Q9JJZ2 · TBA8_MOUSE
- ProteinTubulin alpha-8 chain
- GeneTuba8
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids449 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
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.
Miscellaneous
This tubulin does not have a C-terminal tyrosine; however, its C-terminal phenylalanine residue can be cleaved.
Catalytic activity
- GTP + H2O = GDP + H+ + phosphateThis reaction proceeds in the forward direction.
Cofactor
Features
Showing features for binding site, active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 11 | GTP (UniProtKB | ChEBI) | ||||
Sequence: Q | ||||||
Binding site | 71 | GTP (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 71 | Mg2+ (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 140 | GTP (UniProtKB | ChEBI) | ||||
Sequence: S | ||||||
Binding site | 144 | GTP (UniProtKB | ChEBI) | ||||
Sequence: G | ||||||
Binding site | 145 | GTP (UniProtKB | ChEBI) | ||||
Sequence: T | ||||||
Binding site | 179 | GTP (UniProtKB | ChEBI) | ||||
Sequence: T | ||||||
Binding site | 206 | GTP (UniProtKB | ChEBI) | ||||
Sequence: N | ||||||
Binding site | 228 | GTP (UniProtKB | ChEBI) | ||||
Sequence: N | ||||||
Active site | 254 | |||||
Sequence: E |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | acrosomal vesicle | |
Cellular Component | cytoplasm | |
Cellular Component | microtubule | |
Molecular Function | GTP binding | |
Molecular Function | hydrolase activity | |
Molecular Function | metal ion binding | |
Molecular Function | structural constituent of cytoskeleton | |
Biological Process | microtubule cytoskeleton organization | |
Biological Process | mitotic cell cycle | |
Biological Process | spermatid development | |
Biological Process | spermatogenesis |
Keywords
- Molecular function
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameTubulin alpha-8 chain
- EC number
- Alternative names
- Cleaved into 1 chains
Gene names
Organism names
- Organism
- Strain
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Glires > Rodentia > Myomorpha > Muroidea > Muridae > Murinae > Mus > Mus
Accessions
- Primary accessionQ9JJZ2
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000456435 | 1-448 | Dephenylalaninated tubulin alpha-8 chain | |||
Sequence: MRECISVHVGQAGVQIGNACWELFCLEHGIQADGTFGTQASKINDDDSFTTFFSETGNGKHVPRAVMVDLEPTVVDEVRAGTYRQLFHPEQLITGKEDAANNYARGHYTVGKESIDLVLDRIRKLTDACSGLQGFLIFHSFGGGTGSGFTSLLMERLSLDYGKKSKLEFAIYPAPQVSTAVVEPYNSILTTHTTLEHSDCAFMVDNEAIYDICRRNLDIERPTYTNLNRLISQIVSSITASLRFDGALNVDLTEFQTNLVPYPRIHFPLVTYAPIISAEKAYHEQLSVAEITSSCFEPNSQMVKCDPRHGKYMACCMLYRGDVVPKDVNVAIAAIKTKRTIQFVDWCPTGFKVGINYQPPTVVPGGDLAKVQRAVCMLSNTTAIAEAWARLDHKFDLMYAKRAFVHWYVGEGMEEGEFSEAREDLAALEKDYEEVGTDSFEEENEGEE | ||||||
Chain | PRO_0000048125 | 1-449 | Tubulin alpha-8 chain | |||
Sequence: MRECISVHVGQAGVQIGNACWELFCLEHGIQADGTFGTQASKINDDDSFTTFFSETGNGKHVPRAVMVDLEPTVVDEVRAGTYRQLFHPEQLITGKEDAANNYARGHYTVGKESIDLVLDRIRKLTDACSGLQGFLIFHSFGGGTGSGFTSLLMERLSLDYGKKSKLEFAIYPAPQVSTAVVEPYNSILTTHTTLEHSDCAFMVDNEAIYDICRRNLDIERPTYTNLNRLISQIVSSITASLRFDGALNVDLTEFQTNLVPYPRIHFPLVTYAPIISAEKAYHEQLSVAEITSSCFEPNSQMVKCDPRHGKYMACCMLYRGDVVPKDVNVAIAAIKTKRTIQFVDWCPTGFKVGINYQPPTVVPGGDLAKVQRAVCMLSNTTAIAEAWARLDHKFDLMYAKRAFVHWYVGEGMEEGEFSEAREDLAALEKDYEEVGTDSFEEENEGEEF |
Post-translational modification
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. Cilia and flagella glycylation is required for their stability and maintenance. Flagella glycylation controls sperm motility (PubMed:33414192).
Some glutamate residues at the C-terminus are polyglutamylated, resulting in polyglutamate chains on the gamma-carboxyl group (PubMed:15890843).
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).
Glutamylation is also involved in cilia motility (PubMed:23897886).
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).
Glutamylation is also involved in cilia motility (PubMed:23897886).
The C-terminal phenylalanine residue is cleaved by MATCAP1/KIAA0895L.
Proteomic databases
PTM databases
Expression
Tissue specificity
Expressed at highest levels in the testis, followed by skeletal and heart muscle. Expressed at low levels in the developing brain.
Developmental stage
At embryonic day (E) 13.5, expressed in the cortical preplate and cingulate cortex. By 15.5 dpc, the strongest expression is seen in the cortical plate. By 18.5 dpc, cortical expression is most intense in the upper layers and subplate. There is strong expression in the areas CA1-3 of the hippocampus. At P0, cortical expression is strongest in the dense cortical plate and subplate. Hippocampal expression is more intense in areas CA1-3 than in the dentate gyrus. At P8, lamination is almost complete and cortical expression is strongest in layers II-III and V and the subplate. There is also expression in the mediodorsal nuclei of the thalamus, the mitral cell layer of the olfactory bulb, and the external granular layer, molecular layer, and internal granular cell layer of the cerebellum.
Gene expression databases
Interaction
Subunit
Dimer of alpha and beta chains. A typical microtubule is a hollow water-filled tube with an outer diameter of 25 nm and an inner diameter of 15 nM. Alpha-beta heterodimers associate head-to-tail to form protofilaments running lengthwise along the microtubule wall with the beta-tubulin subunit facing the microtubule plus end conferring a structural polarity. Microtubules usually have 13 protofilaments but different protofilament numbers can be found in some organisms and specialized cells.
Protein-protein interaction databases
Miscellaneous
Structure
Family & Domains
Features
Showing features for motif.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Motif | 1-4 | MREC motif | ||||
Sequence: MREC |
Domain
The MREC motif may be critical for tubulin autoregulation.
Sequence similarities
Belongs to the tubulin family.
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length449
- Mass (Da)50,052
- Last updated2000-10-01 v1
- ChecksumAA979E2DB21FC5DD
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 447 | in Ref. 5; BAB26288 | ||||
Sequence: E → G |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AJ245923 EMBL· GenBank· DDBJ | CAB88033.1 EMBL· GenBank· DDBJ | mRNA | ||
GU591980 EMBL· GenBank· DDBJ | ADD82895.1 EMBL· GenBank· DDBJ | mRNA | ||
CH466523 EMBL· GenBank· DDBJ | EDK99659.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
BC017631 EMBL· GenBank· DDBJ | AAH17631.1 EMBL· GenBank· DDBJ | mRNA | ||
AK009439 EMBL· GenBank· DDBJ | BAB26288.1 EMBL· GenBank· DDBJ | mRNA |