Neisseria Prophage Repressor Implicated in Gonococcal Pathogenesis

Daou, Nadine; Yu, Chunxiao; McClure, Ryan; Gudino, Cynthia V.; Reed, George W.; Genco, Caroline A.

doi:10.1128/iai.00298-13

Cited by 14 publications

(16 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A second target, NGO1646, is predicted to encode a phage-associated protein in the N. gonorrhoeae FA1090 genome. While little is known regarding the role of phage-associated proteins in the regulatory pathways of N. gonorrhoeae, previous studies by our group have identified one such phage-associated protein, Npr, which is involved in gonococcal pathogenesis (36). Lack of Npr leads to increased adherence to and invasion of epithelial cells as well as enhanced colonization in a gonococcal mouse model of infection.…”

Section: Discussionmentioning

confidence: 98%

“…At 2 h, 5 h, and 24 h postincubation, total cell-associated and intracellular bacteria were measured by counting CFU. Counting of total cell-associated bacteria and intracellular bacteria was carried out as described previously (36). The experiments were repeated four times with F62 strains and three times using N. gonorrhoeae FA1090 opaA-K wild-type, arsR, and arsR-complemented strains.…”

Section: Methodsmentioning

confidence: 99%

“…N. gonorrhoeae fur and fur-complemented strains were generated in a previous study (36). All strains were plated on GCB plates, grown overnight at 37°C with 5% CO 2 , and inoculated into chemically defined medium (CDM) (37) containing 0.042% Na 2 HCO 3 with shaking for 2 h. Cultures were diluted into fresh CDM to an optical density at 600 nm (OD 600 ) of 0.1 and incubated for an additional 2 h. Subsequently, 100 M ferric nitrate (for iron-replete [ϩFe] conditions) or 100 M desferal (for iron-depleted [ϪFe] conditions) was added to the culture.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Characterization of the Neisseria gonorrhoeae Iron and Fur Regulatory Network

McClure

Nudel

et al. 2016

J Bacteriol

Self Cite

View full text Add to dashboard Cite

The Neisseria gonorrhoeae ferric uptake regulator (Fur) protein controls expression of iron homeostasis genes in response to intracellular iron levels. In this study, using transcriptome sequencing (RNA-seq) analysis of an N. gonorrhoeae fur strain, we defined the gonococcal Fur and iron regulons and characterized Fur-controlled expression of an ArsR-like DNA binding protein.We observed that 158 genes (8% of the genome) showed differential expression in response to iron in an N. gonorrhoeae wildtype or fur strain, while 54 genes exhibited differential expression in response to Fur. The Fur regulon was extended to additional regulators, including NrrF and 13 other small RNAs (sRNAs), and two transcriptional factors. One transcriptional factor, coding for an ArsR-like regulator (ArsR), exhibited increased expression under iron-replete conditions in the wild-type strain but showed decreased expression across iron conditions in the fur strain, an effect that was reversed in a fur-complemented strain. Fur was shown to bind to the promoter region of the arsR gene downstream of a predicted 70 promoter region. Electrophoretic mobility shift assay (EMSA) analysis confirmed binding of the ArsR protein to the norB promoter region, and sequence analysis identified two additional putative targets, NGO1411 and NGO1646. A gonococcal arsR strain demonstrated decreased survival in human endocervical epithelial cells compared to that of the wild-type and arsR-complemented strains, suggesting that the ArsR regulon includes genes required for survival in host cells. Collectively, these results demonstrate that the N. gonorrhoeae Fur functions as a global regulatory protein to repress or activate expression of a large repertoire of genes, including additional transcriptional regulatory proteins. IMPORTANCEGene regulation in bacteria in response to environmental stimuli, including iron, is of paramount importance to both bacterial replication and, in the case of pathogenic bacteria, successful infection. Bacterial DNA binding proteins are a common mechanism utilized by pathogens to control gene expression under various environmental conditions. Here, we show that the DNA binding protein Fur, expressed by the human pathogen Neisseria gonorrhoeae, controls the expression of a large repertoire of genes and extends this regulon by controlling expression of additional DNA binding proteins. One of these proteins, an ArsRlike regulator, was required for N. gonorrhoeae survival within host cells. These results show that the Fur regulon extends to additional regulatory proteins, which together contribute to gonococcal mechanisms of pathogenesis.

