Abstract

The pathogen Salmonella Typhimurium is a common cause of diarrhea and invades the gut tissue by injecting a cocktail of virulence factors into epithelial cells, triggering actin rearrangements, membrane ruffling and pathogen entry. One of these factors is SopE, a G-nucleotide exchange factor for the host cellular Rho GTPases Rac1 and Cdc42. How SopE mediates cellular invasion is incompletely understood. Using genome-scale RNAi screening we identified 72 known and novel host cell proteins affecting SopE-mediated entry. Follow-up assays assigned these ‘hits’ to particular steps of the invasion process; i.e., binding, effector injection, membrane ruffling, membrane closure and maturation of the Salmonella-containing vacuole. Depletion of the COPI complex revealed a unique effect on virulence factor injection and membrane ruffling. Both effects are attributable to mislocalization of cholesterol, sphingolipids, Rac1 and Cdc42 away from the plasma membrane into a large intracellular compartment. Equivalent results were obtained with the vesicular stomatitis virus. Therefore, COPI-facilitated maintenance of lipids may represent a novel, unifying mechanism essential for a wide range of pathogens, offering opportunities for designing new drugs.

Details

Title
RNAi screen of Salmonella invasion shows role of COPI in membrane targeting of cholesterol and Cdc42
Author
Misselwitz, Benjamin 1 ; Dilling, Sabrina 1 ; Vonaesch, Pascale 1 ; Sacher, Raphael 2 ; Snijder, Berend 2 ; Schlumberger, Markus 1 ; Rout, Samuel 1 ; Stark, Manuel 3 ; Christian von Mering 3 ; Lucas Pelkmans 4 ; Wolf-Dietrich Hardt 1 

 Institute of Microbiology, D-BIOL, ETH Zürich, Zürich, Switzerland 
 Institute of Molecular Systems Biology, D-BIOL, ETH Zürich, Zürich, Switzerland 
 Institute of Molecular Life Sciences, University of Zürich, Zürich, Switzerland 
 Institute of Molecular Systems Biology, D-BIOL, ETH Zürich, Zürich, Switzerland; Institute of Molecular Life Sciences, University of Zürich, Zürich, Switzerland 
Section
Article
Publication year
2011
Publication date
2011
Publisher
EMBO Press
e-ISSN
17444292
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2058914404
Copyright
© 2011. This work is published under http://creativecommons.org/licenses/by-nc-sa/3.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.