Sigma L Is Important for Cold Shock Adaptation of
            <i>Bacillus subtilis</i>

Wiegeshoff, Frank; Beckering, Carsten L.; Débarbouillé, Michel; Marahiel, Mohamed A.

doi:10.1128/jb.188.8.3130-3133.2006

Cited by 37 publications

(34 citation statements)

References 21 publications

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“…COLD-AND PRESSURE-SENSITIVE GENES IN P. PROFUNDUM 1701 (46), and by gene regulation through the activity of alternative sigma factors (74,94). The expression of genes required for low-temperature growth in SS9 could be modulated by specific regulators, such as the PBPRB2014 protein (strain FL1), a transcriptional regulator of the LuxR family, and the PBPRB1757 protein (strain FL21), a hypothetical protein with a response regulator receiver domain (pfam00072) and a partial domain of a signal transduction histidine kinase (COG0642), suggesting its possible role as a hybrid two-component system.…”

Section: Vol 190 2008mentioning

confidence: 99%

Large-Scale Transposon Mutagenesis ofPhotobacterium profundumSS9 Reveals New Genetic Loci Important for Growth at Low Temperature and High Pressure

et al. 2008

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Microorganisms adapted to piezopsychrophilic growth dominate the majority of the biosphere that is at relatively constant low temperatures and high pressures, but the genetic bases for the adaptations are largely unknown. Here we report the use of transposon mutagenesis with the deep-sea bacterium Photobacterium profundum strain SS9 to isolate dozens of mutant strains whose growth is impaired at low temperature and/or whose growth is altered as a function of hydrostatic pressure. In many cases the gene mutation-growth phenotype relationship was verified by complementation analysis. The largest fraction of loci associated with temperature sensitivity were involved in the biosynthesis of the cell envelope, in particular the biosynthesis of extracellular polysaccharide. The largest fraction of loci associated with pressure sensitivity were involved in chromosomal structure and function. Genes for ribosome assembly and function were found to be important for both low-temperature and high-pressure growth. Likewise, both adaptation to temperature and adaptation to pressure were affected by mutations in a number of sensory and regulatory loci, suggesting the importance of signal transduction mechanisms in adaptation to either physical parameter. These analyses were the first global analyses of genes conditionally required for low-temperature or high-pressure growth in a deep-sea microorganism.

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Section: Vol 190 2008mentioning

confidence: 99%

Large-Scale Transposon Mutagenesis ofPhotobacterium profundumSS9 Reveals New Genetic Loci Important for Growth at Low Temperature and High Pressure

et al. 2008

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“…Seven genes that code for the enzymes involved in the deamination of Ile and Val, and in the oxidative decarboxylation of branched-chain alpha-keto acids, are organized in an operon called bkd (10) that was shown to be induced by the presence of Ile and Val in the cultivation medium and also by a downshift in temperature (14). The induction is dependent on the alternative sigma factor SigL (29). The initial condensation step of FA synthesis is catalyzed by the FabH enzyme, which prefers branched-chain substrates to straight-chain ones.…”

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confidence: 99%

Differences in Cold Adaptation of Bacillus subtilis under Anaerobic and Aerobic Conditions

