Expression data from Neisseria gonorrhoeae (FA19)
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ABSTRACT:
ORGANISM(S): Neisseria gonorrhoeae
PROVIDER: GSE12686 | GEO | 2008/12/26
SECONDARY ACCESSION(S): PRJNA112689
REPOSITORIES: GEO
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Project description:Previous studies have shown that the MpeR transcriptional regulator produced by Neisseria gonorrhoeae represses expression of mtrF, which encodes a putative inner membrane protein that works with the MtrC-MtrD-MtrE efflux pump to allow gonococci to resist high levels of multiple hydrophobic antimicrobials. Regulation of mpeR has been reported to occur by an iron-dependent mechanism involving Fur (Ferric uptake regulator). Collectively, these observations suggest the presence of an interconnected regulatory system in gonococci that modulates expression of drug efflux pump protein-encoding genes in an iron-responsive manner. Herein, we describe this connection and report that levels of gonococcal resistance to a substrate of the mtrCDE-encoded efflux pump can be modulated by MpeR and the availability of free iron. Using microarray analysis, we found that the mtrR gene, which encodes the direct transcriptional repressor (MtrR) of mtrCDE, is an MpeR-repressed determinant in the late-logarithmic phase of growth when free iron levels would be reduced due to bacterial consumption. MpeR-mediated repression of mtrR appeared to be direct, as judged by DNA-binding analyses, and was enhanced by conditions of iron-limitation, which resulted in increased expression of the mtrCDE efflux pump operon. Taken together, our results indicate that both genetic and physiologic parameters can influence expression of the mtr efflux system and that these can modulate levels of gonococcal susceptibility to efflux pump substrates.
2012-04-04 | GSE32717 | GEO
Project description:Previous studies have shown that the MpeR transcriptional regulator produced by Neisseria gonorrhoeae represses expression of mtrF, which encodes a putative inner membrane protein that works with the MtrC-MtrD-MtrE efflux pump to allow gonococci to resist high levels of multiple hydrophobic antimicrobials. Regulation of mpeR has been reported to occur by an iron-dependent mechanism involving Fur (Ferric uptake regulator). Collectively, these observations suggest the presence of an interconnected regulatory system in gonococci that modulates expression of drug efflux pump protein-encoding genes in an iron-responsive manner. Herein, we describe this connection and report that levels of gonococcal resistance to a substrate of the mtrCDE-encoded efflux pump can be modulated by MpeR and the availability of free iron. Using microarray analysis, we found that the mtrR gene, which encodes the direct transcriptional repressor (MtrR) of mtrCDE, is an MpeR-repressed determinant in the late-logarithmic phase of growth when free iron levels would be reduced due to bacterial consumption. MpeR-mediated repression of mtrR appeared to be direct, as judged by DNA-binding analyses, and was enhanced by conditions of iron-limitation, which resulted in increased expression of the mtrCDE efflux pump operon. Taken together, our results indicate that both genetic and physiologic parameters can influence expression of the mtr efflux system and that these can modulate levels of gonococcal susceptibility to efflux pump substrates. two strains, two growth phases, three replicates each.
2012-04-03 | E-GEOD-32717 | biostudies-arrayexpress
Project description:Carbon catabolite repression (CCR) is a gene regulation process that allows bacteria to use carbon-energy sources in a hierarchical manner. Thus, the presence of a preferred sugar, usually D-glucose, results in downregulation of genes participating in the transport and catabolic pathways of secondary carbon sources. Further, CCR controls the expression of global regulators that control expression of many genes involved in multiple aspects of bacterial physiology such as stress response proteins and virulence factors. The human-restricted pathogen Neisseria gonorrhoeae can rely upon a limited number of carbon-energy sources, including glucose and lactate and both are available within its infection niches. We recently reported that expression of the L-lactate permease-encoding gene lctP is subjected to glucose repression within physiological concentrations. However, the transducing mechanism or the gene that connect glucose with lctP promoter repression remained unknown. To address this issue, we performed an RNA-Seq analysis to determine the transcriptional landscape of gonococci due to changes in glucose or lactate concentrations in the growth media. Glucose was found to regulate 144 genes (5.5% of total genes in the genome) while lactate influenced the expression of 434 (16.5%) genes with an overlap of 97 genes between the two sugars. Both, glucose and lactate were found to upregulate genes involved in protein translation, a high energy consumption cellular function. Individually, glucose enhanced genes participating in glycolysis and repressed genes in the tricarboxylic acid (TCA) cycle, while lactate enhanced genes encoding respiratory enzymes and ATP synthase. Interestingly, lactate was found to repress expression of several genes encoding known gonococcal virulence factors such as tbpAB encoding the transferrin-binding proteins; the tonB and exbBD genes encoding the membrane energy transfer complex TonB-ExbB-ExbD required for many outer membrane transport systems; katA encoding an important H2O2-inducible catalase and to upregulate mtrR encoding the master repressor of the mtrCDE antimicrobial efflux pump genes. Moreover, glucose repressed mntC encoding a Zn/Mn ABC transporter and lctP, both required for resistance to killing by H2O2. These results set the framework to determine important gonococci virulent factor genes whose expression can be modulated by CCR as well as to discover the corresponding CCR regulators that control such genes.
