PUBLICATION

Involvement of hcp2 on maintaining cell wall integrity and pathogenicity of Vibrio alginolyticus by modulating Sec pathway

Authors
Wu, S., Chen, H., Huang, Y., Wang, B., Amoah, K., Cai, J., Jian, J.
ID
ZDB-PUB-251114-1
Date
2025
Source
The Biochemical journal : (Journal)
Registered Authors
Keywords
LPS, PGN, Sec pathway, cAMP-CRP, hcp2
MeSH Terms
  • Animals
  • Bacterial Proteins*/genetics
  • Bacterial Proteins*/metabolism
  • Cell Wall*/genetics
  • Cell Wall*/metabolism
  • Gene Expression Regulation, Bacterial
  • Humans
  • Lipopolysaccharides/metabolism
  • Peptidoglycan/metabolism
  • Vibrio Infections*/microbiology
  • Vibrio alginolyticus*/genetics
  • Vibrio alginolyticus*/metabolism
  • Vibrio alginolyticus*/pathogenicity
  • Virulence
  • Zebrafish/microbiology
PubMed
41230815 Full text @ Biochem. J.
Abstract
Hemolysin co-regulated protein 2 (Hcp2) is a core component of the type VI secretion system 2 (T6SS2) in Vibrio alginolyticus, a widespread marine pathogen that infects humans and aquaculture species. Deletion of hcp2 (Δhcp2) significantly attenuated virulence in zebrafish larvae, showing reduced abdominal edema and impaired toll like receptor 2 and 4 (tlr2 and tlr4)-mediated innate immune activation compared with the wild-type strain. Enzyme-linked immunosorbent assay (ELISA) and cell lysis assays revealed that the Δhcp2 mutant exhibited decreased levels of lipopolysaccharide (LPS) and peptidoglycan (PGN), along with increased cell permeability and abnormal cell wall structures observed by transmission electron microscopy (TEM). Proteomic and transcriptional analyses further demonstrated that expression of the Sec system components SecB, SecD, and SecF were markedly reduced in the Δhcp2 strain and positively regulated by hcp2. Bioinformatic prediction combined with protein-DNA docking analysis suggested that the transcription of secB, secD, and secF was co-regulated by the cAMP-CRP complex and the sigma factor RpoD, although rpoD expression itself remained unaffected. Together with previous evidence that Hcp2 positively regulates cAMP-CRP, these findings suggested that Hcp2 modulated LPS and PGN translocation probably through the cAMP-CRP pathway, thereby maintaining cell wall integrity and virulence in V. alginolyticus.
Genes / Markers
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping