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Key signals and effects in the prey exit process of predatory bacterium Bdellovibrio bacteriovorus

English title Key signals and effects in the prey exit process of predatory bacterium Bdellovibrio bacteriovorus
Applicant Huwiler Simona
Number 183896
Funding scheme Postdoc.Mobility
Research institution School of Life Sciences The University of Nottingham
Institution of higher education Institution abroad - IACH
Main discipline Molecular Biology
Start/End 01.08.2019 - 31.01.2021
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All Disciplines (4)

Discipline
Molecular Biology
Genetics
Biochemistry
Experimental Microbiology

Keywords (4)

regulation of exit; lysis; predatory bacterium; Bdellovibrio bacteriovorus

Lay Summary (German)

Lead
Das räuberhafte Bakterium Bdellovibrio bacteriovorus zerstört andere Bakterien, darunter Krankheitserreger, wobei es einen komplexen Lebenszykus durchläuft. Das Projekt hat zum Ziel Einsichten zu liefern in die molekularen Mechanismen und Signale in der letzten Phase dieses Lebenszykluses.
Lay summary

Bdellovibrio bacteriovorus ist ein räuberhaftes Bakterium, welches andere Bakterien als Beute befallen kann und sich in ihnen fortpflanzt. Wenn die Resourcen ausgehen, verlassen die jungen Räuber die sie umschliessenden Überreste der Beutezelle. Das Projekt untersuchte die molekularen Hintergründe dieser letzten Phase des Lebenszykluses von B. bacteriovorus einschliesslich eines möglichen Ausbruchs-Signals. Einige Gene des Räubers, welche während dieser Ausbruchs-Phase von Bedeutung zu sein scheinen, wurden mittels molekular-biologischer Methoden ausgeschaltet, um deren Funktion zu ermitteln. Leider schien der Verlust der vermuteten Gen-Kandidaten im Zusammenhang mit dem Ausbruchs-Signal keinen offensichtlichen Einfluss auf die letzte Lebensphase zu haben. Vier weitere Gene, die am Ausbruch aus der Beutezelle in der letzten Lebensphase beteiligt sein könnten, werden momentan weiter untersucht. In Zusammenarbeit wurde das Exit-spezifische Enzym (Lysozym DslA) genauer charakterisiert. DslA stellt ein mögliches Werkzeug dar um die Zellwand von Gram-positiven Krankheitserregern zu untersuchen, welche sich vor konventionellen Lysozymen verstecken durch Zellwandmodifikation. Um dieses räuberhafte Bakterium oder Teile davon zu nutzen, ist es erforderlich die molekularen Mechanismen zu verstehen welche der Räuber nutzt zur Manipulation der Beute-Bakterien.
Direct link to Lay Summary Last update: 15.03.2021

Responsible applicant and co-applicants

Publications

Publication
A lysozyme with altered substrate specificity facilitates prey cell exit by the periplasmic predator Bdellovibrio bacteriovorus
Harding Christopher J., Huwiler Simona G., Somers Hannah, Lambert Carey, Ray Luke J., Till Rob, Taylor Georgina, Moynihan Patrick J., Sockett R. Elizabeth, Lovering Andrew L. (2020), A lysozyme with altered substrate specificity facilitates prey cell exit by the periplasmic predator Bdellovibrio bacteriovorus, in Nature Communications, 11(1), 4817.

Collaboration

Group / person Country
Types of collaboration
Prof. A. L. Lovering, University of Birmingham Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. R. E. Sockett, University of Nottingham Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
LS2 (Life Sciences Switzerland) Annual Meeting 2021 Poster Specific lysis of prey peptidoglycan enabling predatory bacterium Bdellovibrio bacteriovorus to exit from its host bacterium. 17.02.2021 Online, Switzerland Huwiler Simona;
LS2 (Life Sciences Switzerland) Annual Meeting 2021 Talk given at a conference Specific lysis of prey peptidoglycan enabling predatory bacterium Bdellovibrio bacteriovorus to exit from its host bacterium 17.02.2021 Online, Switzerland Huwiler Simona;
Seminar at Department of Fundamental Microbiology at University of Lausanne Individual talk Microbial biotechnology using predatory bacteria. 14.09.2020 Lausanne, Switzerland Huwiler Simona;
Seminar Series in Molecular, Cellular, and Environmental Microbiology of Max Planck Institute for Terrestrial Microbiology Individual talk Learning from predatory bacteria: from ‘omics’ to molecular mechanism. 24.02.2020 Marburg, Germany Huwiler Simona;
Symposium in Environmental Microbiology Talk given at a conference Learning from predatory bacteria: from ‘omics’ to molecular mechanism 04.12.2019 Dübendorf (eawag), Switzerland Huwiler Simona;
EMBO Workshop Bacterial networks (BacNet 19) Poster Signalling in the prey exit process of predatory bacterium Bdellovibrio bacteriovorus 01.09.2019 Sant Feliu de Guixols, Spain Huwiler Simona;


Communication with the public

Communication Title Media Place Year
New media (web, blogs, podcasts, news feeds etc.) New ways to break down walls blog post "Behind the paper" in forum Nature Microbiology Community International 2020
New media (web, blogs, podcasts, news feeds etc.) Predatory bacteria escape unharmed from prey cell using unique tool Birmingham Health Partners International 2020
New media (web, blogs, podcasts, news feeds etc.) Predatory bacteria use unique tools to escape safely from prey cell The Medical News International 2020
New media (web, blogs, podcasts, news feeds etc.) Researchers uncover tools used by predatory bacteria to escape unharmed from prey cell Press release of University of Nottingham International 2020

Awards

Title Year
SNSF Ambizione Fellowship 2020
SNSF Postdoc.Mobility Return Fellowship (only 1/3 of the endowment was activated) 2020

Associated projects

Number Title Start Funding scheme
193401 Learning from predatory bacteria: from ‘omics’ to molecular mechanisms 01.06.2021 Ambizione
194432 Molecular mechanisms in the prey exit process of pathogen-predator Bdellovibrio bacteriovorus 01.02.2021 Return CH Postdoc.Mobility
174680 Pr-exit: Investigation of the predatory bacterium Bdellovibrio bacteriovorus exit phase from depleted prey cells including specific lysis of prey peptidoglycan 01.02.2018 Early Postdoc.Mobility

Abstract

Background: Gram-negative predatory bacterium Bdellovibrio bacteriovorus is prevalent in the environment and might turn out to be very useful as a ‘living antibiotic’. It invades other Gram-negative prey bacteria and replicates in their periplasm. Once resources run out, predator progeny escape the surrounding exhausted prey cell remnants. Objectives: This release process is multifactorial but barely understood from a molecular mechanistic point of view including molecular identity of the signal triggering the exit process and the underlying regulatory network. These aspects were investigated in this research project. Methods and Results: Our newly generated transcriptional data of this exit phase revealed three upregulated genes potentially involved in signalling and four upregulated genes of high interest encoding secreted hypothetical proteins attributed to a periplasmatic predatory lifestyle. All these genes were deleted in this Postdoc.Mobility Fellowship. Research with regards to signalling at the end of the predatory life cycle was stalled, due to a lack of obvious phenotype of three gene-deletion mutants of the predator. In contrast, investigation on four other predatory genes likely involved in the prey exit process is ongoing in the Postdoc.Mobility Return Fellowship. Further, the findings on exit-specific lysozyme DslA of the Early Postdoc.Mobility Fellowship were consolidated by additional controls, affirming a role of DslA in the prey exit process in contrast to other predatory lysozyme homologues.Expected value of the proposed project: This project characterized an exit-specific lysozyme DslA in more detail (collaboration with Prof. R. E. Sockett and Dr. A. L. Lovering), while starting to investigate four additional genes likely involved in the prey escape process. DslA could be a useful tool to investigate and potentially damage Gram-positive pathogens that deacetylate their cell wall to escape conventional lysozyme activity. Novel modes of action, especially in context of bacterial cell envelope damaging activity, are of potential interest for new drugs acting against bacteria. To make use of this predator or parts of it, it is crucial to understand the molecular mechanisms underlying Gram-negative prey manipulation by the predator.
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