Integration host factor is involved in transcriptional regulation of the Brucella abortus virB operon

Type IV secretion systems (T4SSs) are multicomponent machineries that play an essential role in pathogenicity of many facultative intracellular bacteria. The virB operon of Brucella abortus codes for a T4SS essential for virulence and intracellular multiplication. Here, virB expression analyses carr...

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Autores principales: Sieira, R., Comerci, D.J., Pietrasanta, L.I., Ugalde, R.A.
Formato: Artículo publishedVersion
Publicado: 2004
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_0950382X_v54_n3_p808_Sieira
https://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_0950382X_v54_n3_p808_Sieira_oai
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spelling I28-R145-paper_0950382X_v54_n3_p808_Sieira_oai2024-08-16 Sieira, R. Comerci, D.J. Pietrasanta, L.I. Ugalde, R.A. 2004 Type IV secretion systems (T4SSs) are multicomponent machineries that play an essential role in pathogenicity of many facultative intracellular bacteria. The virB operon of Brucella abortus codes for a T4SS essential for virulence and intracellular multiplication. Here, virB expression analyses carried out using lacZ transcriptional fusions showed that virB promoter (PvirB) is temporally activated within J774 cells. Primer extension experiments revealed that virB transcription starts at 27 bp upstream of the first gene of the virB operon. Structural analyses showed that PvirB and regulatory sequences involved in intracellular regulation span 430 bp upstream of the transcription start site. A protein able to bind PvirB was isolated and identified. This protein, homologue to integration host factor (IHF), specifically interacts with PvirB and induces a DNA bending with an angle of 50.36°. DNAse I footprinting experiments showed that IHF protects a 51 bp region that contains two overlapped IHF binding consensus motifs. VirB expression experiments carried out with PvirB-lacZ fusions showed that in B. abortus IHF participates in the regulation of PvirB activity during the intracellular and vegetative growth in different media. A mutant strain with a 20 bp IHF binding site replacement failed to turn on the virB operon during the initial stages of macrophage infection and displayed severe intracellular multiplication defects. These data indicate that IHF plays a key role during intracellular virB operon expression being required for the biogenesis of the endoplasmic reticulum-derived replicative vacuole. Fil:Ugalde, R.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. application/pdf http://hdl.handle.net/20.500.12110/paper_0950382X_v54_n3_p808_Sieira info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar Mol. Microbiol. 2004;54(3):808-822 beta galactosidase curved DNA deoxyribonuclease I integration host factor VirB protein animal cell article bacterial strain bacterial virulence bacterium mutant binding site Brucella abortus cell vacuole consensus sequence endoplasmic reticulum gene overexpression gene replication genetic transcription macrophage mouse nonhuman operon pathogenicity priority journal promoter region protein binding protein protein interaction regulatory sequence transcription initiation site transcription regulation Animals Bacterial Proteins Base Sequence Binding Sites Brucella abortus Cell Line Gene Expression Regulation, Bacterial Genes, Reporter Integration Host Factors Macrophages Mice Operon Promoter Regions (Genetics) Recombinant Fusion Proteins Transcription Factors Transcription, Genetic Animalia Bacteria (microorganisms) Brucella Brucella melitensis biovar Abortus Negibacteria Integration host factor is involved in transcriptional regulation of the Brucella abortus virB operon info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion https://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_0950382X_v54_n3_p808_Sieira_oai
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-145
collection Repositorio Digital de la Universidad de Buenos Aires (UBA)
topic beta galactosidase
curved DNA
deoxyribonuclease I
integration host factor
VirB protein
animal cell
article
bacterial strain
bacterial virulence
bacterium mutant
binding site
Brucella abortus
cell vacuole
consensus sequence
endoplasmic reticulum
gene overexpression
gene replication
genetic transcription
macrophage
mouse
nonhuman
operon
pathogenicity
priority journal
promoter region
protein binding
protein protein interaction
regulatory sequence
transcription initiation site
transcription regulation
Animals
Bacterial Proteins
Base Sequence
Binding Sites
Brucella abortus
Cell Line
Gene Expression Regulation, Bacterial
Genes, Reporter
Integration Host Factors
Macrophages
Mice
Operon
Promoter Regions (Genetics)
Recombinant Fusion Proteins
Transcription Factors
Transcription, Genetic
Animalia
Bacteria (microorganisms)
Brucella
Brucella melitensis biovar Abortus
Negibacteria
spellingShingle beta galactosidase
curved DNA
deoxyribonuclease I
integration host factor
VirB protein
animal cell
article
bacterial strain
bacterial virulence
bacterium mutant
binding site
Brucella abortus
cell vacuole
consensus sequence
endoplasmic reticulum
gene overexpression
gene replication
genetic transcription
macrophage
mouse
nonhuman
operon
pathogenicity
priority journal
promoter region
protein binding
protein protein interaction
regulatory sequence
transcription initiation site
transcription regulation
Animals
Bacterial Proteins
Base Sequence
Binding Sites
Brucella abortus
Cell Line
Gene Expression Regulation, Bacterial
Genes, Reporter
Integration Host Factors
Macrophages
Mice
Operon
Promoter Regions (Genetics)
Recombinant Fusion Proteins
Transcription Factors
Transcription, Genetic
Animalia
Bacteria (microorganisms)
Brucella
Brucella melitensis biovar Abortus
Negibacteria
Sieira, R.
