(I) Model of BspF remodeling of TGN-RE membrane traffic. Bacterially delivered BspF targets RE membranes where it binds ACAP1 and promotes inactivation of Arf6. Increased turnover of active Arf6 results in inhibition of the Arf6/Rab8a cascade and retrograde RE-TGN transport, which alters TGN-derived vesicular traffic and redirects Stx6-positive vesicles to rBCVs in a process that promotes intravacuolar bacterial growth. 