Imperial College London
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ProfessorAlainFilloux

Faculty of Natural Sciences, Department of Life Sciences

Visiting Professor
 
 
 
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Contact

 

+44 (0)20 7594 9651a.filloux Website CV

 
 
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Location

 

1.47Flowers buildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Lin:2018:10.1074/jbc.RA117.001618,
author = {Lin, J-S and Pissaridou, P and Wu, H-H and Tsai, M-D and Filloux, A and Lai, E-M},
doi = {10.1074/jbc.RA117.001618},
journal = {Journal of Biological Chemistry},
pages = {8829--8842},
title = {TagF-mediated repression of bacterial type VI secretion systems involves a direct interaction with the cytoplasmic protein Fha},
url = {http://dx.doi.org/10.1074/jbc.RA117.001618},
volume = {293},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The bacterial type VI secretion system (T6SS) delivers effectors into eukaryotic host cells or toxins into bacterial competitor for survival and fitness. The T6SS is positively regulated by the threonine phosphorylation pathway (TPP) and negatively by the T6SS-accessory protein TagF. Here, we studied the mechanisms underlying TagF-mediated T6SS repression in two distinct bacterial pathogens, Agrobacterium tumefaciens and Pseudomonas aeruginosa. We found that in A. tumefaciens, T6SS toxin secretion and T6SS-dependent antibacterial activity are suppressed by a two-domain chimeric protein consisting of TagF and PppA, a putative phosphatase. Remarkably, this TagF domain is sufficient to post-translationally repress the T6SS, and this inhibition is independent of TPP. This repression requires interaction with a cytoplasmic protein, Fha, critical for activating T6SS assembly. In P. aeruginosa, PppA and TagF are two distinct proteins that repress T6SS in a TPP-dependent and -independent pathways, respectively. P. aeruginosa TagF interacts with Fha1, suggesting that formation of this complex represents a conserved TagF-mediated regulatory mechanism. Using TagF variants with substitutions of conserved amino acid residues at predicted protein-protein interaction interfaces, we uncovered evidence that the TagF-Fha interaction is critical for TagF-mediated T6SS repression in both bacteria. TagF inhibits T6SS without affecting T6SS protein abundance in A. tumefaciens, but TagF overexpression reduces the protein levels of all analyzed T6SS components in P. aeruginosa. Our results indicate that TagF interacts with Fha, which in turn could impact different stages of T6SS assembly in different bacteria, possibly reflecting an evolutionary divergence in T6SS control.
AU  - Lin,J-S
AU  - Pissaridou,P
AU  - Wu,H-H
AU  - Tsai,M-D
AU  - Filloux,A
AU  - Lai,E-M
DO  - 10.1074/jbc.RA117.001618
EP  - 8842
PY  - 2018///
SN  - 0021-9258
SP  - 8829
TI  - TagF-mediated repression of bacterial type VI secretion systems involves a direct interaction with the cytoplasmic protein Fha
T2  - Journal of Biological Chemistry
UR  - http://dx.doi.org/10.1074/jbc.RA117.001618
UR  - https://www.ncbi.nlm.nih.gov/pubmed/29599293
UR  - http://hdl.handle.net/10044/1/59315
VL  - 293
ER  -
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