SPTBN2
Spectrin Beta, Non-Erythrocytic 2
Gene Information Card
| Symbol | SPTBN2 |
|---|---|
| Full Name | Spectrin Beta, Non-Erythrocytic 2 |
| Gene Type | Protein coding |
| Chromosomal Location | 11q13.2 |
| NCBI Gene ID | 6712 ncbi.nlm.nih.gov/gene/6712 |
| Ensembl ID | ENSG00000173898 |
| UniProt ID | O15020 |
| OMIM ID | 604985 |
| HGNC ID | 11277 |
| Aliases | SCA5, beta-III spectrin, BIII spectrin |
Description
SPTBN2 encodes beta-III spectrin, a cytoskeletal protein predominantly expressed in the brain, particularly in Purkinje cells. It stabilizes membrane structures and facilitates intracellular transport. Mutations in SPTBN2 cause spinocerebellar ataxia type 5 (SCA5) and are linked to other neurodegenerative conditions.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Spinocerebellar ataxia type 5 (SCA5) | Missense mutations disrupt spectrin dimerization and membrane stability, leading to Purkinje cell degeneration | ClinVar, OMIM |
| Spinocerebellar ataxia type 5 with infantile onset | Loss-of-function mutations impair cytoskeletal integrity, causing early-onset ataxia | ClinVar |
| Amyotrophic lateral sclerosis (ALS) | Rare variants may contribute to motor neuron vulnerability | NCBI Gene |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Cerebellum | 32.5 | High |
| Cerebral cortex | 18.2 | Medium |
| Hippocampus | 15.8 | Medium |
| Testis | 4.1 | Low |
| Heart | 2.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y | 12.5 | Neuronal model |
| U-87 MG | 8.9 | Glioblastoma |
| HEK293 | 3.2 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1552C>T (p.Arg518Cys) | Missense | <0.01% | Alters spectrin repeat, impairs protein stability (ClinVar) |
| c.2368G>A (p.Glu790Lys) | Missense | <0.01% | Disrupts actin binding, associated with SCA5 (ClinVar) |
| c.2929C>T (p.Arg977Trp) | Missense | <0.01% | Reduces dimerization, causes Purkinje cell loss (ClinVar) |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations leading to truncated protein and haploinsufficiency.
Gain of Function (GOF)
Not well documented; most pathogenic missense mutations are hypomorphic or dominant-negative.
Dominant Negative (DN)
Missense mutations in the spectrin repeat region interfere with wild-type beta-III spectrin assembly, causing dominant-negative effects.
View complete mutation data：
Gene Ontology (GO)
| • actin binding | • structural constituent of cytoskeleton |
| • calmodulin binding | • spectrin binding |
| • protein heterodimerization activity |
Pathways
• Formation of the cornified envelope
• Erythrocyte differentiation pathway
• Cell junction organization
Protein Summary
Beta-III spectrin is a 2391-amino-acid protein that forms heterodimers with alpha-II spectrin. It links the actin cytoskeleton to the plasma membrane, essential for dendritic spine stability and synaptic function in neurons. Mutations cause misfolding and aggregation, leading to cerebellar degeneration.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SPTBN2 Knockout HEK293 Cell Line | EDJ-KQ15502 | Human | 6712 | Details Get a Quote |
| SPTBN2 Knockout HCT 116 Cell Line | EDJ-KQ45066 | Human | 6712 | Details Get a Quote |
| SPTBN2 Knockout A-549 Cell Line | EDJ-KQ46299 | Human | 6712 | Details Get a Quote |
| SPTBN2 Knockout HeLa Cell Line | EDJ-KQ46300 | Human | 6712 | Details Get a Quote |
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