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Updated: Mar 28, 2026

TransFLP — A Method to Genetically Modify Vibrio cholerae Based on Natural Transformation and FLP-recombination
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TransFLP — A Method to Genetically Modify Vibrio cholerae Based on Natural Transformation and FLP-recombination

Published on: October 8, 2012

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Pathogenicity Island Cross Talk Mediated by Recombination Directionality Factors Facilitates Excision from the

Megan R Carpenter1, Sharon Rozovsky2, E Fidelma Boyd3

  • 1Department of Biological Sciences, University of Delaware, Newark, Delaware, USA.

Journal of Bacteriology
|December 16, 2015
PubMed
Abstract

Insights

Recombination directionality factors (RDFs) are crucial for the excision of Vibrio pathogenicity islands (VPIs). These RDFs promote VPI excision and repress integrase activity, revealing cross-talk between mobile genetic elements.

Area of Science:

  • Microbiology
  • Genetics
  • Molecular Biology

Background:

  • Pathogenicity islands (PAIs) are mobile genetic elements that contribute to bacterial virulence.
  • PAI excision is the initial step in their horizontal transfer, a process not fully understood.
  • Understanding PAI excision mechanisms is key to comprehending bacterial evolution and the spread of virulence factors.

Purpose of the Study:

  • To investigate the role of recombination directionality factors (RDFs) in the excision of Vibrio pathogenicity islands (VPIs).
  • To determine if RDFs are essential for the excision of VPI-1 and VPI-2 in Vibrio cholerae.
  • To elucidate the relationship between RDFs and integrases in PAI excision and regulation.

Main Methods:

  • Comparative analysis of PAI excision in the presence and absence of RDFs.
  • Site-specific binding assays to determine RDF-integrase interactions.
  • Gene expression analysis to assess the regulatory role of RDFs on integrase activity.

Main Results:

  • RDFs are required for efficient excision of VPI-2 but not VPI-1.
  • RDFs can induce the excision of both VPI-1 and VPI-2.
  • RDFs function as transcriptional repressors of integrases, binding to promoter regions.
  • Demonstrated cross-talk between VPI-1 and VPI-2 mediated by promiscuous RDFs.

Conclusions:

  • RDFs play a dual role: promoting PAI excision and repressing integrase transcription.
  • Vibrio cholerae RDFs exhibit promiscuity, interacting with multiple PAIs.
  • This cross-talk mechanism highlights the complex interactions between mobile genetic elements in bacteria.

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