scholarly journals Structure of an AMPK complex in an inactive, ATP-bound state

Science ◽  
2021 ◽  
Vol 373 (6553) ◽  
pp. 413-419
Author(s):  
Yan Yan ◽  
Somnath Mukherjee ◽  
Kaleeckal G. Harikumar ◽  
Timothy S. Strutzenberg ◽  
X. Edward Zhou ◽  
...  
Keyword(s):  
Adenine Nucleotides ◽  
Adenosine Monophosphate ◽  
Bound State ◽  
Kinase Domain ◽  
Dynamic State ◽  
Kinase Activation ◽  
Cryo Electron Microscopy ◽  
Energy Stress ◽  
Ampk Activity ◽  
Amp Activated Protein Kinase

Adenosine monophosphate (AMP)–activated protein kinase (AMPK) regulates metabolism in response to the cellular energy states. Under energy stress, AMP stabilizes the active AMPK conformation, in which the kinase activation loop (AL) is protected from protein phosphatases, thus keeping the AL in its active, phosphorylated state. At low AMP:ATP (adenosine triphosphate) ratios, ATP inhibits AMPK by increasing AL dynamics and accessibility. We developed conformation-specific antibodies to trap ATP-bound AMPK in a fully inactive, dynamic state and determined its structure at 3.5-angstrom resolution using cryo–electron microscopy. A 180° rotation and 100-angstrom displacement of the kinase domain fully exposes the AL. On the basis of the structure and supporting biophysical data, we propose a multistep mechanism explaining how adenine nucleotides and pharmacological agonists modulate AMPK activity by altering AL phosphorylation and accessibility.

scholarly journals Structure and Physiological Regulation of AMPK

2018 ◽  
Vol 19 (11) ◽  
pp. 3534 ◽  
Author(s):  
Yan Yan ◽  
X. Zhou ◽  
H. Xu ◽  
Karsten Melcher
Keyword(s):  
Energy Homeostasis ◽  
Adenine Nucleotide ◽  
Energy State ◽  
Adenine Nucleotides ◽  
Adenosine Monophosphate ◽  
Nucleotide Binding ◽  
Kinase Domain ◽  
Catabolic Pathways ◽  
Α Subunit ◽  
Ampk Activity

Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a heterotrimeric αβγ complex that functions as a central regulator of energy homeostasis. Energy stress manifests as a drop in the ratio of adenosine triphosphate (ATP) to AMP/ADP, which activates AMPK’s kinase activity, allowing it to upregulate ATP-generating catabolic pathways and to reduce energy-consuming catabolic pathways and cellular programs. AMPK senses the cellular energy state by competitive binding of the three adenine nucleotides AMP, ADP, and ATP to three sites in its γ subunit, each, which in turn modulates the activity of AMPK’s kinase domain in its α subunit. Our current understanding of adenine nucleotide binding and the mechanisms by which differential adenine nucleotide occupancies activate or inhibit AMPK activity has been largely informed by crystal structures of AMPK in different activity states. Here we provide an overview of AMPK structures, and how these structures, in combination with biochemical, biophysical, and mutational analyses provide insights into the mechanisms of adenine nucleotide binding and AMPK activity modulation.

scholarly journals Insulin antagonizes AMP-activated protein kinase activation by ischemia or anoxia in rat hearts, without affecting total adenine nucleotides

FEBS Letters ◽  
2001 ◽  
Vol 505 (3) ◽  
pp. 348-352 ◽  
Author(s):  
Christophe Beauloye ◽  
Anne-Sophie Marsin ◽  
Luc Bertrand ◽  
Ulrike Krause ◽  
D.Grahame Hardie ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Adenine Nucleotides ◽  
Kinase Activation ◽  
Protein Kinase Activation ◽  
Rat Hearts ◽  
Amp Activated Protein Kinase

scholarly journals Dissecting the Role of 5′-AMP for Allosteric Stimulation, Activation, and Deactivation of AMP-activated Protein Kinase

2006 ◽  
Vol 281 (43) ◽  
pp. 32207-32216 ◽  
Author(s):  
Marianne Suter ◽  
Uwe Riek ◽  
Roland Tuerk ◽  
Uwe Schlattner ◽  
Theo Wallimann ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Phosphatase ◽  
Energy Homeostasis ◽  
Adenine Nucleotides ◽  
Enzyme Preparations ◽  
Activity Measurements ◽  
Ampk Activity ◽  
Amp Activated Protein Kinase

