title: Time-Resolved Analysis of Cytosolic and Surface-Associated Proteins of Staphylococcus aureus HG001 under Planktonic and Biofilm Conditions.
abstract: Staphylococcal biofilms are associated with persistent infections due to their capacity to protect bacteria against the host's immune system and antibiotics. Cell-surface-associated proteins are of great importance during biofilm formation. In the present study, an optimized biotinylation approach for quantitative GeLC-MS-based analysis of the staphylococcal cell-surface proteome was applied and the cytoplasmic protein fraction was analyzed to elucidate proteomic differences between colony biofilms and planktonic cells. The experimental setup enabled a time-resolved monitoring of the proteome under both culture conditions and the comparison of biofilm cells to planktonic cells at several time points. This allowed discrimination of differences attributed to delayed growth phases from responses provoked by biofilm conditions. Biofilm cells expressed CcpA-dependent catabolic proteins earlier than planktonic cells and strongly accumulated proteins that belong to the SigB stress regulon. The amount of the cell-surface protein and virulence gene regulator Rot decreased within biofilms and MgrA-dependent regulations appeared more pronounced. Biofilm cells simultaneously up-regulated activators (e.g., SarZ) as well as repressors (e.g., SarX) of RNAIII. A decreased amount of high-affinity iron uptake systems and an increased amount of the iron-storage protein FtnA possibly indicated a lower demand of iron in biofilms.
authors.affiliation: Institute for Microbiology, Ernst-Moritz-Arndt-University , Friedrich-Ludwig-Jahn-Straße 15, 17487 Greifswald, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Moche
authors.affiliation: Institute for Microbiology, Ernst-Moritz-Arndt-University , Friedrich-Ludwig-Jahn-Straße 15, 17487 Greifswald, Germany.
authors.forename: Rabea
authors.initials: R
authors.lastname: Schlüter
authors.affiliation: Institute for Microbiology, Ernst-Moritz-Arndt-University , Friedrich-Ludwig-Jahn-Straße 15, 17487 Greifswald, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Bernhardt
authors.affiliation: Institute for Microbiology, Ernst-Moritz-Arndt-University , Friedrich-Ludwig-Jahn-Straße 15, 17487 Greifswald, Germany.
authors.forename: Kristina
authors.initials: K
authors.lastname: Plate
authors.affiliation: Institute for Microbiology, Ernst-Moritz-Arndt-University , Friedrich-Ludwig-Jahn-Straße 15, 17487 Greifswald, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Riedel
authors.affiliation: Institute for Microbiology, Ernst-Moritz-Arndt-University , Friedrich-Ludwig-Jahn-Straße 15, 17487 Greifswald, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Hecker
authors.affiliation: Institute for Microbiology, Ernst-Moritz-Arndt-University , Friedrich-Ludwig-Jahn-Straße 15, 17487 Greifswald, Germany.
authors.forename: Dörte
authors.initials: D
authors.lastname: Becher
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D018441:Biofilms; D002853:Chromatography, Liquid; D003600:Cytosol / Q000378:metabolism*; D013058:Mass Spectrometry; D013211:Staphylococcus aureus / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins
keywords: 15N metabolic labeling; Staphylococcus aureus; biotinylation approach; cell-surface proteome; colony biofilm; mass spectrometry