Akt substrate,160kD, phosphorylated (Thr642) (AS160, DKFZp779C0666, KIAA0603, TBC1 domain family member 4, Rab GAP)

The polypeptide insulin is a major hormone controlling critical energy functions such as glucose and lipid metabolism. Insulin binds to and activates the insulin receptor (IR) tyrosine kinase, which phosphorylates and recruits different adaptor proteins. The signaling pathway initiated by insulin and its receptor stimulates glucose uptake in muscle cells and adipocytes through translocation of GLUT4 glucose transporters from the cytoplasm to the plasma membrane (1). A 160 kDa substrate of the Akt serine/threonine kinase (AS160, TBC1D4) is a Rab GTPase activating protein that regulates insulin-stimulated GLUT4 trafficking. AS160 is expressed in many tissues including brain, kidney, liver and brown and white fat (2). Multiple Akt phosphorylation sites were identified on AS160 in vivo, with five sites showing increased phosphorylation following insulin treatment (2,3). Studies using recombinant AS160 demonstrated that insulin-stimulated phosphorylation of AS160 is a crucial step in GLUT4 translocation (3) and is reduced in some patients with type 2 diabetes (4). The interaction of 14-3-3 regulatory proteins with AS160 phosphorylated at Thr642 is another necessary step for GLUT4 translocation (5). Phosphorylation of AS160 by AMPK is involved in the regulation of contraction-stimulated GLUT4 translocation (6). Applications: Suitable for use in Western Blot. Other applications not tested. Recommended Dilutions: Western Blot: 1:1000 Incubate membrane with diluted antibody in 5% w/v BSA, 1X TBS, 0.1% Tween-20 at 4 degrees C with gentle shaking, overnight. Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4 degrees C for short-term only. For long-term storage and to avoid repeated freezing and thawing, add sterile 40-50% glycerol, aliquot and store at -20 degrees C. Aliquots are stable for at least 12 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.