An rhs Gene Linked to the Second Type VI Secretion Cluster Is a Feature of the Pseudomonas aeruginosa Strain PA14
Author(s)
Jones, C
Hachani, A
Manoli, E
Filloux, A
Type
Journal Article
Abstract
The type VI secretion system (T6SS) of Gram-negative bacteria has been involved in various processes, notably bacterial competition and eukaryotic cell subversion. Most Pseudomonas aeruginosa strains possess three T6SS gene clusters, but only the function of the first T6SS (H1-T6SS) has been clearly elucidated. It is involved in the secretion of three toxins (Tse1 to -3) that target bacterial competitors. In the case of the H2- and H3-T6SS, no clear function has been assigned, and only one effector has been associated with these systems. Yet the H2-T6SS was proposed to promote P. aeruginosa internalization in nonphagocytic epithelial cells. Although the H2-T6SS genetic organization is conserved across P. aeruginosa isolates, one feature is the presence of an additional transcriptional unit in the PA14 strain H2-T6SS cluster, which is divergent from the core H2-T6SS genes. A specific set of four genes encodes an Hcp protein (Hcp2), a VgrG protein (VgrG14), an Rhs element (PA14_43100 or RhsP2), and a protein with no homologies with previously characterized proteins (PA14_43090). In this study, we engineered a P. aeruginosa PA14 strain carrying an arabinose-inducible H2-T6SS on the chromosome. We showed that arabinose induction readily promotes assembly of the H2-T6SS, as seen by monitoring Hcp2 secretion. We further studied the secretion fate of VgrG14 and RhsP2, but these were not detectable in the extracellular medium. We finally investigated whether activation of the PA14 H2-T6SS gene cluster could influence phenotypic traits such as internalization in eukaryotic cells, and we reported noteworthy differences compared to strain PAO1, which may be accounted for by the described genetic differences.
Date Issued
2013-12-06
Date Acceptance
2013-11-18
Citation
Journal of Bacteriology, 2013, 196 (4), pp.800-810
ISSN
1098-5530
Publisher
American Society for Microbiology
Start Page
800
End Page
810
Journal / Book Title
Journal of Bacteriology
Volume
196
Issue
4
Copyright Statement
This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 Unported license.
License URL
Sponsor
Medical Research Council (MRC)
Medical Research Council (MRC)
Grant Number
G0800171
MR/K001930/1
Subjects
Science & Technology
Life Sciences & Biomedicine
Microbiology
MICROBIOLOGY
PROTEIN SECRETION
VIBRIO-CHOLERAE
BIOFILM FORMATION
ESCHERICHIA-COLI
TARGET-CELLS
SYSTEM
VIRULENCE
TAIL
ACTIN
BACTERIOPHAGE-T4
Animals
Bacterial Proteins
Bacterial Secretion Systems
Cell Line
Cell Survival
Endocytosis
Gene Expression Regulation, Bacterial
Gene Order
Genes, Bacterial
Macrophages
Mice
Multigene Family
Operon
Pseudomonas aeruginosa
06 Biological Sciences
11 Medical And Health Sciences
07 Agricultural And Veterinary Sciences
Publication Status
Published