AMP-activated protein kinase (AMPK) is a heterotrimeric protein kinase that is crucial for cellular energy homeostasis of eukaryotic cells and organisms. Here we report on the activation of AMPK α1β1γ1 and α2β2γ1 by their upstream kinases (Ca2+/calmodulin-dependent protein kinase kinase-β and LKB1-MO25α-STRADα), the deactivation by protein phosphatase 2Cα, and on the extent of stimulation of AMPK by its allosteric activator AMP, using purified recombinant enzyme preparations. An accurate high pressure liquid chromatography-based method for AMPK activity measurements was established, which allowed for direct quantitation of the unphosphorylated and phosphorylated artificial peptide substrate, as well as the adenine nucleotides. Our results show a 1000-fold activation of AMPK by the combined effects of upstream kinase and saturating concentrations of AMP. The two AMPK isoforms exhibit similar specific activities (6 μmol/min/mg) and do not differ significantly by their responsiveness to AMP. Due to the inherent instability of ATP and ADP, it proved impossible to assay AMPK activity in the absolute absence of AMP. However, the half-maximal stimulatory effect of AMP is reached below 2 μm. AMP does not appear to augment phosphorylation by upstream kinases in the purified in vitro system, but deactivation by dephosphorylation of AMPK α-subunits at Thr-172 by protein phosphatase 2Cα is attenuated by AMP. Furthermore, it is shown that neither purified NAD+ nor NADH alters the activity of AMPK in a concentration range of 0–300 μm, respectively. Finally, evidence is provided that ZMP, a compound formed in 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside-treated cells to activate AMPK in vivo, allosterically activates purified AMPK in vitro, but compared with AMP, maximal activity is not reached. These data shed new light on physiologically important aspects of AMPK regulation.

scholarly journals Polarized activities of AMPK and BRSK in primary hippocampal neurons

2015 ◽  
Vol 26 (10) ◽  
pp. 1935-1946 ◽  
Author(s):  
Vedangi Sample ◽  
Santosh Ramamurthy ◽  
Kirill Gorshkov ◽  
Gabriele V. Ronnett ◽  
Jin Zhang
Keyword(s):  
Hippocampal Neurons ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Adenosine Monophosphate ◽  
Distal Region ◽  
Neuronal Polarity ◽  
Synaptic Development ◽  
Energy Stress ◽  
Ampk Activity ◽  
Developing Neurons

5′-Adenosine monophosphate–activated protein kinase (AMPK) is a master metabolic regulator that has been shown to inhibit the establishment of neuronal polarity/axogenesis under energy stress conditions, whereas brain-specific kinase (BRSK) promotes the establishment of axon-dendrite polarity and synaptic development. However, little information exists regarding the localized activity and regulation of these kinases in developing neurons. In this study, using a fluorescence resonance energy transfer (FRET)-based activity reporter that responds to both AMPK and BRSK, we found that BRSK activity is elevated in the distal region of axons in polarized hippocampal neurons before any stimulation and does not respond to either Ca2+ or 2-deoxyglucose (2-DG) stimulation. In contrast, AMPK activity is stimulated by either Ca2+ or 2-DG in the soma, dendrites, and axons of hippocampal neurons, with maximal stimulated activity observed in the distal region of the axon. Our study shows that the activities of both AMPK and BRSK are polarized in developing hippocampal neurons, with high levels in the distal region of extended axons.

AMP-activated protein kinase activation prevents denervation-induced decline in gastrocnemius GLUT-4

2001 ◽  
Vol 91 (5) ◽  
pp. 2102-2108 ◽  
Author(s):  
S. R. Paulsen ◽  
D. S. Rubink ◽  
W. W. Winder
Keyword(s):  
Protein Kinase ◽  
Chemical Activation ◽  
Carboxylase Activity ◽  
Kinase Activation ◽  
Glut 4 ◽  
Protein Kinase Activation ◽  
Ampk Activity ◽  
Denervated Muscles ◽  
Gastrocnemius Muscles ◽  
Amp Activated Protein Kinase

