Microtubules are cytoskeletal polymers composed of tubulin subunits that reversibly assemble into hollow tubes, alternating between periods of assembly and disassembly. During microtubule disassembly, electron micrographs suggest structural transitions from straight into curved protofilaments at the very tips of disassembling microtubules. However, these transitions of the structure have never been observed in live samples that were not fixed beforehand. Here, employing scattering labels enabling tracking of single-protofilament depolymerization trajectories, we use interferometric scattering microscopy to detect transient structural changes in the disassembling microtubule tips at unprecedented temporal resolution. Our preliminary data reveals transient fluctuations of the protofilament positions, suggesting a stochastic mechanism of switching from the disassembly to the assembly phase. We aim to elucidate the switching from disassembly to assembly, termed ‘rescue’, and provide mechanistic insight into microtubule-dependent processes in cell biology.
Menu