Siderophore production and iron-regulated envelope proteins of Helicobacter pylori

Illingworth, David Simon; Walter, K.S.; Griffiths, P.L.; Barclay, Raymond

doi:10.1016/s0934-8840(11)80946-1

Cited by 24 publications

(16 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, Husson et al [82] failed to detect extracellular siderophore production in H. pylori and suggested that the bacterium possesses a lactoferrin receptor that would allow it to extract iron directly from lactoferrin. These findings conflict with the studies of Illingworth et al [83], who reported the presence of extracellular siderophores produced by H. pylori and found no evidence of direct binding of lactoferrin by the bacterium. Iron-binding proteins with a molecular size of 40 kD and 78 kD were detected by Illingworth's group and this compares well with the 48-, 50-and 77-kD heme binding proteins of Worst et al [81].…”

Section: Iron Metabolismcontrasting

confidence: 99%

How Helicobacter pylori Works: An Overview of the Metabolism of Helicobacter pylori

Hazell

Mendz

1997

Helicobacter

View full text Add to dashboard Cite

Section: Iron Metabolismcontrasting

confidence: 99%

How Helicobacter pylori Works: An Overview of the Metabolism of Helicobacter pylori

Hazell

Mendz

1997

Helicobacter

View full text Add to dashboard Cite

“…The data presented here could provide a tool for construction of H. pylori aroB mutants of potential use in vaccine development and for establishing safe strains for bioengineering. The production of siderophores recently described from H. pylori [23] raises the question if there is a link between iron acquisition and synthesis of aromatic molecules similar to that seen in E. coli. To investigate if mutants which carry defects in the shikimate pathway genes are attenuated in the host, is one of the future goals of ongoing studies.…”

Section: Discussionmentioning

confidence: 98%

Cloning and functional characterization of the genes encoding 3-dehydroquinate synthase (aroB) and tRNA-guanine transglycosylase (tgt) from Helicobacter pylori

Bereswill

Fassbinder

Völzing

et al. 1997

Med Microbiol Immunol

View full text Add to dashboard Cite

The aroB gene from Helicobacter pylori strain P1 was cloned and further characterized by sequence analysis and by functional complementation of the aroB mutation in Escherichia coli. The aroB gene encodes the enzyme 3-dehydroquinate synthase which catalyzes one of the early steps in the shikimate pathway. This pathway, which creates aromatic molecules from sugar precursors, is present in prokaryotes, fungi and plants but is absent from mammalian cells. The predicted amino acid sequence of the H. pylori aroB gene product showed significant homology (30-40% identity and 50-60% similarity) to 3-dehydroquinate synthases from various other prokaryotes and eukaryotes. The single gene on a plasmid was biologically active in E. coli. It suppressed the specific phenotype of aroB mutants by restoring the shikimate pathway-dependent synthesis of aromatic amino acids and the production of the siderophore enterobactin. Two other reading frames were found adjacent to the aroB gene. The first, designated as orf1, had no significant homology to proteins and genes present in databases, whereas the second was found to share a significant degree of homology with the tgt gene encoding tRNA-guanine transglycosylase from a variety of other bacteria (40-50% identity and 60-70% similarity). The function of the tgt gene was confirmed by heterologous complementation. The gene on a plasmid was shown to complement the queuosine biosynthesis defect in a genetically defined tgt- strain of E. coli. The presence of the aroB gene and the putative tgt homologue in unrelated H. pylori strains was confirmed by Southern blot hybridization and by polymerase chain reaction with specific primers.

show abstract

“…Despite one study suggesting the production of siderophores by H. pylori [45], most investigations have been unable to reproduce that finding or to demonstrate the use of exogenous siderophores as a source of iron by this bacterium [44,46]. Nevertheless, the induction of NGAL/Lcn2 is not restricted to microorganisms that produce or uptake siderophores.…”

Section: Discussionmentioning

confidence: 99%

Neutrophil gelatinase-associated lipocalin (NGAL/Lcn2) is upregulated in gastric mucosa infected with Helicobacter pylori

Alpízar‐Alpízar

Lærum

Illemann³

et al. 2009

Virchows Arch

View full text Add to dashboard Cite

Helicobacter pylori infection is one of the most significant risk factors for gastric cancer. The infection is established early in life and persists lifelong leading to a sustained chronic inflammation. Iron is essential for most living organisms. Bacteria use several mechanisms to acquire iron from their hosts, including the synthesis of the potent iron chelators known as siderophores. Hosts cells may express the siderophore-binding protein neutrophil gelatinase-associated lipocalin (NGAL/lipocalin-2 (Lcn2)) in response to infection, thus preventing bacterial iron uptake. We have characterized here the pattern of expression of NGAL/Lcn2 in gastric mucosa (45 non-neoplastic and 38 neoplastic tissue samples) and explored the connection between NGAL/Lcn2 expression and H. pylori infection. Immunohistochemical analysis showed high NGAL/Lcn2 expression in normal and gastritis-affected mucosa compared to low expression in intestinal metaplasia, dysplasia, and gastric cancer. In normal and gastritis-affected mucosa (n=36 tissue samples), NGAL/Lcn2 was more frequently seen in epithelial cells located at the neck and base of the glands in H. pylori-positive cases than in similar epithelial cells of noninfected cases (Fisher's exact test, p=0.04). In conclusion, the high expression of NGAL/Lcn2 in normal and gastritis-affected mucosa infected with H. pylori suggests that NGAL/Lcn2 is upregulated locally in response to this bacterial infection. It is discussed whether this may have a causal relation to the development of gastric cancer.

show abstract

Siderophore production and iron-regulated envelope proteins of Helicobacter pylori

Cited by 24 publications

References 7 publications

How Helicobacter pylori Works: An Overview of the Metabolism of Helicobacter pylori

How Helicobacter pylori Works: An Overview of the Metabolism of Helicobacter pylori

Cloning and functional characterization of the genes encoding 3-dehydroquinate synthase (aroB) and tRNA-guanine transglycosylase (tgt) from Helicobacter pylori

Neutrophil gelatinase-associated lipocalin (NGAL/Lcn2) is upregulated in gastric mucosa infected with Helicobacter pylori

Contact Info

Product

Resources

About