Observing living organisms through the eyes of chemistry

Department of Chemistry: Ozawa Laboratory

Takeaki Ozawa, Professor, Department of Chemistry, School of Science

Degrees and Positions

1993:	Graduated from the Department of Chemistry, School of Science, The University of Tokyo
1998:	Doctor of Science, School of Science, The University of Tokyo, followed by Research Associate
2002:	Assistant Professor, School of Science, The University of Tokyo
2005:	Associate Professor, Institute for Molecular Science, National Institutes of Natural Sciences
2007-present:	Current position

Representative Honors

2004:	Progress Award, the Chemical Society of Japan
2005:	Young Scientists’ Prize, Commendation for Science and Technology from the Ministry of Education, Culture, Sports, Science and Technology
2011:	The 7th Japan Society for the Promotion of Science Prize

Through a microscope, green light emerges from the dark background like shining stars in the night sky. The twinkles move all over the field of view, as if wiggling through a crowd. As you stare longer, they appear more beautiful than the starry sky. They look like light emanating from a diamond.
Professor Takeaki Ozawa remembers vividly the emotion he felt when he first saw living cells using green fluorescent protein (GFP). It was just before accepting a position as an assistant professor after completing his doctoral degree program in 1998.

“It was so beautiful that I was captivated by it right away. I was working on a different project, but my then professor encouraged me to take on a new challenge from scratch.”
The Ozawa laboratory, which is also an analytical chemistry laboratory, is working on three research projects. The first research project is to observe the movements of living cells in situ. To achieve this, they are developing the technology to see where, when, and how biomolecules play their roles in the cells. They have so far developed techniques for visualizing intracellular pH changes using firefly luciferase and for the fluorescence imaging of RNA in cells.

The second research project is to identify chemicals and proteins with unique properties. The discovery of new substances may aid drug discovery. Through screening, they have discovered organelle-localized proteins and compounds that act on receptor proteins called G-protein-coupled receptors.

The third project goes beyond the boundaries of traditional analytical chemistry. The laboratory is developing technology that uses light to control the function of proteins in living cells. By fusing a protein of interest with a light-responsive protein derived from a plant, the function of the protein can be turned on and off using external light as a switch. This is currently a major research area worldwide.
The field of life science has advanced greatly because of innovations in analytical chemistry. It is impossible to measure the huge breakthroughs in the life sciences made possible by DNA sequencing in gene analysis or mass spectrometry for protein analysis.

“We develop techniques needed to observe what we are interested in and to see features of living creatures that no one has ever seen before. That’s our objective and the best part of this research,” says Professor Ozawa.

Professor Ozawa, who encountered GFP and then entered the field as a newcomer, had one central idea. GFP loses its light-emitting ability when the protein structure is split into two fragments; however, when the protein fragments are brought into close proximity, they reconstitute and regain their light-emitting ability. He thought that this phenomenon could be used to reveal protein-protein interactions and protein transport pathways in cells. Professor Ozawa named his idea “the GFP reconstitution method,” and once the idea finally saw the light of day in 2000 after three years of research, the method became a technique used all over the world. The professor looks back and recalls this experience as “the result of what I thought through over and over in my head.”

Based on his own experience, he encourages his students to be independent. “I would like them to experience the pleasure of discovering a new island by swimming in the ocean by themselves,” encourages Professor Ozawa. But he does not forget to give caring words, “If they start drowning, I will support them with everything I’ve got.” His students understand where Professor Ozawa stands: “Professor Ozawa listens to students’ proposals very carefully,” says second year student in the doctoral degree program (D2), Toshimichi Yamada, and Líng Zhī (D3) adds “he takes care of us patiently when we are in trouble”.

International students and postdoctoral fellows have continued to come since Professor Ozawa established his laboratory at The University of Tokyo in 2007. Three international students are currently working in the laboratory, and there are many opportunities to go overseas. Mizuki Endo (D1) visited the Netherlands alone in January 2014 to develop her research ideas. Toshimichi Yamada (D2) makes friends with foreign researchers whenever he attends a meeting overseas.

This verifies that the world is watching the new “eyes” that are born in Professor Ozawa’s laboratory.

Upper panel, the principle of the GFP reconstitution method; lower panel, a single molecule of β-actin mRNA (bright green spot) is visualized using the GFP reconstitution method. The movement of β-actin mRNA along tubulin (red portion) is shown (orange line).

Student Evaluations
 “He is kind to students. I have never seen him being angry at students.” - Líng Zhī. (international student, D3)
“He likes sports. Swimming is like his daily routine, and he also loves climbing and skiing.” Yoshihiro Katsura (D2)
“He is young and friendly. Talking to him is like talking to a student.” Toshimichi Yamada (D2)
“He is the life of the party and always at the center of nomikai.” Mizuki Endo (D1)

― Office of Communication ―