Beyond DNA lie the mysteries of life

Department of Bioinformatics and Systems Biology — Kumiko Ui-Tei

Kumiko Ui-Tei
Associate Professor specialized in Biological Sciences, Graduate School of Science

Professor Ui-Tei completed her Ph.D. at the Waseda University Graduate School of Science and Engineering in 1987, and in the same year became a research fellow at the Mitsubishi Kasei Institute of Life Sciences. Starting in 1989 became an assistant, then a lecturer, then an associate professor at the Nippon Medical School’s School of Medicine. In 2002, she became an associate professor by special appointment in the University of Tokyo Graduate School of Science’s Department of Biophysics and Biochemistry, then in 2006, an associate professor in the same department and an adjunct associate professor at the Department of Bioinformatics and System Biology, the University of Tokyo Graduate School of Frontier Sciences. She took up her current post in 2007.

The genetic information of organisms—their genome—is recorded using base pairs in that the organism’s DNA sequences. That information is copied to RNA, which functions to translate it into proteins necessary for creating life.

The mechanisms underlying that is called the “central dogma” of molecular biology, and has been held as the central principle for explaining genes. Around a decade ago, however, it became clear that there is a more complex mechanism behind the expression of genetic information. Professor Kumiko Ui-Tei describes it as follows, “When the Human Genome Project finished in 2004, we learned that we humans have around 20,000 genes. That isn’t much more than organisms like mice, fruit flies, and nematodes, so we now believe that genes alone are not enough to explain the complexity and diversity of human beings.”

RNA is being looked to as the key to unraveling this mystery. In 2005, it was discovered that in addition to the approximately 20,000 types of RNA related to protein translation, there are another 20,000 or so RNA called “noncoding RNA” (or “functional RNA”) that do not contribute to translation. Among them, some trigger a phenomenon called “RNA interference” or “gene silencing,” in which expression of a certain gene is suppressed. (The two U.S. researchers who discovered this phenomenon were awarded the Nobel Prize in 2006.)

“It seems that only around 2–3% of RNA in the human genome is used for protein synthesis,” says Prof. Ui-Tei, “with the remaining 97% being noncoding DNA. In contrast, around 70–80% of the genome in single-celled E. coli is dedicated to protein synthesis, suggesting that RNA has a deep relation with the complexity and diversity of an organism.”

The main theme of research at the Ui-Tei Laboratory is uncovering the mechanism of gene interference due to microRNA and small RNA, both types of noncoding RNA. While “normal” RNA has a length of several thousand to several tens of thousands of base pairs, microRNA has only a few dozen, yet they are responsible for suppressing the expression of hundreds, even thousands of genes. It is interesting to consider the large role that such tiny objects play in increasing the complexity of life.

Professor Ui-Tei says she is after original research that is unbound by convention, and has emphasized that in her experiments. In the past, she has shown through experimentation that RNA plays an important part in maintaining nerve cells. This was even before RNA’s diverse functioning was widely known.

“When you make a discovery, at that time you’re the only person in the world with that new knowledge,” she says. “That feeling is the thrill of research and experimentation. Of course, getting there means fighting your way through many failed experiments, so it’s a feeling you have to really love.”

Research is a combination of experimentation and thought. When your research isn’t producing any results, that’s when it is most important to reexamine your goals for experimentation and information analysis, and to ensure that your approach is well suited to your goals.

Every member of the Ui-Tei Laboratory has their own area of research, but as Masataka Suzawa (M1) says, “We have many discussions in which everyone participates, regardless of their year in the program.” The lab also has many international exchanges, and for example last summer it hosted short-term exchange students from Germany and Poland. Students are encouraged to spend time overseas, and as Tomoko Takahashi (D3) says, “It’s great to plunge into your research with the feeling that the rest of the world is close at hand.”

Bioinformatics is a new academic field. “It’s an area with many unknown domains, making it wonderfully challenging,” says Fuminori Murakami (M1). “It’s one where I feel like I can make discoveries, ahead of veteran researchers.” New fields of study offer greater opportunities for excelling on an international scale.

The molecular mechanism of RNA silencing. The diagram shows RNA silencing due to microRNA (miRNA) and small interfering RNA (siRNA) in a mammalian cell.

Student evaluations
“She’s like a parent who’s always there when you need to talk about something.” (Tomoko Takahashi, D3)
“She is excellent at what she does, and is always striving to go further.” (Fuminori Murakami, M1)
“She gives us many opportunities for presentations and discussion, which helps me feel how much I’m growing.” (Sotaka Suzawa, M1).

― Office of Communication ―