AMP-Activated Protein Kinase (AMPK)

Sino Biological provides a comprehensive set of tools for AMP-activated protein kinase (AMPK) related studies, including proteins, antibodies (rabbit mAbs, mouse mAbs, and rabbit pAbs), ELISA kits, and ORF cDNA clones. 5' AMP-activated protein kinase (AMPK) is an enzyme that plays a role in maintaining energy homeostasis. AMPK induces a cascade of events within cells in response to the ever changing energy charge of the cell. Once activated, AMPK-mediated phosphorylation events switch cells from active ATP consumption to active ATP production. AMPK also plays important role in regulation of insulin synthesis and secretion in pancreatic islet β-cells and modulation of hypothalamic functions involved in the regulation of satiety, thus intimately related with obesity and diabetes.

AMP-Activated Protein Kinase (AMPK) Products

• AMPK (A1/B1/G1)
• AMPK (A2/B2/G1)
• AMPKb1 / PRKAB1
• AMPK (A1/B2/G1)
• AMPKa1 / PRKAA1
• AMPKb2 / PRKAB2
• AMPK (A2/B1/G1)
• AMPKa2 / PRKAA2
• AMPKg1 / PRKAG1

AMP-Activated Protein Kinase (AMPK) Background

5' AMP-activated protein kinase or AMPK is an enzyme that plays a role in maintaining energy homeostasis. AMP-activated protein kinase was first discovered as an activity that inhibited preparations of acetyl-CoA carboxylase (ACC) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase, HMGR) and was induced by AMP. AMPK induces a cascade of events within cells in response to the ever changing energy charge of the cell. Once activated, AMPK-mediated phosphorylation events switch cells from active ATP consumption to active ATP production. These phosphorylation events are rapidly initiated and results in the stimulation of hepatic fatty acid oxidation and ketogenesis, inhibition of cholesterol synthesis, lipogenesis, and triglyceride synthesis, inhibition of adipocyte lipolysis and lipogenesis, stimulation of skeletal muscle fatty acid oxidation and muscle glucose uptake. Other important activities attributable to AMPK are regulation of insulin synthesis and secretion in pancreatic islet β-cells and modulation of hypothalamic functions involved in the regulation of satiety.

The mammalian AMPK is a trimeric enzyme composed of a catalytic α subunit and the non-catalytic β and γ subunits. There are two genes encoding isoforms of both the α and β subunits (α1, α2, β1 and β2) and three genes encoding isoforms of the γ subunit (γ1-γ3). The N-terminal half of the α subunits of AMPK contains a typical serine/threonine kinase catalytic domain. Interaction with the β and γ subunits occurs via the C-terminal half of the α subunits. The γ subunit of AMPK includes four particular Cystathionine beta synthase (CBS) domains giving AMPK its ability to sensitively detect shifts in the AMP:ATP ratio. Two conditions must be met in triggering the activation of AMPK. First, the γ subunit of AMPK must undergo a conformational change which can be accomplished under the increased concentration of AMP, so as to expose the active site (Thr-172) on the α subunit. The second condition that must be met is the phosphorylation and consequent activation of AMPK on its activating loop at Thr-172 of the α subunit brought about by an upstream kinase (AMPKK).

AMP-Activated Protein Kinase (AMPK) Related Studies

1. Winder WW, et al. (1999) AMP-activated protein kinase, a metabolic master switch: possible roles in type 2 diabetes. Am. J. Physiol. 277 (1 Pt 1): E1–10.
2. Rutter G. et al. (2003) Roles of 5'-AMP-activated protein kinase (AMPK) in mammalian glucose homoeostasis. Biochem J. 375(Pt 1): 1–16.
3. Kraegen EW, et al. (2009) AMP-activated protein kinase and muscle insulin resistance. Front Biosci. 14:4658-72.
4. Li C, et al. (2010) AMP-activated protein kinase: a stress-responsive kinase with implications for cardiovascular disease. Curr Opin Pharmacol. 10(2):111-5.
5. Hardie DG. (2011) Sensing of energy and nutrients by AMP-activated protein kinase. Am J Clin Nutr.