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In Salmonella enterica, the pathogenicity island 2 (SPI-2) regulator PagR regulates its own expression and the expression of a five-gene operon that encodes transketolase C
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  • Jorge Escalante-Semerena,
  • Anastacia R. Parks,
  • Regan D. McCormick,
  • Jordan A. Byrne
Jorge Escalante-Semerena
University of Georgia Department of Microbiology

Corresponding Author:jcescala@uga.edu

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Anastacia R. Parks
University of Georgia Department of Microbiology
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Regan D. McCormick
University of Georgia Department of Microbiology
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Jordan A. Byrne
University of Georgia Department of Microbiology
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Abstract

The enteropathogen Salmonella enterica subsp. enterica sv. Typhimurium str. LT2 (hereafter S. Typhimurium) utilizes a cluster of genes encoded within the pathogenicity island 2 (SPI-2) of its genome to proliferate inside macrophages. The expression of SPI-2 is controlled by a complex network of transcriptional regulators and environmental cues, which now include a recently characterized DNA-binding protein named PagR. Growth of S. Typhimurium in low phosphate low magnesium medium mimics conditions inside macrophages. Under such conditions, PagR ensures SPI-2 induction by upregulating the transcription of slyA, a known activator of SPI-2. Here we report that PagR represses the expression of a divergently transcribed polycistronic operon that encodes the two subunits of transketolase TktC ( i.e., tktD, tktE) of this bacterium. Transketolases contribute to the non-redox rearrangements of phosphorylated sugars of the pentose phosphate pathway, which provide building blocks for amino acids, nucleotides, cofactors, etc. We also demonstrate that PagR represses the expression of its own gene and define two PagR binding sites between stm2344 and pagR.
09 Jun 2023Submitted to Molecular Microbiology
12 Jun 2023Submission Checks Completed
12 Jun 2023Assigned to Editor
12 Jun 2023Reviewer(s) Assigned
04 Jul 2023Review(s) Completed, Editorial Evaluation Pending
05 Jul 2023Editorial Decision: Revise Minor
05 Aug 20231st Revision Received
07 Aug 2023Submission Checks Completed
07 Aug 2023Assigned to Editor
07 Aug 2023Editorial Decision: Accept