Fig. 5

NIR biosensors for detection of PKA and JNK kinase activities. a Schematic representation of miRFP670nano-miRFP720-based NIR FRET biosensor for kinase activity. b Time-lapse FRET/miRFP670nano ratio images of HeLa cell expressing NIR PKA biosensor stimulated with 1 mM dbcAMP and visualized using pseudocolor. c FRET/miRFP670nano ratio time courses of HeLa cells expressing PKA biosensor stimulated with dbcAMP in the presence (red) and absence (black) of chemical PKA inhibitor, AT13148 (n = 3 independent experiments). d Time-lapse FRET/miRFP670nano ratio images of HeLa cell expressing NIR JNK biosensor stimulated with 1 μg ml⁻¹ anisomycin and visualized using pseudocolor. e FRET/miRFP670nano ratio time courses of HeLa cells expressing JNK biosensor stimulated with anisomycin in the presence (red) and absence (black) of chemical JNK inhibitor, SP600125 (n = 3 independent experiments). In b–e the miRFP670nano and FRET fluorescence signals were detected at 667 and 725 nm, respectively. Scale bars, 10 μm