CKI-7 free base is a potent and ATP-competitive inhibitor of casein kinase 1 (CK1; IC50: 6 μM; Ki: 8.5 μM) and a selective Cdc7 kinase inhibitor. CKI-7 free base also inhibits SGK, ribosomal S6 kinase-1 (S6K1), and MSK1.
PDK1-IN-RS2 inhibits the activation of the downstream kinases S6K1 by PDK1. PDK1-IN-RS2 is a mimic of the peptide docking motif (PIFtide) and is a substrate-selective PDK1 inhibitor (Kd: 9 μM).