First Author | Stokoe D | Year | 1997 |
Journal | Science | Volume | 277 |
Issue | 5325 | Pages | 567-70 |
PubMed ID | 9228007 | Mgi Jnum | J:41988 |
Mgi Id | MGI:894908 | Doi | 10.1126/science.277.5325.567 |
Citation | Stokoe D, et al. (1997) Dual role of phosphatidylinositol-3,4,5-trisphosphate in the activation of protein kinase B [see comments]. Science 277(5325):567-70 |
abstractText | Protein kinase B (PKB) is a proto-oncogene that is activated in signaling pathways initiated by phosphoinositide 3-kinase. Chromatographic separation of brain cytosol revealed a kinase activity that phosphorylated and activated PKB only in the presence of phosphatidylinositol-3,4,5-trisphosphate [PtdIns(3,4,5)P3]. Phosphorylation occurred exclusively on threonine-308, a residue implicated in activation of PKB in vivo. PtdIns(3,4,5)P3 was determined to have a dual role: Its binding to the pleckstrin homology domain of PKB was required to allow phosphorylation by the upstream kinase and it directly activated the upstream kinase. |