Changes in DNA supertwist as a response of Bacillus subtilis towards different kinds of stress

Krispin, Oliver

doi:10.1016/0378-1097(95)00386-7

Cited by 27 publications

(28 citation statements)

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“…Interestingly, an increase in plasmid Lk has also been reported in E. coli and B. subtilis during a heat shock, despite the substantially different topoisomerase systems of hyperthermophilic archaea and mesophilic bacteria (Mizushima ef a/., 1993;Krispin and Allmansberger, 1995).…”

Section: Discussionmentioning

confidence: 97%

DNA topology in hyperthermophilic archaea: reference states and their variation with growth phase, growth temperature, and temperature stresses

López‐García¹,

Forterre²

1997

Molecular Microbiology

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SummaryIn order to address the dynamics of DNA topology in hyperthermophilic archaea, we analysed the topological state of several plasmids recently discovered in Thermococcales and Sulfolobales. All of these plasmids were from relaxed to highly positively supercoiled in wifro, i.e. they exhibited a significant linking excess compared to the negatively supercoiled plasmids from mesophilic organisms (both Archaea and Bacteria). In the two archaeal orders, plasmid linking number (Lk) decreased as growth temperature was lowered from its optimal value, i.e. positively supercoiled plasmids were relaxed whereas relaxed plasmids became negatively supercoiled. Growth temperatures above the optimum correlated with higher positive supercoiling in Sulfolobales (Lk increase) but with relaxation of positive supercoils in Thermucoccus sp. GE31. The topological variation of plasmid DNA isolated from cells at different growth phases were found to be species specific in both archaeal orders. In contrast, the direction of topological variation under temperature stress was the same, i.e. a heat shock correlated with an increase in plasmid positive supercoiling, whilst a cold shock induced negative supercoiling. The kinetics of these effects were analysed in Sulfolobales. In both temperature upshift (from 80 to 85°C) and downshift (from 80 to 65"C), a transient sharp variation of Lk occurred first, and then DNA supercoiling progressively reached levels typical of steady-state growth at the final temperature. These results indicate that DNA topology can change with physiological states and environmental modifications in hyperthermophilic archaea.

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Section: Discussionmentioning

confidence: 97%

DNA topology in hyperthermophilic archaea: reference states and their variation with growth phase, growth temperature, and temperature stresses

López‐García¹,

Forterre²

1997

Molecular Microbiology

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“…However, our present results show that the gyrA and gyrB genes encoding DNA gyrase were twofold induced, whereas the topA gene encoding DNA topoisomerase I was twofold repressed. This antagonistic regulation likely results in the previously observed negative supercoil of DNA after cold shock (22).…”

Section: Translation Machinerymentioning

confidence: 89%

Genomewide Transcriptional Analysis of the Cold Shock Response in Bacillus subtilis

