GenomeRNAi - a database for RNAi phenotypes and reagents
TitleScreen TitleAssayBiomodelSpecies
RNAi screen of Salmonella invasion shows role of COPI in membrane targeting of cholesterol and Cdc42. Misselwitz et al. (2011) Salmonella enterica subspecies 1 serovar Typhimurium invasion (4) SipA-β-lactamase effector injection assayHeLaH. sapiens

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.

Screen details


Stable Id: GR00133-A-4
Screen title: Salmonella enterica subspecies 1 serovar Typhimurium invasion (4)
Assay: SipA-β-lactamase effector injection assay
Method: Fluorescence
Scope: Selected genes
Screen type: Cell-based
Species: Homo sapiens
Biosource: Cell line
Biomodel: HeLa
Library: Qiagen, Druggable genome library V2.0
Reagent type: siRNA
Score type: log2 median
Cutoff: >= 0.3 OR <= -0.5
Notes: