The Regulation of the ospZ and ORF-2 promoters in the Shigella flexneri by the virulence factor VirB
Location
University of Nevada Las Vegas
Start Date
6-8-2009 9:30 AM
End Date
6-8-2009 12:00 PM
Description
Shigella flexneri is a pathogenic bacterium that is the causative agent of shigellosis, an illness characterized by severe dysentery. Shigella carries many of its virulence genes on a large virulence plasmid and consequently this plasmid is the focus of research in the Wing lab. My research focuses on the transcriptional regulation of a newly identified gene called ospZ. This gene’s protein product is secreted outside the bacterial cell and assists in polymorphonuclear leukocyte migration, a function that is believed to enhance the virulence of Shigella. Many genes encoded by the Shigella virulence plasmid are regulated by the transcription factor VirB, which is also encoded by the virulence plasmid. VirB regulates the expression of IcsP, a gene 1.6 kilobase pairs upstream of ospZ on the divergent strand. To determine the role VirB plays in the regulation of ospZ, reporter plasmids will be constructed in which the ospZ promoter region is fused to lacZ (a gene that encodes the enzyme betagalactosidase) and transformed into wild type and VirB mutant strains of Shigella. Promoter activity of ospZ will then be measured using beta-galactosidase assays. My hypothesis is that VirB, which binds to DNA 100 base pairs upstream of the ospZ gene, regulates the expression of this gene also.
Keywords
Bacteria; Dysentery; ospZ gene; Plasmids; Shigella flexneri
Disciplines
Bacterial Infections and Mycoses | Digestive System Diseases
Language
English
The Regulation of the ospZ and ORF-2 promoters in the Shigella flexneri by the virulence factor VirB
University of Nevada Las Vegas
Shigella flexneri is a pathogenic bacterium that is the causative agent of shigellosis, an illness characterized by severe dysentery. Shigella carries many of its virulence genes on a large virulence plasmid and consequently this plasmid is the focus of research in the Wing lab. My research focuses on the transcriptional regulation of a newly identified gene called ospZ. This gene’s protein product is secreted outside the bacterial cell and assists in polymorphonuclear leukocyte migration, a function that is believed to enhance the virulence of Shigella. Many genes encoded by the Shigella virulence plasmid are regulated by the transcription factor VirB, which is also encoded by the virulence plasmid. VirB regulates the expression of IcsP, a gene 1.6 kilobase pairs upstream of ospZ on the divergent strand. To determine the role VirB plays in the regulation of ospZ, reporter plasmids will be constructed in which the ospZ promoter region is fused to lacZ (a gene that encodes the enzyme betagalactosidase) and transformed into wild type and VirB mutant strains of Shigella. Promoter activity of ospZ will then be measured using beta-galactosidase assays. My hypothesis is that VirB, which binds to DNA 100 base pairs upstream of the ospZ gene, regulates the expression of this gene also.
Comments
Abstract & poster