From eukaryotic to bacterial cells, cytoskeletal proteins play critical roles in various aspect of cell physiology, including cell shape and cytokinesis, chromosomes partitioning, and intracellular transport. In bacteria, MreB, an homolog of eukaryotic actin, is part of the “Rod complex”, a group of essential protein that synthesize the cell wall (CW), the extracellular shell that maintains cell shape and integrity (and the target of numerous antibiotics).
We use a combination of microscopic, genetic and biochemistry approaches to study the Rod complex, with a focus on some of the main actors including actin-like MreBs. We recently overcame the main bottleneck for the in vitro study of Gram-positive (G+) MreB that leads us to propose a new model describing how is controlled its polymerization. These new findings open a large avenue of research and exciting perspectives on MreB and its cognate proteins involved in CW synthesis.
On the long run, our goal is to decipher in detail at the mechanistic level the CW assembly by the Rod complex in bacteria. Here, we will focus on the polymerization properties of MreB, and how the protein switches from a monomeric soluble state into membrane-associated polymers, and back. In the present internship, we will focus in designing, producing and test mutants of MreB defective for their ability to bundle into higher order structures, and link their properties with in vivo phenotypes.
Techniques used during the internship:
The project will use a combination of biochemistry/structural biology/microscopy approaches (directed mutagenesis, basic molecular cloning technics, protein purification, Transmission Electron microscopy, epifluorescence and TIRF microscopy…).
Bibliography:
The project is a direct follow up of a publication currently in review in eLife. doi: 10.1101/2022.10.19.512861 .
Informations:
Contact: Dr. Arnaud Chastanet (ProCeD)
Starting period: January, 2025
