Post-transcriptional regulation of bacterial motility by aconitase proteins.
Escherichia coli and Bacillus subtilis aconitases can act as iron and oxidative stress-responsive post-transcriptional regulators. Here, it is shown that a Salmonella enterica serovar Typhimurium LT2 acnB mutant exhibits impaired binding to the surface of J774 macrophage-like cells. Proteomic analyses were used to investigate further the binding defect of the acnB mutant. These revealed that the levels of the flagellum protein FliC were much lower for the acnB mutant. This strain was correspondingly less motile and possessed fewer flagella than either the parental strain or the acnA and acnAB mutants. The acnB lesion did not alter fliC transcription, nor did apo-AcnB select the fliC transcript from a library of S. enterica transcripts; thus, the effect of AcnB on FliC is indirect. Evidence is presented to show that apo-AcnB regulates FliC synthesis via interaction with the ftsH transcript to decrease the intracellular levels of FtsH. The lower levels of FtsH protease activity then influence sigma32, DnaK and, ultimately, FliC production.
Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
Yue
Y
Tang
John R
JR
Guest
Peter J
PJ
Artymiuk
Robert C
RC
Read
Jeffrey
J
Green
D049069:ATP-Dependent Proteases; D000154:Aconitate Hydratase / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D002460:Cell Line; D029968:Escherichia coli Proteins; D005408:Flagellin / Q000096:biosynthesis / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008264:Macrophages / Q000382:microbiology / Q000648:ultrastructure; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology; D051379:Mice; D008854:Microscopy, Electron; D009068:Movement; D009154:Mutation; D014176:Protein Biosynthesis / Q000502:physiology; D020543:Proteome; D012323:RNA Processing, Post-Transcriptional; D012486:Salmonella typhimurium / Q000201:enzymology / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D020543:Proteome; D005408:Flagellin; D049069:ATP-Dependent Proteases; C513383:FtsH protein, E coli; D000154:Aconitate Hydratase