et al. 2002

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Previous studies with two-dimensional gel electrophoresis techniques revealed that the cold shock response in Bacillus subtilis is characterized by rapid induction and accumulation of two classes of specific proteins, which have been termed cold-induced proteins (CIPs) and cold acclimatization proteins (CAPs), respectively. Only recently, the B. subtilis two-component system encoded by the desKR operon has been demonstrated to be essential for the cold-induced expression of the lipid-modifying desaturase Des, which is required for efficient cold adaptation of the membrane in the absence of isoleucine. At present, one of the most intriguing questions in this research field is whether DesKR plays a global role in cold signal perception and transduction in B. subtilis. In this report, we present the first genomewide transcriptional analysis of a cold-exposed bacterium and demonstrate that the B. subtilis two-component system DesKR exclusively controls the desaturase gene des and is not the cold-triggered regulatory system of global relevance. In addition to this, we identified a set of genes that might participate as novel players in the cold shock adaptation of B. subtilis. Two cold-induced genes, the elongation factor homolog ylaG and the L -dependent transcriptional activator homolog yplP, have been examined by construction and analysis of deletion mutants.Free-living prokaryotic organisms have the capacity to react rapidly to fluctuations of growth temperature. These responses are regulated at transcriptional and posttranscriptional levels and have been extensively characterized for heat shock, but only partially characterized for cold shock. In recent years, Bacillus subtilis has become a model organism for studies of the bacterial cold shock response representing the gram-positive branch of mesophilic soil bacteria (14).Many reports have dealt with the function of the cold shock proteins (CSPs), a widespread protein family representing a model for the nucleic acid binding cold-shock domain (CSD). The CSD is highly conserved from bacteria to humans (15,39,40) and is involved in coupling transcription to translation (36). Only recently the CSDBase database was established (http: //www.chemie.uni-marburg.de/ϳcsdbase), which includes detailed information about the CSD (37). This protein family has been identified in almost all psychrotrophic, mesophilic, thermophilic, and hyperthermophilic bacteria examined so far, and their presence in Thermotoga and Aquifex indicates an ancient origin (15). In B. subtilis, csp double-deletion strains show a variety of phenotypes, such as altered protein synthesis, aberrant nucleoid structure, cell lysis upon entry into the stationary growth phase, and impairment in sporulation (13, 39). The latter two defects were shown to be cured by heterologous expression of translation initiation factor IF1 from Escherichia coli (36).Other investigations have revealed how B. subtilis prevents rigidification of the membrane at low temperatures. The fluidity of the membrane is maintained by i...

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“…DNA supercoiling is used as a sensor for environmental changes for many pathogenic and nonpathogenic organisms (4,20,28,31,37). Raising the culture's temperature can induce a reduction in DNA twists, while changing to a lower temperature may increase the number of DNA twists (28,37).…”

Section: Discussionmentioning

confidence: 99%

“…For that purpose, DNA from bacteria grown at 23°C and from those grown at 34°C was purified and analyzed by electrophoresis in chloroquine-agarose gels followed by Southern blotting. Different concentrations of chloroquine, a DNA intercalator, were added to each gel, as this unwinds the double helix and slows down the migration of negatively supercoiled circular DNA (4,20,31,37,39). Neither the cp32-1-specific probe 1 nor the generic cp32-labeling probe 2 detected any differences in the migration pattern of supercoiled plasmid DNA extracted from cultures grown at 23°C or from cultures shifted from 23 to 34°C (Fig.…”

Section: Coexpression Of Erp Proteinsmentioning

confidence: 98%

Simultaneous Coexpression ofBorrelia burgdorferiErp Proteins Occurs through a Specific,erpLocus-Directed Regulatory Mechanism

El‐Hage

Stevenson

2002

J Bacteriol

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An individual Borrelia burgdorferi bacterium can encode as many as 13 different Erp (OspE/F-related) proteins from mono-and bicistronic loci that are carried on up to 10 separate plasmids. We demonstrate through multilabel immunofluorescence analyses that individual bacteria simultaneously coexpress their entire Erp protein repertoire. While it has been proposed that B. burgdorferi controls expression of Erp and other plasmid-encoded proteins through changes in DNA topology, we observed regulated Erp expression in the absence of detectable differences in DNA supercoiling. Likewise, inhibition of DNA gyrase had no detectable effect on Erp expression. Furthermore, expression of loci physically adjacent to erp loci was observed to be independently regulated. It is concluded that Erp expression is regulated by a mechanism(s) directed at erp loci and not by a global, plasmid-wide mechanism.

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Changes in DNA supertwist as a response of Bacillus subtilis towards different kinds of stress

Cited by 27 publications

References 0 publications

DNA topology in hyperthermophilic archaea: reference states and their variation with growth phase, growth temperature, and temperature stresses

DNA topology in hyperthermophilic archaea: reference states and their variation with growth phase, growth temperature, and temperature stresses

Genomewide Transcriptional Analysis of the Cold Shock Response in Bacillus subtilis

Simultaneous Coexpression ofBorrelia burgdorferiErp Proteins Occurs through a Specific,erpLocus-Directed Regulatory Mechanism

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