GBE1 Gene: 1,4-Alpha-Glucan Branching Enzyme 1
Glycogen Branching Enzyme Deficiency (Andersen Disease, GSD IV)
Gene Information Card
| Symbol | GBE1 |
|---|---|
| Full Name | 1,4-Alpha-Glucan Branching Enzyme 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 3p12.2 |
| NCBI Gene ID | 2632 ncbi.nlm.nih.gov/gene/2632 |
| Ensembl ID | ENSG00000114480 |
| UniProt ID | Q04446 |
| OMIM ID | 607839 |
| HGNC ID | 4180 |
| Aliases | GBE, GSD4, APBD |
Description
The GBE1 gene encodes the glycogen branching enzyme (GBE), which catalyzes the transfer of alpha-1,4-linked glucan chains to form alpha-1,6 linkages during glycogen synthesis. This enzyme is essential for creating the branched structure of glycogen. Mutations in GBE1 cause glycogen storage disease type IV (Andersen disease) and adult polyglucosan body disease (APBD), characterized by accumulation of abnormally structured glycogen (polyglucosan) in tissues.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Glycogen storage disease type IV (Andersen disease) | Loss-of-function mutations in GBE1 lead to deficient branching enzyme activity, resulting in accumulation of amylopectin-like polysaccharides (polyglucosan bodies) in liver, muscle, and heart. | ClinVar, OMIM #232500 |
| Adult polyglucosan body disease (APBD) | Biallelic GBE1 mutations cause late-onset accumulation of polyglucosan bodies in the central and peripheral nervous system, leading to progressive neuropathy, spasticity, and neurogenic bladder. | ClinVar, OMIM #263570 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 8.2 | Medium |
| Skeletal muscle | 12.5 | Medium |
| Heart | 10.1 | Medium |
| Brain | 6.8 | Low |
| Kidney | 7.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 9.4 | Hepatocellular carcinoma cell line |
| SH-SY5Y | 5.2 | Neuroblastoma cell line |
| HeLa | 6.1 | Cervical carcinoma cell line |
| K-562 | 4.8 | Lymphoblastoid cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.986G>A (p.Arg329Gln) | Missense | Common in APBD | Reduced enzyme activity; leads to polyglucosan accumulation |
| c.691+2T>C | Splice site | Rare | Loss of function; associated with severe GSD IV |
| c.1076C>T (p.Pro359Leu) | Missense | Rare | Decreased branching activity; causes GSD IV |
Mutation functional classification
Loss of Function (LOF)
Most GBE1 mutations result in partial or complete loss of branching enzyme activity, leading to glycogen storage disease type IV and APBD.
Gain of Function (GOF)
No gain-of-function mutations have been reported for GBE1.
Dominant Negative (DN)
No dominant-negative effects have been described; disease is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • 1 (GO:0003844) | • glycogen biosynthetic process (GO:0005978) |
| • carbohydrate metabolic process (GO:0005975) | • cytoplasm (GO:0005737) |
Pathways
• Glycogen metabolism (Reactome: R-HSA-8982491)
• Glycogen storage diseases (KEGG: hsa04940)
Protein Summary
The GBE1 protein (UniProt Q04446) is a 702-amino acid monomeric enzyme localized to the cytoplasm. It catalyzes the formation of alpha-1,6 glycosidic bonds by transferring a short glucan chain from the non-reducing end of a glycogen chain to an internal glucose residue. This branching increases glycogen solubility and regulates its degradation. Deficiency leads to accumulation of poorly branched, amylopectin-like polysaccharides (polyglucosan) that form insoluble aggregates in tissues.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GBE1 Knockout HEK293 Cell Line | EDJ-KQ4682 | Human | 2632 | Details Get a Quote |
| GBE1 Knockout A-549 Cell Line | EDJ-KQ27385 | Human | 2632 | Details Get a Quote |
| GBE1 Knockout HCT 116 Cell Line | EDJ-KQ27386 | Human | 2632 | Details Get a Quote |
| GBE1 Knockout HeLa Cell Line | EDJ-KQ27387 | Human | 2632 | Details Get a Quote |
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