A rapid, reversible, and tunable method to regulate protein function in living cells using synthetic small molecules

Rapid and reversible means of perturbing the part of specific proteins are desirable tools for probing complex biological systems. We’ve created a general method to regulate the soundness of specific proteins in mammalian cells using cell-permeable, synthetic molecules. We engineered mutants from the human FKBP12 protein which are quickly and constitutively degraded when expressed in mammalian cells, which instability is conferred with other proteins fused to those destabilizing domains. Inclusion of an artificial ligand that binds towards the destabilizing domains shields them from degradation, allowing fused proteins Shield-1 to do their cellular functions. Genetic fusion from the destabilizing domain to some gene of great interest ensures specificity, and also the attendant small-molecule control confers speed, reversibility, and dose-dependence for this method. This general technique for controlling protein stability should enable conditional perturbation of specific proteins with unparalleled control in a number of experimental settings.