Flagellar rotation and intracellular signalling pathways controlling bacterial chemotaxis
Bacteria live in complex communities and like most organisms in communities they interact with their neighbours and their local environment. They can discriminate between their neighbours, measuring the numbers and the level of relatedness. They can mate, they can fight or they can move away. Our work has concentrated on how bacteria sense changes in their environment and use that information to control their swimming behaviour. This has led us to investigate the biophysics of flagellar motor rotation and the biochemistry of sensing and signalling to control rotation. Along the way we have shown that signals from transmembrane receptors integrate with related receptors in the cytoplasm and these receptors localise to the chromosome surface to ensure that on division each daughter has receptors and can respond to change. Using biophysical approaches we have also shown that the bacterial injectisome, used to insert toxins into host cells, is a dynamic protein complex, similar to the flagellar motor. Recently we have started to examine whether crowding inside bacterial cells can affect the rate of signalling from membrane receptors to the motors using novel imaging approaches.
We use a wide range in in vivo imaging methods combined with molecular genetics, biophysics and modelling.