PRKAG3

PRKAG3 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

protein kinase AMP-activated non-catalytic subunit gamma 3

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. AMPK also acts as a regulator of cellular polarity by remodeling the actin cytoskeleton; probably by indirectly activating myosin. The AMPK gamma3 subunit is a non-catalytic subunit with a regulatory role in muscle energy metabolism (PubMed:17878938).
It mediates binding to AMP, ADP and ATP, leading to AMPK activation or inhibition: 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.

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
Glycogen biosynthetic processIEA:Ensembl
Glycolytic processIEA:Ensembl
Intracellular signal transductionManual Assertion Based On ExperimentTAS:ProtInc
Protein phosphorylationManual Assertion Based On ExperimentIBA:GO_Central
Regulation of catalytic activityManual Assertion Based On ExperimentIBA:GO_Central
Regulation of protein serine/threonine kinase activityIEA:InterPro
Response to muscle activity involved in regulation of muscle adaptationIEA:Ensembl

cytoplasm
cytosol
extracellular space
nucleoplasm
nucleotide-activated protein kinase complex
nucleus

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