Recognition of Bacteria in the Cytosol of Mammalian Cells by the Ubiquitin System

摘要: Abstract Recent studies have suggested the existence of innate host surveillance systems for detection bacteria in cytosol mammalian cells [1–4]. The molecular details how are recognized cytosol, however, remain unclear. Here we examined fate Salmonella typhimurium , a gram-negative bacterial pathogen that can infect variety hosts [5], cells. These typically occupy membrane bound compartment, -containing vacuole (SCV), We show some wild-type escape invasion vacuoles and released into cytosol. Subsequently, polyubiquitinated proteins accumulate on surface, response was witnessed several cell types. In macrophages but not epithelial cells, proteasome observed to undergo dramatic subcellular relocalization become associated with surface Proteasome inhibition promoted replication S. both types, part through destabilization SCV. Surprisingly, cytosol-adapted Listeria monocytogenes avoided recognition by ubiquitin system using actin-based motility. Our findings indicate plays major role pathogens