show abstract

Section: Discussionmentioning

confidence: 98%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of the Neisseria gonorrhoeae Iron and Fur Regulatory Network

McClure

Nudel

et al. 2016

J Bacteriol

Self Cite

View full text Add to dashboard Cite

show abstract

“…This phenomenon of silent Fur binding has been recently demonstrated with a novel gonococcal phage repressor protein, Npr [48]. Under In vivo conditions, some Fur binding sites may not be accessible due to the binding of other transcriptional regulators and nucleoid-associated proteins including H-NS (histone-like nucleoid structuring protein), IHF (integration host factor), HU (heat unstable protein) and Fis (factor for inversion stimulation) [56].…”

Section: Discussionmentioning

confidence: 98%

A High-Throughput Method to Examine Protein-Nucleotide Interactions Identifies Targets of the Bacterial Transcriptional Regulatory Protein Fur

Lopez

et al. 2014

PLoS ONE

Self Cite

View full text Add to dashboard Cite

The Ferric uptake regulatory protein (Fur) is a transcriptional regulatory protein that functions to control gene transcription in response to iron in a number of pathogenic bacteria. In this study, we applied a label-free, quantitative and high-throughput analysis method, Interferometric Reflectance Imaging Sensor (IRIS), to rapidly characterize Fur-DNA interactions in vitro with predicted Fur binding sequences in the genome of Neisseria gonorrhoeae, the causative agent of the sexually transmitted disease gonorrhea. IRIS can easily be applied to examine multiple protein-protein, protein-nucleotide and nucleotide-nucleotide complexes simultaneously and demonstrated here that seventy percent of the predicted Fur boxes in promoter regions of iron-induced genes bound to Fur in vitro with a range of affinities as observed using this microarray screening technology. Combining binding data with mRNA expression levels in a gonococcal fur mutant strain allowed us to identify five new gonococcal genes under Fur-mediated direct regulation.

show abstract

“…Although Mu-like phages were not found in N. gonorrhoeae genomic sequences (104), five different double-stranded DNA (dsDNA) lysogenic phages were identified in strain FA1090 (Ngoφ1-5), and their repressor genes were shown to be functional in E. coli (121). A repressor from Ngoφ4 has been suggested to affect N. gonorrhoeae pathogenesis by regulating the ability of gonococci to adhere and invade human cervical cells (38). Although the dsDNA phages were not able to form plaques in commensal Neisseria, lambda-like particles from N. gonorrhoeae culture supernatants, presumed to be from the integrated prophages, were visualized by electron microscopy (121).…”

Section: Bacteriophagesmentioning

confidence: 98%

The Genetics of Neisseria Species

2014

View full text Add to dashboard Cite

Neisseria gonorrhoeae and Neisseria meningitidis are closely related organisms that cause the sexually transmitted infection gonorrhea and serious bacterial meningitis and septicemia, respectively. Both species possess multiple mechanisms to alter the expression of surface-exposed proteins through the processes of phase and antigenic variation. This potential for wide variability in surface-exposed structures allows the organisms to always have subpopulations of divergent antigenic types to avoid immune surveillance and to contribute to functional variation. Additionally, the Neisseria are naturally competent for DNA transformation, which is their main means of genetic exchange. Although bacteriophages and plasmids are present in this genus, they are not as effective as DNA transformation for horizontal genetic exchange. There are barriers to genetic transfer, such as restriction-modification systems and CRISPR loci, that limit particular types of exchange. These host-restricted pathogens illustrate the rich complexity of genetics that can help define the similarities and differences of closely related organisms.

show abstract

Neisseria Prophage Repressor Implicated in Gonococcal Pathogenesis

Cited by 14 publications

References 36 publications

Characterization of the Neisseria gonorrhoeae Iron and Fur Regulatory Network

Characterization of the Neisseria gonorrhoeae Iron and Fur Regulatory Network

A High-Throughput Method to Examine Protein-Nucleotide Interactions Identifies Targets of the Bacterial Transcriptional Regulatory Protein Fur

The Genetics of Neisseria Species

Contact Info

Product

Resources

About