AMP-activated protein kinase α2β1γ3 heterotrimer (AMPK α2β1γ3)

The AMP-activated protein kinase (AMPK) α2β1γ3 heterotrimer is a specialized isoform of the AMPK complex predominantly expressed in skeletal muscle, particularly in fast-twitch glycolytic fibers (UniProt: Q9UGI9). As a heterotrimeric enzyme consisting of a catalytic α2 subunit (PRKAA2), a scaffolding β1 subunit (PRKAB1), and a regulatory γ3 subunit (PRKAG3), it functions as a critical energy sensor that monitors the cellular AMP/ATP ratio (PubMed: 10409708). During physical exercise or metabolic stress, this specific complex is the primary AMPK isoform activated in human skeletal muscle to stimulate glucose uptake and fatty acid oxidation (PubMed: 12540591). Because of its tissue-specific expression and role in insulin-independent glucose disposal, the α2β1γ3 heterotrimer is a high-interest therapeutic target for treating type 2 diabetes and metabolic syndrome (PubMed: 28847882). Pharmacological activation of this complex, using agents like MK-8722, aims to mimic the beneficial metabolic effects of exercise, improving systemic insulin sensitivity and lipid profiles (Science: 357(6352)).

Other names

PRKAA2-PRKAB1-PRKAG3 complex5'-AMP-activated protein kinase subunit alpha-2/beta-1/gamma-3Skeletal muscle-specific AMPK complexAMPK alpha2-beta1-gamma3

Direct allosteric activation by binding to the Allosteric Drug and Metabolite (ADaM) site at the α-β subunit interface, which induces a conformational change that increases catalytic activity and protects the Thr172 phosphorylation site from phosphatases (PubMed: 28774925).