Comerci, D.J.
Pietrasanta, L.I.
Ugalde, R.A.
Integration host factor is involved in transcriptional regulation of the Brucella abortus virB operon
topic_facet beta galactosidase
curved DNA
deoxyribonuclease I
integration host factor
VirB protein
animal cell
article
bacterial strain
bacterial virulence
bacterium mutant
binding site
Brucella abortus
cell vacuole
consensus sequence
endoplasmic reticulum
gene overexpression
gene replication
genetic transcription
macrophage
mouse
nonhuman
operon
pathogenicity
priority journal
promoter region
protein binding
protein protein interaction
regulatory sequence
transcription initiation site
transcription regulation
Animals
Bacterial Proteins
Base Sequence
Binding Sites
Brucella abortus
Cell Line
Gene Expression Regulation, Bacterial
Genes, Reporter
Integration Host Factors
Macrophages
Mice
Operon
Promoter Regions (Genetics)
Recombinant Fusion Proteins
Transcription Factors
Transcription, Genetic
Animalia
Bacteria (microorganisms)
Brucella
Brucella melitensis biovar Abortus
Negibacteria
description Type IV secretion systems (T4SSs) are multicomponent machineries that play an essential role in pathogenicity of many facultative intracellular bacteria. The virB operon of Brucella abortus codes for a T4SS essential for virulence and intracellular multiplication. Here, virB expression analyses carried out using lacZ transcriptional fusions showed that virB promoter (PvirB) is temporally activated within J774 cells. Primer extension experiments revealed that virB transcription starts at 27 bp upstream of the first gene of the virB operon. Structural analyses showed that PvirB and regulatory sequences involved in intracellular regulation span 430 bp upstream of the transcription start site. A protein able to bind PvirB was isolated and identified. This protein, homologue to integration host factor (IHF), specifically interacts with PvirB and induces a DNA bending with an angle of 50.36°. DNAse I footprinting experiments showed that IHF protects a 51 bp region that contains two overlapped IHF binding consensus motifs. VirB expression experiments carried out with PvirB-lacZ fusions showed that in B. abortus IHF participates in the regulation of PvirB activity during the intracellular and vegetative growth in different media. A mutant strain with a 20 bp IHF binding site replacement failed to turn on the virB operon during the initial stages of macrophage infection and displayed severe intracellular multiplication defects. These data indicate that IHF plays a key role during intracellular virB operon expression being required for the biogenesis of the endoplasmic reticulum-derived replicative vacuole.
format Artículo
Artículo
publishedVersion
author Sieira, R.
Comerci, D.J.
Pietrasanta, L.I.
Ugalde, R.A.
author_facet Sieira, R.
Comerci, D.J.
Pietrasanta, L.I.
Ugalde, R.A.
author_sort Sieira, R.
title Integration host factor is involved in transcriptional regulation of the Brucella abortus virB operon
title_short Integration host factor is involved in transcriptional regulation of the Brucella abortus virB operon
title_full Integration host factor is involved in transcriptional regulation of the Brucella abortus virB operon
title_fullStr Integration host factor is involved in transcriptional regulation of the Brucella abortus virB operon
title_full_unstemmed Integration host factor is involved in transcriptional regulation of the Brucella abortus virB operon
title_sort integration host factor is involved in transcriptional regulation of the brucella abortus virb operon
publishDate 2004
url http://hdl.handle.net/20.500.12110/paper_0950382X_v54_n3_p808_Sieira
https://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_0950382X_v54_n3_p808_Sieira_oai
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AT comercidj integrationhostfactorisinvolvedintranscriptionalregulationofthebrucellaabortusvirboperon
AT pietrasantali integrationhostfactorisinvolvedintranscriptionalregulationofthebrucellaabortusvirboperon
AT ugaldera integrationhostfactorisinvolvedintranscriptionalregulationofthebrucellaabortusvirboperon
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