Date of Award


Degree Type


Degree Name

Master of Science




Biology (MS)

First Advisor/Chairperson

Dr. Josh Sharp


Two-component systems are common gene regulatory pathways seen in bacteria. Gene expression is controlled by these systems through a series of phosphorylation events between two proteins, a membrane bound sensor kinase and a cytoplasmic response regulator. Activation of a two-component system can be caused by biological or environmental stimuli, resulting in altered gene expression. A conserved two-component system was recently discovered in entomopathogenic bacteria, including our model organisms Pseudomonas entomophila and Pseudomonas aeruginosa, and is homologous to the recently identified two-component system, CrbRS, in Vibrio cholerae. In V. cholerae CrbRS regulates acetate metabolism and controls virulence. The aim of this study is to determine whether a homologous two-component system present within our model organisms regulates similar genes within diverse organisms. Experiments by Hang et al., together with the current study, indicate that the deletion of this two-component system results in the down regulation of the gene acsA in V. cholerae, P. entomophila and P. aeruginosa. This study utilized further shows that this two-component system plays an important role in acetate metabolism by regulating expression of acsA in P. aeruginosa and P. entomophila. However, unlike that seen in V. cholerae, it does not regulate the virulence of these organisms.

Access Type

Open Access

Included in

Microbiology Commons