scholarly journals Regulation of the Acetoin Catabolic Pathway Is Controlled by Sigma L in Bacillus subtilis

2001 ◽  
Vol 183 (8) ◽  
pp. 2497-2504 ◽  
Author(s):  
Naima Ould Ali ◽  
Joelle Bignon ◽  
Georges Rapoport ◽  
Michel Debarbouille
Keyword(s):  
Bacillus Subtilis ◽  
Growth Medium ◽  
Dna Sequences ◽  
Transcriptional Start Site ◽  
Specific Interaction ◽  
Carbon Sources ◽  
Upstream Region ◽  
Global Regulator ◽  
Sigma 54 ◽  
Dnase I Footprinting

ABSTRACT Bacillus subtilis grown in media containing amino acids or glucose secretes acetate, pyruvate, and large quantities of acetoin into the growth medium. Acetoin can be reused by the bacteria during stationary phase when other carbon sources have been depleted. TheacoABCL operon encodes the E1α, E1β, E2, and E3 subunits of the acetoin dehydrogenase complex in B. subtilis. Expression of this operon is induced by acetoin and repressed by glucose in the growth medium. The acoR gene is located downstream from the acoABCL operon and encodes a positive regulator which stimulates the transcription of the operon. The product of acoR has similarities to transcriptional activators of sigma 54-dependent promoters. The four genes of the operon are transcribed from a −12, −24 promoter, and transcription is abolished in acoR and sigL mutants. Deletion analysis showed that DNA sequences more than 85 bp upstream from the transcriptional start site are necessary for full induction of the operon. These upstream activating sequences are probably the targets of AcoR. Analysis of an acoR′-′lacZ strain ofB. subtilis showed that the expression of acoRis not induced by acetoin and is repressed by the presence of glucose in the growth medium. Transcription of acoR is also negatively controlled by CcpA, a global regulator of carbon catabolite repression. A specific interaction of CcpA in the upstream region ofacoR was demonstrated by DNase I footprinting experiments, suggesting that repression of transcription of acoR is mediated by the binding of CcpA to the promoter region ofacoR.

scholarly journals Transcriptional Activation of the Bacillus subtilis ackA Promoter Requires Sequences Upstream of the CcpA Binding Site

2001 ◽  
Vol 183 (7) ◽  
pp. 2389-2393 ◽  
Author(s):  
Tessa R. Moir-Blais ◽  
Frank J. Grundy ◽  
Tina M. Henkin
Keyword(s):  
Bacillus Subtilis ◽  
Transcriptional Activation ◽  
Carbon Metabolism ◽  
Promoter Region ◽  
Protein A ◽  
Carbon Sources ◽  
Global Regulator ◽  
Gram Positive Bacteria ◽  
Upstream Element ◽  
Secondary Carbon

ABSTRACT Carbon catabolite protein A (CcpA) is a global regulator of carbon metabolism in gram-positive bacteria, repressing transcription of genes for the utilization of secondary carbon sources in the presence of a readily metabolized carbon source and activating transcription of genes, such as ackA and pta, that are required for carbon excretion. The promoter region of the Bacillus subtilis ackA gene contains two catabolite responsive elements (cre sites), of which only the site closest to the promoter (cre2) binds CcpA to activate transcription. A region immediately upstream of the cre2 site is also important for transcriptional activation. The required elements in this region were further defined by mutagenesis. CcpA binds to the ackApromoter region in gel shift assays even in the presence of mutations in the upstream element that block transcriptional activation, indicating that this region has a function other than promoting binding of CcpA.

The DNA-binding specificity of the Bacillus anthracis AbrB protein

Microbiology ◽  
2005 ◽  
Vol 151 (6) ◽  
pp. 1751-1759 ◽  
Author(s):  
Mark A. Strauch ◽  
Petek Ballar ◽  
Austin J. Rowshan ◽  
Katherine L. Zoller
Keyword(s):  
Bacillus Subtilis ◽  
Dna Binding ◽  
Bacillus Anthracis ◽  
Amino Acid Sequence Identity ◽  
Binding Specificity ◽  
Growth Conditions ◽  
Global Regulator ◽  
Sequence Identity ◽  
Dna Binding Specificity ◽  
Dnase I Footprinting

The Bacillus subtilis AbrB protein is a DNA-binding global regulator of a plethora of functions that are expressed during the transition from exponential growth to stationary phase and under suboptimal growth conditions. AbrB orthologues have been identified in a variety of prokaryotic organisms, notably in all species of Bacillus, Clostridium and Listeria that have been examined. Based on amino acid sequence identity in the N-terminal domains of the orthologues from B. subtilis and Bacillus anthracis, it was predicted that the proteins might display identical DNA-binding specificities. The binding of purified B. anthracis AbrB (AbrBBA) and purified B. subtilis AbrB (AbrBBS) at DNA targets of B. subtilis, B. anthracis and a synthetic origin was compared. In all cases examined, DNA-binding specificity was identical as judged by DNase I footprinting. In B. subtilis cells, the B. anthracis promoters from the atxA and abrB genes were regulated by AbrBBS, and the B. subtilis promoter from the yxbB operon was regulated by AbrBBA.

