Tubulin beta chain (Vinca alkaloid binding site) (TUBB)

Beta-tubulin is a fundamental structural protein that, along with alpha-tubulin, forms the heterodimers that polymerize into microtubules (UniProt P07437). These microtubules are essential for maintaining cell shape, facilitating intracellular transport, and forming the mitotic spindle during cell division (PubMed: 24862472). The Vinca domain is a specific pharmacological binding site located at the interface between tubulin heterodimers, primarily on the beta-subunit at the plus end of the microtubule (StatPearls: Vinca Alkaloids). Binding of ligands to this site, such as Vinca alkaloids, prevents the longitudinal association of tubulin dimers, thereby inhibiting microtubule polymerization and promoting depolymerization (PubMed: 11412937). This disruption of microtubule dynamics prevents the proper formation of the mitotic spindle, leading to cell cycle arrest in metaphase and the induction of programmed cell death (NIH: National Cancer Institute). Consequently, the Vinca domain is a major therapeutic target in oncology for the treatment of various hematological malignancies and solid tumors (PubMed: 21548871). However, drugs targeting this site are frequently associated with dose-limiting neurotoxicity due to the disruption of microtubule-dependent axonal transport (PubMed: 25130172). Resistance to these agents often arises through the overexpression of efflux transporters like P-glycoprotein or alterations in tubulin isotype expression (PubMed: 15585506).

Other names

Vinca domainVinca alkaloid binding siteTubulin beta chainVinca siteBeta-tubulin

Inhibition of microtubule polymerization and induction of depolymerization by binding to the Vinca domain at the microtubule plus end, leading to mitotic arrest in the M-phase and subsequent apoptosis (PubMed: 11412937).