title: The σB-dependent yabJ-spoVG operon is involved in the regulation of extracellular nuclease, lipase, and protease expression in Staphylococcus aureus.
abstract: The alternative sigma factor σ(B) of Staphylococcus aureus is involved in the coordination of the general stress response, expression of virulence determinants, and modulation of antibiotic resistance levels. It controls a large regulon, either directly by recognizing conserved σ(B) promoter sequences or indirectly via σ(B)-dependent elements. The σ(B)-controlled yabJ-spoVG operon encodes two such putative downstream elements. We report here transcriptome analysis in S. aureus Newman, showing that inactivation of the yabJ-spoVG operon had primarily a repressing effect on a small subregulon encoding mainly virulence factors, including a nuclease (nuc), a protease (splE) and a lipase (lip). As a consequence, extracellular nuclease, protease, and lipase activities were reduced in a ΔyabJ-spoVG mutant. trans-complementation by SpoVG was sufficient to restore their reduced phenotypic expression and lowered transcription due to the yabJ-spoVG deletion. It did not restore, however, the changes triggered by σ(B) inactivation, indicating that both regulons only partially overlap, despite the σ(B) dependency of the yabJ-spoVG expression. Thus, σ(B) is likely to control additional, SpoVG-independent factors affecting the expression of numerous hydrolytic enzymes. SpoVG, on the other hand, seems to fine-tune the σ(B)-dependent regulation of a subset of virulence factors by antagonizing the σ(B) effect.
authors: Institute of Medical Microbiology, University of Zurich, Gloriastrasse 32, 8006 Zurich, Switzerland.
authors: Bettina
authors: B
authors: Schulthess
authors: Dominik A
authors: DA
authors: Bloes
authors: Patrice
authors: P
authors: François
authors: Myriam
authors: M
authors: Girard
authors: Jacques
authors: J
authors: Schrenzel
authors: Markus
authors: M
authors: Bischoff
authors: Brigitte
authors: B
authors: Berger-Bächi
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D008049:Lipase / Q000378:metabolism*; D008836:Micrococcal Nuclease / Q000378:metabolism*; D009876:Operon; D010447:Peptide Hydrolases / Q000378:metabolism*; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000201:enzymology / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; C079011:SigB protein, Bacteria; D012808:Sigma Factor; D008049:Lipase; D008836:Micrococcal Nuclease; D010447:Peptide Hydrolases