Microtubule depolymerization catastrophe is the rapid transition from a growing microtubule end to an unstable, shrinking state, driven by the loss of the protective GTP cap. During polymerization, αβ-tubulin dimers are incorporated with GTP bound, which is later hydrolyzed to GDP once the dimer is integrated into the filament. This instability occurs when the rate of GTP hydrolysis to GDP outpaces the incorporation of new GTP-tubulin, exposing the less stable GDP-tubulin core. The resulting str