Microtubule nucleation

In cell biology, microtubule nucleation is the process that initiates the formation of microtubules. These filaments of the cytoskeleton typically form through polymerization of α- and β-tubulin dimers, the basic building blocks of the microtubule, which initially interact to nucleate a seed from which the filament elongates.

Microtubule nucleation occurs spontaneously in vitro, with solutions of purified tubulin giving rise to full-length polymers. The tubulin dimers that make up the polymers have an intrinsic capacity to self-aggregate and assemble into cylindrical tubes, provided there is an adequate supply of guanosine triphosphate (GTP). The kinetics barriers of such a process, however, mean that the rate at which microtubules spontaneously nucleate is relatively low.