title: Control of Listeria superoxide dismutase by phosphorylation.
abstract: Superoxide dismutases (SODs) are enzymes that protect organisms against superoxides and reactive oxygen species (ROS) produced during their active metabolism. ROS are major mediators of phagocytes microbicidal activity. Here we show that the cytoplasmic Listeria monocytogenes MnSOD is phosphorylated on serine and threonine residues and less active when bacteria reach the stationary phase. We also provide evidence that the most active nonphosphorylated form of MnSOD can be secreted via the SecA2 pathway in culture supernatants and in infected cells, where it becomes phosphorylated. A Deltasod deletion mutant is impaired in survival within macrophages and is dramatically attenuated in mice. Together, our results demonstrate that the capacity to counteract ROS is an essential component of L. monocytogenes virulence. This is the first example of a bacterial SOD post-translationally controlled by phosphorylation, suggesting a possible new host innate mechanism to counteract a virulence factor.
authors.affiliation: Institut Pasteur, Unité des Interactions Bactéries-Cellules, Inserm, U604, INRA, USC2020, F-75015 Paris, France.
authors.forename: Cristel
authors.initials: C
authors.lastname: Archambaud
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Nahori
authors.forename: Javier
authors.initials: J
authors.lastname: Pizarro-Cerda
authors.forename: Pascale
authors.initials: P
authors.lastname: Cossart
authors.forename: Olivier
authors.initials: O
authors.lastname: Dussurget
mesh_terms: D000818:Animals; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D008089:Listeria monocytogenes / Q000201:enzymology*; D008264:Macrophages / Q000201:enzymology / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D017382:Reactive Oxygen Species; D012694:Serine / Q000737:chemistry; D013482:Superoxide Dismutase / Q000737:chemistry* / Q000378:metabolism; D013912:Threonine / Q000737:chemistry
chemical_list: D017382:Reactive Oxygen Species; D013912:Threonine; D012694:Serine; D013482:Superoxide Dismutase