TUBB

TUBB is a gene that encodes beta-tubulin, a core component of microtubules in the cytoskeleton. In humans, it is commonly described as encoding the beta-1 tubulin isotype, and it belongs to the larger tubulin family that forms heterodimers with alpha-tubulin to create the microtubule polymers essential for cell structure and function.

Beta-tubulin is a GTPase. Each beta-tubulin subunit binds GTP, and during microtubule assembly, GTP hydrolysis to GDP promotes conformational changes that influence polymer stability. Together with alpha-tubulin, beta-tubulin dimers assemble into protofilaments that curve and interact to form the hollow microtubule lattice. Microtubules exhibit dynamic instability, growing and shrinking in response to cellular needs, and they serve as tracks for motor proteins involved in intracellular transport, chromosome segregation during cell division, and maintenance of cell shape.

There are multiple beta-tubulin genes in humans, yielding a family of isotypes with tissue-specific expression. Beyond TUBB, other beta-tubulin genes include TUBB1, TUBB2A, TUBB2B, TUBB3, and TUBB4A. Some isotypes have specialized roles or distribution patterns; for example, beta-III tubulin (TUBB3) is predominantly expressed in neurons and is used as a neuronal marker in research and diagnostics, while TUBB1 is associated with platelets.

Clinically, alterations in beta-tubulin genes or expression can be linked to neurodevelopmental disorders and certain cancers. Because beta-tubulin is the binding partner for many microtubule-targeting drugs, tubulin dynamics are a common therapeutic target for anticancer treatments such as taxanes and vinca alkaloids.