The regulation of genetic competence in <i>Bacillus subtilis</i>

Dubnau, David

doi:10.1111/j.1365-2958.1991.tb01820.x

Cited by 85 publications

(42 citation statements)

References 58 publications

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“…DNA transport is probably the Ca2+-In Bacillus subtilis it is proposed that competence is requiring step at the expression stage (Lacks & Green-induced in response to a variety of signals including berg, 1973;Set0 & Tomasz, 1974Lacks, 1977; growth stage and nutritional information (for a review, ClavC et al, ClavC & Trombe, 1989). Addition of see Dubnau, 1991). Culture-medium titrations showed C F to the medium did not change the Ca2+ dependence no variation in glucose and phosphate concentrations (Fig.…”

Section: Cf Activation Of Competence and Culture Lysismentioning

confidence: 99%

Calcium regulation of growth and differentiation in Streptococcus pneumoniae

Trombe

Clavé²,

Manias³

1992

Journal of General Microbiology

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Streptococcus pneumonk requires 0.15 mM-Ca2+ in the medium for optimal growth. Increasing the Ca2+ concentration to 1 mM triggers either a differentiathe state, competence for genetic transformation during exponential growth, or partial lysis as won as the cultures enter stationary phase. Genetic and physiological data both suggest that these responses are under the control of activator@), excreted in the presence of high Ca2+ concentrations. 45Ca2+ transport is also stimulated by the activator(s). The amiloride derivative 2',4-dimethylbenzarnil (DMB) inhibits 45Ca2+ transport and prevents lysis and competence development. This provides evidence in favour of the involvement of Ca2+ transport in competence and culture lysis. On the other hand, addition of DNA to a competent culture prevents lysis of wild-type bacteria while a mutant, defective for DNA uptake, is not protected from lysis by exogenous DNA. An hypothesis is proposed for competence induction as a global metabolic response to Ca2+, under the control of competence factor.

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Section: Cf Activation Of Competence and Culture Lysismentioning

confidence: 99%

Calcium regulation of growth and differentiation in Streptococcus pneumoniae

Trombe

Clavé²,

Manias³

1992

Journal of General Microbiology

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“…The AbrB protein acts as repressor during vegetative growth to prevent expression of stationary-phase-specific genes, including aprE, which encodes the major secreted alkaline protease known as subtilisin. However, AbrB can also activate gene transcription, for example of hpr and competence genes (Dubnau, 1991 ;Perego & Hoch, 1988). The sinI-sinR operon also contributes to the regulation of late-growth development in B. subtilis (Smith, 1993).…”

Section: Introductionmentioning

confidence: 99%

Identification of genes involved in the activation of the Bacillus thuringiensis inhA metalloprotease gene at the onset of sporulation The GenBank/EMBL/DDBJ accession number for the sequence reported in this paper is AF287346.

2001

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The immune inhibitor A (InhA) metalloprotease from Bacillus thuringiensis specifically cleaves antibacterial proteins produced by the insect host, suggesting that it may contribute to the overall virulence of B. thuringiensis. The transcriptional regulation of the inhA gene in both B. thuringiensis and Bacillus subtilis was investigated. Using a transcriptional inhA'-lacZ fusion, it was shown that inhA expression is activated at the onset of sporulation.However, the transcriptional start site of inhA is similar to σ A -dependent promoters, and deletion of the sporulation-specific sigma factors σ F or σ E had no effect on inhA expression in B. subtilis. The DNA region upstream from inhA contains two genes encoding polypeptides similar to the SinI and SinR regulators of B. subtilis. SinR is a DNA-binding protein regulating gene expression and SinI inhibits SinR activity. Overexpression of the sin genes affects the expression of the inhA'-lacZ transcriptional fusion in B. thuringiensis : early induction of inhA expression was observed when sinI was overexpressed, whereas inhA expression was reduced in a strain overexpressing sinR, suggesting that inhA transcription is repressed, directly or indirectly, by SinR. inhA transcription was greatly reduced in B. thuringiensis and B. subtilis spo0A mutants. Analysis of the inhA'-lacZ expression in abrB and abrB-spo0A mutants of B. subtilis indicates that the Spo0A-dependent regulation of inhA expression depends on AbrB, which is known to regulate expression of transition state and sporulation genes in B. subtilis.

