UniProt:P68372 Tubb4b

chain
  • chain:1-445
checksum A552C52822AFA072
comment
  • 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 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 (PubMed:37295417, PubMed:37865089, PubMed:37989994).SUBCELLULAR LOCATION Widely expressed. Expressed in the retina and the cochlea.DOMAIN The highly acidic C-terminal region may bind cations such as calcium.DOMAIN The MREI motif is common among all beta-tubulin isoforms and may be critical for tubulin autoregulation.PTM 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).PTM 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).PTM 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.SIMILARITY Belongs to the tubulin family.
created [InstanceEdit:217385] Schmidt, EE, 2008-03-27 06:23:53
crossReference
databaseName UniProt
dbId 250615
description
  • recommendedName: Tubulin beta-4B chain alternativeName: Tubulin beta-2C chain
displayName UniProt:P68372 Tubb4b
geneName
  • Tubb4b
  • Tubb2c
identifier P68372
isSequenceChanged false
keyword
  • 3D-structure
  • Acetylation
  • Cell projection
  • Cilium
  • Cytoplasm
  • Cytoskeleton
  • Direct protein sequencing
  • Flagellum
  • GTP-binding
  • Isopeptide bond
  • Magnesium
  • Metal-binding
  • Microtubule
  • Nucleotide-binding
  • Phosphoprotein
  • Reference proteome
modified [InstanceEdit:9926675] Weiser, Joel, 2024-11-03
moleculeType Protein
name
  • Tubb4b
otherIdentifier
  • 10480628
  • 10519488
  • 1423642_at
  • 17382423
  • 227613
  • 4306143
  • 4318312
  • 4363234
  • 4369506
  • 4429563
  • 4451499
  • 4530700
  • 4644286
  • 4665744
  • 4826274
  • 5104834
  • 5113614
  • 5114915
  • 5140337
  • 5226688
  • 5273007
  • 5301096
  • 5511314
  • A_52_P598278
  • A_66_P111694
  • C77864_rc_f_at
  • GE102244
  • GE133388
  • GO:0000166
  • GO:0000226
  • GO:0000278
  • GO:0003723
  • GO:0003725
  • GO:0003924
  • GO:0005198
  • GO:0005200
  • GO:0005525
  • GO:0005737
  • GO:0005856
  • GO:0005874
  • GO:0005879
  • GO:0005929
  • GO:0007010
  • GO:0007017
  • GO:0007018
  • GO:0015630
  • GO:0016787
  • GO:0022414
  • GO:0030317
  • GO:0031514
  • GO:0036126
  • GO:0042995
  • GO:0043209
  • GO:0043226
  • GO:0045171
  • GO:0045298
  • GO:0046872
  • GO:0048870
  • GO:0072686
  • ILMN_2702061
  • Msa.6932.0_f_at
  • mMC025875
physicalEntity
referenceDatabase [ReferenceDatabase:2] UniProt
referenceGene
referenceTranscript
schemaClass ReferenceGeneProduct
secondaryIdentifier
  • TBB4B_MOUSE
  • P05217
  • Q3TKF0
  • Q3UJ73
  • Q99JZ6
sequenceLength 445
species [Species:48892] Mus musculus
stId uniprot:P68372
url http://purl.uniprot.org/uniprot/P68372
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