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Updated: Aug 23, 2025

A Visual Assay to Monitor T6SS-mediated Bacterial Competition
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A Visual Assay to Monitor T6SS-mediated Bacterial Competition

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The P. aeruginosa effector Tse5 forms membrane pores disrupting the membrane potential of intoxicated bacteria

Amaia González-Magaña1, Jon Altuna1, María Queralt-Martín2

  • 1Fundación Biofísica Bizkaia/Biofisika Bizkaia Fundazioa (FBB) and Departamento de Bioquímica y Biología Molecular, Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940, Leioa, Spain.

Communications Biology
|November 6, 2022
PubMed

Insights

Pseudomonas aeruginosa uses its type VI secretion system (T6SS) to deliver Tse5-CT, a toxic protein that forms pores in membranes, causing bacterial death and aiding in competition. This discovery sheds light on T6SS effector mechanisms.

Area of Science:

  • Microbiology
  • Bacterial Pathogenesis
  • Molecular Biology

Background:

  • The Type VI Secretion System (T6SS) in Pseudomonas aeruginosa is crucial for its survival and virulence.
  • Understanding T6SS effectors is vital for combating this opportunistic pathogen.
  • Many T6SS effectors and their mechanisms remain uncharacterized.

Purpose of the Study:

  • To elucidate the molecular mechanism of Tse5-CT, a P. aeruginosa T6SS effector.
  • To investigate the function and cellular target of Tse5-CT.

Main Methods:

  • Biochemical assays to characterize Tse5-CT.
  • Membrane potential measurements.
  • Bacterial viability assays.

Main Results:

  • Tse5-CT is the toxic, auto-proteolytic product of the T6SS effector Tse5.
  • Tse5-CT functions as a pore-forming toxin.
  • It transports ions across bacterial membranes, leading to membrane depolarization and cell death.

Conclusions:

  • Tse5-CT's pore-forming activity is a key mechanism for P. aeruginosa competition.
  • Membrane depolarization is an effective strategy for P. aeruginosa in polymicrobial environments.
  • This study reveals a novel T6SS effector mechanism contributing to bacterial fitness.

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