TUB3/YML124C Summary 
TUB3 BASIC INFORMATION
| Standard Name | TUB3 |
|---|---|
| Systematic Name | YML124C |
| Feature Type | ORF, Verified |
| Description | Alpha-tubulin; associates with beta-tubulin (Tub2p) to form tubulin dimer, which polymerizes to form microtubules; expressed at lower level than Tub1p (1 and see Summary Paragraph) 
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| Name Description | TUBulin |
| GO Annotations | All TUB3 GO evidence and references |
|---|---|
| View Computational GO annotations for TUB3 | |
| Molecular Function | |
| Manually curated | |
| Biological Process | |
| Manually curated | |
| Cellular Component | |
| Manually curated |
| Mutant Phenotype | All TUB3 Phenotype details and references |
|---|---|
| Classical genetics | |
| null | |
| Large-scale survey | |
| null |
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| Interactions | TUB3 All interactions details and references |
|---|---|
| 192 total interaction(s) for 125 unique genes/features. | |
| Physical Interactions |
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| Genetic Interactions |
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| External Links | All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | UniProtKB |
|---|
| Primary SGDID | S000004593 |
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TUB3 RESOURCES
| SGD ORF map | GBrowse |
|---|---|
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Click on histogram for expression summary
Expression Summary
ADDITIONAL INFORMATION for TUB3
SUMMARY PARAGRAPH for TUB3
In S.cerevisiae, two genes encode alpha-tubulin: TUB1 and TUB3 (2, 1). Tub3p belongs to the tubulin superfamily, which includes beta- and gamma-tubulin and the prokaryotic tubulin-like gene FtsZ (reviewed in 3, 4). Alpha- and beta-tubulin form tubulin heterodimers, which polymerize into microtubules. Microtubules are conserved cytoskeletal elements that function in nuclear processes: chromosome segregation in mitosis and meiosis, spindle orientation, and nuclear migration during mitosis and mating (5; for reviews, see 6, 7). All microtubules in S. cerevisiae emanate from a microtubule organizing center called the spindle pole body (SPB), which is embedded in the nuclear envelope (for review, see 8). Microtubules extend from both faces of the SPB, generating two types of microtubules: nuclear and cytoplasmic microtubules (9; for review, see 8). Distribution and length of these two types of microtubules is regulated throughout the cell cycle 9, (reviewed in 10).
TUB1 and TUB3 were cloned based on strong homology with their counterparts in other eukaryotes (2, 1). It is not clear why S. cerevisiae has two functionally identical genes for alpha-tubulin, but this arrangement may have some significance since it is conserved in the fission yeast, S. pombe (11). However, in vitro experiments suggest there are functional differences, as microtubules containing Tub3p as the sole alpha tubulin are less dynamic than wild-type microtubules (reduced shrinkage and catastrophe rates) while those containing Tub1p are more dynamic than wild-type (12). Relative to TUB1, TUB3 is expressed at low levels and is not essential for growth (1). Further, overexpression of TUB3 can suppress the lethality of a tub1 null mutation (1). tub3 null mutants grow normally under most conditions but are benomyl- (an anti-microtubule drug) and cold-sensitive (1). Tub3p interacts with numerous proteins involved in the regulation of microtubules, such as microtubule motors, SPB components, kinetochore components, tubulin biogenesis factors, and beta-tubulin (Tub2p) (reviewed in 6, 7).
Tub3p is a GTP-binding protein, though the GTP bound to Tub3p (and Tub1p) is non-hydrolyzable, whereas the GTP bound to Tub2p is hydrolyzed following tubulin dimer addition to the microtubule end (13). The structure of tubulin has been crystallized in the polymerized state; Tub3p (and Tub1p), rather than Tub2p, is believed to interact directly with the SPB (14).
Last updated: 2003-12-18
REFERENCES CITED ON THIS PAGE [View Complete Literature Guide for TUB3]
| 1) | Schatz PJ, et al. (1986) Genetically essential and nonessential alpha-tubulin genes specify functionally interchangeable proteins. Mol Cell Biol 6(11):3722-33 |
| 2) | Schatz PJ, et al. (1986) Two functional alpha-tubulin genes of the yeast Saccharomyces cerevisiae encode divergent proteins. Mol Cell Biol 6(11):3711-21 |
| 3) | McKean PG, et al. (2001) The extended tubulin superfamily. J Cell Sci 114(Pt 15):2723-33 |
| 4) | Nogales E, et al. (1998) Tubulin and FtsZ form a distinct family of GTPases. Nat Struct Biol 5(6):451-8 |
| 5) | Jacobs CW, et al. (1988) Functions of microtubules in the Saccharomyces cerevisiae cell cycle. J Cell Biol 107(4):1409-26 |
| 6) | Winsor B and Schiebel E (1997) Review: an overview of the Saccharomyces cerevisiae microtubule and microfilament cytoskeleton. Yeast 13(5):399-434 |
| 7) | Botstein D, et al. (1997) "The yeast cytoskeleton." Pp. 1-90 in The Molecular and Cellular Biology of the Yeast Saccharomyces: Cell Cycle and Cell Biology, edited by Pringle JR, Broach JR and Jones EW. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press |
| 8) | Knop M, et al. (1999) Microtubule organization by the budding yeast spindle pole body. Biol Cell 91(4-5):291-304 |
| 9) | Kilmartin JV and Adams AE (1984) Structural rearrangements of tubulin and actin during the cell cycle of the yeast Saccharomyces. J Cell Biol 98(3):922-33 |
| 10) | Carminati JL and Stearns T (1999) Cytoskeletal dynamics in yeast. Methods Cell Biol 58:87-105 |
| 11) | Adachi Y, et al. (1986) Differential expressions of essential and nonessential alpha-tubulin genes in Schizosaccharomyces pombe. Mol Cell Biol 6(6):2168-78 |
| 12) | Bode CJ, et al. (2003) The two alpha-tubulin isotypes in budding yeast have opposing effects on microtubule dynamics in vitro. EMBO Rep 4(1):94-9 |
| 13) | Carlier MF and Pantaloni D (1981) Kinetic analysis of guanosine 5'-triphosphate hydrolysis associated with tubulin polymerization. Biochemistry 20(7):1918-24 |
| 14) | Nogales E, et al. (1999) High-resolution model of the microtubule. Cell 96(1):79-88 |
