Selective protection of an ARF1-GTP signaling axis by a bacterial scaffold induces bidirectional trafficking arrest

Andrey S. Selyunin, Lovett Evan Reddick, Bethany A. Weigele, Neal M. Alto

Research output: Contribution to journalArticle

19 Scopus citations


Bidirectional vesicular transport between the endoplasmic reticulum (ER) and Golgi is mediated largely by ARF and Rab GTPases, which orchestrate vesicle fission and fusion, respectively. How their activities are coordinated in order to define the successive steps of the secretory pathway and preserve traffic directionality is not well understood in part due to the scarcity of molecular tools that simultaneously target ARF and Rab signaling. Here, we take advantage of the unique scaffolding properties of E.coli secreted protein G (EspG) to describe the critical role of ARF1/Rab1 spatiotemporal coordination in vesicular transport at the ER-Golgi intermediate compartment. Structural modeling and cellular studies show that EspG induces bidirectional traffic arrest by tethering vesicles through select ARF1-GTP/effector complexes and local inactivation of Rab1. The mechanistic insights presented here establish the effectiveness of a small bacterial catalytic scaffold for studying complex processes and reveal an alternative mechanism of immune regulation by an important human pathogen.

Original languageEnglish (US)
Pages (from-to)878-891
Number of pages14
JournalCell Reports
Issue number5
StatePublished - Jan 1 2014


ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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