CqsA-introduced quorum sensing inhibits type VI secretion system 2 through an OpaR-dependent pathway in Vibrio parahaemolyticus

Kui Wu; Yongyan Long; Qian Liu; Wei Wang; Guoyin Fan; Hui Long; Yangyun Zheng; Xiansheng Ni; Shengen Chen; Haiying Chen; Shufen Shuai

doi:10.1016/j.micpath.2021.105334

CqsA-introduced quorum sensing inhibits type VI secretion system 2 through an OpaR-dependent pathway in Vibrio parahaemolyticus

Microb Pathog. 2022 Jan:162:105334. doi: 10.1016/j.micpath.2021.105334. Epub 2021 Dec 13.

Authors

Kui Wu¹, Yongyan Long², Qian Liu², Wei Wang², Guoyin Fan², Hui Long², Yangyun Zheng², Xiansheng Ni², Shengen Chen², Haiying Chen³, Shufen Shuai²

Affiliations

¹ The Collaboration Unit for Field Epidemiology of State Key Laboratory for Infectious Disease Prevention and Control, Jiangxi Province Key Laboratory of Animal-origin and Vector-borne Disease, Nanchang Center for Disease Control and Prevention, Nanchang, 330038, China. Electronic address: wooky07@163.com.
² The Collaboration Unit for Field Epidemiology of State Key Laboratory for Infectious Disease Prevention and Control, Jiangxi Province Key Laboratory of Animal-origin and Vector-borne Disease, Nanchang Center for Disease Control and Prevention, Nanchang, 330038, China.
³ The Collaboration Unit for Field Epidemiology of State Key Laboratory for Infectious Disease Prevention and Control, Jiangxi Province Key Laboratory of Animal-origin and Vector-borne Disease, Nanchang Center for Disease Control and Prevention, Nanchang, 330038, China. Electronic address: nccdcchy@126.com.

PMID: 34915139
DOI: 10.1016/j.micpath.2021.105334

Abstract

The well-known food-borne pathogen Vibrio parahaemolyticus employs at least three quorum sensing signals to maintain its high environmental adaptability. V. parahaemolyticus CqsA, the synthase involved in 3-hydroxyundecan-4-one quorum sensing signal, introduces a quorum sensing network. The V. parahaemolyticus virulent factor type VI secretion system 2 (T6SS2), which is associated with adhesion to host cells, was previously reported to be regulated by a quorum sensing system. Herein, we set out to determine the role of CqsA-introduced quorum sensing (CIQS) in T6SS2-associated virulent regulation. Using a tandem mass tag (TMT)-based quantitative proteomics assay, 17 T6SS2 proteins were found having significantly higher abundances in the ΔcqsA strain than in the wild type strain. TMT proteomics assay results were confirmed by a parallel reaction-monitoring (PRM)-based proteomics assay. Two T6SS2 up-regulators, OpaR and CalR, were found under control of CIQS in the TMT proteomics assay, while OpaR was down-regulated and CalR was up-regulated by CIQS. Thus, it was hypothesized that CIQS would inhibit T6SS2 with an OpaR-dependent mechanism. Epistasis experiment with quantitative PCR was designed to analyze the role of OpaR in the process of CIQS inhibiting T6SS2 production. The mRNA levels of T6SS2 genes were up-regulated in the ΔcqsA strain while down-regulated in the ΔopaR strain and in the ΔcqsAΔopaR mutant, indicating that OpaR plays a predominant role in the regulation of T6SS2 by CIQS. Using a cell adhesion assay, we further found that the T6SS2-dependent adhesion activity of V. parahaemolyticus to Hela cells was also inhibited by CIQS and the inhibition was OpaR-dependent. In this study, we confirmed that V. parahaemolyticus CIQS inhibited T6SS2 through an OpaR-dependent pathway. It enriches the knowledge of how V. parahaemolyticus quorum sensing regulates its virulence.

Keywords: CqsA; OpaR; Quorum sensing; Type VI secretion system 2; Vibrio parahaemolyticus.

MeSH terms

Bacterial Proteins / genetics
Bacterial Proteins / metabolism
Gene Expression Regulation, Bacterial
HeLa Cells
Humans
Promoter Regions, Genetic
Quorum Sensing
Transcription Factors / genetics
Type VI Secretion Systems*
Vibrio parahaemolyticus* / genetics

Substances

Bacterial Proteins
Transcription Factors
Type VI Secretion Systems