A yeast genetic system for the identification and characterization of substrate proteins transferred into host cells by the Legionella pneumophila Dot/Icm system.

摘要: The Dot/Icm system is a type IVb secretion used by Legionella pneumophila to modulate vesicular transport in both protozoan and mammalian host cells. It has been shown that proteins processes are highly conserved all eukaryotic cells targets for some of the injected system. For example, protein RalF was previously be substrate functions as guanine nucleotide exchange factor (GEF) Arf family small GTP-binding proteins. Here we show ectopic production Saccharomyces cerevisiae interferes with yeast growth. Inhibition growth found dependent on ability function an Arf-GEF vivo. possibility other would have capacity interfere rationale screen plasmid libraries containing random fragments chromosomal DNA positioned downstream galactose-inducible promoter. This identified conferred conditional defect when overproduced cultured presence galactose. Most were determined substrates led identification new called YlfA, lethal A. A paralogue YlfA unlinked region chromosome this also translocated hydrophobic near N-terminus adjacent predicted form coiled-coil domain necessary biological activity interfered did not decorate Legionella-containing vacuole during first 7 h infection but could observed endoplasmic reticulum (ER)-derived replicative punctate structures throughout cell at later stages. Ectopic revealed N-terminal able localize early secretory organelles, including reticulum. These studies genetics can exploited identify characterize into bacterial pathogens utilize IV systems pathogenesis.