The AlgZ/R Two-Component System Is Responsible for Attenuation of Virulence in Pseudomonas aeruginosa

• Main Author: Williams, Danielle A
• Format: Others
• Language: English
• Published: Digital Commons @ East Tennessee State University 2017
• Subjects: Pseudomonas aeruginosa; AlgZ; AlgR; two component system; type IV pili; virulence; Biology; Microbiology
• Online Access: https://dc.etsu.edu/etd/3340; https://dc.etsu.edu/cgi/viewcontent.cgi?article=4780&context=etd

Pseudomonas aeruginosa is an important opportunistic pathogen. Many P. aeruginosa virulence factors are regulated by the AlgZ/R two component system. AlgZ is the sensor histidine kinase which phosphorylates AlgR, the response regulator. AlgR activates transcription of different gene targets based upon its phosphorylation state. The genes that encode AlgZ and AlgR are transcribed in an operon. While regulation of algR expression has been well studied, regulation of algZ expression has not. Using a pilW mutant in concert with algZTF-lacZ transcriptional fusion, we conducted a transposon mutagenesis to identify algZ regulators. We identified an unknown autoregulatory loop. The type IV pilus minor pilins prevent the phosphorylation of AlgR by AlgZ . This inhibition of the AlgZ/R system subsequently down-regulates both the expression of the fimU operon and the algZ/R operon. Because AlgR regulates virulence, it is possible that virulence can also be reduced by targeting activation of the AlgZ/R system.