Figure 4.

The L503S polymorphic mutation in type II ROP16 determines its defective Stat3 activation. (A–D) 293T cells were transfected with the APRE-luc plasmid together with the indicated ROP16 expression vectors. Luciferase activities were expressed as fold increases over the background levels shown by lysates prepared from mock-transfected cells. Indicated values are means ± the variation range of duplicates. A list of the chimeric ROP16 expression vectors is shown (B, left). R, RH (pink); M, ME49 (blue). (E) Serum-starved MEFs were infected with an MOI = 10 of the indicated parasites for 18 h. Activation of Stat3 was also determined by Western blot analysis of cell extracts using anti–phospho-Stat3 Tyr 705. Stat3 and actin levels are shown as loading controls. Data are representative of three (A and E) or two (B–D) independent experiments.