4eag | pdb_00004eag
Co-crystal structure of an chimeric AMPK core with ATP
Structural highlights
Function[AAKG1_RAT] 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.[1] [2] [AAKB1_RAT] Non-catalytic 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. Beta non-catalytic subunit acts as a scaffold on which the AMPK complex assembles, via its C-terminus that bridges alpha (PRKAA1 or PRKAA2) and gamma subunits (PRKAG1, PRKAG2 or PRKAG3). Publication Abstract from PubMedThe energy sensor AMP-activated protein kinase (AMPK) is a heterotrimeric complex that is allosterically activated by AMP binding to the gamma subunit. Cocrystal structures of the mammalian AMPK core reveal occlusion of nucleotide-binding site 3 of the gamma subunit in the presence of ATP. However, site 3 is occupied in the presence of AMP. Mutagenesis studies indicate that sites 3 and 4 are important for AMPK allosteric activation. AMP-activated protein kinase undergoes nucleotide-dependent conformational changes.,Chen L, Wang J, Zhang YY, Yan SF, Neumann D, Schlattner U, Wang ZX, Wu JW Nat Struct Mol Biol. 2012 Jun 3;19(7):716-8. doi: 10.1038/nsmb.2319. PMID:22659875[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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