AMPK alpha Protein (Complex)

Protein Background: AMPK is an energy sensor protein kinase that plays a key role in regulating cellular energy metabolism. In response to reduction of intracellular ATP levels, AMPK activates energy-producing pathways and inhibits energy consuming processes: inhibits protein, carbohydrate, and lipid biosynthesis, as well as cell growth and proliferation. AMPK acts via direct phosphorylation of metabolic enzymes, and by longer-term effects via phosphorylation of transcription regulators. It also acts as a regulator of cellular polarity by remodeling the actin cytoskeleton, probably by indirectly activating myosin. AMPK regulates lipid synthesis by phosphorylating and inactivating lipid metabolic enzymes such as ACACA, ACACB, GYS1, HMGCR and LIPE and regulates fatty acid and cholesterol synthesis by phosphorylating acetylCoA carboxylase (ACACA and ACACB) and hormone-sensitive lipase (LIPE) enzymes, respectively. It also regulates insulin-signaling and glycolysis by phosphorylating IRS1, PFKFB2 and PFKFB3. AMPK is a heterotrimer consisting of an alpha catalytic subunit (PRKAA1 or PRKAA2), and non-catalytic beta (PRKAB1 or PRKAB2) and gamma subunits (PRKAG1, PRKAG2 or PRKAG3). Beta non-catalytic subunit acts as a scaffold on which the AMPK complex assembles, via its C-terminus that bridges alpha and gamma subunits. Gamma non-catalytic subunit mediates binding to AMP, ADP and ATP, leading to activate or inhibit AMPK: AMP-binding results in allosteric activation of alpha catalytic subunit (PRKAA1 or PRKAA2) both by inducing phosphorylation and preventing dephosphorylation of catalytic subunits. ADP also stimulates phosphorylation, without stimulating already phosphorylated catalytic subunit. ATP promotes dephosphorylation of catalytic subunit, rendering the AMPK enzyme inactive.

Short Description: Recombinant AMPK Complex (A2+B2+G2) that includes full length human PRKAA2 protein (accession number NP_006243.2) with a N-terminal FLAG tag and full length human PRKAB2 protein (accession number NP_005390.1) without tag and full length human PRKAG2 protein (accession number NP_057287.2) without tag was expressed in Hi5 cells. The molecular weights of PRKAA2, PRKAB2, PRKAG2 are 63.6 kDa, 30.3 kDa and 63.7 kDa respectively.