Clathrin Coats: Now You See It, Now You Don't

Are scientific images a simple visual record of our world? How can they be used most effectively to transmit knowledge and interpretation? Should visual aesthetics influence the scientific endeavor? I will describe how we combine high-resolution snapshots from structural biology with lower-resolution movies recorded from cells or from reconstituted model systems to generate images and molecular 3D animations that inform both the scientist who creates them and the audience that views them, through an active process leading to further inquiry and discovery. A significant portion of our work concerns how macromolecules, macromolecular complexes, and pathogens enter or exit cells, from small proteins to viruses and bacteria. The molecular cargos are too large to simply cross the membrane barrier surrounding cells; instead, they are captured by subcellular membrane-bound containers, whose formation requires the concerted action of dozens to hundreds of proteins, interacting with each other within a very short time frame, typically seconds to minutes. The talk will be based on our efforts to ‘see’ in three dimensions the molecular events responsible for assembly of clathrin-coated pits and coated vesicles -- a conserved "nano-machinery" for generating intracellular vesicular carriers in all animals and plants. The talk will illustrate use of powerful visualization technologies, spanning the range from high-resolution x-ray crystallography and electron cryomicroscopy to single-molecule or subcellular real-time imaging by fluorescence microscopy.