BACKGROUND
Tubulin is a major cytoskeleton component that has three distinct forms, designated alpha, beta and gamma Tubulin. alpha and beta Tubulins form heterodimers, which multimerize to form a microtubule filament. gamma Tubulin forms a soluble multi-protein particle with several other proteins. This particle, designated the gammasome, is required for nucleating microtubule filaments at the centrosome. In several organisms, numerous isoforms of the Tubulins exist that are encoded by different genes. The alpha and beta isoforms undergo a variety of posttranslational modifications, which may affect microtubule stability and protein interactions. High expression of class II beta Tubulin has been seen in elongating axons, indicating a role in neurite outgrowth. Tubulins may also play a role in non-neuronal cell process formation.