The Legionella Pneumophila Effector Protein DrrA Is a Rab1 Guanine Nucleotide-Exchange Factor

Nat Cell Biol. 2006 Sep;8(9):971-7. doi: 10.1038/ncb1463. Epub 2006 Aug 13.

Abstract

The intracellular pathogen Legionella pneumophila avoids fusion with lysosomes and subverts membrane transport from the endoplasmic reticulum to create an organelle that supports bacterial replication. Transport of endoplasmic reticulum-derived vesicles to the Legionella-containing vacuole (LCV) requires bacterial proteins that are translocated into host cells by a type IV secretion apparatus called Dot/Icm. Recent observations have revealed recruitment of the host GTPase Rab1 to the LCV by a process requiring the Dot/Icm system. Here, a visual screen was used to identify L. pneumophila mutants with defects in Rab1 recruitment. One of the factors identified in this screen was DrrA, a new Dot/Icm substrate protein translocated into host cells. We show that DrrA is a potent and highly specific Rab1 guanine nucleotide-exchange factor (GEF). DrrA can disrupt Rab1-mediated secretory transport to the Golgi apparatus by competing with endogenous exchange factors to recruit and activate Rab1 on plasma membrane-derived organelles. These data establish that intracellular pathogens have the capacity to directly modulate the activation state of a specific member of the Rab family of GTPases and thus further our understanding of the mechanisms used by bacterial pathogens to manipulate host vesicular transport.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Biological Transport, Active
  • Cell Membrane / metabolism
  • Cells, Cultured
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Female
  • Golgi Apparatus / metabolism
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism*
  • Legionella pneumophila / genetics
  • Legionella pneumophila / metabolism
  • Legionella pneumophila / physiology*
  • Mice
  • Mutation
  • Protein Transport
  • Vacuoles / metabolism
  • Vacuoles / microbiology
  • rab1 GTP-Binding Proteins / genetics
  • rab1 GTP-Binding Proteins / metabolism*

Substances

  • Bacterial Proteins
  • DNA-Binding Proteins
  • DrrA protein, Bacteria
  • Guanine Nucleotide Exchange Factors
  • rab1 GTP-Binding Proteins