Invitrogen™ AKT Pathway (AKT/GSK/p70 S6K) Activation Profile Multispecies InstantOne™ ELISA Kit

AKT, which exists as multiple isoforms, is one of the principle kinases activated by phosphoinositide 3-kinase (PI3K). Activation of PI3K results in the generation of phosphatidylinositol (3,4,5)-triphosphate (PIP3). These lipid second messengers bind to the pleckstrin homology domain of AKT to promote its translocation to the plasma membrane for activation via phosphorylation at Thr308 and Ser473 by PDK1 and the mTOR TORC2 complex, respectively. Phosphorylation at both these sites is required for full activation of AKT Ser/Thr kinase activity. AKT phosphorylates over 50 known substrates, including GSK3b, p70S6K, AS160, PRAS40, TSC 1, TCS 2, Raf-1, Bad, the FOXO family of transcription factors, and PFK2. Due to its established critical role in numerous biological processes, AKT is a frequent target for oncology-related drug development. Glycogen Synthase Kinase 3 (GSK3) is a Ser/Thr kinase that exists as two isoforms, GSK3a and GSK3β. Unlike other kinases, phosphorylation at Ser9 and Ser21 for GSK3alpha and GSK3beta, respectively, leads to inactivation of this enzyme. GSK3 has been implicated in several diseases, including cancer and diabetes, through its phosphorylation of glycogen synthase. GSK3 has also been associated with neurodegenerative diseases such as Alzheimer's disease due to its phosphorylation of the neuronal Tau protein. p70 S6 Kinase (p70S6K) is a member of the ribosomal S6 kinase family of Ser/Thr kinases. P70 S6K activity is controlled by multiple signaling pathways, including the MAPK, phosphoinositide-3 kinase (PI3K), and mTOR pathways. This regulation results in the phosphorylation of multiple sites of p70 S6K, including Thr389 within the linker domain, which is required for full activation. Activated p70 S6K phosphorylates several residues on the S6 ribosomal protein, thereby leading to increased protein synthesis.