title: Polar positional information in Escherichia coli spherical cells.
abstract: Shigella surface protein IcsA and its cytoplasmic derivatives are localized to the old pole of rod-shaped cells when expressed in Escherichia coli. In spherical mreB cells, IcsA is targeted to ectopic sites and close to one extremity of actin-like MamK filament. To gain insight into the properties of the sites containing polar material, we studied the IcsA localization in spherical cells. GFP was exported into the periplasm via the Tat pathway and used as a periplasmic space marker. GFP displayed zonal fluorescence in both mreB and rodA-pbpA spherical E. coli cells, indicating an uneven periplasmic space. Deconvolution images revealed that the cytoplasmic IcsA fused to mCherry was localized outside or at the edge of the GFP zones. These observations strongly suggest that polar material is restricted to the positions where the periplasm possesses particular structural or biochemical properties.
authors.affiliation: Laboratoire de Chimie Bactérienne, UPR9043, Institut de Biologie Structurale et Microbiologie, CNRS, 31 chemin Joseph Aiguier, F-13402 Marseille cedex 20, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Pradel
authors.forename: Claire-Lise
authors.initials: CL
authors.lastname: Santini
authors.forename: Alain
authors.initials: A
authors.lastname: Bernadac
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Shih
authors.forename: Marcia B
authors.initials: MB
authors.lastname: Goldberg
authors.forename: Long-Fei
authors.initials: LF
authors.lastname: Wu
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D016764:Cell Polarity / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000166:cytology* / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D014157:Transcription Factors; C058483:virG protein, Shigella flexneri; C061683:mrdB protein, E coli; C078473:MreB protein, E coli