TUBB2B Gene - Tubulin Beta 2B Class IIb
Essential for neuronal migration and cortical development; mutations cause complex cortical malformations
Gene Information Card
| Symbol | TUBB2B |
|---|---|
| Full Name | Tubulin Beta 2B Class IIb |
| Gene Type | Protein coding |
| Chromosomal Location | 6p25.2 |
| NCBI Gene ID | 347733 ncbi.nlm.nih.gov/gene/347733 |
| Ensembl ID | ENSG00000137285 |
| UniProt ID | Q9BVA1 |
| OMIM ID | 612850 |
| HGNC ID | 20771 |
| Aliases | MGC8688, TUBB2B, beta-tubulin 2B |
Description
TUBB2B encodes a beta-tubulin protein that forms heterodimers with alpha-tubulin to constitute microtubules. It is critical for neuronal migration, axon guidance, and cortical lamination during brain development. Mutations in TUBB2B disrupt microtubule dynamics and cause a spectrum of cortical malformations, most notably polymicrogyria and microcephaly.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Polymicrogyria, bilateral perisylvian (PMG) | Missense mutations impair microtubule polymerization and neuronal migration | OMIM #612850; ClinVar |
| Microcephaly, cortical malformations | Loss-of-function variants reduce microtubule stability | OMIM #612850; PubMed |
| Complex cortical dysplasia with other brain malformations | Dominant-negative effects on microtubule assembly | ClinVar; COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 32.5 | High |
| Testis | 8.2 | Medium |
| Lung | 4.1 | Low |
| Heart | 3.0 | Low |
| Liver | 1.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 45.2 | High expression in neuronal lineage |
| U-87 MG (glioblastoma) | 28.7 | Moderate expression |
| HeLa (cervical carcinoma) | 12.3 | Low expression |
| HEK293 (embryonic kidney) | 9.8 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.743A>G (p.Asp248Gly) | Missense | Rare | Dominant-negative; disrupts microtubule polymerization |
| c.124G>A (p.Glu42Lys) | Missense | Rare | Loss of function; impaired neuronal migration |
| c.1072C>T (p.Arg358Trp) | Missense | Rare | Gain of function; altered microtubule dynamics |
Mutation functional classification
Loss of Function (LOF)
Reduced microtubule stability and polymerization; associated with microcephaly
Gain of Function (GOF)
Altered microtubule dynamics leading to abnormal neuronal migration
Dominant Negative (DN)
Mutant protein interferes with wild-type tubulin assembly; causes polymicrogyria
View complete mutation data：
Gene Ontology (GO)
| • structural constituent of cytoskeleton (GO:0005200) | • microtubule-based process (GO:0007017) |
| • microtubule (GO:0005874) | • neuron migration (GO:0001764) |
| • cerebral cortex development (GO:0021987) |
Pathways
• Microtubule polymerization (Reactome R-HSA-190236)
• Neuronal system (Reactome R-HSA-112316)
• Developmental biology (Reactome R-HSA-1266738)
Protein Summary
Tubulin beta 2B class IIb is a 445-amino-acid protein that forms the beta subunit of microtubules. It is highly expressed in the developing and adult brain, where it mediates neuronal migration, axon guidance, and cortical lamination. Mutations in TUBB2B are a well-established cause of malformations of cortical development, particularly bilateral perisylvian polymicrogyria and microcephaly.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TUBB2B Knockout HEK293 Cell Line | EDJ-KQ15985 | Human | 347733 | Details Get a Quote |
| TUBB2B Knockout A-549 Cell Line | EDJ-KQ47032 | Human | 347733 | Details Get a Quote |
| TUBB2B Knockout HCT 116 Cell Line | EDJ-KQ47033 | Human | 347733 | Details Get a Quote |
| TUBB2B Knockout HeLa Cell Line | EDJ-KQ59826 | Human | 347733 | Details Get a Quote |
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