TUB4/YLR212C Summary Help

Standard Name TUB4
Systematic Name YLR212C
Feature Type ORF, Verified
Description Gamma-tubulin; involved in nucleating microtubules from both the cytoplasmic and nuclear faces of the spindle pole body; protein abundance increases in response to DNA replication stress (1, 2, 3, 4 and see Summary Paragraph)
Name Description TUBulin
Chromosomal Location
ChrXII:566281 to 564860 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All TUB4 GO evidence and references
  View Computational GO annotations for TUB4
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 5 genes
Classical genetics
Large-scale survey
reduction of function
113 total interaction(s) for 42 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 13
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 24
  • Biochemical Activity: 1
  • Co-localization: 1
  • Co-purification: 3
  • FRET: 4
  • PCA: 1
  • Reconstituted Complex: 6
  • Two-hybrid: 18

Genetic Interactions
  • Dosage Rescue: 10
  • Negative Genetic: 3
  • Phenotypic Enhancement: 1
  • Phenotypic Suppression: 1
  • Synthetic Growth Defect: 3
  • Synthetic Haploinsufficiency: 1
  • Synthetic Lethality: 22

Expression Summary
Length (a.a.) 473
Molecular Weight (Da) 52,627
Isoelectric Point (pI) 4.4
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXII:566281 to 564860 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1422 566281..564860 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000004202

TUB4 encodes the essential gene for gamma-tubulin (1, 5, 2). Gamma-tubulin is a conserved component of microtubule organizing centers and is essential for microtubule nucleation (for review, 6). Tub4p is a member of the tubulin superfamily, which includes alpha- and beta-tubulin, and the prokaryotic tubulin-like gene FtsZ (reviewed in 7, 8). Compared to other members of the gamma-tubulin family, Tub4p is surprisingly divergent, sharing only 29-38% amino acid sequence identity (1, 5, 2). Tub4p is a component of the S.cerevisiae microtubule organizing center, called the Spindle Pole Body (SPB), which is embedded in the nuclear envelope (1, 5, 2). Tub4p localizes to both nuclear (inner plaque) and cytoplasmic (outer plaque) faces of the SPB and is essential for nucleating microtubules from both faces (1, 5, and reviewed in 9).

Pertubation of Tub4p activity, either by conditional mutations at the non-permissive temperature or by depletion, results in mitotic spindle and SPB defects, including failure to form microtubules (1, 5, 2). The carboxy terminus of Tub4p contains the highly conserved motif DYSLD and an acidic tail; mutational analysis has revealed a role for the carboxy terminus in the nucleation of cytoplasmic microtubules during spindle elongation (10). Tub4p is phosphorylated on several residues in vivo (including the tyrosine moiety in DYSLD) and the phosphorylation state of Tub4p is important for regulating both microtubule number and assembly (11). Phosphorylation of Tub4p is maximal at G1 in the cell cycle (11).

Tub4p forms an evolutionarily conserved 2:1:1 stoichiometric complex with the SPB components Spc97p and Spc98p, in which one molecule of Tub4p binds one molecule of either component (12, 13, 14, 15, 16). In vitro, the Tub4p complex is able to bind pre-formed microtubules but has a low nucleation activity, suggesting that other SPB components may participate in microtubule nucleation (13). The Tub4p complex is targeted to the nuclear face of the SPB via the essential SPB component Spc110p that binds both Spc97p and Spc98p (12). Spc98p may direct the localization of the Tub4p complex to the nuclear face of the SPB via its nuclear localization sequence (17). The essential, outer plaque SPB component Spc72p likely anchors Tub4p complexes to the cytoplasmic side of the SPB, as it interacts with both Spc97p and Spc98p and mutations in SPC72 impair cytoplasmic microtubule formation (18).

Last updated: 2003-12-30 Contact SGD

References cited on this page View Complete Literature Guide for TUB4
1) Marschall LG, et al.  (1996) Analysis of Tub4p, a yeast gamma-tubulin-like protein: implications for microtubule-organizing center function. J Cell Biol 134(2):443-54
2) Sobel SG and Snyder M  (1995) A highly divergent gamma-tubulin gene is essential for cell growth and proper microtubule organization in Saccharomyces cerevisiae. J Cell Biol 131(6 Pt 2):1775-88
3) Geissler S, et al.  (1996) The spindle pole body component Spc98p interacts with the gamma-tubulin-like Tub4p of Saccharomyces cerevisiae at the sites of microtubule attachment. EMBO J 15(15):3899-911
4) Tkach JM, et al.  (2012) Dissecting DNA damage response pathways by analysing protein localization and abundance changes during DNA replication stress. Nat Cell Biol 14(9):966-76
5) Spang A, et al.  (1996) gamma-Tubulin-like Tub4p of Saccharomyces cerevisiae is associated with the spindle pole body substructures that organize microtubules and is required for mitotic spindle formation. J Cell Biol 134(2):429-41
6) Moritz M and Agard DA  (2001) Gamma-tubulin complexes and microtubule nucleation. Curr Opin Struct Biol 11(2):174-81
7) McKean PG, et al.  (2001) The extended tubulin superfamily. J Cell Sci 114(Pt 15):2723-33
8) Nogales E, et al.  (1998) Tubulin and FtsZ form a distinct family of GTPases. Nat Struct Biol 5(6):451-8
9) Knop M, et al.  (1999) Microtubule organization by the budding yeast spindle pole body. Biol Cell 91(4-5):291-304
10) Vogel J and Snyder M  (2000) The carboxy terminus of Tub4p is required for gamma-tubulin function in budding yeast. J Cell Sci 113 Pt 21:3871-82
11) Vogel J, et al.  (2001) Phosphorylation of gamma-tubulin regulates microtubule organization in budding yeast. Dev Cell 1(5):621-31
12) Knop M and Schiebel E  (1997) Spc98p and Spc97p of the yeast gamma-tubulin complex mediate binding to the spindle pole body via their interaction with Spc110p. EMBO J 16(23):6985-95
13) Vinh DB, et al.  (2002) Reconstitution and characterization of budding yeast gamma-tubulin complex. Mol Biol Cell 13(4):1144-57
14) Martin OC, et al.  (1998) Xgrip109: a gamma tubulin-associated protein with an essential role in gamma tubulin ring complex (gammaTuRC) assembly and centrosome function. J Cell Biol 141(3):675-87
15) Gunawardane RN, et al.  (2000) Characterization and reconstitution of Drosophila gamma-tubulin ring complex subunits. J Cell Biol 151(7):1513-24
16) Murphy SM, et al.  (1998) The mammalian gamma-tubulin complex contains homologues of the yeast spindle pole body components spc97p and spc98p. J Cell Biol 141(3):663-74
17) Pereira G, et al.  (1998) Spc98p directs the yeast gamma-tubulin complex into the nucleus and is subject to cell cycle-dependent phosphorylation on the nuclear side of the spindle pole body. Mol Biol Cell 9(4):775-93
18) Knop M and Schiebel E  (1998) Receptors determine the cellular localization of a gamma-tubulin complex and thereby the site of microtubule formation. EMBO J 17(14):3952-67