Nicastro, Gianlucca G, Sibinelli-Sousa, Stephanie, Hespanhol, Julia T, Santos, Thomas WC, Munoz, Joseph P, Santos, Rosangela S, Perez-Sepulveda, Blanca M, Miyamoto, Sayuri, Aravind, L, de Souza, Robson F et al (show 1 more authors)
(2026)
Systematic identification of Salmonella T6SS effectors uncovers diverse new families and lipid-targeting activities
PLOS BIOLOGY, 24 (3).
ISSN 1544-9173, 1545-7885
Abstract
Bacterial warfare is a widespread phenomenon in which bacteria deploy toxins to inhibit or kill competitors. These toxins disrupt essential cellular processes, and their diversification is driven by an evolutionary arms race involving toxin and immunity gene acquisition. Here, we used in-silico approaches to analyze genomes from the 10k Salmonella Project and identify effectors secreted via the Type VI Secretion System (T6SS). We uncovered 128 candidates distributed across diverse Salmonella serovars and other bacterial species. Among them, Tox-Act1 was selected for in-depth characterization. Tox-Act1 contains a permuted NlpC/P60 papain-like catalytic core typical of lipid-targeting enzymes. Evolutionary analysis revealed its relationship with acyltransferases. Biochemical assays and lipidomics of intoxicated cells showed that Tox-Act1 acts as a phospholipase, cleaving phosphatidylglycerol and phosphatidylethanolamine. We further demonstrate that Tox-Act1 is secreted in a T6SS-dependent manner and provides a competitive advantage during mouse gut colonization. This study broadens our understanding of toxin domain diversity and provides the first direct characterization of a lipid-targeting NlpC/P60 toxin domain.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Animals, Mice, Salmonella, Phosphatidylethanolamines, Phosphatidylglycerols, Bacterial Proteins, Bacterial Toxins, Phylogeny, Lipid Metabolism, Type VI Secretion Systems |
| Divisions: | Faculty of Health & Life Sciences Faculty of Health & Life Sciences > Inst. Infection, Vet & Ecological Sciences Faculty of Health & Life Sciences > Inst. Infection, Vet & Ecological Sciences > Clinical Infection, Microbiology & Immunology |
| Depositing User: | Symplectic Admin |
| Date Deposited: | 15 Jul 2026 12:26 |
| Last Modified: | 15 Jul 2026 12:26 |
| DOI: | 10.1371/journal.pbio.3003680 |
| Open Access URL: | https://journals.plos.org/plosbiology/article?id=1... |
| Related Websites: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3199417 |
| Disclaimer: | The University of Liverpool is not responsible for content contained on other websites from links within repository metadata. Please contact us if you notice anything that appears incorrect or inappropriate. |
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