How does the cell surface protect cells from environmental assaults, while still permitting the uptake of nutrients and allowing for cell growth and division? 
This is a fundamental question of biology that all organisms must grapple with in their own way.
​In bacteria, the answers to this question have implications for infection, immunity and antibiotic treatment. 
We use forward and reverse genetics, biochemistry and microscopy to address this and related questions.

The mycobacterial cell wall (above) is thick and multi-layered - it's easy to see how it protects the cell. But this structure must be permeable to allow food to get into the cell; under certain conditions we can sneak some antibiotics in as well. In addition, this structure must be expanded to allow for cell growth and then effectively split in half at each cell division event - how does all this happen without compromising the protective role of the cell wall? ​

Projects   in   the   lab:

1. How are mycobacterial cell walls constructed at the cell poles? How does the construction apparatus change under stress?

Mycobacteria elongate their rod-shaped cells by adding new cell wall material at the cell poles. This polar mode of growth is only found in the Actinobacteria and some Alphaproteobacteria, and its mechanisms are poorly understood. We are studying the proteins essential for polar growth, and working to understand how they work together to control cell wall metabolism at the cell poles. 

2. How does the cell wall split during cell division, while preserving the integrity of the wall? 

Cell division is strongly regulated in Mycobacteria under different stress conditions: it is inhibited in DNA damage, and activated under certain types of starvation stress. We are working to identify all the proteins in the mycobacterial divisome - the protein complex that divides the cell wall after chromosome segregation is completed, and to understand how this protein complex assembles. We are also studying how the protein complex changes under stress.