The response regulator SsrB activates transcription and binds to a region overlapping OmpR binding sites at Salmonella pathogenicity island 2

Xiuhong Feng, Don Walthers, Ricardo Oropeza, Linda Kenney

Research output: Contribution to journalArticle

76 Citations (Scopus)

Abstract

OmpR activates expression of the two-component regulatory system located on Salmonella pathogenicity island 2 (SPI-2) that controls the expression of a type III secretion system, as well as many other genes required for systemic infection in mice. Measurements of SsrA and SsrB protein levels under different growth conditions indicate that expression of these two components is uncoupled, i.e. SsrB is produced in the absence of ssrA and vice versa. This result was suggested from our previous studies, in which two promoters at ssrA/B were identified. The isolated C-terminus of SsrB binds to DNA and protects regions upstream of ssrA, ssrB and srfH from DNase I digestion. Furthermore, the C-terminus of SsrB alone is capable of activating transcription in the absence of the N-terminus. Results from β-galactosidase assays indicate that the N-terminal phosphorylation domain inhibits the C-terminal effector domain. A previous study from our laboratory reported that ssrA-lacZ and ssrB-lacZ transcriptional fusions were substantially reduced in an ssrB null strain. Results from DNase I protection assays provide direct evidence that SsrB binds at ssrA and ssrB, although the binding sites lie within the transcribed regions. Additional regulators clearly affect gene expression at this important locus, and here we provide evidence that SlyA, a transcription factor that contributes to Salmonella virulence, also affects ssrA/B gene expression.

Original languageEnglish (US)
Pages (from-to)823-835
Number of pages13
JournalMolecular Microbiology
Volume54
Issue number3
DOIs
StatePublished - Nov 1 2004
Externally publishedYes

Fingerprint

Genomic Islands
Deoxyribonuclease I
Salmonella
Binding Sites
Galactosidases
Gene Expression
Virulence
Digestion
Transcription Factors
Phosphorylation
DNA
Growth
Infection
Genes
Proteins
Type III Secretion Systems

ASJC Scopus subject areas

  • Molecular Biology
  • Microbiology

Cite this

The response regulator SsrB activates transcription and binds to a region overlapping OmpR binding sites at Salmonella pathogenicity island 2. / Feng, Xiuhong; Walthers, Don; Oropeza, Ricardo; Kenney, Linda.

In: Molecular Microbiology, Vol. 54, No. 3, 01.11.2004, p. 823-835.

Research output: Contribution to journalArticle

@article{ed56f05953754f9d9a14dd2f44f64fc9,
title = "The response regulator SsrB activates transcription and binds to a region overlapping OmpR binding sites at Salmonella pathogenicity island 2",
abstract = "OmpR activates expression of the two-component regulatory system located on Salmonella pathogenicity island 2 (SPI-2) that controls the expression of a type III secretion system, as well as many other genes required for systemic infection in mice. Measurements of SsrA and SsrB protein levels under different growth conditions indicate that expression of these two components is uncoupled, i.e. SsrB is produced in the absence of ssrA and vice versa. This result was suggested from our previous studies, in which two promoters at ssrA/B were identified. The isolated C-terminus of SsrB binds to DNA and protects regions upstream of ssrA, ssrB and srfH from DNase I digestion. Furthermore, the C-terminus of SsrB alone is capable of activating transcription in the absence of the N-terminus. Results from β-galactosidase assays indicate that the N-terminal phosphorylation domain inhibits the C-terminal effector domain. A previous study from our laboratory reported that ssrA-lacZ and ssrB-lacZ transcriptional fusions were substantially reduced in an ssrB null strain. Results from DNase I protection assays provide direct evidence that SsrB binds at ssrA and ssrB, although the binding sites lie within the transcribed regions. Additional regulators clearly affect gene expression at this important locus, and here we provide evidence that SlyA, a transcription factor that contributes to Salmonella virulence, also affects ssrA/B gene expression.",
author = "Xiuhong Feng and Don Walthers and Ricardo Oropeza and Linda Kenney",
year = "2004",
month = "11",
day = "1",
doi = "10.1111/j.1365-2958.2004.04317.x",
language = "English (US)",
volume = "54",
pages = "823--835",
journal = "Molecular Microbiology",
issn = "0950-382X",
publisher = "Wiley-Blackwell",
number = "3",

}

TY - JOUR

T1 - The response regulator SsrB activates transcription and binds to a region overlapping OmpR binding sites at Salmonella pathogenicity island 2

AU - Feng, Xiuhong

AU - Walthers, Don

AU - Oropeza, Ricardo

AU - Kenney, Linda

PY - 2004/11/1

Y1 - 2004/11/1

N2 - OmpR activates expression of the two-component regulatory system located on Salmonella pathogenicity island 2 (SPI-2) that controls the expression of a type III secretion system, as well as many other genes required for systemic infection in mice. Measurements of SsrA and SsrB protein levels under different growth conditions indicate that expression of these two components is uncoupled, i.e. SsrB is produced in the absence of ssrA and vice versa. This result was suggested from our previous studies, in which two promoters at ssrA/B were identified. The isolated C-terminus of SsrB binds to DNA and protects regions upstream of ssrA, ssrB and srfH from DNase I digestion. Furthermore, the C-terminus of SsrB alone is capable of activating transcription in the absence of the N-terminus. Results from β-galactosidase assays indicate that the N-terminal phosphorylation domain inhibits the C-terminal effector domain. A previous study from our laboratory reported that ssrA-lacZ and ssrB-lacZ transcriptional fusions were substantially reduced in an ssrB null strain. Results from DNase I protection assays provide direct evidence that SsrB binds at ssrA and ssrB, although the binding sites lie within the transcribed regions. Additional regulators clearly affect gene expression at this important locus, and here we provide evidence that SlyA, a transcription factor that contributes to Salmonella virulence, also affects ssrA/B gene expression.

AB - OmpR activates expression of the two-component regulatory system located on Salmonella pathogenicity island 2 (SPI-2) that controls the expression of a type III secretion system, as well as many other genes required for systemic infection in mice. Measurements of SsrA and SsrB protein levels under different growth conditions indicate that expression of these two components is uncoupled, i.e. SsrB is produced in the absence of ssrA and vice versa. This result was suggested from our previous studies, in which two promoters at ssrA/B were identified. The isolated C-terminus of SsrB binds to DNA and protects regions upstream of ssrA, ssrB and srfH from DNase I digestion. Furthermore, the C-terminus of SsrB alone is capable of activating transcription in the absence of the N-terminus. Results from β-galactosidase assays indicate that the N-terminal phosphorylation domain inhibits the C-terminal effector domain. A previous study from our laboratory reported that ssrA-lacZ and ssrB-lacZ transcriptional fusions were substantially reduced in an ssrB null strain. Results from DNase I protection assays provide direct evidence that SsrB binds at ssrA and ssrB, although the binding sites lie within the transcribed regions. Additional regulators clearly affect gene expression at this important locus, and here we provide evidence that SlyA, a transcription factor that contributes to Salmonella virulence, also affects ssrA/B gene expression.

UR - http://www.scopus.com/inward/record.url?scp=7644229970&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=7644229970&partnerID=8YFLogxK

U2 - 10.1111/j.1365-2958.2004.04317.x

DO - 10.1111/j.1365-2958.2004.04317.x

M3 - Article

VL - 54

SP - 823

EP - 835

JO - Molecular Microbiology

JF - Molecular Microbiology

SN - 0950-382X

IS - 3

ER -