Filament formation and function of the bacterial cytoskeletal element MreB

• Applicant: Professor Dr. Peter Graumann
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms ; Biochemistry ; Cell Biology
• Term: since 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 255621781

MreB is homologous to actin and widely conserved in bacteria. For many species, MreB plays a crucial role in cell shape maintenance, and ensures proper three-dimensional extension of the cell wall. MreB forms short filamentous structures underneath the cell membrane, which are anchored in the membrane through an amphipathic helix or a hydrophobic patch on MreB. Filaments rotate perpendicular or slightly tilted relative to the long axis of rod shaped or helical cells, apparently driven by the transglycosylase activity of membrane-integral enzymes that extend glycan strands in the cell wall, and thus lead to cell wall growth. We have observed that MreB filament dynamics and polymerization of MreB into filaments is strongly affected by growth conditions, nutrient depletion or stress conditions lead to strong reduction on MreB dynamics. Because MreB was shown to interact with translation elongation factor EF-Tu we plan to investigate if this interaction transduces information on the nutritional status of cells to MreB filaments, or if stringent response or interactor RodZ play a role. We would also like to investigate if MreB can directly sense ionic conditions in the cell. We plan to identify and study additional, dynamic interactors that might transduce signals to MreB, and we will study in vitro effects of EF-Tu and RodZ on MreB filament architecture.

• DFG Programme: Research Grants