title: Characterization of a serine/threonine kinase involved in virulence of Staphylococcus aureus.
abstract: Staphylococcus aureus is a common human cutaneous and nasal commensal and a major life-threatening pathogen. Adaptation to the different environments encountered inside and outside the host is a crucial requirement for survival and colonization. We identified and characterized a eukaryotic-like serine/threonine kinase with three predicted extracellular PASTA domains (SA1063, or Stk1) and its associated phosphatase (SA1062, or Stp1) in S. aureus. Biochemical analyses revealed that Stk1 displays autokinase activity on threonine and serine residues and is localized to the membrane. Stp1 is a cytoplasmic protein with manganese-dependent phosphatase activity toward phosphorylated Stk1. In-frame deletions of the stk1 and stp1 genes were constructed in S. aureus strain 8325-4. Phenotypic analyses of the mutants revealed reduced growth of the stk1 mutant in RPMI 1640 defined medium that was restored when adenine was added to the medium. Furthermore, the stk1 mutant displayed increased resistance to Triton X-100 and to fosfomycin, suggesting modifications in cell wall metabolism. The stk1 mutant was tested for virulence in a mouse pyelonephritis model and found to be strongly reduced for survival in the kidneys (approximately 2-log-unit decrease) compared to the parental strain. Renal histopathological analyses showed severe inflammatory lesions in mice infected with the parental S. aureus SH1000 strain, whereas the Deltastk1 mutant led to only minimal renal lesions. These results confirm the important role of Stk1 for full expression of S. aureus pathogenesis and suggest that phosphorylation levels controlled by stk1 are essential in controlling bacterial survival within the host.
authors.affiliation: Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram Positif, Paris Cedex 15, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Débarbouillé
authors.forename: Shaynoor
authors.initials: S
authors.lastname: Dramsi
authors.forename: Olivier
authors.initials: O
authors.lastname: Dussurget
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Nahori
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Vaganay
authors.forename: Grégory
authors.initials: G
authors.lastname: Jouvion
authors.forename: Alain
authors.initials: A
authors.lastname: Cozzone
authors.forename: Tarek
authors.initials: T
authors.lastname: Msadek
authors.forename: Bertrand
authors.initials: B
authors.lastname: Duclos
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D005578:Fosfomycin / Q000494:pharmacology; D005816:Genetic Complementation Test; D015151:Immunoblotting; D008345:Manganese / Q000378:metabolism; D051379:Mice; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D017830:Octoxynol / Q000494:pharmacology; D009876:Operon / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017434:Protein Structure, Tertiary / Q000235:genetics / Q000502:physiology; D013203:Staphylococcal Infections / Q000382:microbiology* / Q000473:pathology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D005578:Fosfomycin; D008345:Manganese; D017830:Octoxynol; D017346:Protein Serine-Threonine Kinases