AMPK

AMPK (AMP-activated Protein Kinase) is a heterotrimeric serine/threonine kinase composed of alpha, beta, and gamma subunits that functions as the cell's primary fuel gauge. It is activated when the AMP-to-ATP ratio rises, signalling an energy deficit, and responds by switching on energy-generating pathways such as fatty acid oxidation, glucose uptake, and mitochondrial biogenesis while switching off energy-consuming processes like protein and lipid synthesis. AMPK directly phosphorylates and inhibits mTORC1, creating a metabolic toggle between growth and conservation states. In metabolic research, AMPK activation improves insulin sensitivity, enhances lipolysis in adipose tissue, and promotes mitochondrial function. GLP-1 receptor agonists like Tirzepatide have been shown to activate AMPK in certain tissues, contributing to their metabolic benefits beyond appetite suppression. AMPK is also a key mediator of exercise-induced metabolic adaptations, making it a target of interest in both anti-obesity and longevity research.