Class III β-tubulin

Class III β-tubulin is a protein that in humans is encoded by the TUBB3 gene. It is a member of the tubulin family, which constitutes the microtubules of the cellular cytoskeleton. Microtubules are involved in many cellular processes, including mitosis, cytokinesis, and vesicular transport. Class III β-tubulin is specifically expressed in neurons and is critical for proper axon guidance and maintenance.

Function

Class III β-tubulin plays a pivotal role in neuronal cell function due to its incorporation into microtubules. These microtubules are essential for the transport of materials within the cell, a process particularly important in the long axons of neurons. The unique properties of Class III β-tubulin allow for the microtubules to have greater flexibility, which is believed to be crucial for the development and maintenance of the delicate and complex structures of the nervous system.

Clinical Significance

Alterations in the expression of Class III β-tubulin have been associated with a variety of neurological diseases and conditions. For example, overexpression of this protein has been observed in certain types of cancer, making it a potential marker for tumor progression and a target for chemotherapy. In particular, it has been studied in relation to resistance to microtubule-targeting drugs in cancer therapy.

Moreover, mutations in the TUBB3 gene have been linked to a range of developmental disorders, including congenital fibrosis of the extraocular muscles, cortical dysplasia, and polymicrogyria. These conditions are characterized by abnormal brain development and function, highlighting the critical role of Class III β-tubulin in neural development.

Genetics

The TUBB3 gene is located on chromosome 16q24.3 and consists of multiple exons that encode the Class III β-tubulin protein. Genetic variations in TUBB3 can lead to altered protein function or expression, contributing to the pathogenesis of neurological disorders.

See Also

• Microtubule
• Cytoskeleton
• Neurodevelopmental disorder
• Chemotherapy resistance