This study was designed to determine whether the reductions in GLUT-4 seen in 3-day-denervated muscles can be prevented through chemical activation of 5′-AMP-activated protein kinase (AMPK). Muscle AMPK can be chemically activated in rats using subcutaneous injections with 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR). In this study, the tibial nerve was sectioned on one side; the other was sham operated but without nerve section. Acute injections of AICAR resulted in significantly increased AMPK activity in denervated gastrocnemius but not soleus muscles. Acetyl-CoA carboxylase activity, a reporter of AMPK activation, declined in both gastrocnemius and soleus in both denervated and contralateral muscles. Three days after denervation, GLUT-4 levels were significantly decreased by ∼40% in gastrocnemius muscles and by ∼30% in soleus muscles. When rats were injected with AICAR (1 mg/g body wt) for 3 days, the decline in GLUT-4 levels was prevented in denervated gastrocnemius muscles but not in denervated soleus muscles. The extent of denervation-induced muscle atrophy was similar in AICAR-treated vs. saline-treated rats. These studies provide evidence that some effects of denervation may be prevented by chemical activation of the appropriate signaling pathways.

scholarly journals Herba houttuyniae Extract Benefits Hyperlipidemic Mice via Activation of the AMPK/PGC-1α/Nrf2 Cascade

Nutrients ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 164
Author(s):  
Ke Cao ◽  
Weiqiang Lv ◽  
Xuyun Liu ◽  
Yingying Fan ◽  
Kexin Wang ◽  
...  
Keyword(s):  
Adenosine Monophosphate ◽  
Poloxamer 407 ◽  
Peroxisome Proliferator ◽  
Related Factor ◽  
Protective Effects ◽  
Peroxisome Proliferator Activated Receptor ◽  
Beneficial Effects ◽  
Ampk Activity ◽  
Amp Activated Protein Kinase ◽  
Complex Activities

Hyperlipidemia is associated with metabolic disorders, but the detailed mechanisms and related interventions remain largely unclear. As a functional food in Asian diets, Herba houttuyniae has been reported to have beneficial effects on health. The present research was to investigate the protective effects of Herba houttuyniae aqueous extract (HAE) on hyperlipidemia-induced liver and heart impairments and its potential mechanisms. Male C57BL/6J mice were administered with 200 or 400 mg/kg/day HAE for 9 days, followed by intraperitoneal injection with 0.5 g/kg poloxamer 407 to induce acute hyperlipidemia. HAE treatment significantly attenuated excessive serum lipids and tissue damage markers, prevented hepatic lipid deposition, improved cardiac remodeling, and ameliorated hepatic and cardiac oxidative stress induced by hyperlipidemia. More importantly, NF-E2 related factor (Nrf2)-mediated antioxidant and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α)-mediated mitochondrial biogenesis pathways as well as mitochondrial complex activities were downregulated in the hyperlipidemic mouse livers and hearts, which may be attributable to the loss of adenosine monophosphate (AMP)-activated protein kinase (AMPK) activity: all of these changes were reversed by HAE supplementation. Our findings link the AMPK/PGC-1α/Nrf2 cascade to hyperlipidemia-induced liver and heart impairments and demonstrate the protective effect of HAE as an AMPK activator in the prevention of hyperlipidemia-related diseases.

scholarly journals Study of the AMP-activated protein kinase role in energy metabolism changes during the postmortem aging of yak longissimus lumborum

2019 ◽  
Author(s):  
Yayuan Yang ◽  
Ling Han ◽  
Qunli Yu ◽  
Yongfang Gao ◽  
Rende Song
Keyword(s):  
Energy Metabolism ◽  
Protein Kinase ◽  
Opposite Effect ◽  
Ph Value ◽  
Physiological Mechanism ◽  
Adenosine Monophosphate ◽  
Postmortem Aging ◽  
Longissimus Lumborum ◽  
Ampk Activity ◽  
Amp Activated Protein Kinase

AbstractTo explore the postmortem physiological mechanism of muscle, activity of adenosine monophosphate activated protein kinase (AMPK) as well as its role in energy metabolism of postmortem yaks were studied. In this experiment, we injected 5-amino-1-beta-d-furanonyl imidazole-4-formamide (AICAR), a specific activator of AMPK, and the specific AMPK inhibitor STO-609, to observe the changes in glycolysis, energy metabolism, AMPK activity and AMPK gene expression (PRKA1 and PRKA2) in postmortem yaks during maturation. The results showed that AICAR could increase the expression of the PRKKA1 and PRKAA2 genes, activate AMPK and increase its activity. The effects of AICAR include a lower concentration of ATP, an increase in AMP production, an acceleration of glycolysis, an increase in the lactic acid concentration, and a decrease in the pH value. In contrast, STO-609 had the opposite effect. Under hypoxic adaptation, the activity of the meat AMPK increased, which accelerated glycolysis and metabolism, and more effectively regulated energy production.

