β-tubulin
β-tubulin
Overview
β-tubulin is one of the two major protein subunits that assemble into microtubules, the dynamic cytoskeletal polymers essential for cell shape, intracellular transport, mitosis, and chromosome segregation. In biomedical research, β-tubulin is especially important because many anticancer and antiparasitic agents act by binding to tubulin and altering microtubule dynamics, thereby disrupting cell division or parasite viability.
As a drug target, β-tubulin is commonly studied through its role in tubulin polymerization and in ligand binding at sites such as the colchicine binding site. Modulation of β-tubulin can lead to microtubule network disruption, cell-cycle arrest, and apoptosis. Recent studies have also examined α-tubulin and β-tubulin together in the context of microtubule-targeting compounds, including agents combined with EGFR inhibition, carbonic anhydrase inhibition, Histone deacetylase 6 modulation, or existing therapies such as Caelyx and paclitaxel.
Focus of Latest Publications
Recent publications have focused on β-tubulin as a drug target in both anticancer and herbicidal discovery, with most studies aiming to disrupt microtubule dynamics by inhibiting tubulin polymerization or binding at the colchicine site. Several medicinal chemistry programs designed heterocyclic and hybrid small molecules, including imidazo[1,2-a]pyridines, pyrrolo[2,3-b]pyrazines, pyrazolo[4,3-c]pyridines, quinoxaline-chalcones, and triaryl-tethered acryloyl derivatives, and then assessed their antiproliferative activity alongside direct tubulin assays, docking, and molecular dynamics simulations. Across these studies, the most active compounds consistently caused microtubule network disruption, G2/M cell-cycle arrest, and apoptosis, supporting β-tubulin inhibition as the mechanistic basis for their anticancer effects.
Among the reported anticancer leads, compound 8o from the imidazo[1,2-a]pyridine series showed submicromolar antiproliferative activity and was confirmed to inhibit tubulin polymerization, while compound 10u from the pyrrolo[2,3-b]pyrazine series suppressed tumor growth in an orthotopic Huh7 mouse model without observable systemic toxicity. Similarly, compound 15u from the pyrazolo[4,3-c]pyridine series inhibited tubulin polymerization, disrupted microtubules, and reduced tumor growth in vivo. Other studies identified compound 4i as a potent β-tubulin polymerization inhibitor in hepatocellular carcinoma cells, with apoptosis linked to B-cell lymphoma 2 downregulation and increased Bax and caspase 9 expression, and compound 10v as a covalent colchicine-site inhibitor that bound β-Cys239, overcame drug resistance in MCF-7/ADM cells, and showed better in vivo antitumor efficacy than paclitaxel.
A separate line of work explored dual-target or structure-guided strategies involving β-tubulin. One study developed carboxamide-substituted imidazo[1,2-a]quinoxalines targeting both EGFR and tubulin, with JRC-6 showing microtubule-stabilizing activity comparable to paclitaxel and inducing ROS generation, mitochondrial depolarization, and G2/M arrest. Another reported coumarin-pyrazolo[1,5-a]pyrimidine hybrids with combined carbonic anhydrase and tubulin polymerization inhibition, where compound 13n displayed balanced activity against hCA IX, hCA XII, and tubulin and triggered p53-associated apoptosis. In addition, phenoxy-linked colchicine derivatives were designed to enhance selectivity through added α-tubulin engagement while retaining colchicine-like β-tubulin binding, yielding highly potent compounds with favorable selectivity indices and confirmed microtubule disruption.
Beyond oncology, β-tubulin was also investigated as a target for herbicidal and anthelmintic lead discovery. The plant-derived compound 4-O-α-thevetopyranosyldiphyllin from Taiwania flousiana inhibited tubulin polymerization, bound β-tubulin with high affinity in docking and dynamics studies, and showed broad-spectrum weed control with systemic translocation and crop selectivity. Likewise, xanthone derivatives from Swertia petiolata were evaluated against Haemonchus contortus, and 1-hydroxy-3,5-dimethoxyxanthone showed the strongest in vitro activity with docking support for high-affinity binding to β-tubulin and impairment of microtubule formation. Together, these publications reinforce β-tubulin as a versatile and actively pursued target for microtubule-disrupting agents across cancer, weed management, and antiparasitic research.