The Per regulon of enteropathogenic Escherichia coli: Identification of a regulatory cascade and a novel transcriptional activator, the locus of enterocyte effacement (LEE)-encoded regulator (Ler)

Jay L. Mellies, Simon J. Elliott, Vanessa Sperandio, Michael S. Donnenberg, James B. Kaper

Research output: Contribution to journalArticle

294 Citations (Scopus)

Abstract

Enteropathogenic Escherichia coli (EPEC) is the prototype organism of a group of pathogenic Gram-negative bacteria that cause attaching and effacing (AE) intestinal lesions. All EPEC genes necessary for the AE phenotype are encoded within a 35.6 kb pathogenicity island termed the locus of enterocyte effacement (LEE). The LEE encodes 41 predicted open reading frames (ORFs), including components of a type III secretion apparatus and secreted molecules involved in the disruption of the host cell cytoskeleton. To initiate our studies on regulation of genes within the LEE, we determined the genetic organization of the LEE, defining transcriptional units and mapping transcriptional start points. We found that components of the type III secretion system are transcribed from three polycistronic operons designated LEE1, LEE2 and LEE3. The secreted Esp molecules are part of a fourth polycistronic operon designated LEE4. Using reporter gene fusion assays, we found that the previously described plasmid-encoded regulator (Per) activated operons LEE1, LEE2 and LEE3, and modestly increased the expression of LEE4 in EPEC. Using single-copy lacZ fusions in K-12-derived strains, we determined that Per only directly activated the LEE1::lacZ fusion, and did not directly activate the other operons. Orf1 of the LEE1 operon activated the expression of single-copy LEE2::lacZ and LEE3::lacZ fusions in trans and modestly increased the expression of LEE4::lacZ in K-12 strains. Orf1 was therefore designated Ler, for LEE-encoded regulator. Thus, the four polycistronic operons of the LEE that encode type III secretion components and secreted molecules are now included in the Per regulon, where Ler participates in this novel regulatory cascade in EPEC.

Original languageEnglish (US)
Pages (from-to)296-306
Number of pages11
JournalMolecular Microbiology
Volume33
Issue number2
DOIs
StatePublished - 1999

Fingerprint

Enteropathogenic Escherichia coli
Regulon
Enterocytes
Operon
Plasmids
Genomic Islands
Genetic Loci
Gene Fusion
Gram-Negative Bacteria
Cytoskeleton
Reporter Genes
Open Reading Frames
Genes
Phenotype

ASJC Scopus subject areas

  • Molecular Biology
  • Microbiology

Cite this

The Per regulon of enteropathogenic Escherichia coli : Identification of a regulatory cascade and a novel transcriptional activator, the locus of enterocyte effacement (LEE)-encoded regulator (Ler). / Mellies, Jay L.; Elliott, Simon J.; Sperandio, Vanessa; Donnenberg, Michael S.; Kaper, James B.

In: Molecular Microbiology, Vol. 33, No. 2, 1999, p. 296-306.

Research output: Contribution to journalArticle

@article{4aa617e5955348cda2197a65b7e1542e,
title = "The Per regulon of enteropathogenic Escherichia coli: Identification of a regulatory cascade and a novel transcriptional activator, the locus of enterocyte effacement (LEE)-encoded regulator (Ler)",
abstract = "Enteropathogenic Escherichia coli (EPEC) is the prototype organism of a group of pathogenic Gram-negative bacteria that cause attaching and effacing (AE) intestinal lesions. All EPEC genes necessary for the AE phenotype are encoded within a 35.6 kb pathogenicity island termed the locus of enterocyte effacement (LEE). The LEE encodes 41 predicted open reading frames (ORFs), including components of a type III secretion apparatus and secreted molecules involved in the disruption of the host cell cytoskeleton. To initiate our studies on regulation of genes within the LEE, we determined the genetic organization of the LEE, defining transcriptional units and mapping transcriptional start points. We found that components of the type III secretion system are transcribed from three polycistronic operons designated LEE1, LEE2 and LEE3. The secreted Esp molecules are part of a fourth polycistronic operon designated LEE4. Using reporter gene fusion assays, we found that the previously described plasmid-encoded regulator (Per) activated operons LEE1, LEE2 and LEE3, and modestly increased the expression of LEE4 in EPEC. Using single-copy lacZ fusions in K-12-derived strains, we determined that Per only directly activated the LEE1::lacZ fusion, and did not directly activate the other operons. Orf1 of the LEE1 operon activated the expression of single-copy LEE2::lacZ and LEE3::lacZ fusions in trans and modestly increased the expression of LEE4::lacZ in K-12 strains. Orf1 was therefore designated Ler, for LEE-encoded regulator. Thus, the four polycistronic operons of the LEE that encode type III secretion components and secreted molecules are now included in the Per regulon, where Ler participates in this novel regulatory cascade in EPEC.",
author = "Mellies, {Jay L.} and Elliott, {Simon J.} and Vanessa Sperandio and Donnenberg, {Michael S.} and Kaper, {James B.}",
year = "1999",
doi = "10.1046/j.1365-2958.1999.01473.x",
language = "English (US)",
volume = "33",
pages = "296--306",
journal = "Molecular Microbiology",
issn = "0950-382X",
publisher = "Wiley-Blackwell",
number = "2",

