PhD forsvar: Vikram Kjøller Bhatia

This thesis addresses the novel concept of biological recognition based on membrane curvature. Membrane curvature is at present perceived as an active way to organize nanoscale centers for membrane traffic in cells. The ability of protein domains to assemble in macromolecular scaffolds in response to membrane organization and molecular cues is a prerequisite for maintaining an effective cell communication and function. We have developed a new fluorescence based assay to quantify and understand the molecular mechanism of membrane curvature sensing by amphipathic anchoring motifs and BAR (Bin, Amphiphysin, Rvs) domains. The new assay is based on single liposomes allowing in a high-throughput fashion, the detection of protein binding to a multitude of curvatures. Using this assay we are able to detect inhomo-geneous and asynchronous activities, something not possible with existing assays. The results suggest that Membrane Curvature Sensing by proteins is not dominated by differences in affinity and thus prompts a re-evaluation of the current model.