PRBB-CRG Sessions Kristen Verhey

31/10/202512:00MARIE CURIEPRBB-CRG SessionsKristen VerheyUniversity of Michigan Medical School"Dynamics and structural changes within the microtubule lattice"Host: Thomas SurreyAbstract:Microtubules are cytoskeletal filaments that self-assemble from the protein tubulin and are critical for a variety of important functions in eukaryotic cells, including cell mechanics, migration, and division. Much work in the field has focused on the dynamics at the ends of microtubules and specifically, how tubulin’s GTP binding and hydrolysis drives the addition and loss of tubulin subunits at the ends. However, an emerging idea in the field is that the structure and dynamics of tubulin subunits can be altered along the lattice. We found that the molecular motor protein kinesin-1 can damage the microtubule while stepping along the lattice and that the damage can be repaired by the incorporation of new GTP-tubulin subunits. These results indicate that the lattice itself is dynamic and capable of continuous repair and remodeling in cells. To further explore the dynamics of the microtubule lattice, we developed three different biosensors for the C-terminal tail of alpha-tubulin. Live imaging of the biosensors demonstrates that the alpha-tubulin tail does not freely protrude from the surface of the microtubule as previously thought, but rather its accessibility is sensitive to the conformational state of the tubulin subunits in the lattice. Together this work supports recent findings that the microtubule is a plastic medium in which the conformational state of tubulin can be altered along the microtubule lattice in order to carry out microtubule functions.