We study how microtubule networks are regulated to drive different processes in cells. We use an array of model systems including primary neurons, immortalized cancer cell lines, budding yeast, and in vitro reconstitution. Our approaches combine genetics with quantitative microscopy and protein biochemistry to investigate basic molecular mechanisms that regulate dynamics and transport. Our goals are to build an understanding of how the microtubule network organizes the cell, how these processes are tuned for different contexts, and how defects in network function contribute to human disease.