Tubulin alpha-beta dimer

Tubulin alpha-beta dimer is the core structural unit of microtubules, which are cylindrical polymers forming a major component of the eukaryotic cytoskeleton. Each dimer consists of two globular proteins: alpha-tubulin and beta-tubulin, both of which bind guanine nucleotides but in different fashions—the alpha subunit binds non-exchangeable GTP, while the beta subunit binds exchangeable GTP or GDP. Dimers polymerize head-to-tail into protofilaments, which laterally associate to form the hollow microtubule structure typically composed of 13 protofilaments. Microtubules are essential for intracellular transport, mitosis, cell shape maintenance, and motility via cilia and flagella. The tubulin dimer is the molecular target of several clinically important drugs, especially anticancer agents such as taxanes and Vinca alkaloids, which interfere with microtubule dynamics, disrupting cell division and inducing apoptosis in rapidly proliferating cells[1][2][3][4][5][7][8]. Overexpression or mutation of tubulin isotypes has been implicated in drug resistance, cancer progression, and various neurologic disorders.

Other names

Alpha-beta tubulin dimerαβ-tubulinTubulin heterodimerMicrotubule subunit

Microtubule stabilization (e.g., by taxanes and epothilones) Microtubule depolymerization or inhibition of polymerization (e.g., by Vinca alkaloids and colchicine)