Beta-tubulin taxane binding site

Microtubules are essential cytoskeletal components formed by the polymerization of alpha- and beta-tubulin heterodimers, playing critical roles in cell division, intracellular transport, and structural maintenance [7, 11]. The taxane binding site is a distinct hydrophobic pocket located on the luminal surface of the beta-tubulin subunit, specifically near the M-loop which is involved in lateral protofilament contacts [6, 12, 18]. Drugs such as paclitaxel and docetaxel bind to this site to promote tubulin assembly and stabilize the microtubule lattice against depolymerization [8, 10]. This stabilization suppresses the dynamic instability of microtubules, effectively freezing the mitotic spindle and causing cell cycle arrest at the metaphase-anaphase transition [7, 14]. The resulting mitotic catastrophe triggers programmed cell death (apoptosis), making this site a cornerstone target in the treatment of various malignancies, including breast, lung, and ovarian cancers [9, 15]. However, clinical utility is often challenged by the emergence of resistance mechanisms, such as the overexpression of the beta-III tubulin isoform (TUBB3) or drug efflux transporters like P-glycoprotein [1, 4, 9].

Other names

Taxane binding siteTaxol binding siteTaxoid binding sitePaclitaxel binding siteMicrotubule taxane site

Binds to the taxane site on the beta-tubulin subunit of the microtubule, promoting tubulin polymerization and stabilizing existing microtubules against depolymerization, which suppresses dynamic instability and leads to mitotic arrest and apoptosis.