PRKAB2 is a regulatory subunit of the AMP-activated protein kinase (AMPK). AMPK is a heterotrimer consisting of an alpha catalytic subunit, and non-catalytic beta and gamma subunits. AMPK is an important energy-sensing enzyme that monitors cellular energy status and plays a role in protecting cells from stresses that cause ATP depletion by switching off ATP-consuming biosynthetic pathways. AMPK is responsible for the regulation of fatty acid synthesis by phosphorylation of acetyl-CoA carboxylase (ACC). It also regulates cholesterol synthesis via phosphorylation and inactivation of hydroxymethylglutaryl-CoA reductase (HMGCR) and hormone-sensitive lipase. PRKAB2 may be a positive regulator of AMPK activity.