Background information
The 5 AMP activated protein kinase (AMPK), a member of the SNF1 (sucrose non fermentor) kinase family, is a heterotrimeric protein comprise of alpha (63 kDa), beta (30 kDa) and gamma (38 kDa) subunits. The alpha subunit is the catalytic subunit, while beta and gamma are non catalytic subunits (although they have been found to interact with the active subunit in liver). AMPK regulates fatty acid and sterol synthesis by phosphorylation of acetyl CoA as well as cholesterol synthesis via phosphorylation and inactivation of hydroxymethylglutaryl CoA reductase. AMPK is activated by AMP and can be also regulated by treatment with purified protein phosphatase in vitro.