State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, 100071 Beijing, China.
J Proteome Res. 2010 Feb 5;9(2):843-54. doi: 10.1021/pr9007514.
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.
福氏志贺菌是一种重要的人类病原体，可引起痢疾，仍然对公共卫生构成重大威胁，尤其是在发展中国家。该病原体的毒力依赖于获得性毒力质粒。为了研究细菌染色体与外源毒力质粒之间的串扰，使用质粒不相容性构建了一种毒力质粒消除株。使用 2-DE 结合 MALDI-TOF MS 分析了该菌株与野生型菌株的基因表达的全局模式。在 2-DE 凝胶中鉴定出了大多数已知的福氏志贺菌毒力因子。有趣的是，当毒力质粒不存在时，甘油 3-磷酸（glp）调控子编码蛋白的表达增加。微阵列分析证实了转录水平的调节。亲和纯化和鉴定具有 glp 基因调控区结合活性的 DNA 结合蛋白表明，毒力质粒介导的对 glp 调控子表达的调控可能反过来由蛋白 GlpR 介导。据我们所知，这是首次在蛋白质组水平上分析病原体染色体与毒力质粒之间的相互作用。
