GYG2: Glycogenin 2, a Key Initiator of Glycogen Biosynthesis
Comprehensive gene card for GYG2, including genomic context, expression, mutations, and associated diseases.
Gene Information Card
| Symbol | GYG2 |
|---|---|
| Full Name | Glycogenin 2 |
| Gene Type | Protein coding |
| Chromosomal Location | Xp22.33 |
| NCBI Gene ID | 8908 ncbi.nlm.nih.gov/gene/8908 |
| Ensembl ID | ENSG00000102078 |
| UniProt ID | O15488 |
| OMIM ID | 300199 |
| HGNC ID | 4699 |
| Aliases | GN2, glycogenin-2 |
Description
GYG2 encodes glycogenin 2, a self-glucosylating protein that serves as the primer for glycogen synthesis in the liver and other tissues. It initiates glycogen biosynthesis by autoglucosylation, forming an oligosaccharide chain that is extended by glycogen synthase and branching enzyme. GYG2 is the X-linked paralog of GYG1 and is predominantly expressed in liver, heart, and skeletal muscle.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Glycogen storage disease XV (GSD XV) | Loss-of-function mutations in GYG2 impair glycogenin priming, leading to reduced glycogen synthesis and accumulation of abnormal glycogen particles. | ClinVar, OMIM |
| Polyglucosan body myopathy 2 (PGBM2) | Defects in GYG2 disrupt normal glycogen structure, causing accumulation of polyglucosan bodies in muscle tissue. | OMIM, ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Heart | 8.3 | Medium |
| Skeletal muscle | 6.1 | Low |
| Kidney | 3.2 | Low |
| Pancreas | 2.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 10.1 | Hepatocellular carcinoma cell line |
| HL-60 | 4.5 | Promyeloblast |
| K-562 | 3.8 | Lymphoblast |
| MCF7 | 2.1 | Breast cancer |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.439C>T (p.Arg147*) | Nonsense | <0.01% | Premature stop; loss of function |
| c.676G>A (p.Gly226Arg) | Missense | <0.01% | Impaired autoglucosylation activity |
| c.1A>G (p.Met1?) | Start loss | <0.01% | No protein translation |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations (e.g., p.Arg147*) lead to truncated protein lacking catalytic activity, resulting in glycogen deficiency.
Gain of Function (GOF)
No gain-of-function mutations reported for GYG2.
Dominant Negative (DN)
No dominant-negative mutations reported; GYG2 is X-linked and hemizygous in males.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Glycogen biosynthesis (Reactome: R-HSA-8982491)
• Metabolism of carbohydrates (Reactome: R-HSA-71387)
Protein Summary
Glycogenin 2 (UniProt O15488) is a 501-amino acid protein that catalyzes the self-glucosylation of a tyrosine residue, creating a short glucose polymer that serves as the primer for glycogen synthase. It is localized to the cytoplasm and is essential for normal glycogen storage in liver and muscle. The protein contains a glycosyltransferase domain and a conserved DXD motif required for catalytic activity.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GYG2 Knockout HEK293 Cell Line | EDJ-KQ6393 | Human | 8908 | Details Get a Quote |
| GYG2 Knockout A-549 Cell Line | EDJ-KQ30418 | Human | 8908 | Details Get a Quote |
| GYG2 Knockout HeLa Cell Line | EDJ-KQ55031 | Human | 8908 | Details Get a Quote |
| GYG2 Knockout HCT 116 Cell Line | EDJ-KQ71983 | Human | 8908 | Details Get a Quote |
