This gene encodes a homodimeric protein that catalyses the cleavage of alpha-1,4-glucosidic bonds to release glucose-1-phosphate from liver glycogen stores. This protein switches from inactive phosphorylase B to active phosphorylase A by phosphorylation of serine residue 15. Activity of this enzyme is further regulated by multiple allosteric effectors and hormonal controls. Humans have three glycogen phosphorylase genes that encode distinct isozymes that are primarily expressed in liver, brain and muscle, respectively. The liver isozyme serves the glycemic demands of the body in general while the brain and muscle isozymes supply just those tissues. In glycogen storage disease type VI, also known as Hers disease, mutations in liver glycogen phosphorylase inhibit the conversion of glycogen to glucose and results in moderate hypoglycemia, mild ketosis, growth retardation and hepatomegaly. Alternative splicing results in multiple transcript variants encoding different isoforms.[provided by RefSeq, Feb 2011]
Transcription factors with Perturb-seq knockdown data for PYGL. The Binding column indicates whether any binding evidence exists for this TF–gene pair (ChIP-seq or motif footprint peaks). The Mean coef is the average Perturb-seq regression coefficient across active gRNAs (positive = PYGL upregulated upon KD; negative = downregulated). The Outlier column indicates whether this gene is in the top or bottom 5% of all TF knockdown effects.
| TF | Mean coef | Binding | Outlier | TF→Gene link |
|---|
Open chromatin peaks (ATAC-seq) in the genomic neighbourhood of PYGL, linked by TSS proximity or chromatin conformation (Multiome / HiCAR). Each element overlaps at least one TF ChIP-seq binding site — the TFs column shows how many distinct TFs bind that element.
| Accessibility | Element | Dist. to TSS | Link type | TFs |
|---|---|---|---|---|
| chr14:50,667,319–50,668,903 | 276.2 kb | Distal (>10kb) Multiome | 914 | |
| chr14:50,823,525–50,824,353 | 120.5 kb | Distal (>10kb) Multiome | 183 | |
| chr14:50,829,783–50,831,951 | 113.3 kb | Distal (>10kb) Multiome | 634 | |
| chr14:50,871,977–50,872,487 | 72.2 kb | Distal (>10kb) Multiome | 114 | |
| chr14:50,943,178–50,945,258 | 79 bp | At TSS Multiome | 823 | |
| chr14:51,093,327–51,096,214 | 150.8 kb | Distal (>10kb) Multiome | 700 | |
| chr14:51,239,746–51,240,810 | 295.8 kb | Distal (>10kb) Multiome | 737 |
Genomic view of the PYGL locus showing ATAC-seq accessibility and RNA-seq expression across the ESC → DE time course, together with TF binding peaks and element-to-TSS loop connections.