5'-AMP-activated protein kinase (AMPK) (AMPK)

5'-AMP-activated protein kinase (AMPK) is a heterotrimeric enzyme complex that serves as the primary energy sensor in eukaryotic cells, maintaining energy homeostasis by monitoring the AMP:ATP ratio [2, 4]. It consists of a catalytic alpha subunit and regulatory beta and gamma subunits; activation occurs under conditions of energy stress, such as exercise, hypoxia, or nutrient deprivation, which elevate AMP or ADP levels [2, 14]. Once active, AMPK initiates a metabolic switch that promotes ATP-generating catabolic pathways, including fatty acid oxidation and glucose uptake, while suppressing ATP-consuming anabolic processes like lipid, protein, and cholesterol synthesis [1, 10, 20]. This signaling axis is a major therapeutic target for metabolic disorders such as type 2 diabetes and obesity, as well as for cancer and cardiovascular diseases [3, 4, 7]. Beyond metabolism, AMPK regulates autophagy, cell proliferation, and inflammation, making it a target of interest in oncology and cardiovascular research [5, 22]. While traditional drugs like metformin activate AMPK indirectly by altering mitochondrial function, modern drug discovery focuses on direct, isoform-selective activators to improve efficacy and minimize off-target effects like cardiac hypertrophy or hypothalamic-driven weight gain [9, 11, 24]. Despite these challenges, AMPK remains a pivotal node in metabolic regulation with significant translational potential for treating chronic diseases [4, 23, 25].

Other names

AMP-activated protein kinase5' adenosine monophosphate-activated protein kinaseAMP-activated protein kinase signaling axisPRKAAPRKABPRKAGSNF1-like kinase

AMPK is activated by an increase in the cellular AMP:ATP or ADP:ATP ratio, which leads to allosteric activation and promotes phosphorylation of the catalytic alpha subunit at Thr172 by upstream kinases like LKB1 or CaMKK2 [2, 4, 14]. Direct small-molecule activators can also bind to the gamma subunit (AMP mimics) or the allosteric drug and metabolite (ADaM) site at the alpha-beta subunit interface to induce activation and protect against dephosphorylation [9, 19, 24].