PYGL
PYGL (glycogen phosphorylase L, also known as GSD6) is the liver isozyme of glycogen phosphorylase. This allosteric enzyme catalyses the rate-limiting step of glycogen breakdown, releasing glucose-1-phosphate and helping to maintain glucose homeostasis. Browse Assay Genie's current range of PYGL research reagents below, or read on for the biology behind the target.
PYGL is an allosteric enzyme that catalyses the rate-limiting step in glycogen catabolism: the phosphorolytic cleavage of glycogen to produce glucose-1-phosphate. In doing so it plays a central role in maintaining cellular and organismal glucose homeostasis. The enzyme cleaves alpha-1,4-glucosidic bonds and acts on liver glycogen stores.
The PYGL protein is a homodimer that belongs to the glycogen phosphorylase family and is found in the cytosol. It switches from inactive phosphorylase B to active phosphorylase A through phosphorylation of serine residue 15, and its activity is further regulated by multiple allosteric effectors and hormonal controls. Humans have three glycogen phosphorylase genes encoding distinct isozymes that are primarily expressed in liver, brain and muscle. The liver isozyme serves the glycaemic demands of the body in general, while the brain and muscle isozymes supply only those tissues. Alternative splicing of the PYGL gene results in multiple transcript variants encoding different isoforms.
HGNC lists the gene as glycogen phosphorylase L, with the previous name phosphorylase, glycogen; liver, and the alias GSD6. In glycogen storage disease type VI, also known as Hers disease, mutations in liver glycogen phosphorylase inhibit the conversion of glycogen to glucose. The result is moderate hypoglycaemia, mild ketosis, growth retardation and hepatomegaly. Mouse and rat both carry a Pygl ortholog.
PYGL catalyses the rate-limiting step of glycogen catabolism, making it a central enzyme for studying how glycogen stores are mobilised.
The liver isozyme serves the glycaemic demands of the whole body, so PYGL is relevant to research on organismal glucose control.
Mutations in liver glycogen phosphorylase cause glycogen storage disease type VI (Hers disease), linking PYGL to inherited metabolic disorder research.
Conversion from phosphorylase B to A by phosphorylation of serine 15, plus allosteric and hormonal control, makes PYGL a model for regulated enzymes.
PYGL is the liver form of glycogen phosphorylase. It catalyses the rate-limiting step of glycogen breakdown, the phosphorolytic cleavage of glycogen to glucose-1-phosphate, and so contributes to cellular and organismal glucose homeostasis. It is an allosteric enzyme found in the cytosol.
PYGL is also known as GSD6, glycogen phosphorylase L, glycogen phosphorylase, liver form, and by the previous name phosphorylase, glycogen; liver. Alternative splicing of the gene produces multiple transcript variants that encode different isoforms. Humans also have separate brain and muscle glycogen phosphorylase genes.
Mutations in PYGL cause glycogen storage disease type VI (Hers disease), with moderate hypoglycaemia, mild ketosis, growth retardation and hepatomegaly. Orthologs named Pygl exist in mouse and rat; check the datasheet of any product for its validated reactivity.
Other glycogen phosphorylase isozymes and glycogen metabolism enzymes relevant to glucose homeostasis research.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P06737; product specifications from Assay Genie datasheets.