scholarly journals Study of the AMP-activated Protein Kinase Role in Energy Metabolism Changes during the Postmortem Aging of Yak Longissimus dorsal

Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 427
Author(s):  
Yayuan Yang ◽  
Ling Han ◽  
Qunli Yu ◽  
Yongfang Gao ◽  
Rende Song
Keyword(s):  
Energy Metabolism ◽  
Protein Kinase ◽  
Opposite Effect ◽  
Ph Value ◽  
Physiological Mechanism ◽  
Adenosine Monophosphate ◽  
Theoretical System ◽  
Postmortem Aging ◽  
Ampk Activity ◽  
Amp Activated Protein Kinase

To explore the postmortem physiological mechanism of muscle, activity of adenosine monophosphate activated protein kinase (AMPK) as well as its role in energy metabolism of postmortem yaks were studied. In this experiment, we injected 5-amino-1-beta-d-furanonyl imidazole-4-formamide (AICAR), a specific activator of AMPK, and STO-609 to observe the changes in glycolysis, energy metabolism, AMPK activity, and AMPK gene expression (PRKA1 and PRKA2) in postmortem yaks during maturation. The results showed that AICAR could increase the expression of the PRKKA1 and PRKAA2 genes, activate AMPK and increase its activity. The effects of AICAR include a lower concentration of ATP, an increase in AMP production, an acceleration of glycolysis, an increase in the lactic acid concentration, and a decrease in the pH value. In contrast, STO-609 had the opposite effect. Under hypoxic adaptation, the activity of the meat AMPK increased, which accelerated glycolysis and metabolism and more effectively regulated energy metabolism. Therefore, this study lays the foundation for establishing a theoretical system of energy metabolism in postmortem yak meat.

scholarly journals Phosphorylation of AMPK by upstream kinases is required for activity in mammalian cells

2017 ◽  
Vol 474 (17) ◽  
pp. 3059-3073 ◽  
Author(s):  
Robin Willows ◽  
Matthew J. Sanders ◽  
Bing Xiao ◽  
Bhakti R. Patel ◽  
Stephen R. Martin ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Kinase Domain ◽  
Carbohydrate Binding ◽  
Activation Loop ◽  
Γ Subunit ◽  
Cellular Context ◽  
Ampk Activity ◽  
Amp Activated Protein Kinase ◽  
Significant Attention

AMP-activated protein kinase (AMPK) plays a major role in regulating metabolism and has attracted significant attention as a therapeutic target for treating metabolic disorders. AMPK activity is stimulated more than 100-fold by phosphorylation of threonine 172 (Thr172). Binding of AMP to the γ subunit allosterically activates the kinase. Additionally, many small molecules, e.g. 991, have been identified that bind between the kinase domain and the carbohydrate-binding module of the β subunit, stabilising their interaction and leading to activation. It was reported recently that non-phosphorylated Thr172 AMPK is activated by AMP and A769662. We present here the crystal structure of non-phosphorylated Thr172 AMPK in complex with AMP and 991. This structure reveals that the activation loop, as well as the complex overall, is similar to the Thr172 phosphorylated complex. We find that in the presence of AMP and 991 non-phosphorylated Thr172, AMPK is much less active than the Thr172 phosphorylated enzyme. In human cells, the basal level of Thr172 phosphorylation is very low (∼1%), but is increased 10-fold by treatment with 2-deoxyglucose. In cells lacking the major Thr172 kinases, LKB1 and CaMKKβ, Thr172 phosphorylation is almost completely abolished, and AMPK activity is virtually undetectable. Our data show that AMP and 991 binding to non-phosphorylated Thr172 AMPK can induce an ordered, active-like, conformation of the activation loop explaining how AMPK activity can be measured in vitro without Thr172 phosphorylation. However, in a cellular context, phosphorylation of Thr172 is critical for significant activation of AMPK.

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