title: Subcellular localization, interactions and dynamics of the phage-shock protein-like Lia response in Bacillus subtilis.
abstract: The liaIH operon of Bacillus subtilis is the main target of the envelope stress-inducible two-component system LiaRS. Here, we studied the localization, interaction and cellular dynamics of Lia proteins to gain insights into the physiological role of the Lia response. We demonstrate that LiaI serves as the membrane anchor for the phage-shock protein A homologue LiaH. Under non-inducing conditions, LiaI locates in highly motile membrane-associated foci, while LiaH is dispersed throughout the cytoplasm. Under stress conditions, both proteins are strongly induced and colocalize in numerous distinct static spots at the cytoplasmic membrane. This behaviour is independent of MreB and does also not correlate with the stalling of the cell wall biosynthesis machinery upon antibiotic inhibition. It can be induced by antibiotics that interfere with the membrane-anchored steps of cell wall biosynthesis, while compounds that inhibit the cytoplasmic or extracytoplasmic steps do not trigger this response. Taken together, our data are consistent with a model in which the Lia system scans the cytoplasmic membrane for envelope perturbations. Upon their detection, LiaS activates the cognate response regulator LiaR, which in turn strongly induces the liaIH operon. Simultaneously, LiaI recruits LiaH to the membrane, presumably to protect the envelope and counteract the antibiotic-induced damage.
authors.affiliation: Max Planck Institute of Biochemistry, AG Cellular Dynamics and Cell Patterning, Martinsried, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Domínguez-Escobar
authors.forename: Diana
authors.initials: D
authors.lastname: Wolf
authors.forename: Georg
authors.initials: G
authors.lastname: Fritz
authors.forename: Carolin
authors.initials: C
authors.lastname: Höfler
authors.forename: Roland
authors.initials: R
authors.lastname: Wedlich-Söldner
authors.forename: Thorsten
authors.initials: T
authors.lastname: Mascher
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism; D001412:Bacillus subtilis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D011485:Protein Binding; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; C069816:phage shock protein, Bacteria