Synthesis and evaluation of indazole based analog sensitive Akt inhibitorsElectronic supplementary information (ESI) available: Supplementary Table 1. See DOI: 10.1039/c003917aThis article is part of a Molecular BioSystems themed issue on Chemical Genomics

The kinase Akt is a key signaling node in regulating cellular growth and survival. It is implicated in cancer by mutation and its role in the downstream transmission of aberrant PI3K signaling. For these reasons, Akt has become an increasingly important target of drug development efforts and several inhibitors are now reaching clinical trials. Paradoxically it has been observed that active site kinase inhibitors of Akt lead to hyperphosphorylation of Akt itself. To investigate this phenomenon we here describe the application of a chemical genetics strategy that replaces native Akt with a mutant version containing an active site substitution that allows for the binding of an engineered inhibitor. This analog sensitive strategy allows for the selective inhibition of a single kinase. In order to create the inhibitor selective for the analog sensitive kinase, a diversity of synthetic approaches was required, finally resulting in the compound PrINZ, a 7-substiututed version of the Abbott Labs Akt inhibitor A-443654. A chemical genetics method to selectively target individual Akt kinase isoforms was developed that employed analog sensitive proteins paired with new engineered inhibitors.