Ōsumi Yoshinori Wins Medicine Nobel for Autophagy Research

The Japanese cell biologist Ōsumi Yoshinori has won the 2016 Nobel Prize in Physiology or Medicine for his groundbreaking discoveries of the mechanisms of autophagy, or “self-eating,” the process by which cells break down and recycle their own proteins. The 71-year-old Ōsumi, now a professor emeritus at the Tokyo Institute of Technology, received his phone call from the Nobel Committee in the evening of October 3.

The Nobel Assembly at Karolinska Institutet, which awards the medicine prize, explained the importance of autophagy in living organisms:

“We now know that autophagy controls important physiological functions where cellular components need to be degraded and recycled. Autophagy can rapidly provide fuel for energy and building blocks for renewal of cellular components, and is therefore essential for the cellular response to starvation and other types of stress. After infection, autophagy can eliminate invading intracellular bacteria and viruses. Autophagy contributes to embryo development and cell differentiation. Cells also use autophagy to eliminate damaged proteins and organelles, a quality control mechanism that is critical for counteracting the negative consequences of aging.”

Ōsumi’s “paradigm-shifting” work to elucidate autophagy’s processes and roles could lead to important medical breakthroughs, noted the institute: “Disrupted autophagy has been linked to Parkinson’s disease, type 2 diabetes and other disorders that appear in the elderly. Mutations in autophagy genes can cause genetic disease. Disturbances in the autophagic machinery have also been linked to cancer. Intense research is now ongoing to develop drugs that can target autophagy in various diseases.”

Ōsumi becomes the twenty-fifth Japan-born recipient of a Nobel Prize. In the sciences, he has brought Japan its third straight year of recognition, following the 2014 prize in physics, shared by Akasaki Isamu, Amano Hiroshi, and Nakamura Shūji; the 2015 prize in medicine, which went to three scientists including Ōmura Satoshi; and the 2015 prize in physics, shared by Kajita Takaaki.

Genetic Answers in Yeast Cells

The cells in all living creatures’ bodies are constantly replacing parts of themselves. Autophagy allows them to break down and recycle matter that is no longer needed, to envelop and dispatch attackers like viruses and bacteria, and even to consume their own proteins when the body is facing starvation conditions. This mechanism was known as early as the 1960s, but its details remained murky until Ōsumi’s groundbreaking experiments.

In 1988, while he was an associate professor at the University of Tokyo, Ōsumi examined yeast cells that had been subjected to starvation conditions. In the cellular organelle called the vacuole, he successfully observed autophagy taking place through his microscope. By comparing yeast cells that did not undergo autophagy even in starvation with ordinary yeast cells, he successfully isolated the gene responsible for the process in 1993.

An image captured by Ōsumi when he first observed autophagy with an optical microscope in 1988 (left) and an electron microscope view of a starving yeast cell (right). The blank spots in the circular vacuole show where “self-eating” is taking place. (Photos provided by Tokyo Institute of Technology; © Jiji)

Ōsumi was born in Fukuoka Prefecture in 1945. After earning his degree from the University of Tokyo, he was a researcher at Rockefeller University in New York, among other positions, before returning to his alma mater to take the lectern as an associate professor in 1988. He would go on to serve as a professor at the National Institute for Basic Biology in Aichi Prefecture and the Graduate University for Advanced Studies in Kanagawa Prefecture. He came to the Tokyo Institute of Technology in 2009, becoming a professor emeritus there in 2014.

His work has previously earned him recognition including the Canada Gairdner Award, considered a stepping-stone to the Nobel Prize, in 2015. Upon winning this year’s Nobel, he held a press conference on the Tokyo Institute of Technology campus on October 3, stating: “I’ve won various prizes during my career, but the Nobel has a special significance. . . . There’s nothing more fortunate than to win this prize for basic scientific research.”

(Originally written in Japanese. Banner photo: 2016 Nobel Prize winner Ōsumi Yoshinori accepts congratulations at a press conference in Meguro, Tokyo, on October 3. © Jiji.)