AMPKa2/PRKAA2

PRKAA2 encodes the alpha 2 catalytic subunit of AMP-activated protein kinase, the isoform enriched in skeletal muscle, heart, liver, and hypothalamic neurons. Alpha 2-containing heterotrimers localize partly to the nucleus and respond to energetic challenges such as exercise, hypoxia, and ischemia. They stimulate glucose uptake and fatty acid oxidation, promote mitochondrial biogenesis through PGC-1 alpha, and preserve ATP during cardiac stress. Muscle-specific alpha 2 deletion impairs exercise-stimulated glucose uptake, whereas cardiac alpha 2 loss increases susceptibility to ischemic injury and electrical remodeling. Sequence variants in PRKAA2 have been associated with human metabolic traits, and the enzyme remains central to exercise physiology research.