AMP-activated protein kinase--the key role in metabolic regulation

AMP-activated protein kinase (AMPK) is the central component of a protein kinase cascade that acts as an energy sensor maintaining the energy balance at the cellular as well as at the whole body level. Within the healthy cell, metabolic stress leading to an increase in AMP concentration results in AMPK activation. Once activated, AMPK "switches off" many anabolic pathways e.g. fatty acid and protein synthesis while "switches on" catabolic pathways such as fatty acid oxidation or glycolysis which serve to restore intracellular ATP level. Adipocyte derived hormones leptin and adiponectin activate AMPK in peripheral tissues increasing energy expenditure. AMPK also regulates food intake due to response to hormonal and nutrient signals in hypothalamus. Antidiabetic drugs that mimic the action of insulin activate the AMPK signaling pathways. Further studies are needed to clarify the importance of the AMPK activation for therapeutic effects of this drugs.