TUBB2B

TUBB2B is a beta isoform of tubulin, which binds GTP and is a major component of microtubules. It is highly similar to TUBB2A and TUBB2C. Defects in this gene can cause asymmetric polymicrogyria.

Tubulin Beta 2B Class IIB

Tubulin is the major constituent of microtubules, a cylinder consisting of laterally associated linear protofilaments composed of alpha- and beta-tubulin heterodimers (PubMed:23001566, PubMed:28013290, PubMed:26732629).
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. Plays a critical role in proper axon guidance in both central and peripheral axon tracts (PubMed:23001566).
Implicated in neuronal migration (PubMed:19465910).

Biological Process embryonic brain development Source:Ensembl
Biological Process microtubule cytoskeleton organization Source:GO_Central1 Publication
Biological Process microtubule-based process Source:UniProtKB1 Publication
Biological Process mitotic cell cycle Source:GO_Central1 Publication
Biological Process modulation of chemical synaptic transmission Source:Ensembl
Biological Process neuron migration Source:UniProtKB1 Publication
Biological Process positive regulation of axon guidance Source:UniProtKB1 Publication

Cytoplasm, cytoskeleton

Cortical dysplasia, complex, with other brain malformations 7 (CDCBM7):
A malformation of the cortex in which the brain surface is irregular and characterized by an excessive number of small gyri with abnormal lamination. Polymicrogyria is a heterogeneous disorder, considered to be the result of postmigratory abnormal cortical organization.

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.