AMP-activated protein kinase α1β1γ1 complex (AMPK α1β1γ1)

The AMP-activated protein kinase (AMPK) α1β1γ1 complex is a ubiquitously expressed heterotrimeric enzyme that serves as a central fuel gauge for cellular energy homeostasis [2, 6]. It consists of a catalytic α1 subunit (PRKAA1), a scaffolding β1 subunit (PRKAB1), and a regulatory γ1 subunit (PRKAG1) [4, 17]. The complex is activated in response to metabolic stresses that deplete ATP and increase the AMP/ATP or ADP/ATP ratios, such as exercise, hypoxia, or nutrient deprivation [2, 8]. Once activated, AMPK α1β1γ1 restores energy balance by stimulating catabolic pathways, such as glucose uptake and fatty acid oxidation, while inhibiting energy-consuming anabolic processes like protein, fatty acid, and cholesterol synthesis [7, 8]. Due to its critical role in metabolic control, this complex is a major therapeutic target for type 2 diabetes, obesity, and metabolic syndrome [4, 6]. Pharmacological activation can be achieved indirectly through mitochondrial inhibition (e.g., metformin) or directly via small molecules binding to the Allosteric Drug and Metabolite (ADaM) site [5, 15].

Other names

AMPK alpha-1 beta-1 gamma-1PRKAA1-PRKAB1-PRKAG1 complex5'-AMP-activated protein kinase subunit alpha-1, beta-1, gamma-1 complex

The complex is activated allosterically by AMP binding to the γ1 subunit and by phosphorylation of Thr172 on the α1 subunit by upstream kinases such as LKB1 or CaMKK2 [2, 17]. Direct activators like A-769662 and 991 bind to the Allosteric Drug and Metabolite (ADaM) site at the α-β interface, which enhances activity and prevents dephosphorylation of Thr172 [5, 6, 15].