Borowiak, M. et al. Cell 162, 403–411 (2015).

Mitosis, motility and transport processes in the cell all rely on microtubule growth and shrinkage. The drugs paclitaxel and colchicine are popular tools for studying microtubule dynamics, but their actions are not immediately reversible and cannot be spatially confined to individual cells within a tissue or culture. Borowiak et al. have overcome these drawbacks by creating photoswitchable compounds that inhibit microtubule polymerization. When illuminated with ultraviolet or violet light, these photostatins are active and inhibit microtubule dynamics, and they can be switched off with green light exposure. By targeting light to the cells of interest, the researchers could spatially confine drug action. They demonstrated that these photostatins can cause mitotic arrest in cell culture and in Caenorhabditis elegans embryos.