TUBB2A

Microtubules, key participants in processes such as mitosis and intracellular transport, are composed of heterodimers of alpha- and beta-tubulins. The protein encoded by this gene is a beta-tubulin. Defects in this gene are associated with complex cortical dysplasia with other brain malformations-5. Two transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq, Jul 2015]

TUBB2A Gene(Protein Coding) Tubulin Beta 2A Class IIa

Tubulin is the major constituent of microtubules, a cylinder consisting of laterally associated linear protofilaments composed of alpha- and beta-tubulin heterodimers. Microtubules grow by the addition of GTP-tubulin dimers to the microtubule end, where a stabilizing cap forms. Below the cap, tubulin dimers are in GDP-bound state, owing to GTPase activity of alpha-tubulin.

Biological Process microtubule cytoskeleton organization Source:GO_Central1 Publication
Biological Process mitotic cell cycle Source:GO_Central1 Publication
Biological Process neuron migration Source:GO_Central1 Publication

Cytoplasm, cytoskeleton

Cortical dysplasia, complex, with other brain malformations 5 (CDCBM5):
A disorder of aberrant neuronal migration and disturbed axonal guidance. Clinical features include seizures, global developmental delay, and various brain malformations such as a diffuse simplified gyral pattern with reduced volume of white matter, globular basal ganglia, thin and dysmorphic corpus callosum, mild brainstem hypoplasia with a flat pons, mild cerebellar vermis hypoplasia, and mildly enlarged posterior fossa.

Some glutamate residues at the C-terminus are polyglutamylated, resulting in polyglutamate chains on the gamma-carboxyl group (PubMed:26875866).
Polyglutamylation plays a key role in microtubule severing by spastin (SPAST). SPAST preferentially recognizes and acts on microtubules decorated with short polyglutamate tails: severing activity by SPAST increases as the number of glutamates per tubulin rises from one to eight, but decreases beyond this glutamylation threshold (PubMed:26875866).
Glutamylation is also involved in cilia motility (By similarity).
Some glutamate residues at the C-terminus are monoglycylated but not polyglycylated due to the absence of functional TTLL10 in human. Monoglycylation is mainly limited to tubulin incorporated into cilia and flagella axonemes, which is required for their stability and maintenance. Flagella glycylation controls sperm motility. Both polyglutamylation and monoglycylation can coexist on the same protein on adjacent residues, and lowering glycylation levels increases polyglutamylation, and reciprocally.
Phosphorylated on Ser-172 by CDK1 during the cell cycle, from metaphase to telophase, but not in interphase. This phosphorylation inhibits tubulin incorporation into microtubules.