Q6P9T8 · TBB4B_RAT
- ProteinTubulin beta-4B chain
- GeneTubb4b
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids445 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score4/5
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
all annotations | all molecular function | virus receptor activity | dna binding | rna binding | cytoskeletal motor activity | catalytic activity | gtpase activity | structural molecule activity | transporter activity | cytoskeletal protein binding | lipid binding | cyclase activity | antioxidant activity | oxidoreductase activity | transferase activity | hydrolase activity | lyase activity | isomerase activity | ligase activity | protein tag activity | cargo receptor activity | histone binding | protein folding chaperone | translation regulator activity | nutrient reservoir activity | receptor ligand activity | molecular transducer activity | molecular adaptor activity | toxin activity | cell adhesion mediator activity | molecular function regulator activity | virus coreceptor activity | catalytic activity, acting on a protein | catalytic activity, acting on dna | catalytic activity, acting on rna | molecular carrier activity | transcription regulator activity | general transcription initiation factor activity | molecular sensor activity | molecular sequestering activity | atp-dependent activity | other molecular function | all biological process | mitotic cell cycle | cytokinesis | cytoplasmic translation | immune system process | muscle system process | circulatory system process | renal system process | respiratory system process | carbohydrate metabolic process | generation of precursor metabolites and energy | dna replication | dna repair | dna recombination | chromatin organization | dna-templated transcription | regulation of dna-templated transcription | trna metabolic process | protein folding | protein glycosylation | amino acid metabolic process | modified amino acid metabolic process | lipid metabolic process | vitamin metabolic process | sulfur compound metabolic process | intracellular protein transport | nucleocytoplasmic transport | autophagy | inflammatory response | mitochondrion organization | cytoskeleton organization | microtubule-based movement | peroxisome organization | lysosome organization | chromosome segregation | cell adhesion | establishment or maintenance of cell polarity | programmed cell death | photosynthesis | mrna metabolic process | snrna metabolic process | vesicle-mediated transport | reproductive process | digestive system process | signaling | cell differentiation | protein catabolic process | extracellular matrix organization | regulatory ncrna-mediated gene silencing | telomere organization | cell junction organization | wound healing | ribosome biogenesis | cilium organization | anatomical structure development | cell motility | nervous system process | endocrine process | protein maturation | transmembrane transport | nucleobase-containing small molecule metabolic process | hepaticobiliary system process | membrane organization | protein-containing complex assembly | cell wall organization or biogenesis | nitrogen cycle metabolic process | protein localization to plasma membrane | defense response to other organism | detoxification | meiotic nuclear division | mitotic nuclear division | mitochondrial gene expression | carbohydrate derivative metabolic process | other biological process | all cellular component | nuclear chromosome | extracellular region | extracellular space | cell wall | nucleus | nuclear envelope | nucleoplasm | chromosome | nucleolus | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | lipid droplet | microtubule organizing center | cytosol | ribosome | cytoskeleton | plasma membrane | cilium | plastid | thylakoid | external encapsulating structure | extracellular matrix | cytoplasmic vesicle | organelle | other cellular component | |||
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Aspect | Term | |
---|---|---|
Cellular Component | axonemal microtubule | |
Cellular Component | cytoplasm | |
Cellular Component | microtubule | |
Molecular Function | double-stranded RNA binding | |
Molecular Function | GTP binding | |
Molecular Function | GTPase activity | |
Molecular Function | metal ion binding | |
Molecular Function | structural constituent of cytoskeleton | |
Biological Process | microtubule cytoskeleton organization | |
Biological Process | mitotic cell cycle |
Keywords
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameTubulin beta-4B chain
- Alternative names
Gene names
Organism names
- Organism
- Strain
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Glires > Rodentia > Myomorpha > Muroidea > Muridae > Murinae > Rattus
Accessions
- Primary accessionQ6P9T8
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain, modified residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000270755 | 1-445 | Tubulin beta-4B chain | |||
Sequence: MREIVHLQAGQCGNQIGAKFWEVISDEHGIDPTGTYHGDSDLQLERINVYYNEATGGKYVPRAVLVDLEPGTMDSVRSGPFGQIFRPDNFVFGQSGAGNNWAKGHYTEGAELVDSVLDVVRKEAESCDCLQGFQLTHSLGGGTGSGMGTLLISKIREEYPDRIMNTFSVVPSPKVSDTVVEPYNATLSVHQLVENTDETYCIDNEALYDICFRTLKLTTPTYGDLNHLVSATMSGVTACLRFPGQLNADLRKLAVNMVPFPRLHFFMPGFAPLTSRGSQQYRALTVPELTQQMFDAKNMMAACDPRHGRYLTVAAVFRGRMSMKEVDEQMLNVQNKNSSYFVEWIPNNVKTAVCDIPPRGLKMSATFIGNSTAIQELFKRISEQFTAMFRRKAFLHWYTGEGMDEMEFTEAESNMNDLVSEYQQYQDATAEEEGEFEEEAEEEVA | ||||||
Modified residue | 55 | Phosphothreonine | ||||
Sequence: T | ||||||
Modified residue | 58 | N6-acetyllysine | ||||
Sequence: K | ||||||
Modified residue | 172 | Phosphoserine; by CDK1 | ||||
Sequence: S | ||||||
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.
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).
Glutamylation is also involved in cilia motility (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).
Glutamylation is also involved in cilia motility (By similarity).
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
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. Component of sperm flagellar doublet microtubules.
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for motif, region, compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Motif | 1-4 | MREI motif | ||||
Sequence: MREI | ||||||
Region | 426-445 | Disordered | ||||
Sequence: QDATAEEEGEFEEEAEEEVA | ||||||
Compositional bias | 428-445 | Acidic residues | ||||
Sequence: ATAEEEGEFEEEAEEEVA |
Domain
The highly acidic C-terminal region may bind cations such as calcium.
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)49,801
- Last updated2004-07-05 v1
- Checksum4BA931832C5B0B78
Computationally mapped potential isoform sequences
There are 2 potential isoforms mapped to this entry
Entry | Entry name | Gene name | Length | ||
---|---|---|---|---|---|
A0A8I5Y8E3 | A0A8I5Y8E3_RAT | Tubb4b | 547 | ||
G3V7C6 | G3V7C6_RAT | Tubb4b | 435 |
Features
Showing features for compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 428-445 | Acidic residues | ||||
Sequence: ATAEEEGEFEEEAEEEVA |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
BC060597 EMBL· GenBank· DDBJ | AAH60597.1 EMBL· GenBank· DDBJ | mRNA |