AMPK

AMPK (AMP-activated protein kinase) is a heterotrimeric serine/threonine kinase composed of catalytic α and regulatory β and γ subunits that functions as the principal cellular energy sensor. A rising AMP:ATP ratio, sensed by the γ subunit, allows the upstream kinases LKB1 and CaMKKβ to activate AMPK, which then phosphorylates ACC, TSC2 and Raptor to switch on catabolism while suppressing anabolic processes and mTORC1 signaling. Pharmacological activation by metformin, salicylate and direct AMPK activators places the complex at the center of diabetes, obesity and cancer metabolism research.