Expression of the type VI secretion system 1 component Hcp1 is indirectly repressed by OpaR in Vibrio parahaemolyticus

ScientificWorldJournal. 2012;2012:982140. doi: 10.1100/2012/982140. Epub 2012 Jul 31.


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 of Vibrio parahaemolyticus, respectively. This work disclosed that the master quorum sensing (QS) regulator OpaR repressed the transcription of hcp1 encoding the structural component Hcp1 of T6SS1 in V. parahaemolyticus, indicating that QS had a negative regulatory action on T6SS1. A single σ(54)-dependent promoter was transcribed for hcp1 in V. parahaemolyticus, and its activity was repressed by the OpaR regulator. Since the OpaR protein could not bind to the upstream region of hcp1, OpaR would repress the transcription of hcp1 in an indirect manner.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Bacterial Secretion Systems*
  • Base Sequence
  • Chromosomes, Bacterial / genetics
  • Chromosomes, Bacterial / metabolism
  • DNA, Bacterial / genetics
  • DNA, Bacterial / metabolism
  • Gene Expression Regulation, Bacterial*
  • Genes, Bacterial
  • Genetic Loci
  • Molecular Sequence Data
  • Promoter Regions, Genetic
  • Quorum Sensing
  • Regulatory Sequences, Nucleic Acid
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcription, Genetic
  • Vibrio parahaemolyticus / genetics
  • Vibrio parahaemolyticus / metabolism*


  • Bacterial Proteins
  • Bacterial Secretion Systems
  • DNA, Bacterial
  • OpaR protein, Vibrio parahaemolyticus
  • Repressor Proteins
  • Transcription Factors