Yang, X. et al. Mol. Biol. Cell 10.1091/mbc.E13-03-0126 (12 June 2013).

The temporal and spatial precision of optogenetics makes it an ideal approach for protein localization and functional studies. The PhyB-PIF system is a light-inducible protein-protein interaction system that takes advantage of the light-controllable interaction between PhyB and PIF phytochrome fragments after conjugation with a small chromophore. The system has been used to recruit proteins to the plasma membrane, enabling control of the activation of intracellular signals, but to date it has not been optimized for the targeting of proteins to other organelles or cellular localizations besides the membrane. Yang et al. now report a library of constructs in which PhyB was fused to different anchoring sequences and localized to various subcellular places in budding yeast. The collection of probes includes tools for nuclear, endosome or peroxisome protein localization control. The researchers demonstrated the value of these tools for recruiting proteins to or away from their normal sites of action and for studying the effect on cell function.