Q7TMM9 · TBB2A_MOUSE
- ProteinTubulin beta-2A chain
- GeneTubb2a
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids445 (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.
Cofactor
Features
Showing features for binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 11 | GTP (UniProtKB | ChEBI) | ||||
Sequence: Q | ||||||
Binding site | 69 | GTP (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 69 | Mg2+ (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 138 | GTP (UniProtKB | ChEBI) | ||||
Sequence: S | ||||||
Binding site | 142 | GTP (UniProtKB | ChEBI) | ||||
Sequence: G | ||||||
Binding site | 143 | GTP (UniProtKB | ChEBI) | ||||
Sequence: T | ||||||
Binding site | 144 | GTP (UniProtKB | ChEBI) | ||||
Sequence: G | ||||||
Binding site | 204 | GTP (UniProtKB | ChEBI) | ||||
Sequence: N | ||||||
Binding site | 226 | GTP (UniProtKB | ChEBI) | ||||
Sequence: N |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Cellular Component | intercellular bridge | |
Cellular Component | microtubule | |
Cellular Component | mitotic spindle | |
Molecular Function | GTP binding | |
Molecular Function | GTPase activity | |
Molecular Function | metal ion binding | |
Molecular Function | structural constituent of cytoskeleton | |
Biological Process | cerebral cortex development | |
Biological Process | microtubule cytoskeleton organization | |
Biological Process | mitotic cell cycle |
Keywords
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameTubulin beta-2A chain
Gene names
Organism names
- Organism
- Strains
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Glires > Rodentia > Myomorpha > Muroidea > Muridae > Murinae > Mus > Mus
Accessions
- Primary accessionQ7TMM9
Proteomes
Organism-specific databases
Subcellular Location
PTM/Processing
Features
Showing features for chain, modified residue, cross-link.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000262650 | 1-445 | Tubulin beta-2A chain | |||
Sequence: MREIVHIQAGQCGNQIGAKFWEVISDEHGIDPTGSYHGDSDLQLERINVYYNEAAGNKYVPRAILVDLEPGTMDSVRSGPFGQIFRPDNFVFGQSGAGNNWAKGHYTEGAELVDSVLDVVRKESESCDCLQGFQLTHSLGGGTGSGMGTLLISKIREEYPDRIMNTFSVMPSPKVSDTVVEPYNATLSVHQLVENTDETYSIDNEALYDICFRTLKLTTPTYGDLNHLVSATMSGVTTCLRFPGQLNADLRKLAVNMVPFPRLHFFMPGFAPLTSRGSQQYRALTVPELTQQMFDSKNMMAACDPRHGRYLTVAAIFRGRMSMKEVDEQMLNVQNKNSSYFVEWIPNNVKTAVCDIPPRGLKMSATFIGNSTAIQELFKRISEQFTAMFRRKAFLHWYTGEGMDEMEFTEAESNMNDLVSEYQQYQDATADEQGEFEEEEGEDEA | ||||||
Modified residue | 40 | Phosphoserine | ||||
Sequence: S | ||||||
Modified residue | 58 | N6-acetyllysine; alternate | ||||
Sequence: K | ||||||
Modified residue | 58 | N6-succinyllysine; alternate | ||||
Sequence: K | ||||||
Cross-link | 58 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin); alternate | ||||
Sequence: K | ||||||
Modified residue | 172 | Phosphoserine; by CDK1 | ||||
Sequence: S | ||||||
Modified residue | 285 | Phosphothreonine | ||||
Sequence: T | ||||||
Modified residue | 290 | Phosphothreonine | ||||
Sequence: T | ||||||
Modified residue | 318 | Omega-N-methylarginine | ||||
Sequence: R | ||||||
Cross-link | 324 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin) | ||||
Sequence: K | ||||||
Modified residue | 438 | 5-glutamyl polyglutamate | ||||
Sequence: E |
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).
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.
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Gene expression databases
Interaction
Subunit
Part of a complex composed at least of ASH2L, EMSY, HCFC1, HSPA8, CCAR2, MATR3, MKI67, RBBP5, TUBB2A, WDR5 and ZNF335; this complex may have a histone H3-specific methyltransferase activity (By similarity).
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. Interacts with ZNRF1
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. Interacts with ZNRF1
Protein-protein interaction databases
Miscellaneous
Structure
Family & Domains
Features
Showing features for motif, region, compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Motif | 1-4 | MREI motif | ||||
Sequence: MREI | ||||||
Region | 422-445 | Disordered | ||||
Sequence: YQQYQDATADEQGEFEEEEGEDEA | ||||||
Compositional bias | 431-445 | Acidic residues | ||||
Sequence: DEQGEFEEEEGEDEA |
Domain
The MREI motif is common among all beta-tubulin isoforms and may be critical for tubulin autoregulation.
Sequence similarities
Belongs to the tubulin family.
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length445
- Mass (Da)49,907
- Last updated2003-10-01 v1
- Checksum93B3213EB2A9367B
Features
Showing features for compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 431-445 | Acidic residues | ||||
Sequence: DEQGEFEEEEGEDEA |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AK134545 EMBL· GenBank· DDBJ | BAE22178.1 EMBL· GenBank· DDBJ | mRNA | ||
BC055441 EMBL· GenBank· DDBJ | AAH55441.1 EMBL· GenBank· DDBJ | mRNA |