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Coordinated control of the type IV pili and c-di-GMP-dependent antifungal antibiotic production in Lysobacter by the response regulator PilR.
- Source :
-
Molecular plant pathology [Mol Plant Pathol] 2021 May; Vol. 22 (5), pp. 602-617. Date of Electronic Publication: 2021 Mar 11. - Publication Year :
- 2021
-
Abstract
- In the soil gammaproteobacterium Lysobacter enzymogenes, a natural fungal predator, the response regulator PilR controls type IV pili (T4P)-mediated twitching motility as well as synthesis of the heat-stable antifungal factor (HSAF). Earlier we showed that PilR acts via the second messenger, c-di-GMP; however, the mechanism remained unknown. Here, we describe how PilR, c-di-GMP signalling, and HSAF synthesis are connected. We screened genes for putative diguanylate cyclases (c-di-GMP synthases) and found that PilR binds to the promoter region of lchD and down-regulates its transcription. The DNA-binding affinity of PilR, and therefore its repressor function, are enhanced by phosphorylation by its cognate histidine kinase, PilS. The lchD gene product is a diguanylate cyclase, and the decrease in LchD levels shifts the ratio of c-di-GMP-bound and c-di-GMP-free transcription factor Clp, a key activator of the HSAF biosynthesis operon expression. Furthermore, Clp directly interacts with LchD and enhances its diguanylate cyclase activity. Therefore, the PilS-PilR two-component system activates T4P-motility while simultaneously decreasing c-di-GMP levels and promoting HSAF production via the highly specific LchD-c-di-GMP-Clp pathway. Coordinated increase in motility and secretion of the "long-distance" antifungal weapon HSAF is expected to ensure safer grazing of L. enzymogenes on soil or plant surfaces, unimpeded by fungal competitors, or to facilitate bacterial preying on killed fungal cells. This study uncovered the mechanism of coregulated pili-based motility and production of an antifungal antibiotic in L. enzymogenes, showcased the expanded range of functions of the PilS-PilR system, and highlighted exquisite specificity in c-di-GMP-mediated circuits.<br /> (© 2021 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)
- Subjects :
- Bacterial Proteins genetics
Bacterial Proteins metabolism
Cyclic GMP analogs & derivatives
Cyclic GMP metabolism
Escherichia coli Proteins genetics
Lysobacter metabolism
Models, Biological
Phosphorus-Oxygen Lyases genetics
Phosphorylation
Promoter Regions, Genetic genetics
Signal Transduction
Transcription Factors genetics
Antifungal Agents metabolism
Escherichia coli Proteins metabolism
Fimbriae, Bacterial metabolism
Lysobacter genetics
Phosphorus-Oxygen Lyases metabolism
Transcription Factors metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1364-3703
- Volume :
- 22
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Molecular plant pathology
- Publication Type :
- Academic Journal
- Accession number :
- 33709522
- Full Text :
- https://doi.org/10.1111/mpp.13046