TUBB1

TUBB1 is a gene that encodes beta-1 tubulin, a member of the beta-tubulin family. Beta-tubulins pair with alpha-tubulins to form microtubules, which are essential components of the cytoskeleton involved in cell shape, division, and intracellular transport. In humans, TUBB1 is expressed prominently in megakaryocytes and platelets, where it contributes to the specialized microtubule networks that shape and release platelets during thrombopoiesis.

The beta-1 tubulin protein forms heterodimers with alpha-tubulin to polymerize microtubules. In platelets, TUBB1-containing microtubules participate in the formation of the marginal band and in proplatelet elongation, helping to determine platelet size and morphology. This microtubule-based framework supports platelet formation and stability, influencing how platelets develop and function.

Mutations in TUBB1 have been linked to congenital macrothrombocytopenia, a rare platelet disorder characterized by abnormally large platelets and reduced platelet counts. Affected individuals may exhibit variable bleeding symptoms. The mutations are typically missense changes that are believed to disrupt microtubule dynamics in megakaryocytes, impairing platelet production and proplatelet formation.

Genetic inheritance patterns reported for TUBB1-related macrothrombocytopenia include autosomal dominant or de novo cases, and the full genotype-phenotype relationship is still being investigated. Beyond its role in platelets, TUBB1 is part of the broader tubulin family, with tissue-specific isotypes that influence microtubule behavior in different cell types.