The Mechanism of Tubulin Assembly into Microtubules: Insights from Structural Studies

Marcel Knossow (1, 2) , Valérie Campanacci (1, 2) , Liza Ammar-Khodja (1, 2) , Benoît Gigant (1, 2)

1 I2BC - Institut de Biologie Intégrative de la Cellule
2 MIKICA - Biochimie Structurale des Microtubules, des Kinésines et de leurs Cargos

Microtubules are cytoskeletal components involved in pivotal eukaryotic functions such as cell division, ciliogenesis, and intracellular trafficking. They assemble from αβ-tubulin heterodimers and disassemble in a process called dynamic instability, which is driven by GTP hydrolysis. Structures of the microtubule and of soluble tubulin have been determined by cryo-EM and by X-ray crystallography, respectively. Altogether, these data define the mechanism of tubulin assembly-disassembly at atomic or near-atomic level. We review here the structural changes that occur during assembly, tubulin switching from a curved conformation in solution to a straight one in the microtubule core. We also present more subtle changes associated with GTP binding, leading to tubulin activation for assembly. Finally, we show how cryo-EM and X-ray crystallography are complementary methods to characterize the interaction of tubulin with proteins involved either in intracellular transport or in microtubule dynamics regulation.

Mots clés: Biochemistry Methods; Cell Biology; Structural Biology

Domaines: Sciences du Vivant [q-bio]

Marcel Knossow, Valérie Campanacci, Liza Ammar-Khodja, Benoît Gigant. The Mechanism of Tubulin Assembly into Microtubules: Insights from Structural Studies. iScience, 2020, 23 (9), pp.101511. ⟨10.1016/j.isci.2020.101511⟩. ⟨hal-02944252⟩