Organelle-Specific, Rapid Induction of Molecular Activities

We have previously demonstrated that a series of chemical dimerization probes for Rho GTPases can rapidly induce distinctive morphology changes depending on which Rho GTPase was activated (Movie #7). Using a series of novel chemically-inducible dimerization probes, we generated a system in which proteins were rapidly targeted to individual intracellular organelles such as plasma membrane, endoplasmic reticulum, Golgi, lysosome, and mitochondria (Movie #8-12). We demonstrated that a Ras GTPase can be activated at distinct intracellular locations and that membranes from two organelles can be inducibly tethered. We are also extending this technique to achieve activation at distinct subcellular locations at the cell surface.  A newly synthesized photocaged rapamycin derivative induced rapid dimerization of protein dimerization upon UV irradiation.  By combining this system with highly spatially confined UV-irradiation, we achieved subcellularly localized activation of Rac, a member of the family of small GTPases (Movie #13). Our technique offers a powerful approach to studies of dynamic intracellular signaling events
Chemically inducible recruitment of cytoplasmic proteins to various organelles. (Komatsu et al. Nat Methods, 2010)