Optochemical activation of kinase function in live cells.

Manipulation of protein kinase activity is widely used to dissect signaling pathways controlling physiological and pathological processes. Common methods often cannot provide the desired spatial and temporal resolution in control of kinase activity. Regulation of kinase activity by photocaged kinase inhibitors has been successfully used to achieve tight temporal and local control, but inhibitors are limited to inactivation of kinases and often do not provide the desired specificity. Here we report detailed methods for light-mediated activation of kinases in living cells using engineered rapamycin-regulated kinases in conjunction with a photocaged analog of rapamycin.