Protein Domain : Protein Kinase B, pleckstrin homology domain IPR039026

Type	Domain
Description	PKB (also called Akt) is a phosphatidylinositol 3'-kinase (PI3K)-dependent Ser/Thr kinase which alters the activity of the targeted protein [ ]. Among its many roles, Akt appears to be common to signaling pathways that mediate the metabolic effects of insulin in several physiologically important target tissues[]. Human Akt has three isoforms derived for distinct genes: Akt1/PKBalpha, Akt2/PKBbeta, and Akt3/PKBgamma. All Akts have an N-terminal PH domain with an activating Thr phosphorylation site, a kinase domain, and a short C-terminal regulatory tail with an activating Ser phosphorylation site []. The PH domain recruits Akt to the plasma membrane by binding to phosphoinositides (PtdIns-3,4-P2) and is required for activation. The phosphorylation of Akt at its Thr and Ser phosphorylation sites leads to increased Akt activity toward forkhead transcription factors, the mammalian target of rapamycin (mTOR), and the Bcl-xL/Bcl-2-associated death promoter (BAD), all of which possess a consensus motif R-X-R-XX-ST-B (X = amino acid, B = bulky hydrophobic residue) for Akt phosphorylation [, ].PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized [ ].
Short Name	PH_PKB