Finally, to assess whether LegG1 requires the Ran GTPase to exert its effect on microtubule polymerization, A549 cells (Fig. S1) were treated with siRNA oligonucleotides silencing Ran for 2 days, followed by 1 μM nocodazole for 1 h and infection with Y. enterocolitica WA (pT3SS) producing YopE1–53 or YopE1–53-LegG1 for 2 h (Figure 5F). Here, RAN is linked to infection.