LMPD Database

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LMP000658

UniProt Annotations

Entry Information
Gene Nameprotein kinase, AMP-activated, gamma 3 non-catalytic subunit
Protein EntryAAKG3_HUMAN
UniProt IDQ9UGI9
SpeciesHuman
Comments
Comment typeDescription
Alternative ProductsEvent=Alternative splicing; Named isoforms=2; Name=1; IsoId=Q9UGI9-1; Sequence=Displayed; Name=2; IsoId=Q9UGI9-2; Sequence=VSP_015587;
DomainThe AMPK pseudosubstrate motif resembles the sequence around sites phosphorylated on target proteins of AMPK, except the presence of a non-phosphorylatable residue in place of Ser. In the absence of AMP this pseudosubstrate sequence may bind to the active site groove on the alpha subunit (PRKAA1 or PRKAA2), preventing phosphorylation by the upstream activating kinase STK11/LKB1.
DomainThe CBS domains mediate binding to AMP, ADP and ATP. 2 sites bind either AMP or ATP, whereas a third site contains a tightly bound AMP that does not exchange. Under physiological conditions AMPK mainly exists in its inactive form in complex with ATP, which is much more abundant than AMP.
FunctionAMP/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
PolymorphismPRKAG3 genetic variants can be associated with increased glycogen content in skeletal muscle [MIM
PtmPhosphorylated by ULK1; leading to negatively regulate AMPK activity and suggesting the existence of a regulatory feedback loop between ULK1 and AMPK.
SimilarityBelongs to the 5'-AMP-activated protein kinase gamma subunit family.
SimilarityContains 4 CBS domains. {ECO
SubunitAMPK is a heterotrimer of an alpha catalytic subunit (PRKAA1 or PRKAA2), a beta (PRKAB1 or PRKAB2) and a gamma non- catalytic subunits (PRKAG1, PRKAG2 or PRKAG3). Interacts with FNIP1 and FNIP2 (By similarity).
Tissue SpecificitySkeletal muscle, with weak expression in heart and pancreas.