1. Real-time imaging of type III secretion: Salmonella SipA injection into host cells
- Author
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Brit Winnen, Markus C. Schlumberger, Bärbel Stecher, Kristin Ehrbar, Wolf-Dietrich Hardt, Iwan Duss, and Andreas Müller
- Subjects
DNA, Bacterial ,Salmonella typhimurium ,Salmonella ,Recombinant Fusion Proteins ,Biological Transport, Active ,Virulence ,medicine.disease_cause ,Time-lapse microscopy ,Microbiology ,Bacterial Proteins ,Chlorocebus aethiops ,medicine ,Animals ,Secretion ,Adhesins, Bacterial ,Multidisciplinary ,COS cells ,Base Sequence ,biology ,Effector ,Microfilament Proteins ,Biological Sciences ,biology.organism_classification ,Kinetics ,Microscopy, Fluorescence ,Genes, Bacterial ,COS Cells ,Signal transduction ,Bacteria - Abstract
Many pathogenic and symbiotic Gram-negative bacteria employ type III secretion systems to inject “effector” proteins into eukaryotic host cells. These effectors manipulate signaling pathways to initiate symbiosis or disease. By using time-lapse microscopy, we have imaged delivery of the Salmonella type III effector protein SipA/SspA into animal cells in real time. SipA delivery mostly began 10-90 sec after docking and proceeded for 100-600 sec until the bacterial SipA pool (6 ± 3 × 10 3 molecules) was exhausted. Similar observations were made for the effector protein SopE. This visualization of type III secretion in real time explains the efficiency of host cell manipulation by means of this virulence system.
- Published
- 2005
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