CED-3-activated phosphoinositide binding of CNT-1 blocks PIP3 binding by AKT and SGK kinases. (a) Lipid binding assays of CNT-1 in the presence of CED-3. The indicated proteins labeled with 35S-Methionine (*) were incubated with or without CED-3 and then incubated with membrane strips (see METHODS). (b) AKT-1 lipid binding assay in the presence of CNT-1 and CED-3. Unlabeled GST-CNT-1a and GST-CNT-1b were incubated with CED-3 and then added to membrane strips with radiolabeled AKT-1(*) as described in METHODS. (c) AKT-2 and SGK-1 lipid binding assay in the presence of CNT-1 and CED-3. Radiolabeled AKT-2(*) and SGK-1(*) were incubated with membrane strip as described in (b). In all panels, lipids spotted on the strips are: triacylglyceride (TAG), diacylglyceride (DAG), phosphatidic acid (PA), phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylglycerol (PG), cardiolipin (CL), phosphatidylinositol (PI), Phosphatidylinositol (4)-phosphate (PIP), Phosphatidylinositol (4,5)-bisphosphate (PIP2), Phosphatidylinositol (3,4,5)-trisphosphate (PIP3), cholesterol (Chol), sphingomyelin (SM), and 3-sulfogalactosylceramide (SGC).