title: Global analysis of a plasmid-cured Shigella flexneri strain: new insights into the interaction between the chromosome and a virulence plasmid.
abstract: Shigella flexneri is an important human pathogen that causes dysentery, and remains a significant threat to public health, particularly in developing countries. The virulence of this pathogen is dependent on an acquired virulence plasmid. To investigate the crosstalk between the bacterial chromosome and the exogenous virulence plasmid, a virulence plasmid-cured strain was constructed using plasmid incompatibility. The global patterns of gene expression of this strain compared with the wild-type strain were analyzed using 2-DE combined with MALDI-TOF MS. Most known virulence factors of S. flexneri were identified in the 2-DE gels. Interestingly, the expression of the glycerol 3-phosphate (glp) regulon-encoded proteins was increased when the virulence plasmid was absent. Microarray analysis confirmed that regulation occurred at the transcriptional level. Purification and identification of DNA binding proteins with affinity for the regulatory region of the glp genes revealed that regulation mediated by the virulence plasmid to control the expression of the glp regulon might in turn be mediated by protein GlpR. To our knowledge, this is the first study analyzing the interaction between a pathogen chromosome and a virulence plasmid at the proteomic level.
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, 100071 Beijing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.forename: Xiankai
authors.initials: X
authors.lastname: Liu
authors.forename: Xuexue
authors.initials: X
authors.lastname: Zheng
authors.forename: Xin
authors.initials: X
authors.lastname: Bu
authors.forename: Ge
authors.initials: G
authors.lastname: Zhao
authors.forename: Chaohua
authors.initials: C
authors.lastname: Xie
authors.forename: Jingfei
authors.initials: J
authors.lastname: Zhang
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Erling
authors.initials: E
authors.lastname: Feng
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Jiang
authors.forename: Peitang
authors.initials: P
authors.lastname: Huang
authors.forename: Hengliang
authors.initials: H
authors.lastname: Wang
mesh_terms: D002876:Chromosomes, Bacterial; D015180:Electrophoresis, Gel, Two-Dimensional; D010957:Plasmids; D012763:Shigella flexneri / Q000235:genetics* / Q000472:pathogenicity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014774:Virulence