Hypothalamic AMPK as a Regulator of Energy Homeostasis

Figure 1

The structure and regulation of AMPK. AMP-activated protein kinase (AMPK) complexes are heterotrimeric kinase composed of α, β, and γ subunits in a 1 : 1 : 1 ratio. AMPK is specifically activated by AMP and its analogues via allosteric activation. The activity of AMPK is also induced through reversible phosphorylation, especially on Thr-172 residue. Calcium and calmodulin increase the phosphorylation of AMPK through Ca²⁺/calmodulin-dependent protein kinase kinase β (CaMKKβ) while the elevated AMP : ATP ratio can enhance liver kinase B1 (LKB1) activity. AMPK activation is also regulated by the ubiquitin proteasome system.