Pseudomonas aeruginosa Quorum-Sensing and Type VI Secretion System Can Direct Interspecific Coexistence During Evolution

The type VI secretion system (T6SS) is bacterial protein injection machinery with roles in virulence, symbiosis, interbacterial interaction, antipathogenesis, and environmental stress responses. There are two T6SS loci, T6SS1 and T6SS2, in the two chromosomes ofVibrio parahaemolyticus, respectively. This work disclosed that the master quorum sensing (QS) regulator OpaR repressed the transcription ofhcp1encoding the structural component Hcp1 of T6SS1 inV. parahaemolyticus, indicating that QS had a negative regulatory action on T6SS1. A singleσ54-dependent promoter was transcribed forhcp1inV. parahaemolyticus, and its activity was repressed by the OpaR regulator. Since the OpaR protein could not bind to the upstream region ofhcp1, OpaR would repress the transcription ofhcp1in an indirect manner.

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Corrigendum: Transcriptional Regulation of the Type VI Secretion System 1 Genes by Quorum Sensing and ToxR in Vibrio parahaemolyticus

Frontiers in Microbiology ◽

10.3389/fmicb.2020.616153 ◽

2020 ◽

Vol 11 ◽

Author(s):

Yiquan Zhang ◽

He Gao ◽

George Osei-Adjei ◽

Ying Zhang ◽

Wenhui Yang ◽

...

Keyword(s):

Transcriptional Regulation ◽

Quorum Sensing ◽

Vibrio Parahaemolyticus ◽

Secretion System ◽

Type Vi Secretion System ◽

Type Vi Secretion ◽

System 1

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YbeY controls the type III and type VI secretion systems and biofilm formation through RetS in Pseudomonas aeruginosa

Applied and Environmental Microbiology ◽

10.1128/aem.02171-20 ◽

2020 ◽

Author(s):

Yushan Xia ◽

Congjuan Xu ◽

Dan Wang ◽

Yuding Weng ◽

Yongxin Jin ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Type Iii Secretion ◽

Biofilm Formation ◽

Small Rnas ◽

Type Iii Secretion System ◽

Secretion System ◽

Type Vi Secretion System ◽

Chronic Infections ◽

Type Iii ◽

Type Vi Secretion

YbeY is a highly conserved RNase in bacteria and plays essential roles in the maturation of 16S rRNA, regulation of small RNAs (sRNAs) and bacterial responses to environmental stresses. Previously, we verified the role of YbeY in rRNA processing and ribosome maturation in Pseudomonas aeruginosa and demonstrated YbeY-mediated regulation of rpoS through a sRNA ReaL. In this study, we demonstrate that mutation of the ybeY gene results in upregulation of the type III secretion system (T3SS) genes as well as downregulation of the type VI secretion system (T6SS) genes and reduction of biofilm formation. By examining the expression of the known sRNAs in P. aeruginosa, we found that mutation of the ybeY gene leads to downregulation of the small RNAs RsmY/Z that control the T3SS, the T6SS and biofilm formation. Further studies revealed that the reduced levels of RsmY/Z are due to upregulation of retS. Taken together, our results reveal the pleiotropic functions of YbeY and provide detailed mechanisms of YbeY-mediated regulation in P. aeruginosa. IMPORTANCE Pseudomonas aeruginosa causes a variety of acute and chronic infections in humans. The type III secretion system (T3SS) plays an important role in acute infection and the type VI secretion system (T6SS) and biofilm formation are associated with chronic infections. Understanding of the mechanisms that control the virulence determinants involved in acute and chronic infections will provide clues for the development of effective treatment strategies. Our results reveal a novel RNase mediated regulation on the T3SS, T6SS and biofilm formation in P. aeruginosa.

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ClpV3 of the H3-Type VI Secretion System (H3-T6SS) Affects Multiple Virulence Factors in Pseudomonas aeruginosa

Frontiers in Microbiology ◽

10.3389/fmicb.2020.01096 ◽

2020 ◽

Vol 11 ◽

Cited By ~ 1

Author(s):

Yanqi Li ◽

Lin Chen ◽

Pansong Zhang ◽

Anjali Y. Bhagirath ◽

Kangmin Duan

Keyword(s):

Pseudomonas Aeruginosa ◽

Virulence Factors ◽

Secretion System ◽

Type Vi Secretion System ◽

Type Vi Secretion

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Type VI Secretion System Dynamics Reveals a Novel Secretion Mechanism in Pseudomonas aeruginosa

Journal of Bacteriology ◽

10.1128/jb.00744-17 ◽

2018 ◽

Vol 200 (11) ◽

Cited By ~ 8

Author(s):

Jacqueline Corbitt ◽

Jun Seok Yeo ◽

C. Ian Davis ◽

Michele LeRoux ◽

Paul A. Wiggins

Keyword(s):

Pseudomonas Aeruginosa ◽

Vibrio Cholerae ◽

Conformational Change ◽

Secretion System ◽

Force Generation ◽

Type Vi Secretion System ◽

Content Type ◽

Evolutionary Diversification ◽

Type Vi Secretion ◽

Generation Mechanisms

ABSTRACT The type VI secretion system (T6SS) inhibits the growth of neighboring bacterial cells through a contact-mediated mechanism. Here, we describe a detailed characterization of the protein localization dynamics in the Pseudomonas aeruginosa T6SS. It has been proposed that the type VI secretion process is driven by a conformational-change-induced contraction of the T6SS sheath. However, although the contraction of an optically resolvable TssBC sheath and the subsequent localization of ClpV are observed in Vibrio cholerae , coordinated assembly and disassembly of TssB and ClpV are observed without TssB contraction in P. aeruginosa . These dynamics are inconsistent with the proposed contraction sheath model. Motivated by the phenomenon of dynamic instability, we propose a new model in which ATP hydrolysis, rather than conformational change, generates the force for secretion. IMPORTANCE The type VI secretion system (T6SS) is widely conserved among Gram-negative bacteria and is a central determinant of bacterial fitness in polymicrobial communities. The secretion system targets bacteria and secretes effectors that inhibit the growth of neighboring cells, using a contact-mediated-delivery system. Despite significant homology to the previously characterized Vibrio cholerae T6SS, our analysis reveals that effector secretion is driven by a distinct force generation mechanism in Pseudomonas aeruginosa . The presence of two distinct force generation mechanisms in T6SS represents an example of the evolutionary diversification of force generation mechanisms.

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