GYG1: Glycogenin-1, Master Initiator of Glycogen Biosynthesis
Essential for glycogen synthesis; mutations cause Glycogen Storage Disease XV
Gene Information Card
| Symbol | GYG1 |
|---|---|
| Full Name | Glycogenin-1 |
| Gene Type | Protein coding |
| Chromosomal Location | 3q24 |
| NCBI Gene ID | 2992 ncbi.nlm.nih.gov/gene/2992 |
| Ensembl ID | ENSG00000163788 |
| UniProt ID | P46976 |
| OMIM ID | 603942 |
| HGNC ID | 4699 |
| Aliases | GYG, GN-1, glycogenin |
Description
GYG1 encodes glycogenin-1, a self-glucosylating protein that serves as the primer for glycogen synthesis. It catalyzes the addition of glucose residues from UDP-glucose to itself, forming a short oligosaccharide chain that is then extended by glycogen synthase and branching enzyme. GYG1 is expressed in muscle, heart, and other tissues. Biallelic loss-of-function mutations cause Glycogen Storage Disease XV (GSD XV), characterized by cardiomyopathy, skeletal myopathy, and accumulation of polyglucosan bodies.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Glycogen Storage Disease XV (GSD XV) | Loss of glycogenin-1 function prevents normal glycogen synthesis, leading to accumulation of polyglucosan bodies in muscle and heart. | ClinVar, OMIM #603942 |
| Polyglucosan Body Myopathy 2 | Defective glycogen initiation results in abnormal glycogen aggregates causing myopathy. | OMIM #616199 |
| Cardiomyopathy, dilated, with polyglucosan bodies | GYG1 mutations impair cardiac glycogen metabolism, leading to dilated cardiomyopathy. | ClinVar, NCBI |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | 28.5 | High |
| Heart | 22.1 | High |
| Liver | 6.3 | Medium |
| Brain | 4.8 | Medium |
| Kidney | 3.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Skeletal muscle myoblasts | 35.2 | High expression |
| Cardiomyocytes | 30.1 | High expression |
| HepG2 | 8.5 | Medium expression |
| SH-SY5Y | 5.0 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.304C>T (p.Arg102*) | Nonsense | Rare | Loss of function; truncation of glycogenin-1 |
| c.458G>A (p.Trp153*) | Nonsense | Rare | Loss of function; premature stop codon |
| c.1A>G (p.Met1?) | Start loss | Rare | Loss of function; no translation initiation |
| c.928G>A (p.Gly310Arg) | Missense | Rare | Loss of function; impaired glucosyltransferase activity |
Mutation functional classification
Loss of Function (LOF)
Biallelic loss-of-function mutations in GYG1 cause Glycogen Storage Disease XV with cardiomyopathy and myopathy.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported; disease is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • glycogenin activity | • glycogen biosynthetic process |
| • UDP-glucose:glycogenin glucosyltransferase activity | • glycogen metabolic process |
| • transferase activity | • transferring hexosyl groups |
Pathways
• Glycogen biosynthesis (Reactome R-HSA-8982491)
• Metabolism of carbohydrates (Reactome R-HSA-71387)
• Glycogen storage diseases (KEGG hsa04940)
Protein Summary
Glycogenin-1 is a 332-amino acid protein that self-glucosylates using UDP-glucose as substrate, creating a short oligosaccharide primer essential for glycogen synthesis. It forms a homodimer and interacts with glycogen synthase. The protein is localized to the cytoplasm and is highly expressed in muscle and heart. Mutations that disrupt its catalytic activity or stability lead to glycogen deficiency and accumulation of polyglucosan bodies.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GYG1 Knockout HEK293 Cell Line | EDJ-KQ4820 | Human | 2992 | Details Get a Quote |
| GYG1 Knockout A-549 Cell Line | EDJ-KQ27596 | Human | 2992 | Details Get a Quote |
| GYG1 Knockout HCT 116 Cell Line | EDJ-KQ27597 | Human | 2992 | Details Get a Quote |
| GYG1 Knockout HeLa Cell Line | EDJ-KQ27598 | Human | 2992 | Details Get a Quote |
