Purified anti-Akt Phospho (Ser473)

Akt (also known as protein kinase B alpha) is a 60 kD serine/threonine specific kinase containing a pleckstrin domain. Akt plays a critical role in controlling survival and apoptosis. This kinase is ubiquitously expressed and translocates to the membrane upon activation. This protein kinase is activated by insulin and various growth and survival factors to function in a wortmannin-sensitive pathway involving PI 3-kinase. Akt is activated by phospholipid binding and activation loop phosphorylation at Thr308 by PDK1 (4) and by phosphorylation within the carboxy terminus at Ser473. The previously elusive PDK2, responsible for phosphorylation of Akt at Ser473, has been identified as a mammalian target of rapamycin (mTOR) in a rapamycin-insensitive complex with rictor and Sin1. Activated Akt can then phosphorylate a wide range of substrates including transcription factors (e.g. FOXO1), kinases (GSK-3,Raf-1, ASK, Chk1) and other proteins with important signaling roles (e.g. Bad, MDM2). Akt promotes cell survival by inhibiting apoptosis through phosphorylation and by inactivation of several targets, including Bad, forkhead transcription factor, c-Raf and caspase-9. Akt also plays a critical role in cell growth by directly phosphorylating mTOR in a rapamycin-sensitive complex containing raptor. More importantly, Akt phosphorylates and inactivates tuberin (TSC2), an inhibitor of mTOR within the mTOR-raptor complex. The phosphor-Akt (S473) antibody specifically detects phosphorlated Akt at the Ser473 site.