PHKG1 Gene: Phosphorylase Kinase Catalytic Subunit Gamma 1
A key regulator of glycogen metabolism and energy homeostasis
Gene Information Card
| Symbol | PHKG1 |
|---|---|
| Full Name | phosphorylase kinase catalytic subunit gamma 1 |
| Gene Type | protein coding |
| Chromosomal Location | 19p13.3 |
| NCBI Gene ID | 5260 ncbi.nlm.nih.gov/gene/5260 |
| Ensembl ID | ENSG00000104879 |
| UniProt ID | Q16816 |
| OMIM ID | 172470 |
| HGNC ID | 8926 |
| Aliases | PHKG, PHKgamma1, phosphorylase kinase gamma subunit 1 |
Description
The PHKG1 gene encodes the gamma catalytic subunit of phosphorylase kinase (PhK), a key enzyme in glycogen metabolism. PhK phosphorylates and activates glycogen phosphorylase, which catalyzes the rate-limiting step of glycogenolysis. PHKG1 is expressed predominantly in muscle and heart, and mutations in this gene are associated with glycogen storage disease type IX (GSD IX), a disorder characterized by exercise intolerance, muscle weakness, and hypoglycemia.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Glycogen storage disease IX (GSD IX) | Loss-of-function mutations in PHKG1 impair phosphorylase kinase activity, reducing glycogen breakdown and leading to glycogen accumulation in muscle and liver. | ClinVar, OMIM #172470 |
| Exercise intolerance with myopathy | Defective glycogenolysis due to PHKG1 mutations limits ATP production during exercise, causing muscle cramps and fatigue. | NCBI Gene, OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | 42.3 | High |
| Heart | 28.1 | High |
| Liver | 5.2 | Low |
| Brain | 3.8 | Low |
| Kidney | 2.1 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| H9c2 (rat cardiomyoblasts) | 35.0 | High expression in cardiac muscle cells |
| C2C12 (mouse myoblasts) | 28.5 | High expression in muscle cells |
| HepG2 (human hepatoma) | 4.1 | Low expression in liver cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.100C>T (p.Arg34*) | Nonsense | Rare | Loss of function; truncation of catalytic domain |
| c.361G>A (p.Gly121Arg) | Missense | Rare | Loss of function; reduced kinase activity |
| c.682C>T (p.Arg228Trp) | Missense | Rare | Loss of function; impaired substrate binding |
Mutation functional classification
Loss of Function (LOF)
Most PHKG1 mutations are loss-of-function, leading to phosphorylase kinase deficiency and glycogen storage disease IX.
Gain of Function (GOF)
No gain-of-function mutations reported in PHKG1.
Dominant Negative (DN)
No dominant-negative mutations reported in PHKG1.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Glycogen metabolism (Reactome: R-HSA-70221)
• Phosphorylase kinase activation (Reactome: R-HSA-163754)
• Glycogen breakdown (KEGG: hsa00500)
Protein Summary
The PHKG1 protein is the catalytic gamma subunit of phosphorylase kinase (PhK), a hexadecameric enzyme complex. It contains a serine/threonine kinase domain that phosphorylates and activates glycogen phosphorylase. PHKG1 is highly expressed in skeletal muscle and heart, where it regulates glycogenolysis in response to hormonal and neuronal signals. Mutations in PHKG1 cause glycogen storage disease type IX, characterized by exercise intolerance and muscle weakness.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PHKG1 Knockout HEK293 Cell Line | EDJ-KQ1634 | Human | 5260 | Details Get a Quote |
| PHKG1 Knockout HCT 116 Cell Line | EDJ-KQ21348 | Human | 5260 | Details Get a Quote |
| PHKG1 Knockout HeLa Cell Line | EDJ-KQ54134 | Human | 5260 | Details Get a Quote |
| PHKG1 Knockout A-549 Cell Line | EDJ-KQ62625 | Human | 5260 | Details Get a Quote |
