title: DegU-phosphate activates expression of the anti-sigma factor FlgM in Bacillus subtilis.
abstract: The bacterial flagellum is a complex molecular machine that is assembled by more than 30 proteins and is rotated to propel cells either through liquids or over solid surfaces. Flagellar gene expression is extensively regulated to co-ordinate flagellar assembly in both space and time. In Bacillus subtilis, the proteins of unknown function, SwrA and SwrB, and the alternative sigma factor σ(D) are required to activate expression of the flagellar filament protein, flagellin. Here we determine that in the absence of SwrA and SwrB, the phosphorylated form of the response regulator DegU inhibits σ(D) -dependent gene expression indirectly by binding to the P(flgM) promoter region and activating expression of the anti-sigma factor FlgM. We further demonstrate that DegU-P-dependent activation of FlgM is essential to inhibit flagellin expression when flagellar basal body assembly is disrupted. Regulation of FlgM is poorly understood outside of Salmonella, and differential control of FlgM expression may be a common means of coupling flagellin expression to flagellar assembly.
authors: Department of Biology, Indiana University, 1001 East Third Street, Bloomington, IN 47405, USA.
authors: Yi-Huang
authors: YH
authors: Hsueh
authors: Loralyn M
authors: LM
authors: Cozy
authors: Lok-To
authors: LT
authors: Sham
authors: Rebecca A
authors: RA
authors: Calvo
authors: Alina D
authors: AD
authors: Gutu
authors: Malcolm E
authors: ME
authors: Winkler
authors: Daniel B
authors: DB
authors: Kearns
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D023061:Gene Order; D008969:Molecular Sequence Data; D010710:Phosphates / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012808:Sigma Factor
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; C066497:DegU protein, Bacteria; D010710:Phosphates; D012808:Sigma Factor; C071266:FlgM protein, Bacteria