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“…To determine whether any of the gene products known to alter gene expression during stationary growth phase also regulate hut expression, histidase expression was examined in strains containing mutations in the comA (9), comP (9), degUS (30), sin (28,32), pai (16), hpr (32), sigH (28), spoOA (28), spoOB (28) the autoradiogram showed that the relative levels of hutP RNA were 1 in T0.85 cells (Fig. 2, lane 1 Regulation ofhut expression by catabolite repression during stationary growth phase.…”

Section: Methodsmentioning

confidence: 99%

Activation of the Bacillus subtilis hut operon at the onset of stationary growth phase in nutrient sporulation medium results primarily from the relief of amino acid repression of histidine transport

1993

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During growth of Bacillus subtilis in nutrient sporulation medium containing histidine (DSM-His medium), the expression of histidase, the first enzyme in the histidine-degradative pathway (hut), is derepressed 40-to 200- When Bacillus subtilis cultures enter stationary growth phase in nutrient sporulation medium, the expression of gene products which allow the bacteria to adapt to their altered growth conditions is derepressed. Cells become motile, secrete a number of degradative enzymes, synthesize antibiotics, and, ultimately, can initiate the process of sporulation (28,30,32). All of these processes help the cells to survive under environmental conditions which are not optimal for growth.We have been studying the regulation of the enzymes responsible for histidine utilization (hut) in B. subtilis. The genes encoding the four enzymes that catalyze histidine degradation are organized as a multicistronic operon in B. subtilis (5,17,26). The first open reading frame in the hut operon, hutP, encodes a regulatory protein, which activates hut expression in trans (10,26). Downstream of the hutP gene is the hutH gene, which encodes histidase, the first enzyme in histidine degradation (26). A nucleotide sequence which could form a stem-loop structure lies between the hutP and hutH genes. Antitermination of hut transcription at this putative stem-loop structure has been proposed to mediate histidine-dependent induction of hut expression (26).Expression of the hut operon is highly regulated in response to nutrient availability in B. subtilis. hut expression is induced by histidine and repressed by rapidly metabolizable carbon compounds such as glucose, glycerol, or malate (5). Growth in the presence of a mixture of amino acids strongly inhibits synthesis of the hut enzymes (2). Mutations which alter regulation of the hut operon have been isolated. The * Corresponding author. hutC1 mutation allows expression of the hut enzymes in the absence of the inducer, histidine (5). hut expression is insensitive to regulation by catabolite repression in strains containing the hutR4 mutation (2, 11). Both the hutCl and hutR4 mutations are tightly linked to the hutH locus by transformation (5, 11).In this article, we report that hut expression is repressed during exponential growth in nutrient sporulation medium, but its expression completely derepresses at the onset of stationary growth phase. The postexponential activation of hut expression in this medium was investigated to identify factors regulating gene expression during this period of environmental stress. Derepression of hut expression during stationary growth in nutrient sporulation medium appears to be mediated primarily by the relief of amino acid repression of histidine transport. MATERIALS AND METHODS

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The regulation of genetic competence in Bacillus subtilis

Cited by 85 publications

References 58 publications

Calcium regulation of growth and differentiation in Streptococcus pneumoniae

Calcium regulation of growth and differentiation in Streptococcus pneumoniae

Identification of genes involved in the activation of the Bacillus thuringiensis inhA metalloprotease gene at the onset of sporulation The GenBank/EMBL/DDBJ accession number for the sequence reported in this paper is AF287346.

Activation of the Bacillus subtilis hut operon at the onset of stationary growth phase in nutrient sporulation medium results primarily from the relief of amino acid repression of histidine transport

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