title: Regulated shift from helical to polar localization of Listeria monocytogenes cell wall-anchored proteins.
abstract: Many virulence factors of Gram-positive bacterial pathogens are covalently anchored to the peptidoglycan (PG) by sortase enzymes. However, for rod-shaped bacteria little is known about the spatiotemporal organization of these surface proteins in the cell wall. Here we report the three-dimensional (3D) localization of the PG-bound virulence factors InlA, InlH, InlJ, and SvpA in the envelope of Listeria monocytogenes under different growth conditions. We found that all PG-anchored proteins are positioned along the lateral cell wall in nonoverlapping helices. However, these surface proteins can also become localized at the pole and asymmetrically distributed when specific regulatory pathways are activated. InlA and InlJ are enriched at poles when expressed at high levels in exponential-phase bacteria. InlA and InlH, which are σ(B)dependent, specifically relocalize to the septal cell wall and subsequently to the new pole in cells entering stationary phase. The accumulation of InlA and InlH in the septal region also occurs when oxidative stress impairs bacterial growth. In contrast, the iron-dependent protein SvpA is present at the old pole and is excluded from the septum and new pole of bacteria grown under low-iron conditions. We conclude that L. monocytogenes rapidly reorganizes the spatial localization of its PG proteins in response to changes in environmental conditions such as nutrient deprivation or other stresses. This dynamic control would distribute virulence factors at specific sites during the infectious process.
authors: Institut Pasteur, Unité des Interactions Bactéries Cellules, Paris F-75015, France.
authors: Serawit
authors: S
authors: Bruck
authors: Nicolas
authors: N
authors: Personnic
authors: Marie-Christine
authors: MC
authors: Prevost
authors: Pascale
authors: P
authors: Cossart
authors: Hélène
authors: H
authors: Bierne
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D015151:Immunoblotting; D008089:Listeria monocytogenes / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008968:Molecular Conformation; D018384:Oxidative Stress; D010457:Peptidoglycan / Q000378:metabolism*; D037521:Virulence Factors / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D010457:Peptidoglycan; D037521:Virulence Factors