A Light-gated Integrator for Imaging Kinase Activity in Living Cells

Kinase signaling pathways regulate many cellular processes and are often dysregulated in cancers. The intratumoral heterogeneity of kinase activity in the context of tumor microenvironment presents a challenge for kinase‐targeted cancer therapeutics. Therefore, characterizing kinase activity profiles in complex tumor environment can help address this challenge. Current genetically encoded fluorescent biosensors have been widely used in kinase signaling research. Even with the sensitive and dynamic readout of these biosensors, it is difficult to capture transient changes across a whole tumor section. Herein, we developed a light‐gated kin ase a ctivity c oupled t ranscriptional (KINACT) integrator, which has the capability of “memorizing” differences in kinase activities over a certain period of time. The KINACT integrators have been applied for imaging PKA, PKC and Fyn activities in live cells, as well reporting subcellular changes in PKA activity. Moreover, we applied the PKA integrator to evaluate PKA response to a panel of G‐protein coupled receptor agonists and different kinase inhibitors, suggesting that KINACT integrator is a potential platform for screening various small molecule drugs. The KINACT integrator can also be applied to monitor PKA activity enhancement under pro‐inflammatory conditions. Support or Funding Information This work was supported by the National Institutes of Health (R35 CA197622 and R01 DK073368 to J.Z.)