TUBB8: Tubulin Beta 8 Class VIII
A key gene in oocyte maturation and early embryonic development, associated with female infertility and zygotic arrest.
Gene Information Card
| Symbol | TUBB8 |
|---|---|
| Full Name | Tubulin Beta 8 Class VIII |
| Gene Type | Protein coding |
| Chromosomal Location | 10p15.3 |
| NCBI Gene ID | 347688 ncbi.nlm.nih.gov/gene/347688 |
| Ensembl ID | ENSG00000196313 |
| UniProt ID | Q3ZCM7 |
| OMIM ID | 616768 |
| HGNC ID | 20773 |
| Aliases | MGC120420, bA631M21.1, TUBB8.1 |
Description
TUBB8 encodes a beta-tubulin protein that is a core component of microtubules. It is specifically expressed in oocytes and early embryos, where it is essential for meiotic spindle formation, chromosome segregation, and symmetric cell division. Mutations in TUBB8 are a known cause of female infertility due to oocyte maturation arrest, fertilization failure, or early embryonic developmental arrest.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Oocyte maturation arrest (female infertility) | Disrupted microtubule polymerization leads to abnormal meiotic spindle assembly, causing oocyte arrest at metaphase I or II. | ClinVar, OMIM |
| Zygotic arrest (early embryonic arrest) | Mutations impair microtubule function in the zygote, preventing cleavage and normal embryonic development. | ClinVar, OMIM |
| Recurrent pregnancy loss | Defective spindle formation may cause aneuploidy and early miscarriage. | ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Ovary | 0.0 | Not detected (specific to oocytes, not bulk tissue) |
| Testis | 0.0 | Not detected |
| Brain | 0.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Oocyte (human) | High (qualitative) | Specifically expressed in oocytes; essential for meiosis. |
| Embryonic stem cells | Low | Minimal expression in somatic cells. |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.2T>C (p.Met1?) | Missense | Rare | Loss of start codon, no protein produced. |
| c.4C>T (p.Arg2Trp) | Missense | Rare | Disrupts N-terminal domain, impairs microtubule assembly. |
| c.10G>A (p.Glu4Lys) | Missense | Rare | Alters GTP-binding region, reduces polymerization. |
| c.20A>G (p.Asn7Ser) | Missense | Rare | Affects microtubule stability. |
| c.29G>A (p.Gly10Asp) | Missense | Rare | Causes oocyte arrest at metaphase I. |
Mutation functional classification
Loss of Function (LOF)
Most TUBB8 mutations are loss-of-function, reducing microtubule polymerization or stability, leading to meiotic spindle defects.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
Heterozygous missense mutations often act in a dominant-negative manner, as mutant tubulin incorporates into microtubules and disrupts their function.
View complete mutation data：
Gene Ontology (GO)
| • structural constituent of cytoskeleton (GO:0005200) | • microtubule (GO:0005874) |
| • microtubule-based process (GO:0007017) | • microtubule cytoskeleton organization (GO:0000226) |
| • chromosome segregation (GO:0007059) | • meiotic nuclear division (GO:0007126) |
| • axon (GO:0030424) |
Pathways
• Microtubule polymerization (Reactome: R-HSA-190840)
• Cell cycle
• mitotic (Reactome: R-HSA-69278)
• Meiosis (Reactome: R-HSA-1500620)
Protein Summary
TUBB8 is a beta-tubulin isoform specifically expressed in oocytes and early embryos. It polymerizes with alpha-tubulin to form microtubules, which are critical for meiotic spindle assembly, chromosome segregation, and cell division. Mutations in TUBB8 disrupt these processes, leading to female infertility characterized by oocyte maturation arrest, fertilization failure, or early embryonic arrest. The protein is 445 amino acids long and contains a GTP-binding domain essential for microtubule dynamics.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TUBB8 Knockout HEK293 Cell Line | EDJ-KQ15986 | Human | 347688 | Details Get a Quote |
| TUBB8B Knockout HEK293 Cell Line | EDJ-KQ15987 | Human | 260334 | Details Get a Quote |
| TUBB8B Knockout HCT 116 Cell Line | EDJ-KQ47034 | Human | 260334 | Details Get a Quote |
| TUBB8 Knockout HeLa Cell Line | EDJ-KQ59822 | Human | 347688 | Details Get a Quote |
| TUBB8 Knockout A-549 Cell Line | EDJ-KQ68291 | Human | 347688 | Details Get a Quote |
| TUBB8 Knockout HCT 116 Cell Line | EDJ-KQ76665 | Human | 347688 | Details Get a Quote |
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