TBA1_CHICK

Function

Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain.

Post-translational modifications

Some glutamate residues at the C-terminus are polyglycylated, resulting in polyglycine chains on the gamma-carboxyl group. Glycylation is mainly limited to tubulin incorporated into axonemes (cilia and flagella) whereas glutamylation is prevalent in neuronal cells, centrioles, axonemes, and the mitotic spindle. Both modifications can coexist on the same protein on adjacent residues, and lowering polyglycylation levels increases polyglutamylation, and reciprocally. The precise function of polyglycylation is still unclear.

Some glutamate residues at the C-terminus are polyglutamylated, resulting in polyglutamate chains on the gamma-carboxyl group (By similarity). 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 (By similarity).

Undergoes a tyrosination/detyrosination cycle, the cyclic removal and re-addition of a C-terminal tyrosine residue by the enzymes tubulin tyrosine carboxypeptidase (VASH1 or VASH2) and tubulin tyrosine ligase (TTL), respectively.

Tubulin alpha-1 chain

Tyrosination promotes microtubule interaction with CAP-Gly microtubule plus-end tracking proteins. Tyrosinated tubulins regulate the initiation of dynein-driven motility.

Detyrosinated tubulin alpha-1 chain

Detyrosination is involved in metaphase plate congression by guiding chromosomes during mitosis (By similarity). Detyrosination increases microtubules-dependent mechanotransduction in dystrophic cardiac and skeletal muscle. In cardiomyocytes, detyrosinated microtubules are required to resist to contractile compression during contraction (By similarity).

Sequence similarities

Belongs to the tubulin family.

Cellular localization

• Cytoplasm
• Cytoskeleton

Alternative names

• Tubulin alpha-1 chain

Database links

• swissprot:P02552

Target type

Proteins

Molecular weight

45901Da