AMPK as a cellular energy sensor and its function in the organism

The adenine monophosphate (AMP) activated protein kinase (AMPK), is a heterotrimeric complex that is activated by an increase in the AMP/ATP ratio, and is considered to be a cellular energy sensor that contributes to regulate energy balance and caloric intake. AMPK is activated by LKB1 hinase and it can phophorylate several enzymes involved in anabolism to prevent further ATP consumption, and induces some catabolic enzymes to increase ATP generation. Furthermore, AMPK regulates the expression of genes involved in lipogenesis and mitochondrial biogenesis, among others. AMPK is distributed in most organs including, liver, skeletal muscle, heart and hypothalamus; and even in adipose cells. In addition, AMPK is activated in the hypothalamus stimulating appetite due to energy depletion. AMPK also participates in glycolysis regulation, glucose uptake, lipid oxidation, fatty acid synthesis, cholesterol synthesis and gluconeogenesis, and it has been considered as a possible target enzyme in the treatment of some diseases such as obesity, type 2 diabetes and hepatic steatosis. This review provides a general overview of AMPK structure, its activators and its function in the organism.