scholarly journals Regulation of l-Lactate Utilization by the FadR-Type Regulator LldR of Corynebacterium glutamicum

2007 ◽  
Vol 190 (3) ◽  
pp. 963-971 ◽  
Author(s):  
Tobias Georgi ◽  
Verena Engels ◽  
Volker F. Wendisch
Keyword(s):  
Energy Source ◽  
Corynebacterium Glutamicum ◽  
Mutational Analysis ◽  
Transcriptional Start Site ◽  
Carbon Sources ◽  
Upstream Region ◽  
Growth Defect ◽  
Mrna Levels ◽  
Lactate Utilization ◽  
In Cells

ABSTRACT Corynebacterium glutamicum can grow on l-lactate as a sole carbon and energy source. The NCgl2816-lldD operon encoding a putative transporter (NCgl2816) and a quinone-dependent l-lactate dehydrogenase (LldD) is required for l-lactate utilization. DNA affinity chromatography revealed that the FadR-type regulator LldR (encoded by NCgl2814) binds to the upstream region of NCgl2816-lldD. Overexpression of lldR resulted in strongly reduced NCgl2816-lldD mRNA levels and strongly reduced LldD activity, and as a consequence, a severe growth defect was observed in cells grown on l-lactate as the sole carbon and energy source, but not in cells grown on glucose, ribose, or acetate. Deletion of lldR had no effect on growth on these carbon sources but resulted in high NCgl2816-lldD mRNA levels and high LldD activity in the presence and absence of l-lactate. Purified His-tagged LldR bound to a 54-bp fragment of the NCgl2816-lldD promoter, which overlaps with the transcriptional start site determined by random amplification of cDNA ends-PCR and contains a putative operator motif typical of FadR-type regulators, which is −1TNGTNNNACNA10. Mutational analysis revealed that this motif with hyphenated dyad symmetry is essential for binding of LldD to the NCgl2816-lldD promoter. l-Lactate, but not d-lactate, interfered with binding of LldRHis to the NCgl2816-lldD promoter. Thus, during growth on media lacking l-lactate, LldR represses expression of NCgl2816-lldD. In the presence of l-lactate in the growth medium or under conditions leading to intracellular l-lactate accumulation, the l-lactate utilization operon is induced.

scholarly journals Interaction of Ler at the LEE5 (tir) Operon of Enteropathogenic Escherichia coli

2003 ◽  
Vol 71 (1) ◽  
pp. 384-392 ◽  
Author(s):  
Kenneth R. Haack ◽  
Christopher L. Robinson ◽  
Kristie J. Miller ◽  
Jonathan W. Fowlkes ◽  
Jay L. Mellies
Keyword(s):  
Escherichia Coli ◽  
Dna Sequences ◽  
Transcriptional Start Site ◽  
Dnase I ◽  
Regulatory Sequences ◽  
Global Regulator ◽  
Mobility Shift ◽  
Amino Acid Similarity ◽  
Enterocyte Effacement ◽  
Upstream Regulatory Sequences

ABSTRACT The genome of enteropathogenic Escherichia coli (EPEC) encodes a global regulator, Ler (locus of enterocyte effacement [LEE]-encoded regulator), which activates expression of several polycistronic operons within the 35.6-kb LEE pathogenicity island, including the LEE2-LEE3 divergent operon pair containing overlapping −10 regions and the LEE5 (tir) operon. Ler is a predicted 15-kDa protein that exhibits amino acid similarity with the nucleoid protein H-NS. In order to study Ler-mediated activation of virulence operons in EPEC, we used a molecular approach to characterize the interactions of purified Ler protein with the upstream regulatory sequences of the LEE5 operon. We determined the cis-acting DNA sequences necessary for Ler binding at LEE5 by mobility shift and DNase I protection assays, demonstrating that Ler acts directly at LEE5 by binding sequences between positions −190 and −73 in relation to the transcriptional start site. Based on the molecular weight of Ler, the similarity to H-NS, and the extended region of protection observed in a DNase I footprint at LEE5, we hypothesized that multiple Ler proteins bind upstream of the LEE5 promoter to increase transcriptional activity from a distance. Using an hns deletion strain, we demonstrated that like the LEE2-LEE3 operon pair, H-NS represses LEE5 transcription. We describe a model in which Ler activates transcription at both divergent overlapping paired and single promoters by displacing H-NS, which results in the disruption of a repressing nucleoprotein complex.

