Mott and Owen Group

Welcome to the website of the lab of Darerca Owen and Helen Mott. We co-run a research team who are interested in the structures and functions of small G proteins and their downstream effector molecules.

Small G Proteins

The small G proteins of the Ras superfamily behave as molecular switches. In the cell they are usually GDP-bound and switched off. In response to external stimuli, a guanine nucleotide exchange factor (GEF) is activated and stimulates dissociation of the GDP. Subsequent binding of GTP activates the G protein and allows it to bind to downstream effectors. G proteins are switched off again when the bound GTP is hydrolysed. This is catalysed by the intrinsic GTPase activity of the small G protein, which is stimulated by the action of GTPase activating proteins (GAPs).

There are 5 families within the Ras family of small G proteins and between them they control many of the fundamental processes in the cell. They all have the same overall structure, which they use as a scaffold for interacting with lots of different proteins. One reason that they can do this is because the main regions that bind other proteins are inherently flexible. We are interested in how small G proteins bind to their effectors because many of them are involved in diseases like cancer. If we can understand more about the precise details of the interactions between these pairs of proteins we will be able to work out how to dusrupt them. This information is useful for understanding the pathways involved as well as for the design of therapeutics.