Using a kinase-inducible bimolecular switch to control enzyme activity in living cells

Molecular switches have been instrumental in the development of powerful and versatile genetic tools for directly probing biochemical processes, such as intracellular signaling, within their native contexts. A molecular switch can be broadly defined as a molecular system capable of existing in either of two states (e.g., conformations), which can be converted from one state to the other by a specific input stimulus. This protocol outlines a method for using a kinase-inducible bimolecular switch, along with live-cell fluorescence microscopy, to directly control and monitor the activity of a specific enzyme in living cells.