The Nobel Prize in Physiology and Medicine for 2016 has been awarded to Yoshinori Ohsumi for his path breaking discoveries on the mechanisms of autophagy. Autophagy is a fundamental process existing in all cells for degrading and recycling cellular components.
Yoshinori Ohsumi is a Japanese cell biologist specializing in autophagy and is a professor in Tokyo Institute of Technology‘s Frontier Research Center. After completing his doctoral studies from Tokyo University, he moved to the Rockefeller University in New York City to pursue his post-doctoral research from 1974-1977. Upon his return to University of Tokyo, he worked as a Research Associate and promoted to Associate Professor in 1988. It was here that he made his first major finding by proving that autophagy exists in yeast cells. Thereafter, he moved to National Institute for Basic Biology in Okazaki as a professor and finally to Tokyo Institute of Technology.
During his illustrious career, Dr. Ohsumi has been rewarded with a number of prestigious recognitions. Earlier this year, he was awarded the Wiley Prize in Biomedical Sciences. Prior to that, he has also received the Kyoto Prize for Basic Science in 2012.
Autophagy originates from Greek words auto and phagein meaning “self-eat”. During this process, targeted cellular constituents are isolated from the rest of the cell by forming a separate compartment called autophagosome. This autophagosome fuses with another cellular component called lysosome and the contents thereafter are degraded and recycled.
“This concept emerged during the 1960s, when researchers first observed that the cell could destroy its own contents by enclosing it in membranes, forming sack-like vesicles that were transported to a recycling compartment, called the lysosome, for degradation,” the Nobel Assembly at Karolinska Institutet in Stockholm said in announcing the prize.
The term autophagy was coined by the Belgian biochemist Christian de Duve in 1963. Due to difficulties in studying the phenomenon little was known about it. Oshuri, in a series of brilliant experiments in the early 1990s, identified the genes essential for autophagy in baker’s yeasts. He went on to show the same mechanism is at work in humans and this is how cells recycle their contents.
The Nobel Assembly further mentioned, “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 ageing.”
Ohsumi’s discoveries led to a new paradigm in our understanding of how the cell recycles its content. His discoveries opened the path to understanding the fundamental importance of autophagy in many physiological processes, such as in the adaptation to starvation or response to infection. Mutations in autophagy genes can cause disease, and the autophagic process is involved in several conditions including cancer and neurological disease.
Dr. David Rubinsztein, professor of Molecular Neurogenetics at Cambridge University expressed his satisfaction with the award, “I’m very happy he’s got this year’s nobel prize, it’s very well deserved.” He further told the Guardian, “It shows the importance of basic science and it shows you can make great discoveries that transform a field by starting in a model system like yeast. So when people worry about what should science funding be used for, it’s very difficult to predict what’s ultimately going to come up trumps, and by being restrictive, or penalising people who work on model systems that don’t look like they’re obviously related to human disease, you risk hampering the development of that field. You have to think of science in a holistic way, and understand that key discoveries that can be truly transformative can be made maybe more easily in these systems. It’s a really nice example of how basic science in a model system can be truly transformative.”
Last year, William C. Campbell, Satoshi Omura and Tu Youyou were recognized by the Nobel Committee for their use of modern laboratory techniques to discover anti-parasitic drugs long hidden in herbs and soil.