"Vivid Application of Super-duper Chemiluminescent Proteins - From Bioactivity Imaging to Glowing Plants"

Takeharu Nagai, Ph.D.
Distinguished Professor
Department of Biomolecular Science and Engineering
The Institute of Scientific and Industrial Research
Osaka University

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Fluorescent proteins are an indispensable tool for live imaging of cells and cell structures. But the requirement for external illumination definitely precludes its universal application because it can induce problems including photobleaching, photodamage and the unintended activation of other light-responsive proteins. Bioluminescence caused by chemical reaction by luciferase is an alternative to fluorescence because it does not require an excitation light. One big problem in the application of luciferase to bioimaging was dim brightness and lack of color variation. To overcome this drawback, we developed super-duper chemiluminescent proteins (Nano-lantern series) by hybrid of a luciferase with various color variant of fluorescent proteins with very efficient BRET (bioluminescence resonance energy transfer). In addition, we applied these Nano-lanterns to design Ca2+, cAMP, and ATP indicators, thereby succeeded imaging these bioactive molecules in environments where fluorescent indicators have failed. One notable application of this imaging modality is simultaneous use with multi-color optogenetics that is now essential tools for neuroscience. These chemiluminescent probes will revolutionize conventional bioimaging by allowing visualization of biological phenomena not seen before at the single-cell, organ, and whole-body level, in animals and plants. Furthermore, we made brightly and colorfully chemiluminescent plants (Marchantia) by introduction of genes for Nano-lanterns. These glowing plants would be used in future for lighting the way of town as well as the interior of house without consumption of electrical energy.

Representative publications
1. Wazawa T, Arai Y, Kawahara Y, Takauchi H, Washio T & Nagai T. Highly biocompatible super-resolution fluorescence imaging using the fast photoswitching fluorescent protein Kohinoor and SPoD-ExPAN with Lp-regularized image reconstruction. Microscopy, accepted.
2. Kushida Y, Arai Y, ShimonoK & Nagai T. Biomimetic chemical sensing by fluorescence signals using a virus-like particle-based platform. ACS Sensors, in press.
3. Maeshima K, Matsuda T, ShindoY, Imamura H, Tamura S, Imai R, Kawakami S, Nagashima R, Soga T, Noji H, Oka K & Nagai T. A transient rise in free Mg2+ released from ATP-Mg by its hydrolysis contributes to mitotic chromosome condensation. Current Biology, in press.
4. Shinoda H, Ma Y, Nakashima R, Sakurai K, Matsuda T & Nagai T. Acid-tolerant monomeric GFP from Olindias Formosa. Cell Chemical Biology, 25, 1-9, 2018.
5. Inagaki S, Tsutsui H, Suzuki K, Agetsuma M, Arai Y, Jinno Y, Bai G, Daniels MJ, Okamura Y, Matsuda T & Nagai T. Genetically encoded bioluminescent voltage indicator for multi-purpose use in wide range of bioimaging. Scientific Reports, 7, 42398, 2017.
6. Suzuki K, Kimura T, Shinoda H, Bai G, Daniels MJ, Arai Y, Nakano M & Nagai T. Five colour variants of bright luminescent protein for real-time multicolour bioimaging. Nature Communications, 7, 13718, 2016.
7. Tiwari DK, Arai Y, Yamanaka M, Matsuda T, Agetsuma M, Nakano M, Fujita K & Nagai T. Fast positively-photoswitchable fluorescent protein for ultra-low laser power RESOLFT nanoscopy. Nature Methods, 12, 515-518, 2015.
8. Saito K, Chang YF, Horikawa K, Hatsugai N, Higuchi Y, Hashida M, Yoshida Y, Matsuda T, Arai Y & Nagai T. Luminescent protein for high-speed single-cell and whole-body imaging. Nature Communications, 3, 1262, 2012

Research Focus:
My research is focusing on development of molecular probes for bioimaging by engineering both fluorescent and bioluminescent proteins. Recent representative works in my laboratory are invention of an ultrasensitive Ca2+ indicator (yellow cameleon Nano), super-duper bioluminescent proteins (Nano-Lantern), a fast photoswitchable fluorescent protein (Kohinoor), a world first bioluminescent membrane potential indicator (LOTUS-V), and an acid-tolerant green fluorescent protein (Gamillus), and so on. With these probes, my laboratory is trying to decipher how few number element (DNA, protein, virus and cell, etc) can cause singularity in biological system. My laboratory is also developing glowing plant that would be usable for electrical power free lightning devices. 



The Bioengineering Seminar Series is co-hosted by the Parker H. Petit Institute for Bioengineering and Bioscience, and the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.