title: Filament formation of Salmonella Paratyphi A accompanied by FtsZ assembly impairment and low level ppGpp.
abstract: Previously, we reported that Salmonella enterica serovar Paratyphi A strain S602 grew into multinuclear, nonseptate, and nonlethal filaments on agar plates containing nitrogenous salts. Strain S602 was more sensitive to osmotic and oxidative stress than the reference strain 3P243 of nonfilamentous Salmonella Paratyphi A. Strain S602 had an amber mutation (C154T) in rpoS. The revertant of this mutant, SR603, was repressed to form filaments under conditions with abundant nitrogenous salts. However, 3PR244, an rpoS mutant of 3P243 (C154T), did not form filaments, which implies that the rpoS mutation is not the sole cause of filamentation in strain S602. Next, we examined whether the level of guanosine 5'-diphosphate 3'-diphosphate (ppGpp) in S602 strain is involved in filament formation. The intracellular ppGpp level in filamentous cells was lower than that in nonfilamentous cells. Furthermore, cells belonging to strain RE606, a derivative of S602 where the intracellular concentration of ppGpp was increased by overexpression of the relA gene, exhibited normal Z-ring formation and cell division. In the S602 strain, the decrease in the ppGpp level induced by the presence of nitrogenous salt and the rpoS mutation led to the inhibition of Z-ring formation and the subsequent filamentation of cells.
authors.affiliation: a Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: a Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Ken-Ichiro
authors.initials: K
authors.lastname: Iida
authors.affiliation: b Department of Oral Health, Growth, and Development, Division of Oral Infectious Diseases and Immunology, Faculty of Dental Science, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Shiota
authors.affiliation: a Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakayama
authors.affiliation: a Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Yoshida
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D006159:Guanosine Tetraphosphate / Q000378:metabolism; D009154:Mutation; D012482:Salmonella paratyphi A / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D006159:Guanosine Tetraphosphate
keywords: FtsZ assembly; assemblage de FtsZ; cell division; division cellulaire; ppGpp; rpoS