Modern molecular biology presents us with a growing list of molecules that build a living cell. However, how the diverse activities of these molecules are coordinated in space and time to generate functional cell biology is an increasingly complex and essentially unresolved question. My research program focuses on the microtubule cytoskeleton, a highly dynamic filament system inside cells that is critically important to spatially and temporally organize eukaryotic cells during cell migration, division and differentiation. One of my long-term scientific goals is to elucidate molecular mechanisms by which local control of the MT cytoskeleton guides complex cell behaviors, and we are particularly interested in the function of protein complexes at growing microtubule ends. Addressing questions on local dynamic processes in cells also requires novel experimental approaches, and to achieve this goal we are employing advanced quantitative live cell microscopy combined with ‘opto-cell biology’ that we define as synthetic light-control of cellular protein activity with high spatial and temporal precision.