AMP-activated protein kinase alpha subunit (AMPKα)

AMP-activated protein kinase alpha subunit (AMPKα) is the catalytic subunit of the AMPK enzyme complex, a heterotrimeric kinase that serves as the central cellular energy sensor in eukaryotic cells[1][3][5][7]. The alpha subunit contains the kinase domain that is activated by phosphorylation at Thr172 (human α1) and is essential for catalyzing phosphorylation of downstream targets involved in energy metabolism[1][3][5][7]. AMPKα is activated by cellular stresses that deplete ATP and increase AMP, such as low glucose, hypoxia, and exercise. Upon activation, AMPKα orchestrates a metabolic switch by promoting ATP-generating catabolic pathways (e.g., fatty acid oxidation, glucose uptake, autophagy) and inhibiting ATP-consuming anabolic pathways (e.g., lipid, protein, and carbohydrate biosynthesis)[6][7]. AMPKα is a major therapeutic target in metabolic diseases, cardiovascular disease, cancer, and other disorders, with several drugs acting directly or indirectly through this subunit to regulate cellular and systemic metabolism[2][4][6][8]. Genetic variants encode two major isoforms in humans: AMPKα1 (PRKAA1) and AMPKα2 (PRKAA2)[1].

Other names

AMPK alpha subunitProtein kinase AMP-activated catalytic subunit alphaPRKAA1 (gene, human isoform 1)PRKAA2 (gene, human isoform 2)AMPKα1AMPKα2

Direct allosteric activation by AMP binding Thr172 phosphorylation by upstream kinases (LKB1, CaMKK2) Indirect activation via energy stress or pharmacological activators Drugs activate AMPK to promote catabolic processes (FA oxidation, autophagy) and inhibit anabolic ones (lipogenesis, gluconeogenesis)