title: A systematic proteomic analysis of Listeria monocytogenes house-keeping protein secretion systems.
abstract: Listeria monocytogenes is a firmicute bacterium causing serious infections in humans upon consumption of contaminated food. Most of its virulence factors are secretory proteins either released to the medium or attached to the bacterial surface. L. monocytogenes encodes at least six different protein secretion pathways. Although great efforts have been made in the past to predict secretory proteins and their secretion routes using bioinformatics, experimental evidence is lacking for most secretion systems. Therefore, we constructed mutants in the main housekeeping protein secretion systems, which are the Sec-dependent transport, the YidC membrane insertases SpoIIIJ and YqjG, as well as the twin-arginine pathway, and analyzed their secretion and virulence defects. Our results demonstrate that Sec-dependent secretion and membrane insertion of proteins via YidC proteins are essential for viability of L. monocytogenes. Depletion of SecA or YidC activity severely affected protein secretion, whereas loss of the Tat-pathway was without any effect on secretion, viability, and virulence. Two-dimensional gel electrophoresis combined with protein identification by mass spectrometry revealed that secretion of many virulence factors and of enzymes synthesizing and degrading the cell wall depends on the SecA route. This finding was confirmed by SecA inhibition experiments using sodium azide. Analysis of secretion of substrates typically dependent on the accessory SecA2 ATPase in wild type and azide resistant mutants of L. monocytogenes revealed for the first time that SecA2-dependent protein secretion also requires the ATPase activity of the house-keeping SecA protein.
authors: From the ‡Robert Koch Institute, FG11 - Division of Enteropathogenic Bacteria and Legionella, Burgstrasse 37, 38855 Wernigerode, Germany; halbedels@rki.de fliegera@rki.de.
authors: Sven
authors: S
authors: Halbedel
authors: §Institute of Microbiology, University of Greifswald, F.-L.-Jahn-Strasse 15, 17487 Greifswald, Germany;
authors: Swantje
authors: S
authors: Reiss
authors: From the ‡Robert Koch Institute, FG11 - Division of Enteropathogenic Bacteria and Legionella, Burgstrasse 37, 38855 Wernigerode, Germany;
authors: Birgit
authors: B
authors: Hahn
authors: §Institute of Microbiology, University of Greifswald, F.-L.-Jahn-Strasse 15, 17487 Greifswald, Germany;
authors: Dirk
authors: D
authors: Albrecht
authors: ¶Institute of Medical Microbiology, University of Gießen, Schubertstrasse 81, 35392 Gießen, Germany;
authors: Gopala Krishna
authors: GK
authors: Mannala
authors: ¶Institute of Medical Microbiology, University of Gießen, Schubertstrasse 81, 35392 Gießen, Germany;
authors: Trinad
authors: T
authors: Chakraborty
authors: ¶Institute of Medical Microbiology, University of Gießen, Schubertstrasse 81, 35392 Gießen, Germany;
authors: Torsten
authors: T
authors: Hain
authors: §Institute of Microbiology, University of Greifswald, F.-L.-Jahn-Strasse 15, 17487 Greifswald, Germany; ‖Institute of Microbiology, Technical University of Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany; **Helmholtz Centre for Infection Research, Microbial Proteomics, Inhoffenstrasse 7, 38124 Braunschweig, Germany.
authors: Susanne
authors: S
authors: Engelmann
authors: From the ‡Robert Koch Institute, FG11 - Division of Enteropathogenic Bacteria and Legionella, Burgstrasse 37, 38855 Wernigerode, Germany; halbedels@rki.de fliegera@rki.de.
authors: Antje
authors: A
authors: Flieger
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001120:Arginine / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D058947:Bacterial Secretion Systems / Q000235:genetics*; D045744:Cell Line, Tumor; D020869:Gene Expression Profiling; D006367:HeLa Cells; D006801:Humans; D008089:Listeria monocytogenes / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D026901:Membrane Transport Proteins / Q000235:genetics*; D051379:Mice; D040901:Proteomics; D000069816:SEC Translocation Channels; D000081416:SecA Proteins; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; D037521:Virulence Factors; D001120:Arginine; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins