Equipe d’Accueil : BCCM (Bacterial Cell Cycle Mechanisms)
Intitulé de l’Unité : BCCM (Bacterial Cell Cycle Mechanisms)
Nom du Responsable de l’Unité : Anne Marie Wehenkel
Nom du Responsable de l’Équipe : Anne Marie Wehenkel
Adresse : Institut Pasteur, 25 rue du Docteur Roux (75015 Paris)
Responsable de l’encadrement : Adrià Sogues
Tél : +33(0) 140 613 917 Fax : ……………………… E-mail: asoguesc@pasteur.fr
Résumé du projet (environ une demi-page)
Bacteria deploy an arsenal of molecular strategies to survive unfavourable conditions such as nutrient starvation, oxidative stress and exposure to toxic molecules. One of the most extreme of these survival strategies is sporulation, in which the cell follows a genetically programmed differentiation pathway that produces a dormant spore able to withstand extreme conditions such as desiccation, UV radiation or even antibiotic exposure for hundreds of years. Understanding the molecular principles behind this process is the central question of the project.
Sporulation is widespread among members of the Firmicutes, a group that includes important human pathogens such as Bacillus anthracis and Clostridioides difficile. When nutrients are available, bacterial cells divide by binary fission (the vegetative cycle), a highly coordinated process in which the cell divides at midcell to produce two identical daughter cells. Cell division is carried out by a macromolecular complex known as the divisome, which spans the cytoplasm, membrane and cell wall to drive constriction. Remarkably, the same machinery also carries out the first steps of sporulation, dividing the cell close to one pole when conditions become unfavourable; in this context, it is referred to as the polar divisome. Although the core machinery that constricts the cell is shared between the vegetative and sporulation cycles, key differences exist, which is why we have renamed the polar divisome the sporosome. The sporosome is a specialised divisome that forms two unequally sized compartments, each following a different genetic fate. The main goal of the project is to understand the differences in assembly, structure and regulation between the divisome and the sporosome.
To answer these questions, the lab uses an integrative approach that combines in vitro biochemical characterisation and structure determination by crystallography and cryo-electron microscopy with in vivo cell imaging and genetic engineering. The project will use Bacillus subtilis as a model organism, for which we have an extensive genetic toolkit, including CRISPR/Cas9, and engineered strains for native protein purification.
The discoveries made in this project will not only advance our understanding of the fundamental process of cell differentiation in bacteria but will also likely identify new potential drug targets, specifically targeting sporulating cells, with a direct impact on biomedical research.
Dernières Publications en lien avec le projet :
Sogues A, Martinez M, Gaday Q, et al. Essential dynamic interdependence of FtsZ and SepF for Z-ring and septum formation in Corynebacterium glutamicum. Nat Commun. 2020;11(1):1641. Published 2020 Apr 2. doi:10.1038/s41467-020-15490-8
- Sleutel M, Sogues A, Remaut H. Auto-crosslinking sporesilk fibers promote endospore and Cry toxin clustering. Nat Commun. 2026;17(1):3809. Published 2026 Mar 11. doi:10.1038/s41467-026-70495-z
- Martinez M, Petit J, Leyva A, et al. Eukaryotic-like gephyrin and cognate membrane receptor coordinate corynebacterial cell division and polar elongation. Nat Microbiol. 2023;8(10):1896-1910. doi:10.1038/s41564-023-01473-0
- Carloni G, Gaday Q, Megrian D, et al. Mechanistic insights into SteAB regulation of cell wall hydrolase RipA in Mycobacterium tuberculosis. mBio. 2026;17(3):e0370025. doi:10.1128/mbio.03700-25
Ce projet ne s’inscrit pas dans la perspective d’une thèse