His lab studied the lateral organisation of proteins and lipids within the plasma membrane, and the relationship between this organisation and sorting into different endocytic pathways. The goal was to understand how lateral heterogeneity in both protein and lipid composition within membranes is generated and exploited to generate differentiated regions of membrane. This is important during membrane trafficking, where transport intermediates or vesicles with a different composition from the rest of the membrane must be generated, and on a larger distance scale during cell polarisation or establishment of functionally specialised cell surfaces.

His group continued to study the mechanisms underlying several important aspects of plasma membrane cell biology: particularly, how regions of the membrane are specialised for different functions, and how proteins and lipids are internalised from the membrane. They focussed on the role of oligomeric protein assemblies that form specific microdomains. Caveolae, flask-shaped membrane invaginations formed by cavin and caveolin proteins, constitute one kind of microdomain, and flotillin proteins form another. The Group’s achievements over the years have included revealing functions for flotillin proteins in cell migration, determining key protein actors at the neck of caveolae, characterising the large 80S protein complex that generates the bulb of caveolae, and quantifying flux through different endocytic pathways in tissue culture cells. Studies in cultured cells and model organisms have been successful in identifying many molecular components and specific protein-protein interactions.