et al. 2010

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Bacillus subtilis, which grows under aerobic conditions, employs fatty acid desaturase (Des) to fluidize its membrane when subjected to temperature downshift. Des requires molecular oxygen for its activity, and its expression is regulated by DesK-DesR, a two-component system. Transcription of des is induced by the temperature downshift and is decreased when membrane fluidity is restored. B. subtilis is also capable of anaerobic growth by nitrate or nitrite respiration. We studied the mechanism of cold adaptation in B. subtilis under anaerobic conditions that were predicted to inhibit Des activity. We found that in anaerobiosis, in contrast to aerobic growth, the induction of des expression after temperature downshift (from 37°C to 25°C) was not downregulated. However, the transfer from anaerobic to aerobic conditions rapidly restored the downregulation. Under both aerobic and anaerobic conditions, the induction of des expression was substantially reduced by the addition of external fluidizing oleic acid and was fully dependent on the DesK-DesR twocomponent regulatory system. Fatty acid analysis proved that there was no desaturation after des induction under anaerobic conditions despite the presence of high levels of the des protein product, which was shown by immunoblot analysis. The cold adaptation of B. subtilis in anaerobiosis is therefore mediated exclusively by the increased anteiso/iso ratio of branched-chain fatty acids and not by the temporarily increased level of unsaturated fatty acids that is typical under aerobic conditions. The degrees of membrane fluidization, as measured by diphenylhexatriene fluorescence anisotropy, were found to be similar under both aerobic and anaerobic conditions.Bacterial growth requires an appreciable fraction of the acyl chains of the membrane lipids to be in a disordered state. Such disordered states are brought about by fatty acids that act to offset the closely packed ordered arrangement of the lipid bilayer acyl chains that are imparted by the straight-chain saturated acyl chains. In most bacteria, the role of introducing acyl chain disorder is fulfilled by unsaturated fatty acids. Some bacteria synthesize UFAs by the process of desaturation, an oxygen-requiring reaction that introduces the double bond into a single concerted reaction. However, this is not an option for bacteria that grow under anaerobic conditions. For example, in the upper layers of soil, which are the natural habitat of Bacillus subtilis, the fluctuations in oxygen availability that are mostly caused by the changing water content are common.Even though B. subtilis is still generally considered to be an obligate aerobe, several recent studies have proved that this bacterium is in fact a facultative anaerobe, which is capable of both fermentation and anaerobic respiration with either nitrate or nitrite used as the terminal electron acceptor (19,20). The key role in the complex regulation of anaerobic metabolism of B. subtilis can be attributed to the genes resD and resE (21, 26) and fnr (23).A decreas...

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“…The role of Sigma 54 in cold shock survival of B. subtilis has been linked previously to synthesis of branched chain fatty acids which can be formed by degradation of branched amino acids, such as isoleucine (Wiegeshoff et al 2006). Enzymes encoded by the bkd operon are involved in this conversion.…”

Section: Transcriptome Responses Linked To Phenotypes and Prediction mentioning

confidence: 99%

“…In L. plantarum only the mannose PTS system is directly regulated by Sigma 54, which also imports glucose in low amounts and influences carbohydrate metabolism (Stevens et al 2010). Other functionalities reported for Sigma 54 are flagellar biosynthesis and motility (Cases et al 2003, Jones et al 2007, Mattila et al 2012), virulence (Hendrickson et al 2000, Ancona et al 2013, Hao et al 2013, biofilm formation and colonisation (Jones et al 2007, Iyer and Hancock 2012, Hao et al 2013, antibiotic resistance (Jones et al 2007), stress resistance (Hwang et al 2011) and cold shock adaptation (Wiegeshoff et al 2006). …”

Section: Sigma Factor 54 Functionmentioning

confidence: 99%

“…The role of Sigma 54 becomes important in suboptimal environments, for example under nutrient limitation (Reitzer and Schneider 2001), cold temperature or anaerobic conditions (Wiegeshoff et al 2006)(Chapter 5). Sigma 54 may also play a role in regulation of virulence since it influences the expression of the virulence regulator PlcR (Chapter 5).…”

Section: Adaptation Of B Cereus To Different Environmental Nichesmentioning

confidence: 99%

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Bacillus cereus growth and biofilm formation: the impact of substratum, iron sources, and transcriptional regulator Sigma 54

Hayrapetyan¹

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Sigma L Is Important for Cold Shock Adaptation of Bacillus subtilis

Cited by 37 publications

References 21 publications

Large-Scale Transposon Mutagenesis ofPhotobacterium profundumSS9 Reveals New Genetic Loci Important for Growth at Low Temperature and High Pressure

Large-Scale Transposon Mutagenesis ofPhotobacterium profundumSS9 Reveals New Genetic Loci Important for Growth at Low Temperature and High Pressure

Differences in Cold Adaptation of Bacillus subtilis under Anaerobic and Aerobic Conditions

Bacillus cereus growth and biofilm formation: the impact of substratum, iron sources, and transcriptional regulator Sigma 54

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