A live-cell marker to visualize the dynamics of stable microtubules throughout the cell cycle

Jansen et al. introduce StableMARK (Stable Microtubule-Associated Rigor-Kinesin), a live-cell marker to visualize stable microtubules. This live-cell marker enables the exploration of different MT subsets throughout the cell cycle to understand how they contribute to cellular organization and transport. The microtubule (MT) cytoskeleton underlies processes such as intracellular transport and cell division. Immunolabeling for posttranslational modifications of tubulin has revealed the presence of different MT subsets, which are believed to differ in stability and function. Whereas dynamic MTs can readily be studied using live-cell plus-end markers, the dynamics of stable MTs have remained obscure due to a lack of tools to directly visualize these MTs in living cells. Here, we present StableMARK (Stable Microtubule-Associated Rigor-Kinesin), a live-cell marker to visualize stable MTs with high spatiotemporal resolution. We demonstrate that a rigor mutant of Kinesin-1 selectively binds to stable MTs without affecting MT organization and organelle transport. These MTs are long-lived, undergo continuous remodeling, and often do not depolymerize upon laser-based severing. Using this marker, we could visualize the spatiotemporal regulation of MT stability before, during, and after cell division. Thus, this live-cell marker enables the exploration of different MT subsets and how they contribute to cellular organization and transport.

Automated summary

Jansen et al. have developed a live-cell marker called StableMARK, which allows for visualization of stable microtubules. This marker facilitates the study of different subsets of microtubules throughout the cell cycle and their role in cellular organization and transport.