A new perspective on microtubule dynamics: destruction by molecular motors and self-repair.

Microtubules are dynamic polymers, permanently assembling and disassembling, that serve as tracks for intra-cellular transport by molecular motors. We recently found that the low energy of tubulin dimer interactions allows for spontaneous loss of tubulin dimers from the microtubule lattice [1]. This raised the possibility that the mechanical work produced by molecular motors as they move on microtubules can break dimer interactions and trigger microtubule disassembly. In a recent study, we tested this hypothesis by studying the interplay between microtubules and moving molecular motors in vitro [2]. Our results show that molecular motors can remove tubulin dimers from the lattice and rapidly destroy microtubules. We also found that dimer removal by motors was compensated by the insertion of free tubulin dimers into the microtubule lattice. This self-repair mechanism allows microtubules to survive the damage induced by molecular motors as they move along their tracks. Our study reveals the existence of coupling between the motion of molecular motors and the renewal of the microtubule lattice.