P81947 · TBA1B_BOVIN

  • Protein
    Tubulin alpha-1B chain
  • Status
    UniProtKB reviewed (Swiss-Prot)
  • Amino acids
  • Protein existence
    Evidence at protein level
  • Annotation score
    5/5

Function

function

Tubulin is the major constituent of microtubules, a cylinder consisting of laterally associated linear protofilaments composed of alpha- and beta-tubulin heterodimers (PubMed:2207090, PubMed:6504138, PubMed:7704569).
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 (PubMed:2207090, PubMed:6504138, PubMed:7704569).

Catalytic activity

Cofactor

Mg2+ (UniProtKB | Rhea| CHEBI:18420 )

Features

Showing features for binding site, active site, site.

TypeIDPosition(s)Description
Binding site11GTP (UniProtKB | ChEBI)
Binding site71GTP (UniProtKB | ChEBI)
Binding site71Mg2+ (UniProtKB | ChEBI)
Binding site140GTP (UniProtKB | ChEBI)
Binding site144GTP (UniProtKB | ChEBI)
Binding site145GTP (UniProtKB | ChEBI)
Binding site179GTP (UniProtKB | ChEBI)
Binding site206GTP (UniProtKB | ChEBI)
Binding site228GTP (UniProtKB | ChEBI)
Active site254
Site451Involved in polymerization

GO annotations

AspectTerm
Cellular Componentcytoplasm
Cellular Componentcytosol
Cellular Componentmicrotubule
Cellular Componentmicrotubule cytoskeleton
Molecular FunctionGTP binding
Molecular FunctionGTPase activity
Molecular Functionmetal ion binding
Molecular Functionstructural constituent of cytoskeleton
Biological Processmicrotubule cytoskeleton organization
Biological Processmitotic cell cycle

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

Organism names

  • Taxonomic identifier
  • Organism
  • Strain
    • Hereford
  • Taxonomic lineage
    Eukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Laurasiatheria > Artiodactyla > Ruminantia > Pecora > Bovidae > Bovinae > Bos

Accessions

  • Primary accession
    P81947
  • Secondary accessions
    • A6H700

Proteomes

Subcellular Location

PTM/Processing

Features

Showing features for chain, modified residue, cross-link.

TypeIDPosition(s)Description
ChainPRO_00004373971-450Detyrosinated tubulin alpha-1B chain
ChainPRO_00000481141-451Tubulin alpha-1B chain
Modified residue40N6,N6,N6-trimethyllysine; alternate
Modified residue40N6-acetyllysine; alternate
Modified residue48Phosphoserine
Modified residue232Phosphoserine
Modified residue2823'-nitrotyrosine
Cross-link326Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin)
Modified residue339Omega-N-methylarginine
Cross-link370Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin)
Modified residue439Phosphoserine
Modified residue4435-glutamyl polyglutamate
Modified residue4455-glutamyl polyglutamate
Modified residue4513'-nitrotyrosine

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).
Acetylation of alpha chains at Lys-40 is located inside the microtubule lumen. This modification has been correlated with increased microtubule stability, intracellular transport and ciliary assembly.
Methylation of alpha chains at Lys-40 is found in mitotic microtubules and is required for normal mitosis and cytokinesis contributing to genomic stability.
Nitration of Tyr-451 is irreversible and interferes with normal dynein intracellular distribution.
Undergoes a tyrosination/detyrosination cycle, the cyclic removal and re-addition of a C-terminal tyrosine residue by the enzymes tubulin tyrosine carboxypeptidase (MATCAP, VASH1 or VASH2) and tubulin tyrosine ligase (TTL), respectively.

Tubulin alpha-1B chain

Tyrosination promotes microtubule interaction with CAP-Gly domain-containing proteins such as CLIP1, CLIP2 and DCTN1 (By similarity).
Tyrosination regulates the initiation of dynein-dynactin motility via interaction with DCTN1, which brings the dynein-dynactin complex into contact with microtubules. In neurons, tyrosinated tubulins mediate the initiation of retrograde vesicle transport (By similarity).

Detyrosinated tubulin alpha-1B chain

Detyrosination is involved in metaphase plate congression by guiding chromosomes during mitosis: detyrosination promotes interaction with CENPE, promoting pole-proximal transport of chromosomes toward the equator (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: detyrosination promotes association with desmin (DES) at force-generating sarcomeres, leading to buckled microtubules and mechanical resistance to contraction (By similarity).

Keywords

Proteomic databases

PTM databases

Interaction

Subunit

Dimer of alpha and beta chains (PubMed:2207090, PubMed:6504138, PubMed:7704569).
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

Family & Domains

Features

Showing features for region.

TypeIDPosition(s)Description
Region432-451Disordered

Sequence similarities

Belongs to the tubulin family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    451
  • Mass (Da)
    50,152
  • Last updated
    2009-02-10 v2
  • Checksum
    94355B4EC2086429
MRECISIHVGQAGVQIGNACWELYCLEHGIQPDGQMPSDKTIGGGDDSFNTFFSETGAGKHVPRAVFVDLEPTVIDEVRTGTYRQLFHPEQLITGKEDAANNYARGHYTIGKEIIDLVLDRIRKLADQCTGLQGFLVFHSFGGGTGSGFTSLLMERLSVDYGKKSKLEFSIYPAPQVSTAVVEPYNSILTTHTTLEHSDCAFMVDNEAIYDICRRNLDIERPTYTNLNRLISQIVSSITASLRFDGALNVDLTEFQTNLVPYPRIHFPLATYAPVISAEKAYHEQLSVAEITNACFEPANQMVKCDPRHGKYMACCLLYRGDVVPKDVNAAIATIKTKRSIQFVDWCPTGFKVGINYQPPTVVPGGDLAKVQRAVCMLSNTTAIAEAWARLDHKFDLMYAKRAFVHWYVGEGMEEGEFSEAREDMAALEKDYEEVGVDSVEGEGEEEGEEY

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
BC146060
EMBL· GenBank· DDBJ
AAI46061.1
EMBL· GenBank· DDBJ
mRNA

Genome annotation databases

Similar Proteins

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