title: Real-time imaging of type III secretion: Salmonella SipA injection into host cells.
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 x 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.
authors.affiliation: Institute of Microbiology, Eidgenössische Technische Hochschule, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland.
authors.forename: Markus C
authors.initials: MC
authors.lastname: Schlumberger
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Müller
authors.forename: Kristin
authors.initials: K
authors.lastname: Ehrbar
authors.forename: Brit
authors.initials: B
authors.lastname: Winnen
authors.forename: Iwan
authors.initials: I
authors.lastname: Duss
authors.forename: Bärbel
authors.initials: B
authors.lastname: Stecher
authors.forename: Wolf-Dietrich
authors.initials: WD
authors.lastname: Hardt
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000502:physiology; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D001693:Biological Transport, Active; D019556:COS Cells; D002522:Chlorocebus aethiops; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D007700:Kinetics; D008840:Microfilament Proteins / Q000235:genetics / Q000502:physiology*; D008856:Microscopy, Fluorescence; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012486:Salmonella typhimurium / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D014774:Virulence / Q000502:physiology
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D008840:Microfilament Proteins; D011993:Recombinant Fusion Proteins; C118287:SipA protein, Salmonella; C082314:SspA protein, bacteria