Adenosine monophosphate-activated protein kinase (AMPK) (AMPK)

Adenosine monophosphate-activated protein kinase (AMPK) is a highly conserved heterotrimeric enzyme complex that serves as the master regulator of cellular energy homeostasis [UniProt P54646]. It consists of a catalytic alpha subunit and regulatory beta and gamma subunits, which allow it to sense fluctuations in the cellular AMP:ATP and ADP:ATP ratios [Hardie et al., 2012, Nature Reviews Molecular Cell Biology]. When energy levels are low, AMPK is activated to restore balance by promoting catabolic pathways that generate ATP, such as glucose uptake and fatty acid oxidation, while simultaneously inhibiting energy-consuming anabolic processes like lipid and protein synthesis [PubMed: 22551880]. Due to its central role in metabolism, AMPK is a primary therapeutic target for type 2 diabetes and metabolic syndrome, with metformin being its most well-known indirect activator [PubChem: 4091]. Furthermore, AMPK's influence on cell growth, autophagy, and mitochondrial health has made it a subject of intense research in oncology and neurodegenerative diseases [PubMed: 27229108].

Other names

5'-AMP-activated protein kinasePRKAAMP-activated protein kinaseHMG-CoA reductase kinase

AMPK acts as a cellular energy sensor activated by increases in the AMP:ATP and ADP:ATP ratios. It is activated allosterically by AMP/ADP binding to the gamma subunit and by phosphorylation of the alpha subunit at Thr172 by upstream kinases such as LKB1 and CaMKK2 [Hardie et al., 2012, Nature Reviews Molecular Cell Biology]. Once active, AMPK phosphorylates downstream targets to switch off ATP-consuming anabolic pathways and switch on ATP-producing catabolic pathways.