title: Altered proteome in Burkholderia pseudomallei rpoE operon knockout mutant: insights into mechanisms of rpoE operon in stress tolerance, survival, and virulence.
abstract: We have previously shown that the alternative sigma factor sigmaE (RpoE), encoded by rpoE, is involved in stress tolerance and survival of Burkholderia pseudomallei. However, its molecular and pathogenic mechanisms remain unclear. In the present study, we applied gel-based, differential proteomics to compare the cellular proteome of an rpoE operon knockout mutant (RpoE Mut) to that of wild-type (K96243 WT) B. pseudomallei. Quantitative intensity analysis (n = 5 gels from 5 individual culture flasks in each group) revealed significantly differential expression of 52 proteins, which were subsequently identified by Q-TOF MS/MS. These included oxidative, osmotic, and other stress response proteins; chaperones; transcriptional/translational regulators; metabolic enzymes; proteins involved in cell wall synthesis, fatty synthesis, glycogen synthesis, and storage; exported proteins; secreted proteins; adhesion molecule; protease/peptidase; protease inhibitor; signaling proteins; and other miscellaneous proteins. The down-regulation of several stress response proteins, chaperones, transcriptional/translational regulators, and proteins involved in cell wall synthesis in RpoE Mut provided some new insights into the mechanisms of the rpoE operon for the stress tolerance and survival of B. pseudomallei. In addition, the proteomic data and in vivo study indicated that the rpoE operon is also involved in the virulence of B. pseudomallei. Our findings underscore the usefulness of proteomics for unraveling pathogenic mechanisms of diseases at the molecular level.
authors.affiliation: Medical Molecular Biology Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. thongboonkerd@dr.com
authors.forename: Visith
authors.initials: V
authors.lastname: Thongboonkerd
authors.forename: Muthita
authors.initials: M
authors.lastname: Vanaporn
authors.forename: Napat
authors.initials: N
authors.lastname: Songtawee
authors.forename: Rattiyaporn
authors.initials: R
authors.lastname: Kanlaya
authors.forename: Supachok
authors.initials: S
authors.lastname: Sinchaikul
authors.forename: Shui-Tein
authors.initials: ST
authors.lastname: Chen
authors.forename: Anna
authors.initials: A
authors.lastname: Easton
authors.forename: Karen
authors.initials: K
authors.lastname: Chu
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Bancroft
authors.forename: Sunee
authors.initials: S
authors.lastname: Korbsrisate
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000378:metabolism*; D016957:Burkholderia pseudomallei / Q000378:metabolism / Q000472:pathogenicity*; D009154:Mutation; D009876:Operon / Q000235:genetics / Q000502:physiology*; D009997:Osmotic Pressure; D018384:Oxidative Stress / Q000235:genetics; D020543:Proteome / Q000032:analysis / Q000378:metabolism*; D012808:Sigma Factor / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D020543:Proteome; D012808:Sigma Factor; D014157:Transcription Factors; C063202:sporulation-specific sigma factors