LOVTRAP: A Versatile Method to Control Protein Function with Light.

We describe a detailed procedure for the use of LOVTRAP, an approach to reversibly sequester and release proteins from cellular membranes using light. In the application described here, proteins that act at the plasma membrane are held at mitochondria in the dark, and reversibly released by irradiation. The technique relies on binding of an engineered Zdk domain to a LOV2 domain, with affinity <30 nM in the dark and >500 nM upon irradiation between 400 and 500 nm. LOVTRAP can be applied to diverse proteins, as it requires attaching only one member of the Zdk/LOV2 pair to the target protein, and the other to the membrane where the target protein is to be sequestered. Light-induced protein release occurs in less than a second, and the half-life of return can be adjusted using LOV point mutations (∼2 to 500 sec). © 2016 by John Wiley & Sons, Inc.