scholarly journals Functional Analysis of the Bacillus subtilis Zur Regulon

2002 ◽  
Vol 184 (23) ◽  
pp. 6508-6514 ◽  
Author(s):  
Ahmed Gaballa ◽  
Tao Wang ◽  
Rick W. Ye ◽  
John D. Helmann
Keyword(s):  
Bacillus Subtilis ◽  
Metal Ion ◽  
Dna Microarrays ◽  
Optimal Growth ◽  
Zinc Uptake ◽  
Uptake System ◽  
Mobility Shift ◽  
Transport Pathway ◽  
Dnase I Footprinting ◽  
Transporter Family

ABSTRACT The Bacillus subtilis zinc uptake repressor (Zur) regulates genes involved in zinc uptake. We have used DNA microarrays to identify genes that are derepressed in a zur mutant. In addition to members of the two previously identified Zur-regulated operons (yciC and ycdHI-yceA), we identified two other genes, yciA and yciB, as targets of Zur regulation. Electrophoretic mobility shift experiments demonstrated that all three operons are direct targets of Zur regulation. Zur binds to an ∼28-bp operator upstream of the yciA gene, as judged by DNase I footprinting, and similar operator sites are found preceding each of the previously described target operons, yciC and ycdHI-yceA. Analysis of a yciA-lacZ fusion indicates that this operon is induced under zinc starvation conditions and derepressed in the zur mutant. Phenotypic analyses suggest that the YciA, YciB, and YciC proteins may function as part of the same Zn(II) transport pathway. Mutation of yciA or yciC, singly or in combination, had little effect on growth of the wild-type strain but significantly impaired the growth of the ycdH mutant under conditions of zinc limitation. Since the YciA, YciB, and YciC proteins are not obviously related to any known transporter family, they may define a new class of metal ion uptake system. Mutant strains lacking all three identified zinc uptake systems (yciABC, ycdHI-yceA, and zosA) are dependent on micromolar levels of added zinc for optimal growth.

scholarly journals Chicken beta B1-crystallin gene expression: presence of conserved functional polyomavirus enhancer-like and octamer binding-like promoter elements found in non-lens genes.

1991 ◽  
Vol 11 (3) ◽  
pp. 1488-1499 ◽  
Author(s):  
H J Roth ◽  
G C Das ◽  
J Piatigorsky
Keyword(s):  
Transcription Factors ◽  
Hela Cell ◽  
Dna Sequences ◽  
Nuclear Extract ◽  
Regulatory Elements ◽  
Dnase I ◽  
Flanking Sequence ◽  
Mobility Shift ◽  
Promoter Elements ◽  
Dnase I Footprinting

Expression of the chicken beta B1-crystallin gene was examined. Northern (RNA) blot and primer extension analyses showed that while abundant in the lens, the beta B1 mRNA is absent from the liver, brain, heart, skeletal muscle, and fibroblasts of the chicken embryo, suggesting lens specificity. Promoter fragments ranging from 434 to 126 bp of 5'-flanking sequence (plus 30 bp of exon 1) of the beta B1 gene fused to the bacterial chloramphenicol acetyltransferase gene functioned much more efficiently in transfected embryonic chicken lens epithelial cells than in transfected primary muscle fibroblasts or HeLa cells. Transient expression of recombinant plasmids in cultured lens cells, DNase I footprinting, in vitro transcription in a HeLa cell extract, and gel mobility shift assays were used to identify putative functional promoter elements of the beta B1-crystallin gene. Sequence analysis revealed a number of potential regulatory elements between positions -126 and -53 of the beta B1 promoter, including two Sp1 sites, two octamer binding sequence-like sites (OL-1 and OL-2), and two polyomavirus enhancer-like sites (PL-1 and PL-2). Deletion and site-specific mutation experiments established the functional importance of PL-1 (-116 to -102), PL-2 (-90 to -76), and OL-2 (-75 to -68). DNase I footprinting using a lens or a HeLa cell nuclear extract and gel mobility shifts using a lens nuclear extract indicated the presence of putative lens transcription factors binding to these DNA sequences. Competition experiments provided evidence that PL-1 and PL-2 recognize the same or very similar factors, while OL-2 recognizes a different factor. Our data suggest that the same or closely related transcription factors found in many tissues are used for expression of the chicken beta B1-crystallin gene in the lens.

