PHKG2

Phosphorylase kinase is a polymer of 16 subunits, four each of alpha, beta, gamma and delta. The alpha subunit includes the skeletal muscle and hepatic isoforms, encoded by two different genes. The beta subunit is the same in both the muscle and hepatic isoforms, and encoded by one gene. The gamma subunit also includes the skeletal muscle and hepatic isoforms, and the hepatic isoform is encoded by this gene. The delta subunit is a calmodulin and can be encoded by three different genes. The gamma subunits contain the active site of the enzyme, whereas the alpha and beta subunits have regulatory functions controlled by phosphorylation. The delta subunit mediates the dependence of the enzyme on calcium concentration. Mutations in this gene cause glycogen storage disease type 9C, also known as autosomal liver glycogenosis. Alternatively spliced transcript variants encoding different isoforms have been identified in this gene.[provided by RefSeq, Feb 2010]

Full Name

Phosphorylase Kinase Catalytic Subunit Gamma 2

Function

Catalytic subunit of the phosphorylase b kinase (PHK), which mediates the neural and hormonal regulation of glycogen breakdown (glycogenolysis) by phosphorylating and thereby activating glycogen phosphorylase. May regulate glycogeneolysis in the testis. In vitro, phosphorylates PYGM (By similarity).

Biological Process

Generation of precursor metabolites and energyManual Assertion Based On ExperimentTAS:ProtInc
Glycogen biosynthetic processIEA:InterPro
Glycogen metabolic processManual Assertion Based On ExperimentTAS:ProtInc
Positive regulation of glycogen catabolic processManual Assertion Based On ExperimentTAS:UniProtKB
Protein phosphorylationManual Assertion Based On ExperimentTAS:ProtInc

Cellular Location

cytosol
phosphorylase kinase complex

Involvement in disease

Glycogen storage disease 9C (GSD9C):
A metabolic disorder manifesting in infancy with hepatomegaly, growth retardation, hypotonia, liver dysfunction, and elevated plasma aminotransferases and lipids. These symptoms improve with age in most cases; however, some patients may develop hepatic fibrosis or cirrhosis.