Regulation of the Type III Secretion System by PtsN in Pseudomonas aeruginosa

Abstract

There are many virulence factors in Pseudomonas aeruginosa that contribute to this opportunistic pathogen's ability to evade the immune system and persist during drug therapy. Previous studies recognized the protein PtsN of the nitrogen-related phosphotransferase system (Nitro-PTS) as having a connection to virulence in P. aeruginosa by impacting biofilm levels through an unknown mechanism. Preliminary transcriptomic sequencing data identified that PtsN differentially regulates another virulence factor: the Type III Secretion System (T3SS). The T3SS is a needle-like protein structure embedded in the membrane of many Gram-negative, pathogenic bacteria. This protein complex gives bacteria the ability to inject effector proteins directly into host cells' cytoplasm, increasing the pathogen's ability to colonize the host. My research utilizes luciferase reporter strains to measure the activity of promoters of T3SS genes identified in transcriptome data. These experiments will observe the effect of PtsN on T3SS gene expression, help determine if PtsN is a novel regulator of T3SS in P. aeruginosa and develop a hypothesis for how PtsN interacts with the regulatory proteins that control the expression levels of the T3SS.