Multiplexable fluorescence lifetime imaging (FLIM) probes for Abl and Src-family kinases

Abstract

Most commonly employed strategies to map kinase activities in live cells require expression of genetically-encoded proteins (e.g. FRET sensors). In this work, we describe development and preliminary application of a set of cell-penetrating, fluorophore labelled peptide substrates for fluorescence lifetime imaging (FLIM) of Abl and Src-family kinase activities. These probes do not rely on FRET pairs or genetically-encoded protein expression. We also demonstrate image-by-image and pixel-by-pixel quantification of probe phosphorylation ratio, suggesting that this strategy will be useful for detailed mapping of single cell and subcellular kinase activity in live cells.