ARF1 and infection: As GAT can bind multiple Arf isoforms (Nakayama and Takatsu, 2005), we sought to confirm that Arf1 localizes to membrane ruffles induced by Salmonella by performing the same infection with HeLa cells expressing Arf1RFP (Figure 3D), which behaves indistinguishably from endogenous Arf1 in cells (Cohen et al., 2007).