Takai, A. et al. Proc. Natl. Acad. Sci. 112, 4352–4356 (2015).

Bioluminescence is widely used in cell-based assays and for in vivo imaging. However, naturally bioluminescent proteins such as luciferases suffer from limitations including low brightness. To overcome this problem, researchers created a protein called Nano-lantern by fusing a mutant version of Renilla luciferase (Rluc) to the yellow fluorescent protein Venus. In the presence of luciferase substrate, the emitted light from Rluc is transferred by bioluminescence resonance energy transfer to Venus, yielding bright yellow emitted light. Takai et al. now extend this work to generate bright cyan and orange probes called cyan Nano-lantern and orange Nano-lantern. For cyan Nano-lantern, Venus from the original Nano-lantern was replaced with mTurquoise; for orange Nano-lantern, it was replaced with mKusabiraOrange2. These probes are ∼20-fold brighter than wild-type Rluc and enable enhanced multicolor bioluminescence imaging.