FIS and Nucleoid Dynamics upon Exit from Lag Phase

Muskhelishvili, Georgi; Travers, Andrew

doi:10.1007/978-90-481-3473-1_14

Cited by 3 publications

(3 citation statements)

References 162 publications

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“…Unlike the inducible lac promoter, fis promoter activity is exquisitely sensitive to changes of DNA supercoiling, due in part to the GC-rich discriminator sequence between the −10 hexamer and the transcription start site ( 45 ), which mediates the growth phase- and growth rate-dependent control ( 26 , 28 ). This sensitivity to supercoiling might also be related to the observations that the fis promoter region, highly conserved in all pathogenic E. coli and Shigella strains, is characterized by strong intrinsic curvature ( 46 ), is regulated by a higher-order RNA polymerase complex involved in sensing the topological state of DNA ( 41 , 44 ) and appears evolutionarily streamlined to act as a topological switch ( 47 , 48 ). Some or all of these differences could contribute to disparate effects exerted by the insertions of lac and fis promoter constructs on their immediate surroundings.…”

Section: Discussionmentioning

confidence: 92%

Chromosomal position shift of a regulatory gene alters the bacterial phenotype

et al. 2015

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Recent studies strongly suggest that in bacterial cells the order of genes along the chromosomal origin-to-terminus axis is determinative for regulation of the growth phase-dependent gene expression. The prediction from this observation is that positional displacement of pleiotropic genes will affect the genetic regulation and hence, the cellular phenotype. To test this prediction we inserted the origin-proximal dusB-fis operon encoding the global regulator FIS in the vicinity of replication terminus on both arms of the Escherichia coli chromosome. We found that the lower fis gene dosage in the strains with terminus-proximal dusB-fis operons was compensated by increased fis expression such that the intracellular concentration of FIS was homeostatically adjusted. Nevertheless, despite unchanged FIS levels the positional displacement of dusB-fis impaired the competitive growth fitness of cells and altered the state of the overarching network regulating DNA topology, as well as the cellular response to environmental stress, hazardous substances and antibiotics. Our finding that the chromosomal repositioning of a regulatory gene can determine the cellular phenotype unveils an important yet unexplored facet of the genetic control mechanisms and paves the way for novel approaches to manipulate bacterial physiology.

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Section: Discussionmentioning

confidence: 92%

Chromosomal position shift of a regulatory gene alters the bacterial phenotype

et al. 2015

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“…They also provide mechanisms for regulation of gene expression and recombination by modulating local DNA configurations. As there are several recent reviews on these small NAPs 27,32,34,39,114,122–124 , this review highlights other aspects of the “histone-like” proteins relevant to their role in nucleoid organization.…”

Section: The Nucleoidmentioning

confidence: 98%

Role of RNA Polymerase and Transcription in the Organization of the Bacterial Nucleoid

2013

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Nucleoid Expansion in RNAP Mutants Defective in rRNA Synthesis in Nutrient-Rich LB 8673 3.7.3. Lacking Transcription Foci and Expanded Nucleoid in Δ6rrn Mutant Cells 8674 3.7.4. Apparent Transcription Foci and Nucleoid Compaction in the "Relaxed" relA Mutant Cells during Amino Acid Starvation 8674 3.7.5. Evident Transcription Foci and Nucleoid Compaction in Cells Treated with Protein Synthesis Inhibitors 8674 3.8. Transcribing RNAP Locates at the Surface of the Nucleoid 8674 3.8.1. Transcription Foci Appear to Position at the Voids of the Nucleoid 8675 3.8.2. DNA Loops Enriched with RNAP Locate at the Periphery of the Nucleoid 8675 3.8.3. Non-Transcribing RNAP Scatters across the Nucleoid 8675 4. Model: Transcription Foci Condense the Nucleoid 8675 5. Conclusion and Perspectives 8677 Author Information 8677 Corresponding Author 8677 Notes 8677 Biographies 8677 Acknowledgments 8678 References 8678

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“…coli and Salmonella enterica serovar Typhimurium) display some similarities in size, DNA-binding characteristics (each contains one helix-turn-helix motif, located in the C terminus of the protein), growth cycle-dependent patterns of expression, and control over the expression of a range of operons (25). Fis is involved in the end of the lag phase (46). The accumulation in B.…”

Section: Discussionmentioning

confidence: 99%

Bacillus cereus cshA Is Expressed during the Lag Phase of Growth and Serves as a Potential Marker of Early Adaptation to Low Temperature and pH

Français

Carlin

Broussolle

et al. 2019

Appl Environ Microbiol

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Bacterial adaptation is characterized by a lag phase during which cells do not multiply or modify their physiology to cope with the constraints of their environment. Our aim was to determine a sequence of events during the lag phase of growth at low temperature and pH for three Bacillus cereus strains. The onsets of expression of two genes, one of which is essential for stress adaptation (cshA, coding for a RNA helicase) and one of which is involved in the transition between lag phase and exponential phase (abrB, coding for a transition regulator), were determined using fluorescent transcriptional reporter systems. Regardless of the stressing conditions and the tested strains, the cshA promoter was active very early, while the biomass increased and always did so before the first cell division. At 12°C and pH 7.0, the onset of cshA promoter activity occurred at between 3 h and 7 h, while the bacterial counts started to increase at between 12 h and 13 h. At pH 5.0 and at 20°C or 30°C, the onset of cshA promoter activity occurred before 1 h and earlier than at pH 7.0. In contrast, the onset of abrB promoter activity depended on the strain and the stressing conditions. In the ATCC 14579 strain, the onset of abrB promoter activity always started at between 30 min and 3 h, before biomass increased and cell division occurred. For the other strains, it took place along with the first cell division at 12°C but did so much later during growth under the other tested conditions. IMPORTANCE The spore-forming bacterium B. cereus is a major cause of foodborne outbreaks in Europe. Some B. cereus strains can grow at low temperatures and low pH in many processed foods. Modeling of the bacterial lag time is hampered by a lack of knowledge of the timing of events occurring during this phase. In this context, the identification of lag phase markers, not currently available, could be a real advance for the better prediction of lag time duration. Currently, no molecular markers of this phase are available. By determining that cshA was always expressed early during the lag phase, we provide a molecular marker of the early adaptation process of B. cereus cells when exposed to low temperature and pH.

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FIS and Nucleoid Dynamics upon Exit from Lag Phase

Cited by 3 publications

References 162 publications

Chromosomal position shift of a regulatory gene alters the bacterial phenotype

Chromosomal position shift of a regulatory gene alters the bacterial phenotype

Role of RNA Polymerase and Transcription in the Organization of the Bacterial Nucleoid

Bacillus cereus cshA Is Expressed during the Lag Phase of Growth and Serves as a Potential Marker of Early Adaptation to Low Temperature and pH

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