Design of a Genetically Encoded Reporter for Imaging Kinase Activities

The genetically encoded Kinase Activity Reporter (KAR) contains a phosphoamino-acid-binding domain and kinase substrate sequence, sandwiched between a pair of fluorescent proteins that are capable of undergoing FRET. Phosphorylation of the substrate sequence by the kinase of interest results in the binding of the phosphoamino-acid-binding domain, induces a conformational change in the reporter that leads to an increase in FRET between the two fluorescent proteins.