Abstract

: In most Gram-negative pathogens, genes involved in iron acquisition and virulence are transcriptionally regulated by the availability of iron through the ferric uptake regulator protein, Fur. The etiological agent of the sexually transmitted disease gonorrhea, Neisseria gonorrhoeae, produces a number of iron regulated proteins which are utilized for iron transport and expression of these proteins is thought to be under the control of Fur; however, the role of Fur in controlling expression of iron transport genes or virulence factors in N. gonorrhoeae is not well defined. This application proposes to further our understanding of the regulation of genes involved in iron transport and virulence by the transcriptional regulator protein Fur, and to define the role of the Fur-regulon in N. gonorrhoeae pathogenesis. Our hypothesis is that Fur controls the expression of a number of genes in addition to iron transport genes that are required for the virulence of N. gonorrhoeae.
The specific aims of this proposal are as follows:
Aim 1. To identify the minimal essential gonococcal nucleotide sequence for Fur binding and characterize the interactions of gonococcal Fur with iron-regulated promoters.
Aim 2. To isolate and characterize iron-independent mutants of gonococcal Fur.
Aim 3. To define the Fur regulon in N gonorrhoeae.
Aim 4. To define the role of the gonococcal Fur regulon in pathogenesis. These studies are based on the premise that gonococcal Fur binds to a unique and specific array of DNA sequences within the promoter regions of a number of Fur-regulated genes. This allows gonococcal Fur to function as a general global regulator controlling the expression of numerous genes in Neisseria. The intracellular iron concentration and the variability and extension of sequences targeted by Fur may cause a wide range of responses. Therefore, there may be many genes that are regulated by Fur that are unidentified. The results obtained in these studies will enable us to define the binding of gonococcal Fur to gonococcal Fur-regulated promoters, to identify additional genes which are regulated by Fur in N. gonorrhoeae, to define the mechanisms of Fur mediated regulation, and to correlate this with the pathogenic potential of N gonorrhoeae.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI048611-05
Application #
6888963
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Program Officer
Hiltke, Thomas J
Project Start
2001-07-15
Project End
2007-05-31
Budget Start
2005-06-01
Budget End
2007-05-31
Support Year
5
Fiscal Year
2005
Total Cost
$402,500
Indirect Cost

  Institution

Name
Boston Medical Center
Department
Type
DUNS #
005492160
City
Boston
State
MA
Country
United States
Zip Code
02118

  Publications

Yu, Chunxiao; McClure, Ryan; Nudel, Kathleen et al. (2016) Characterization of the Neisseria gonorrhoeae Iron and Fur Regulatory Network. J Bacteriol 198:2180-91
Yu, Chunxiao; Lopez, Carlos A; Hu, Han et al. (2014) A high-throughput method to examine protein-nucleotide interactions identifies targets of the bacterial transcriptional regulatory protein fur. PLoS One 9:e96832
McClure, Ryan; Balasubramanian, Divya; Sun, Yan et al. (2013) Computational analysis of bacterial RNA-Seq data. Nucleic Acids Res 41:e140
Daou, Nadine; Yu, Chunxiao; McClure, Ryan et al. (2013) Neisseria prophage repressor implicated in gonococcal pathogenesis. Infect Immun 81:3652-61
Yu, Chunxiao; Genco, Caroline Attardo (2012) Fur-mediated activation of gene transcription in the human pathogen Neisseria gonorrhoeae. J Bacteriol 194:1730-42
Mellin, J R; McClure, Ryan; Lopez, Delia et al. (2010) Role of Hfq in iron-dependent and -independent gene regulation in Neisseria meningitidis. Microbiology 156:2316-26
Follows, S A; Murlidharan, J; Massari, P et al. (2009) Neisseria gonorrhoeae infection protects human endocervical epithelial cells from apoptosis via expression of host antiapoptotic proteins. Infect Immun 77:3602-10
Agarwal, Sarika; Sebastian, Shite; Szmigielski, Borys et al. (2008) Expression of the gonococcal global regulatory protein Fur and genes encompassing the Fur and iron regulon during in vitro and in vivo infection in women. J Bacteriol 190:3129-39
Mellin, J R; Goswami, Sulip; Grogan, Susan et al. (2007) A novel fur- and iron-regulated small RNA, NrrF, is required for indirect fur-mediated regulation of the sdhA and sdhC genes in Neisseria meningitidis. J Bacteriol 189:3686-94
Agarwal, Sarika; King, Carol A; Klein, Ellen K et al. (2005) The gonococcal Fur-regulated tbpA and tbpB genes are expressed during natural mucosal gonococcal infection. Infect Immun 73:4281-7

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