PRKAG1

PRKAG1 is a regulatory subunit of the AMP-activated protein kinase (AMPK). AMPK is a heterotrimer consisting of an alpha catalytic subunit, and non-catalytic beta and gamma subunits. AMPK is an important energy-sensing enzyme that monitors cellular energy status. In response to cellular metabolic stresses, AMPK is activated, and thus phosphorylates and inactivates acetyl-CoA carboxylase (ACC) and beta-hydroxy beta-methylglutaryl-CoA reductase (HMGCR), key enzymes involved in regulating de novo biosynthesis of fatty acid and cholesterol.

Full Name

Protein Kinase AMP-Activated Non-Catalytic Subunit Gamma 1

Function

AMP/ATP-binding subunit of AMP-activated protein kinase (AMPK), an energy sensor protein kinase that plays a key role in regulating cellular energy metabolism. In response to reduction of intracellular ATP levels, AMPK activates energy-producing pathways and inhibits energy-consuming processes: inhibits protein, carbohydrate and lipid biosynthesis, as well as cell growth and proliferation. AMPK acts via direct phosphorylation of metabolic enzymes, and by longer-term effects via phosphorylation of transcription regulators. Also acts as a regulator of cellular polarity by remodeling the actin cytoskeleton; probably by indirectly activating myosin. Gamma non-catalytic subunit mediates binding to AMP, ADP and ATP, leading to activate or inhibit AMPK: AMP-binding results in allosteric activation of alpha catalytic subunit (PRKAA1 or PRKAA2) both by inducing phosphorylation and preventing dephosphorylation of catalytic subunits. ADP also stimulates phosphorylation, without stimulating already phosphorylated catalytic subunit. ATP promotes dephosphorylation of catalytic subunit, rendering the AMPK enzyme inactive.

Biological Process

Cellular response to glucose starvationManual Assertion Based On ExperimentIBA:GO_Central
Cellular response to nutrient levelsManual Assertion Based On ExperimentIDA:ComplexPortal
Fatty acid biosynthetic processIEA:UniProtKB-KW
Import into nucleusIEA:Ensembl
Positive regulation of gene expressionManual Assertion Based On ExperimentIDA:UniProtKB
Positive regulation of protein kinase activityManual Assertion Based On ExperimentTAS:BHF-UCL
Protein phosphorylationManual Assertion Based On ExperimentIDA:UniProtKB
Regulation of catalytic activityManual Assertion Based On ExperimentIBA:GO_Central
Regulation of glycolytic processManual Assertion Based On ExperimentTAS:BHF-UCL
Regulation of protein serine/threonine kinase activityIEA:InterPro
Signal transductionManual Assertion Based On ExperimentTAS:ProtInc
SpermatogenesisManual Assertion Based On ExperimentTAS:ProtInc

Cellular Location

cytoplasm
cytosol
membrane
nucleoplasm
nucleotide-activated protein kinase complex
nucleus

PTM

Phosphorylated by ULK1 and ULK2; leading to negatively regulate AMPK activity and suggesting the existence of a regulatory feedback loop between ULK1, ULK2 and AMPK.