The synthetic peptide RPRAATF allows specific assay of akt activity in cell lysates

Abstract

The Akt protein kinase is a critical signaling molecule in a range of cellular processes. A key to identifying the role of this pleiotropic kinase in any particular process is the ability to quantitate its activity. In this study we show that the synthetic peptide RPRAATF is a specific substrate for the kinase in crude cell extracts, thus enabling rapid, convenient, and sensitive assay of Akt activity. Peptide kinase activity was confined to a single peak upon sequential ion-exchange chromatography of whole-cell extracts of Balb/c 3T3 fibroblasts. This activity was stimulated by both platelet-derived growth factor and pervanadate, phosphatidyl inositol 3-kinase dependent, and inhibited by sp..