CalR is required for the expression of T6SS2 and the adhesion of Vibrio parahaemolyticus to HeLa cells

Arch Microbiol. 2017 Aug;199(6):931-938. doi: 10.1007/s00203-017-1361-6. Epub 2017 Apr 4.

Abstract

Vibrio parahaemolyticus expresses one major virulence determinant T6SS2, which is constituted into three putative operons, i.e., VPA1027-1024, VPA1043-1028, and VPA1044-1046. CalR, a LysR-type transcriptional regulator, was originally identified as a repressor of the swarming motility and T3SS1 gene expression. As shown in this study, CalR binds to the promoter-proximal region of each of the three operons to activate their transcription, and moreover, CalR activates the adhesion of V. parahaemolyticus to HeLa cells. In addition, competitive EMSAs demonstrated that CalR acts as an antagonist of H-NS in V. parahaemolyticus. Collectively, these studies confirmed a new physiological role for CalR in V. parahaemolyticus.

Keywords: CalR; T6SS2; Vibrio parahaemolyticus.

MeSH terms

  • Bacterial Adhesion
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Electrophoretic Mobility Shift Assay
  • Gene Expression Regulation, Bacterial*
  • HeLa Cells
  • Humans
  • Operon
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Type VI Secretion Systems / genetics
  • Type VI Secretion Systems / metabolism*
  • Vibrio Infections / microbiology*
  • Vibrio parahaemolyticus / genetics
  • Vibrio parahaemolyticus / metabolism*

Substances

  • Bacterial Proteins
  • Transcription Factors
  • Type VI Secretion Systems