}

TY - JOUR

T1 - The Per regulon of enteropathogenic Escherichia coli

T2 - Identification of a regulatory cascade and a novel transcriptional activator, the locus of enterocyte effacement (LEE)-encoded regulator (Ler)

AU - Mellies, Jay L.

AU - Elliott, Simon J.

AU - Sperandio, Vanessa

AU - Donnenberg, Michael S.

AU - Kaper, James B.

PY - 1999

Y1 - 1999

N2 - Enteropathogenic Escherichia coli (EPEC) is the prototype organism of a group of pathogenic Gram-negative bacteria that cause attaching and effacing (AE) intestinal lesions. All EPEC genes necessary for the AE phenotype are encoded within a 35.6 kb pathogenicity island termed the locus of enterocyte effacement (LEE). The LEE encodes 41 predicted open reading frames (ORFs), including components of a type III secretion apparatus and secreted molecules involved in the disruption of the host cell cytoskeleton. To initiate our studies on regulation of genes within the LEE, we determined the genetic organization of the LEE, defining transcriptional units and mapping transcriptional start points. We found that components of the type III secretion system are transcribed from three polycistronic operons designated LEE1, LEE2 and LEE3. The secreted Esp molecules are part of a fourth polycistronic operon designated LEE4. Using reporter gene fusion assays, we found that the previously described plasmid-encoded regulator (Per) activated operons LEE1, LEE2 and LEE3, and modestly increased the expression of LEE4 in EPEC. Using single-copy lacZ fusions in K-12-derived strains, we determined that Per only directly activated the LEE1::lacZ fusion, and did not directly activate the other operons. Orf1 of the LEE1 operon activated the expression of single-copy LEE2::lacZ and LEE3::lacZ fusions in trans and modestly increased the expression of LEE4::lacZ in K-12 strains. Orf1 was therefore designated Ler, for LEE-encoded regulator. Thus, the four polycistronic operons of the LEE that encode type III secretion components and secreted molecules are now included in the Per regulon, where Ler participates in this novel regulatory cascade in EPEC.

AB - Enteropathogenic Escherichia coli (EPEC) is the prototype organism of a group of pathogenic Gram-negative bacteria that cause attaching and effacing (AE) intestinal lesions. All EPEC genes necessary for the AE phenotype are encoded within a 35.6 kb pathogenicity island termed the locus of enterocyte effacement (LEE). The LEE encodes 41 predicted open reading frames (ORFs), including components of a type III secretion apparatus and secreted molecules involved in the disruption of the host cell cytoskeleton. To initiate our studies on regulation of genes within the LEE, we determined the genetic organization of the LEE, defining transcriptional units and mapping transcriptional start points. We found that components of the type III secretion system are transcribed from three polycistronic operons designated LEE1, LEE2 and LEE3. The secreted Esp molecules are part of a fourth polycistronic operon designated LEE4. Using reporter gene fusion assays, we found that the previously described plasmid-encoded regulator (Per) activated operons LEE1, LEE2 and LEE3, and modestly increased the expression of LEE4 in EPEC. Using single-copy lacZ fusions in K-12-derived strains, we determined that Per only directly activated the LEE1::lacZ fusion, and did not directly activate the other operons. Orf1 of the LEE1 operon activated the expression of single-copy LEE2::lacZ and LEE3::lacZ fusions in trans and modestly increased the expression of LEE4::lacZ in K-12 strains. Orf1 was therefore designated Ler, for LEE-encoded regulator. Thus, the four polycistronic operons of the LEE that encode type III secretion components and secreted molecules are now included in the Per regulon, where Ler participates in this novel regulatory cascade in EPEC.

UR - http://www.scopus.com/inward/record.url?scp=0032998631&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032998631&partnerID=8YFLogxK

U2 - 10.1046/j.1365-2958.1999.01473.x

DO - 10.1046/j.1365-2958.1999.01473.x

M3 - Article

C2 - 10411746

AN - SCOPUS:0032998631

VL - 33

SP - 296

EP - 306

JO - Molecular Microbiology

JF - Molecular Microbiology

SN - 0950-382X

IS - 2

ER -