3 independent experiments as in Fig 5. Statistical significance was assessed using ANOVA and Bonferroni post-test. (B) Time-resolved immunoblot analysis of DCs derived from Gnai2-/—(upper panel), Gnai3-/—(lower panel) mice or wild type littermates (Gnai2+/+, upper panel; Gnai3+/+, lower panel) after infection with wild type Salmonella (S. Tm infection) (MOI = 30, 30 min) for indicated times. Proteins were analyzed by specific antibodies (GαQE, Gαi1+2 and actin). (C-E) Gnai2-/- DCs were transfected with Gαi2, Gαi2Q205E or empty vector. Chemotaxis in a collagen matrix (C) with CCL19 gradient was measured by cell tracking using time-lapse microscopy. Chemotactic index (D) and migration speed (E) were calculated as described in Fig 5. Statistical significance was assessed using ANOVA (Bonferroni post-test).