How cargo transporters switch into microtubule organisers

Every second, tiny molecular motors inside human cells walk along microscopic tracks called microtubules, carrying cargo to where it is needed—but sometimes they stop transporting and start rearranging the tracks themselves, and no one knows how they switch between these two jobs. This project addresses a fundamental gap in cell biology: how the same motor proteins that deliver building blocks also bundle and slide microtubules to organise the cell’s internal skeleton. Without this switching ability, cells cannot maintain their shape, divide properly, or establish the front-to-back polarity that allows tissues to function. Mutations in these motors cause human disease, but the underlying mechanism has remained mysterious. If successful, this work will reveal how teams of motors coordinate to generate collective forces without wasting energy in a tug-of-war. It will also explain how cells create extensile forces in parallel microtubule arrays—a common arrangement in polarised cells that has been poorly understood. This is fundamental science with no immediate practical application, but understanding how cells organise their interiors could eventually illuminate why certain neurodegenerative and developmental disorders arise when these motors fail. Past discoveries about motor proteins have already informed drug design for cancer and ciliopathies; this project lays the groundwork for similar future insights.