2022-12-31 | GSE148774 | GEO
Project description:A whole transcriptome comparison of N. gonorrhoeae strain FA19, which bears a wild-type mtr locus, and FA19mtr120, which contains a C-to-T transition mutation 120 base pairs upstream of the mtrC start codon that generates a second promoter for mtrCDE transcription, was performed to determine the effects of high-level expression of the mtrCDE efflux pump operon on global transcription within the gonococcus.
2013-05-18 | GSE47048 | GEO
Project description:A whole transcriptome comparison of N. gonorrhoeae strain FA19, which bears a wild-type mtr locus, and FA19mtr120, which contains a C-to-T transition mutation 120 base pairs upstream of the mtrC start codon that generates a second promoter for mtrCDE transcription, was performed to determine the effects of high-level expression of the mtrCDE efflux pump operon on global transcription within the gonococcus. Examination of the transcriptomes of N. gonorrhoeae wild-type strain FA19 and the isogenic FA19mtr120 mutant to determine the effect of overexpression of mtrCDE on gonococcal cells grown under laboratory conditions. Illumina HiSeq-2000 next generation sequencing was used to sequence the transcriptomes of each strain. Reads were mapped against the N. gonorrhoeae FA1090 genome (NCBI accession number NC_002946) because at the time this experiment was run the FA19 genome was incomplete.
2013-05-18 | E-GEOD-47048 | biostudies-arrayexpress
Project description:Maintenance of an anaerobic respiratory system in the obligate human pathogen, Neisseria gonorrhoeae, suggests that an anaerobic lifestyle may be important during the course of infection. However, at this point there have been no studies analyzing the complete gonococcal transcriptome response to anaerobiosis. Here we performed deep sequencing to compare the gonococcal transcriptomes of aerobic and anaerobically grown cells. We found that the anaerobic stimulon in gonococci was large, and that 198 chromosomal genes were found to be differentially expressed. We also observed a large induction of genes encoded within the cryptic plasmid, pJD1. Secondary analysis of genes found to be differentially expressed by RNA-seq using translational-lacZ fusions or RT-PCR demonstrated the RNA-seq results to be very reproducible. Surprisingly, many genes of prophage origin were induced anaerobically, as well as several transcriptional regulators previously unknown to be involved in anaerobic growth. We also confirmed expression and regulation of a small RNA, likely a functional equivalent of fnrS in the Enterobacteriaceae family. Several novel factors were identified to be anaerobically regulated, as well as a large number of hypothetical proteins were induced.
2011-01-26 | GSE26444 | GEO
Project description:To compare the expression profile of B. cenocepacia mutants impaired in RND efflux pump encoding genes
2011-04-23 | E-MEXP-2999 | biostudies-arrayexpress
Project description:To compare the expression profile of B. cenocepacia mutants impaired in RND efflux pump encoding genes
2011-04-23 | E-MEXP-2997 | biostudies-arrayexpress
Project description:Maintenance of an anaerobic respiratory system in the obligate human pathogen, Neisseria gonorrhoeae, suggests that an anaerobic lifestyle may be important during the course of infection. However, at this point there have been no studies analyzing the complete gonococcal transcriptome response to anaerobiosis. Here we performed deep sequencing to compare the gonococcal transcriptomes of aerobic and anaerobically grown cells. We found that the anaerobic stimulon in gonococci was large, and that 198 chromosomal genes were found to be differentially expressed. We also observed a large induction of genes encoded within the cryptic plasmid, pJD1. Secondary analysis of genes found to be differentially expressed by RNA-seq using translational-lacZ fusions or RT-PCR demonstrated the RNA-seq results to be very reproducible. Surprisingly, many genes of prophage origin were induced anaerobically, as well as several transcriptional regulators previously unknown to be involved in anaerobic growth. We also confirmed expression and regulation of a small RNA, likely a functional equivalent of fnrS in the Enterobacteriaceae family. Several novel factors were identified to be anaerobically regulated, as well as a large number of hypothetical proteins were induced. Two biological replicates of cells grown aerobically or anaerobically with nitrite were analyzed, for a total of four samples subject to SOLiD RNA sequencing.
2011-01-26 | E-GEOD-26444 | biostudies-arrayexpress
Project description:Neisseria gonorrhoeae, the etiologic agent of gonorrhea, is frequently asymptomatic in women, often leading to chronic infections. One factor contributing to this may be biofilm formation. N. gonorrhoeae can form biofilms over glass and plastic surfaces. There is also evidence that biofilm formation may occur during natural cervical infection. To further study the mechanism of this biofilm formation, transcriptional profiles of N. gonorrhoeae biofilm were compared to planktonic profiles. Biofilm RNA was extracted from N. gonorrhoeae 1291 grown for 48 hours in continuous flow chambers over glass. Planktonic RNA was extracted from the biofilm runoff. When biofilm was compared to planktonic growth, 3.8 % of the genome was differentially regulated. Genes highly up-regulated in biofilm included aniA, norB, and ccp, which play critical roles in anaerobic metabolism and oxidative stress tolerance. Down-regulated genes included the nuo gene cluster (NADH dehydrogenase) and the cytochrome bcI complex, which are involved in aerobic respiration and are thought to contribute to endogenous oxidative stress. Furthermore, we determined that aniA, ccp, and norB insertional mutants are attenuated for biofilm formation over glass and transformed human cervical epithelial cells (THCEC). This data suggests that biofilm formation could minimize oxidative stress during cervical infection and allow N. gonorrhoeae to maintain a nitric oxide steady state that may be anti-inflammatory.
2009-02-27 | GSE14815 | GEO