Participation of the upstream region of the fibroin gene in the formation of transcription complex in vitro

1986 ◽  
Vol 6 (11) ◽  
pp. 3928-3933
Author(s):  
M Tsuda ◽  
S Hirose ◽  
Y Suzuki
Keyword(s):  
Complex Formation ◽  
Specific Interaction ◽  
Inhibitory Effect ◽  
Silk Gland ◽  
Upstream Region ◽  
Fibroin Gene ◽  
Transcription Complexes ◽  
Posterior Silk Gland

The addition of exogenous histones has an inhibitory effect on fibroin gene transcription in posterior silk gland extracts. The histones probably disturb a process in complex formation, because when transcription complexes were constructed by preincubation of the templates with the extracts, the inhibitory effect of histones was greatly reduced. Transcription of a fibroin gene construct, pFb5' delta-238, having the upstream region beyond the TATA box was relatively less inhibited than that of pFb5' delta-44 lacking the upstream region. This tendency toward differential inhibition was observed in the silk gland extracts but not in a HeLa cell extract and persisted even after complex formation in the silk gland extracts, suggesting a specific interaction of the upstream region with some factors in the extracts. The complexes formed on pFb5' delta-44 are probably more susceptible to the inhibitory effect of histones. On the basis of these results we propose a participation of the upstream region of the fibroin gene in the formation of stable transcription complexes at the promoter through an interaction with specific factors in the silk gland. Since the transcription-enhancing effect via the upstream region is augmented at a high histone/DNA ratio, it may mimic the in vivo situation in which the fibroin gene can be transcribed in the posterior silk gland even in the presence of excess suppressive materials.

scholarly journals Spo0A-Dependent Activation of an Extended −10 Region Promoter in Bacillus subtilis

2006 ◽  
Vol 188 (4) ◽  
pp. 1411-1418 ◽  
Author(s):  
Guangnan Chen ◽  
Amrita Kumar ◽  
Travis H. Wyman ◽  
Charles P. Moran
Keyword(s):  
Bacillus Subtilis ◽  
Base Pair ◽  
Promoter Activity ◽  
Mutational Analysis ◽  
Dna Binding Protein ◽  
Base Pairs ◽  
Dnase I Footprinting ◽  
Level Of Activity ◽  
High Level ◽  
Activity Dependent

ABSTRACT At the onset of endospore formation in Bacillus subtilis the DNA-binding protein Spo0A directly activates transcription from promoters of about 40 genes. One of these promoters, Pskf, controls expression of an operon encoding a killing factor that acts on sibling cells. AbrB-mediated repression of Pskf provides one level of security ensuring that this promoter is not activated prematurely. However, Spo0A also appears to activate the promoter directly, since Spo0A is required for Pskf activity in a ΔabrB strain. Here we investigate the mechanism of Pskf activation. DNase I footprinting was used to determine the locations at which Spo0A bound to the promoter, and mutations in these sites were found to significantly reduce promoter activity. The sequence near the −10 region of the promoter was found to be similar to those of extended −10 region promoters, which contain a TRTGn motif. Mutational analysis showed that this extended −10 region, as well as other base pairs in the −10 region, is required for Spo0A-dependent activation of the promoter. We found that a substitution of the consensus base pair for the nonconsensus base pair at position −9 of Pskf produced a promoter that was active constitutively in both ΔabrB and Δspo0A ΔabrB strains. Therefore, the base pair at position −9 of Pskf makes its activity dependent on Spo0A binding, and the extended −10 region motif of the promoter contributes to its high level of activity.

scholarly journals Quantitative analysis questions the role of MeCP2 as a global regulator of alternative splicing

2020 ◽  
Author(s):  
Kashyap Chhatbar ◽  
Justyna Cholewa-Waclaw ◽  
Ruth Shah ◽  
Adrian Bird ◽  
Guido Sanguinetti
Keyword(s):  
Alternative Splicing ◽  
Dna Sequences ◽  
Molecular Mechanisms ◽  
Data Sets ◽  
Learning Approaches ◽  
Global Regulator ◽  
Major Function ◽  
Quantitative Analyses ◽  
Different Levels

AbstractMeCP2 is an abundant protein in mature nerve cells, where it binds to DNA sequences containing methylated cytosine. Mutations in the MECP2 gene cause the severe neurological disorder Rett syndrome (RTT), provoking intensive study of the underlying molecular mechanisms. Multiple functions have been proposed, one of which involves a regulatory role in splicing. Here we leverage the recent availability of high-quality transcriptomic data sets to probe quantitatively the potential influence of MeCP2 on alternative splicing. Using a variety of machine learning approaches that can capture both linear and non-linear associations, we show that widely different levels of MeCP2 have a minimal effect on alternative splicing in three different systems. Alternative splicing was also apparently indifferent to developmental changes in DNA methylation levels. Our results suggest that regulation of splicing is not a major function of MeCP2. They also highlight the importance of multi-variate quantitative analyses in the formulation of biological hypotheses.

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