TUBA8
Domain
The MREC motif may be critical for tubulin autoregulation.
Function
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.
Involvement in disease
Macrothrombocytopenia, isolated, 2, autosomal dominant
MACTHC2
A congenital blood disorder characterized by increased platelet size and decreased number of circulating platelets. Affected individuals usually are asymptomatic and do not have increased bleeding episodes.
None
The disease may be caused by variants affecting the gene represented in this entry.
Post-translational modifications
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.
The C-terminal phenylalanine residue is cleaved by MATCAP1/KIAA0895L.
Sequence Similarities
Belongs to the tubulin family.
Tissue Specificity
Preferentially expressed in heart, skeletal muscle and testis. Expressed at low levels in the developing brain. Expressed in megakaryocytes and platelets (PubMed:34704371).
Cellular localization
- Cytoplasm
- Cytoskeleton
Alternative names
TUBAL2, TUBA8, Tubulin alpha-8 chain, Alpha-tubulin 8, Tubulin alpha chain-like 2