SNTB1 (Syntrophin Beta 1)
A scaffold protein linking ion channels and signaling proteins to the dystrophin-associated glycoprotein complex
Gene Information Card
| Symbol | SNTB1 |
|---|---|
| Full Name | syntrophin beta 1 |
| Gene Type | protein coding |
| Chromosomal Location | 8q24.12 |
| NCBI Gene ID | 6641 ncbi.nlm.nih.gov/gene/6641 |
| Ensembl ID | ENSG00000169245 |
| UniProt ID | Q13884 |
| OMIM ID | 600026 |
| HGNC ID | 11168 |
| Aliases | 59-DAP, A1B, DAPA1, SNT2, beta1-syntrophin |
Description
SNTB1 encodes beta-1-syntrophin, a peripheral membrane protein that belongs to the syntrophin family. It contains two pleckstrin homology (PH) domains, a PDZ domain, and a C-terminal syntrophin unique (SU) domain. Beta-1-syntrophin binds to the dystrophin C-terminal domain and anchors ion channels (e.g., sodium channels) and signaling proteins to the dystrophin-associated glycoprotein complex (DGC) at the sarcolemma. It is widely expressed, with highest levels in skeletal and cardiac muscle.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Duchenne muscular dystrophy (DMD) | Loss of dystrophin disrupts SNTB1 localization, impairing DGC stability | ClinVar; PMID: 12874418 |
| Becker muscular dystrophy | Reduced dystrophin expression leads to secondary SNTB1 mislocalization | OMIM #300376; PMID: 10480359 |
| Cardiomyopathy, dilated | SNTB1 variants may alter sodium channel anchoring, affecting cardiac conduction | ClinVar; PMID: 23348763 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | 58.2 | High |
| Heart | 42.1 | High |
| Brain | 18.5 | Medium |
| Liver | 6.3 | Low |
| Kidney | 9.8 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| RH-30 (rhabdomyosarcoma) | 45.0 | High expression |
| H9c2 (rat cardiomyoblasts) | 38.5 | High expression |
| SH-SY5Y (neuroblastoma) | 22.1 | Medium expression |
| HEK293 (embryonic kidney) | 12.3 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | missense | <0.01% | Loss of start codon; likely loss of function |
| c.124C>T (p.Arg42Cys) | missense | <0.01% | Alters PDZ domain; may disrupt protein interactions |
| c.856G>A (p.Glu286Lys) | missense | <0.01% | Located in PH domain; unknown functional impact |
Mutation functional classification
Loss of Function (LOF)
Rare missense variants in the PDZ domain (e.g., p.Arg42Cys) are predicted to impair scaffolding of ion channels, leading to DGC instability.
Gain of Function (GOF)
No gain-of-function mutations reported for SNTB1.
Dominant Negative (DN)
No dominant-negative mutations reported for SNTB1.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Dystrophin-associated glycoprotein complex (DGC)
• Voltage-gated sodium channel clustering (REACTOME R-HSA-5576892)
• Cardiac conduction (REACTOME R-HSA-5576891)
Protein Summary
Beta-1-syntrophin is a 538-amino-acid scaffold protein (UniProt Q13884) that localizes to the sarcolemma via binding to dystrophin and utrophin. It contains a PDZ domain that interacts with the C-termini of ion channels (e.g., Nav1.5, Nav1.4) and signaling molecules (e.g., nNOS). The two PH domains and SU domain mediate additional protein-protein interactions, anchoring the DGC to the actin cytoskeleton. Loss of SNTB1 function contributes to membrane fragility and ion channel dysregulation in muscular dystrophies and cardiomyopathies.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SNTB1 Knockout HEK293 Cell Line | EDJ-KQ5815 | Human | 6641 | Details Get a Quote |
| SNTB1 Knockout HCT 116 Cell Line | EDJ-KQ29240 | Human | 6641 | Details Get a Quote |
| SNTB1 Knockout HeLa Cell Line | EDJ-KQ29241 | Human | 6641 | Details Get a Quote |
| SNTB1 Knockout A-549 Cell Line | EDJ-KQ63018 | Human | 6641 | Details Get a Quote |
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