Dynamic spatio-temporal regulation of peptidoglycan synthesis by the actin-like protein MreB in Caulobacter crescentus
Dr. Régis Hallez
Peptidoglycan (PG) is a giant meshwork molecule that surrounds the bacterial cytoplasmic membrane, providing physical strength to counteract the turgor pressure and determining cell shape. Importantly, PG synthesis is tightly regulated in time and space to drive cell elongation and division, but also the building of stalks in prosthecate bacteria. The actin-like protein MreB is a master regulator of PG elongation but the mechanism by which such cytoplasmic filaments pilot PG synthesis is not totally understood. In this project, we propose to use a mreB* mutant of C. crescentus, which produces fatter and stalkless cells, to uncover the MreB-dependent control of PG synthesis. First, we will localize the PG synthesis machinery and determine the PG composition in mreB* cells. Then, we will combine genetics and biochemistry to identify and characterize the mechanisms responsible for the phenotypes. Finally, the conservation of these mechanisms will be studied in other bacterial models.