Bacterial cell cycle control

MICHIELS LAB

VIB-KU Leuven Center for Microbiology

KU Leuven Centre of Microbial and Plant Genetics

Research carried out by Liselot Dewachter

Since the discovery of bacteria in the 17^th century, our understanding of their physiology and life cycle has increased exponentially. However, even bacteria – arguably the simplest organisms on earth – are far from being completely understood. Although a rather detailed picture of bacterial growth, DNA replication and division has emerged, insight into the regulatory network that controls and coordinates these processes severely lags behind.

We aim to elucidate mechanisms by which bacteria regulate cell cycle progression and coordinate important processes to each other. We do so by focusing on the GTPase ObgE. This protein is conserved and essential in all bacterial species investigated to date. Moreover, ObgE has been implicated in a myriad of important cellular functions, such as ribosome assembly, DNA replication, chromosome segregation and cell division. We therefore hypothesize that ObgE acts as a central regulator of bacterial growth.

We try to unravel the molecular mechanisms by which ObgE influences key processes of the bacterial cell cycle. We thereby hope to contribute towards a better understanding of bacterial growth regulation, which could be translated into important applications. It could, for example, inspire novel ways to halt bacterial growth by interfering with the underlying regulatory network.

The bacterial cell cycle, depicted for E. coli. Bacteria have to replicate their DNA, segregate the duplicated chromosomes to opposite cell halves and ultimately divide to start the cycle anew. It is currently unclear how these different processes are coordinated to each other, but it appears as though the GTPase ObgE could play an important role in regulating the bacterial cell cycle.

Further reading

Dewachter L., Verstraeten N., Monteyne D., Kint CI., Versées W., Pérez-Morga D., Michiels J.*, Fauvart M.* (2015). A single-amino-acid substitution in Obg activates a new programmed cell death pathway in Escherichia coli. mBio, 6(6):e01935-15.
Dewachter L., Verstraeten N., Fauvart M., Michiels J. (2016). The bacterial cell cycle checkpoint protein Obg and its role in programmed cell death. Microbial Cell, 3 (6):255-256.
Dewachter L., Herpels P., Verstraeten N., Fauvart M., Michiels J. (2016). Reactive oxygen species do not contribute to ObgE*-mediated programmed cell death. Scientific Reports, 6:Art.No. 33723.
Dewachter L., Verstraeten N., Jennes M., Verbeelen T., Biboy J., Monteyne D., Pérez-Morga D., Verstrepen K., Vollmer W., Fauvart M., Michiels J. (2017). A mutant isoform of ObgE causes cell death by interfering with cell division. Frontiers in Microbiology, 8:Art.No. 1193.
Dewachter L., Verstraeten N., Fauvart M.*, Michiels J.* (2018). An integrative view of cell cycle control in Escherichia coli. FEMS Microbiology Reviews, 42(2):116-136.