Project description:Sigma and anti-sigma factor systems enable bacteria to rapidly remodel transcriptional programs in response to environmental changes. Pseudomonas aeruginosa relies on these regulatory modules to coordinate diverse physiological states, including motility, biofilm formation, secondary metabolism and virulence-associated behaviors. In this study, RNA sequencing was performed to characterize transcriptional changes caused by representative anti-sigma factor deletions in Pseudomonas aeruginosa PAO1. Transcriptomic analysis of ΔPA1774, ΔflgM (PA3351) and ΔfiuR (PA0471) mutants revealed distinct regulatory states associated with SigX, FliA and FiuI pathway activation. These data provide insights into how anti-sigma factor perturbation reshapes sigma-dependent transcriptional programs and contributes to adaptive-state transitions in P. aeruginosa.
Project description:To further determine the origin of the increased virulence of Pseudomonas aeruginosa PA14 compared to Pseudomonas aeruginosa PAO1, we report a transcriptomic approach through RNA sequencing. Next-generation sequencing (NGS) has revolutioned sistems-based analsis of transcriptomic pathways. The goals of this study are to compare the transcriptomic profile of all 5263 orthologous genes of these nearly two strains of Pseudomonas aeruginosa.
Project description:Analysis of Pseudomonas aeruginosa PAO1 treated with 200 µM sphingomyelin. Results provide insight into the response to sphingomyelin in P. aeruginosa.
Project description:Regulatory networks including virulence-related transcriptional factors (TFs) determine bacterial pathogenicity in response to different environmental cues. Pseudomonas aeruginosa, a Gram-negative opportunistic pathogen of humans, recruits numerous TFs in quorum sensing (QS) system, type III secretion system (T3SS) and Type VI secretion system (T6SS) to mediate the pathogenicity. Although many virulence-related TFs have been illustrated individually, very little is known about their crosstalks and regulatory network. Here, based on chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) and transcriptome profiling (RNA-seq), we primarily focused on understanding the crosstalks of 20 virulence-related TFs, which led to construction of a virulence regulatory network named PAGnet (Pseudomonas aeruginosa Genomic integrated regulatory network), including 82 crosstalk targets. The PAGnet uncovered the intricate mechanism of virulence regulation and revealed master regulators in QS, T3SS and T6SS pathways. In particular, GacA and ExsA showed novel functions in QS and nitrogen metabolism. In addition, an online PAGnet platform was provided to analyze these TFs and more virulence factors. Taken together, the present study revealed the function-specific crosstalks of virulence regulatory network, which might provide new strategies for treating infections in P. aeruginosa in the future.
