AMPK

AMPK (AMP-activated protein kinase) is a cellular energy sensor activated when AMP and/or ADP relative to ATP rise, signaling low energy availability. Once active, it stimulates catabolic pathways like fatty acid oxidation and autophagy while inhibiting anabolic processes such as mTORC1-driven protein synthesis. AMPK activation mimics aspects of caloric restriction, and age-related changes in AMPK signaling can contribute to impaired metabolic regulation. Metformin and exercise are well-known indirect AMPK activators.