Open AccessRNAi screen of Salmonella invasion shows role of COPI in membrane targeting of cholesterol and Cdc42
Author(s) -
Misselwitz Benjamin,
Dilling Sabrina,
Vonaesch Pascale,
Sacher Raphael,
Snijder Berend,
Schlumberger Markus,
Rout Samuel,
Stark Manuel,
von Mering Christian,
Pelkmans Lucas,
Hardt WolfDietrich
Publication year - 2011
Publication title -
molecular systems biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.523
H-Index - 148
ISSN - 1744-4292
DOI - 10.1038/msb.2011.7
Subject(s) - biology , membrane ruffling , adp ribosylation factor , rac1 , microbiology and biotechnology , cdc42 , virulence factor , copi , effector , virulence , gtpase , endocytosis , vacuole , golgi apparatus , cytoskeleton , cell , genetics , signal transduction , secretory pathway , gene , endoplasmic reticulum , cytoplasm
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.