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A Visual Assay to Monitor T6SS-mediated Bacterial Competition
Published on: March 20, 2013
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Type VI Secretion System Toxins Horizontally Shared between Marine Bacteria.
Dor Salomon1, John A Klimko1, David C Trudgian2
1Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
Plos Pathogens
|August 26, 2015
Summary
Marine bacteria Vibrio alginolyticus uses two type VI secretion systems (T6SSs) for interbacterial competition. These systems deliver multiple antibacterial effectors, including MIX-effectors, which are shared via horizontal gene transfer, enhancing bacterial fitness.
Area of Science:
- Microbiology
- Bacterial Genetics
- Molecular Biology
Background:
- The type VI secretion system (T6SS) is a critical apparatus in Gram-negative bacteria for delivering toxic proteins.
- Vibrio alginolyticus, a marine pathogen, possesses two distinct T6SSs.
Purpose of the Study:
- To investigate the role of T6SSs in interbacterial competition in Vibrio alginolyticus.
- To identify and characterize the effector proteins secreted by the two T6SSs.
Main Methods:
- Comparative proteomics to identify effector repertoires.
- Genetic analyses to confirm effector function.
- Ectopic expression studies in other Vibrio species.
Main Results:
- TSS1 secretes at least four antibacterial effectors, including three MIX-effectors.
- TSS2 secretes at least three antibacterial effectors.
- Many MIX-effectors (clan V) are mobile and shared among marine bacteria via horizontal gene transfer.
- A MIX V-effector from V. alginolyticus functions in another Vibrio species.
Conclusions:
- V. alginolyticus utilizes its T6SSs for potent interbacterial competition.
- Mobile MIX V-effectors represent a reservoir for diversifying antibacterial arsenals in marine bacteria.
- Horizontal gene transfer of T6SS effectors contributes to bacterial adaptation and competitive fitness in marine environments.
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