The effect of pmpR on the type III secretion system in Pseudomonas aeruginosa

Abstract

The type III secretion system (T3SS) plays important roles in Pseudomonas aeruginosa pathogenicity. Previously, we reported that the uncharacterized protein PmpR could regulate pqsR, an important regulator in the quorum-sensing system, by directly binding to its promoter region. As the T3SS is controlled by the quorum-sensing system, here, we investigated the relationship between PmpR and the T3SS. Our data showed that expression of the T3SS genes exoS, exoY, exoT, and exsD was dramatically increased in a pmpR-deletion mutant compared with that in the wild-type P. aeruginosa strain PAO1. Data from DNA mobility assays indicated that PmpR affects the T3SS indirectly. It is unlikely that PmpR controls the T3SS via the Pseudomonas quinolone signal (PQS) because the PQS negatively regulates the T3SS, while pmpR negatively regulates the PQS. The effect of PmpR on the T3SS seems to be independent of the PQS; further investigation is required to uncover the underlying regulatory pathways. P. aeruginosa, pmpR, PQS, type III secretion system Citation:Liang H H, Kong W N, Shen T, et al. The effect of pmpR on the type III secretion system in Pseudomonas aeruginosa.

Synthesis and biological evaluation of triazole-containing N-acyl homoserine lactones as quorum sensing modulators

“…This contrasting activity trend for IV-AE between to the two receptors is notable, as LasR and AbaR share very similar native ligands (OdDHL and OH-dDHL, respectively), and have high sequence homology in their ligand-binding sites (note, this site is only putative in the case of AbaR). 61, 65 Additional biochemical studies are warranted to probe this disparity further. Lastly, the type V triazoles containing multiple HL groups displayed modest LasR agonistic and antagonistic activities at best, suggesting that while additional study of such multivalent structures could be fruitful, ligand redesign ( e.g.…”

Conjugated Oligo- and Polymers for Bacterial Sensing

“…A hyperpiliated pilT mutant, known to show increased cell-to-cell and cell-to-surface adhesion, exhibited increased electrogenicity (Chiang and Burrows, 2003). In contrast, a deletion in the pmpR gene, known to inhibit the type III secretion system, generated less current than the wild type (Liang et al, 2012). Collectively, this work presents an important milestone toward redox-based sensing of bacteria using conducting polymers.…”